an eruptive history of maderas volcano ... thesis, “an eruptive history of maderas volcano using...
TRANSCRIPT
AN ERUPTIVE HISTORY OF MADERAS VOLCANO USING NEW 40Ar/39Ar AGES AND GEOCHEMICAL ANALYSES
By
Lara N. Kapelanczyk
A THESIS
Submitted in partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE
(Geology)
MICHIGAN TECHNOLOGICAL UNIVERSITY
2011
Copyright © 2011 Lara N. Kapelanczyk
All rights reserved
INFORMATION TO ALL USERSThe quality of this reproduction is dependent on the quality of the copy submitted.
In the unlikely event that the author did not send a complete manuscriptand there are missing pages, these will be noted. Also, if material had to be removed,
a note will indicate the deletion.
All rights reserved. This edition of the work is protected againstunauthorized copying under Title 17, United States Code.
ProQuest LLC.789 East Eisenhower Parkway
P.O. Box 1346Ann Arbor, MI 48106 - 1346
UMI 1505870
Copyright 2012 by ProQuest LLC.
UMI Number: 1505870
This thesis, “An Eruptive History of Maderas Volcano Using New 40Ar/39Ar Ages and Geochemical Analyses,” is hereby approved in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE IN GEOLOGY.
Department of Geological and Mining Engineering and Sciences
Signatures:
Thesis Advisor ___________________________________________
Dr. William I Rose
Department Chair ___________________________________________ Dr. Wayne D. Pennington
Date ___________________________________________
v
Table of Contents LIST OF FIGURES ................................................................................................................................... vii
LIST OF TABLES .......................................................................................................................................ix
ACKNOWLEDGEMENTS .........................................................................................................................xi
ABSTRACT ............................................................................................................................................... xiii
1. INTRODUCTION ................................................................................................................................. 1
2. GEOLOGIC SETTING ........................................................................................................................ 3 2.1. REGIONAL SETTING: CENTRAL AMERICA ......................................................................................... 3
2.2. REGIONAL SETTING: NICARAGUA .................................................................................................... 3
2.3. LOCAL SETTING: OMETEPE ............................................................................................................... 4
2.4. LOCAL SETTING: MADERAS VOLCANO ............................................................................................. 5
3. METHODOLOGY ................................................................................................................................ 9 3.1. FIELD METHODS ............................................................................................................................... 9 3.2. THIN SECTIONS ................................................................................................................................. 9
3.3. GEOCHEMICAL ANALYSIS METHODS ................................................................................................ 9
3.4. 40AR/39AR METHODS ...................................................................................................................... 10
4. RESULTS ............................................................................................................................................. 13 4.1. PETROGRAPHY ................................................................................................................................ 13
4.1.1. Basalts .................................................................................................................................... 13 4.1.2. Basaltic Andesites .................................................................................................................. 13
4.1.3. Andesites and Dacites ............................................................................................................ 14
4.1.4. Comparison of Phenocryst Mineralogy ................................................................................. 14
4.2. GEOCHEMICAL ANALYSIS RESULTS ............................................................................................... 16
4.2.1. General Characteristics ......................................................................................................... 16 4.2.2. Bulk Composition of Ometepe lavas ...................................................................................... 17
4.2.3. Incompatible Elements ........................................................................................................... 19
4.2.4. Fenner Diagrams ................................................................................................................... 22
4.2.5. Analogy to paired volcanoes of Halsor and Rose (1988) ....................................................... 23
4.3. 40AR/39AR RESULTS ........................................................................................................................ 23
5. DISCUSSION ....................................................................................................................................... 27 5.1. GEOLOGICAL MAP .......................................................................................................................... 27
5.1.1. Dominant structural feature: A cross-cutting graben ............................................................ 27
5.1.2. Existence of an older cone ..................................................................................................... 29
5.1.3. Alluvial Deposits .................................................................................................................... 29
5.1.4. Lava Flows ............................................................................................................................. 30
vi
5.1.5. Central Crater and Vents ...................................................................................................... 31
5.2. GEOCHEMICAL DATA ..................................................................................................................... 33
5.3. 40AR/39AR AGE DATES ................................................................................................................... 35 5.3.1. Phases of volcanism .............................................................................................................. 35
5.3.2. Implications of ages for shorelines at Maderas and Concepción .......................................... 35
5.3.3. Comparison of age dates to other Central American volcanoes ........................................... 36
5.4. AN ERUPTIVE HISTORY OF MADERAS ............................................................................................. 38
5.5. IMPLICATIONS FOR GEOLOGIC HAZARDS ........................................................................................ 40
5.5.1. History of geologic hazards................................................................................................... 40 5.5.2. Implications for Future Hazards ........................................................................................... 43
6. FUTURE WORK ................................................................................................................................ 47
7. CONCLUSIONS ................................................................................................................................. 49
8 REFERENCES.................................................................................................................................... 51
9 APPENDICES ..................................................................................................................................... 57 9.1 APPENDIX A: GEOCHEMICAL DATA ............................................................................................... 57 9.2 APPENDIX B: 40AR/39AR RESULTS.................................................................................................. 68
9.2.1 Sample MADERAS-002 ......................................................................................................... 68
9.2.2 Sample MADERAS-003 ......................................................................................................... 78
9.2.3 Sample MADERAS-004 ......................................................................................................... 88
9.2.4 Sample MADERAS-011 ......................................................................................................... 99
9.2.5 Sample MADERAS-013 ....................................................................................................... 109
vii
List of Figures FIGURE 1.1: MAP OF CENTRAL AMERICA WITH INSET OF LAKE NICARAGUA AND OMETEPE.. ......................... 2 FIGURE 2.1: LOCATIONS OF TOWNS AND COMMUNITIES AROUND MADERAS AND EXTENT OF FORESTATION ON
MADERAS.. ............................................................................................................................................. 6 FIGURE 3.1: 40AR/39AR AND GEOCHEMICAL SAMPLE LOCATIONS BY COLLECTOR AND ROCK TYPE BASED ON
LE BAS ET AL. (1986).. ......................................................................................................................... 12 FIGURE 4.1: PHENOCRYST MINERALOGY OF MADERAS AND CONCEPCIÓN VOLCANOES.. ............................... 16 FIGURE 4.2. TOTAL ALKALIES VS. SILICA FOR OMETEPE ROCKS. .................................................................... 17 FIGURE 4.3. TOTAL ALKALIES VS. SILICA FOR ROCKS FROM CENTRAL AMERICA. .......................................... 17 FIGURE 4.4: SILICA DISTRIBUTION FOR LAVAS FROM MADERAS VOLCANO. ................................................... 18 FIGURE 4.5: SILICA DISTRIBUTION FOR CONCEPCIÓN VOLCANO..................................................................... 18 FIGURE 4.6: SILICA DISTRIBUTION FOR SAMPLES FROM NICARAGUA. ............................................................ 19 FIGURE 4.7. K2O VS. SIO2 FOR CENTRAL AMERICAN VOLCANIC ROCKS. ....................................................... 19 FIGURE 4.8: PLOTS OF INCOMPATIBLE ELEMENTS VS. MGO WITH REGRESSION LINES FOR MADERAS AND
CONCEPCIÓN VOLCANOES. ................................................................................................................... 20 FIGURE 4.9: PLOT OF INCOMPATIBLE TRACE ELEMENTS VS. MGO COMPARING MADERAS AND CONCEPCIÓN
TO OTHER CENTRAL AMERICAN VOLCANOES. ...................................................................................... 21 FIGURE 4.10. FENNER DIAGRAMS FOR CENTRAL AMERICAN VOLCANIC ROCKS. ............................................ 22 FIGURE 4.11 AGE PLATEAU DIAGRAM AND INVERSE ISOCHRON DIAGRAM FOR SAMPLE MADERAS-013. .... 24 FIGURE 5.1: GEOLOGIC MAP OF MADERAS VOLCANO. ................................................................................... 28 FIGURE 5.2: A) SUMMIT PROFILE AND CROSS-SECTION OF MADERAS VOLCANO. ........................................... 29 FIGURE 5.3: SLOPE MAP OF MADERAS VOLCANO IN DEGREES. ....................................................................... 30 FIGURE 5.4. PLOT OF VENT HEIGHT VS. WT. % SIO2. ...................................................................................... 34 FIGURE 5.5: PLOT OF WT. % SIO2 VERSUS AGE OF THE LAVA FLOW. .............................................................. 34 FIGURE 5.6: RANGES OF AGE DATES ANALYZED FOR CENTRAL AMERICAN VOLCANOES. .............................. 37 FIGURE 9.1: AGE PLATEAU FOR MADERAS-002 .......................................................................................... 76 FIGURE 9.2: K-CA PLATEAU FOR MADERAS-002 ........................................................................................ 76 FIGURE 9.3: NORMAL ISOCHRON FOR MADERAS-002 ................................................................................. 77 FIGURE 9.4: INVERSE ISOCHRON FOR MADERAS-002 .................................................................................. 77 FIGURE 9.5: AGE PLATEAU FOR MADERAS-003 .......................................................................................... 86 FIGURE 9.6: K-CA PLATEAU FOR MADERAS-003 ........................................................................................ 86 FIGURE 9.7: NORMAL ISOCHRON FOR MADERAS-003 ................................................................................. 87 FIGURE 9.8: INVERSE ISOCHRON FOR MADERAS-003 .................................................................................. 87 FIGURE 9.9: AGE PLATEAU FOR MADERAS-004 .......................................................................................... 97 FIGURE 9.10: K-CA PLATEAU FOR MADERAS-004 ...................................................................................... 97 FIGURE 9.11: NORMAL ISOCHRON FOR MADERAS-004 ............................................................................... 98
viii
FIGURE 9.12: INVERSE ISOCHRON FOR MADERAS-004 ............................................................................... 98 FIGURE 9.13: AGE PLATEAU FOR MADERAS-011 ...................................................................................... 107 FIGURE 9.14: K-CA PLATEAU FOR MADERAS-011 .................................................................................... 107 FIGURE 9.15: NORMAL ISOCHRON FOR MADERAS-011 ............................................................................. 108 FIGURE 9.16: INVERSE ISOCHRON FOR MADERAS-011 ............................................................................. 108 FIGURE 9.17: AGE PLATEAU FOR MADERAS-013 ...................................................................................... 117 FIGURE 9.18: K-CA PLATEAU FOR MADERAS-013 .................................................................................... 117 FIGURE 9.19: NORMAL ISOCHRON FOR MADERAS-013 ............................................................................. 118 FIGURE 9.20: INVERSE ISOCHRON FOR MADERAS-013 ............................................................................. 118
ix
List of Tables TABLE 4.1: RESULTS OF THIN SECTION ANALYSIS. ......................................................................................... 15 TABLE 4.2. SUMMARY OF 40AR/39AR EXPERIMENTS ....................................................................................... 25 TABLE 5.1: ARTICLES FEATURING STRUCTURAL MAPS OF MADERAS ............................................................. 27 TABLE 9.1: WHOLE-ROCK CHEMICAL ANALYSIS FOR SAMPLES COLLECTED DURING THIS STUDY. ................. 57 TABLE 9.2: GEOCHEMICAL INFORMATION FROM MADERAS VOLCANO (LINDSAY 2009). ............................... 59 TABLE 9.3: RARE EARTH ELEMENT ANALYSES OF MADERAS VOLCANO FROM LINDSAY (2009). ................... 60 TABLE 9.4: WHOLE ROCK AND TRACE ELEMENT ANALYSES OF MADERAS VOLCANO FROM VAN WYK DE
VRIES (UNPUBLISHED). ......................................................................................................................... 61 TABLE 9.5: WHOLE ROCK AND TRACE ELEMENT DATA FOR CONCEPCIÓN VOLCANO FROM VAN WYK DE VRIES
(1993). .................................................................................................................................................. 62 TABLE 9.6: RARE EARTH ELEMENTS AT CONCEPCIÓN VOLCANO FROM VAN WYK DE VRIES (1993). ............. 65 TABLE 9.7: WHOLE ROCK AND TRACE ELEMENT ANALYSES FROM CONCEPCIÓN VOLCANO FROM BORGIA AND
VAN WYK DE VRIES (2003) AND FROM CARR AND ROSE (1987). ......................................................... 66 TABLE 9.8: RARE EARTH ELEMENTS AT CONCEPCIÓN VOLCANO FROM CARR AND ROSE (1987). .................. 67 TABLE 9.9: INCREMENTAL HEATING SUMMARY FOR MADERAS-002 ........................................................... 68 TABLE 9.10: NORMAL ISOCHRON TABLE FOR MADERAS-002...................................................................... 69 TABLE 9.11: INVERSE ISOCHRON TABLE FOR MADERAS-002 ...................................................................... 69 TABLE 9.12: RELATIVE ABUNDANCES FOR MADERAS-002 ......................................................................... 70 TABLE 9.13: DEGASSING PATTERNS FOR MADERAS-002 ............................................................................ 71 TABLE 9.14: ADDITIONAL PARAMETERS FOR MADERAS-002 ...................................................................... 72 TABLE 9.15: PROCEDURE BLANKS FOR MADERAS-002 ............................................................................... 73 TABLE 9.16: INTERCEPT VALUES FOR MADERAS-002 ................................................................................. 73 TABLE 9.17: SAMPLE PARAMETERS FOR MADERAS-002 ............................................................................. 74 TABLE 9.18: IRRADIATION CONSTANTS FOR MADERAS-002 ....................................................................... 75 TABLE 9.19: INCREMENTAL HEATING SUMMARY FOR MADERAS-003 ......................................................... 78 TABLE 9.20: NORMAL ISOCHRON TABLE FOR MADERAS-003...................................................................... 79 TABLE 9.21: INVERSE ISOCHRON TABLE FOR MADERAS-003 ...................................................................... 79 TABLE 9.22: RELATIVE ABUNDANCES FOR MADERAS-003 ......................................................................... 80 TABLE 9.23: DEGASSING PATTERNS FOR MADERAS-003 ............................................................................ 81 TABLE 9.24: ADDITIONAL PARAMETERS FOR MADERAS-003 ...................................................................... 82 TABLE 9.25: PROCEDURE BLANKS FOR MADERAS-003 ............................................................................... 83 TABLE 9.26: INTERCEPT VALUES FOR MADERAS-003 ................................................................................. 83 TABLE 9.27: SAMPLE PARAMETERS FOR MADERAS-003 ............................................................................. 84 TABLE 9.28: IRRADIATION CONSTANTS FOR MADERAS-003 ....................................................................... 85
x
TABLE 9.29: INCREMENTAL HEATING SUMMARY FOR MADERAS-004 ........................................................ 88 TABLE 9.30: NORMAL ISOCHRON TABLE FOR MADERAS-004 ..................................................................... 89 TABLE 9.31: INVERSE ISOCHRON TABLE FOR MADERAS-004 ..................................................................... 89 TABLE 9.32: RELATIVE ABUNDANCES FOR MADERAS-004 ......................................................................... 90 TABLE 9.33: DEGASSING PATTERNS FOR MADERAS-004 ............................................................................ 91 TABLE 9.34: ADDITIONAL PARAMETERS FOR MADERAS-004 ..................................................................... 92 TABLE 9.35: PROCEDURE BLANKS FOR MADERAS-004 .............................................................................. 93 TABLE 9.36: INTERCEPT VALUES FOR MADERAS-004 ................................................................................ 94 TABLE 9.37: SAMPLE PARAMETERS FOR MADERAS-004 ............................................................................ 95 TABLE 9.38: IRRADIATION CONSTANTS FOR MADERAS-004 ...................................................................... 96 TABLE 9.39: INCREMENTAL HEATING SUMMARY FOR MADERAS-011 ........................................................ 99 TABLE 9.40: NORMAL ISOCHRON TABLE FOR MADERAS-011 .................................................................. 100 TABLE 9.41: INVERSE ISOCHRON TABLE FOR MADERAS-011 ................................................................... 100 TABLE 9.42: RELATIVE ABUNDANCES FOR MADERAS-011 ....................................................................... 101 TABLE 9.43: DEGASSING PATTERNS FOR MADERAS-011 .......................................................................... 102 TABLE 9.44: ADDITIONAL PARAMETERS FOR MADERAS-011 ................................................................... 103 TABLE 9.45: PROCEDURE BLANKS FOR MADERAS-011 ............................................................................ 104 TABLE 9.46: INTERCEPT VALUES FOR MADERAS-011 .............................................................................. 104 TABLE 9.47: SAMPLE PARAMETERS FOR MADERAS-011 .......................................................................... 105 TABLE 9.48: IRRADIATION CONSTANTS FOR MADERAS-011 ..................................................................... 106 TABLE 9.49: INCREMENTAL HEATING SUMMARY FOR MADERAS-013 ...................................................... 109 TABLE 9.50: NORMAL ISOCHRON TABLE FOR MADERAS-013 ................................................................... 110 TABLE 9.51: INVERSE ISOCHRON TABLE FOR MADERAS-013 ................................................................... 110 TABLE 9.52: RELATIVE ABUNDANCES FOR MADERAS-013 ....................................................................... 111 TABLE 9.53: DEGASSING PATTERNS FOR MADERAS-013 .......................................................................... 112 TABLE 9.54: ADDITIONAL PARAMETERS FOR MADERAS-013 ................................................................... 113 TABLE 9.55: PROCEDURE BLANKS FOR MADERAS-013 ............................................................................ 114 TABLE 9.56: INTERCEPT VALUES FOR MADERAS-013 .............................................................................. 114 TABLE 9.57: SAMPLE PARAMETERS FOR MADERAS-013 .......................................................................... 115 TABLE 9.58: IRRADIATION CONSTANTS FOR MADERAS-013 ..................................................................... 116
xi
Acknowledgements First and foremost I’d like to thank my advisor Dr. Bill Rose for all of his support throughout this project both while I was in Nicaragua and at Michigan Tech. His help has been essential to this project. I would also like to thank my other committee members Benjamin van Wyk de Vries and Greg Waite for their time and expertise. I would like to thank my Nicaraguan guides for their help and company while in the field: Javier, Manuel, Norlan, Luis, and Francisco. Thanks to my family and friends in Mérida for their kindness and acceptance of me into their community. Thanks to Maria Antonia Mallona and Lisette Carranza at the Peace Corps office who were generous with their help and always very supportive in allowing me time for my master’s research. Many thanks to the other staff members of Peace Corps Nicaragua and NICA 48 for countless other acts of kindness. Thanks to the many people at Michigan Tech who helped me along the way: Bob Barron, John Gierke, Amie Ledgerwood, Kelly McLean, Rudiger Escobar-Wolf, and numerous other graduate students, faculty and staff. It takes a whole department to write a thesis. Thanks to Brian Jicha at the University of Wisconsin-Madison who dated my samples. Thanks to Heather Cunningham for helping me prepare the samples, teaching me about the process, and allowing me to invade her house for a few days. Thanks to Lucie Mathieu for allowing me to accompany her in the field and for her insights into Maderas volcano. Lastly I’d like to thank my family and friends for their support throughout the last four years. I’d especially like to thank my parents for always supporting my decisions, even when they continuously take me to far-away places. This project was funded by the NSF PIRE Grant #0530109.
xiii
Abstract Maderas volcano is a small, andesitic stratovolcano located on the island of Ometepe, in
Lake Nicaragua, Nicaragua with no record of historic activity. Twenty-one samples were
collected from lava flows from Maderas in 2010. Selected samples were analyzed for
whole-rock geochemical data using ICP-AES and/or were dated using the 40Ar/39Ar
method. The results of these analyses were combined with previously collected data from
Maderas as well as field observations to determine the eruptive history of the volcano and
create a geologic map. The results of the geochemical analyses indicate that Maderas is a
typical Central American andesitic volcano similar to other volcanoes in Nicaragua and
Costa Rica and to its nearest neighbor, Concepción volcano. It is different from
Concepción in one important way – higher incompatible elements. Determined age dates
range from 176.8 ± 6.1 ka to 70.5 ± 6.1 ka. Based on these ages and the geomorphology
of the volcano which is characterized by a bisecting graben, it is proposed that Maderas
experienced two clear generations of development with three separate phases of
volcanism: initial build-up of the older cone, pre-graben lava flows, and post-graben lava
flows. The ages also indicate that Maderas is markedly older than Concepción which is
historically active. Results were also analyzed regarding geologic hazards. The 40Ar/39Ar
ages indicate that Maderas has likely been inactive for tens of thousands of years and the
risk of future volcanic eruptions is low. However, earthquake, lahar and landslide hazards
exist for the communities around the volcano. The steep slopes of the eroded older cone
are the most likely source of landslide and lahar hazards.
1
1. Introduction Maderas is a small (1394 m.a.s.l.), asymmetrical stratovolcano located at 11°26'44"N and
85°30'54"W on the island of Ometepe in Lake Nicaragua, Nicaragua (Figure 1.1). The
dumbbell-shaped Ometepe, which means “two mountains” in the Nahuatl language, is
formed by Maderas and its neighbor, the highly symmetrical stratovolcano Concepción.
Due to its remote location and lack of historic activity, relatively little is known about
Maderas when compared to other Central American volcanoes. Field observations and
hand samples were collected over a one-year period during the author’s two years of
residence, as a Peace Corps volunteer, in Mérida, a small village on the western flanks of
the volcano. Field observations were combined with 21 new geochemical analyses of
Maderas lavas, 88 previously collected geochemical analyses from both Maderas and
Concepción volcanoes, five new 40Ar/39Ar age determinations, and one previously
determined 40Ar/39Ar age to create a new geologic map of Maderas and to assess the
eruptive history and hazards posed by the volcano.
Small communities are located around the flanks of Maderas, and, as an island, Ometepe
and its inhabitants are vulnerable to hazards for a number of geographic, social, and
economic reasons. Developing an understanding of the eruptive history of Maderas will
help with the assessment of the hazards on the volcano and will reduce the vulnerabilities
that exist for the communities there.
2
Figure 1.1: Map of Central America with inset of Lake Nicaragua and Ometepe. Dashed lines represent the boundaries of the Nicaraguan depression (ND) in the south and the Median Trough (MT) to the north. Triangles represent volcanic centers. Grey lines represent the location of breaks in strike along the volcanic front. Political boundaries are from GADM (2011).
3
2. Geologic Setting
2.1. Regional Setting: Central America
Maderas is one of 39 Quaternary volcanic centers that form the Central American
volcanic front (CAVF), a 1,100-km chain of volcanoes that range from the Guatemala-
Mexico border to central Costa Rica, and it is the southernmost of 12 volcanic centers
located in Nicaragua (Carr et al., 2003). The CAVF was formed by subduction of the
Cocos plate moving northeast beneath the Caribbean plate at a rate of 84 ± 5 mm yr-1 near
Nicaragua (DeMets, 2001) (Figure 1.1).
The volcanic centers along the CAVF form 8 segments, each between 100 and 300 km
long. Segments are recognized by linear arrays that form right steps along the volcanic
front (Carr, 1984) (Figure 1.1). The largest of these right steps, ~40 km, occurs between
Maderas volcano and Orosí volcano in Costa Rica and is accompanied by a large change
in depth to the slab from the volcano of ~150 km beneath Maderas to ~80 km beneath
Orosí (Funk et al., 2009). Estimates of the dip angle of the slab below Maderas range
from 65° (Syracuse and Abers, 2006) to 80° (Funk et al., 2009). Both the depth to the
slab and the slab dip generally decrease to the north and south along the CAVF from
Maderas volcano. The crust beneath Maderas is thought to be ~35 km thick (Carr et al.,
2007a).
2.2. Regional Setting: Nicaragua
From west to east Nicaragua is divided into four geological regions: the Pacific Coastal
Plain, the Nicaraguan depression, the interior highlands made up largely of Tertiary
volcanics, and the Atlantic Coastal Plain (McBirney and Williams, 1965). The Pacific
Coastal Plain in southern Nicaragua, near Ometepe, is comprised of Cretaceous to
Oligocene sedimentary rocks (Funk et al., 2009). To the east, the CAVF, including
Maderas, lies within and nearly parallel to a roughly 1,000 km long and 40-70 km wide
depression (Figure 1.1). In the south the depression is known as the Nicaraguan
depression and it runs from the Caribbean coast of central Costa Rica through western
Nicaragua and into El Salvador near the Gulf of Fonseca. Lake Nicaragua and Lake
4
Managua are prominent features of this basin. It continues north from the Gulf of
Fonseca in El Salvador to southern Guatemala as a less geomorphologically-evident
feature, called the Median Trough.
Three tectonic phases have been proposed for the formation of the depression: Miocene
convergence, Pliocene extension, and Pleistocene to present transtensional deformation
(Funk et al., 2009). The initial formation of the depression is thought to have occurred
near Lake Nicaragua during the Oligocene-early Miocene. From there it is thought to
have spread north to the Gulf of Fonseca during the Miocene to Pliocene (Funk et al.,
2009). The actual structure of the depression is still debated due to a lack of information
about the subsurface. Three models have been discussed: the depression formed as an
asymmetrical half-graben (McBirney and Williams, 1965), the depression formed by
large-scale folding (Borgia and van Wyk de Vries, 2003), and the Nicaraguan depression
formed as an asymmetrical graben (Funk et al., 2009).
2.3. Local Setting: Ometepe
Ometepe is ~275 km2 in area and is located in Lake Nicaragua, the largest lake in Central
America, with an area of ~8,000 km2 (Swain, 1966; Freundt et al., 2007). The island
consists of Maderas volcano and its neighbor Concepción volcano, connected by the
Istián isthmus. Concepción volcano is 31 km3 in volume (Carr et al., 2007b), ~1600
m.a.s.l. in elevation, and is historically active with explosions and ashfall occurring as
recently as 2010 (Wilder, 2010). It has been studied extensively by van Wyk de Vries
(1993) and by Borgia and van Wyk de Vries (2003).
Based on the latest census data from Nicaragua taken in 2005 by the National Institute of
Development Information (Instituto Nacional de Información de Desarrollo or INIDE),
approximately 30,000 people inhabit the island of Ometepe (Goffin et al., 2006).
However, in 2010, while Concepción volcano was experiencing gas and ash explosions,
the newspaper La Prensa wrote that the island had a population of 44,000 (Wilder, 2010).
This total likely includes the large number of tourists on the island.
5
The stratigraphy and structure of the rocks of the Pacific lowlands and within the
Nicaraguan depression of southwestern Nicaragua and, therefore, underneath Maderas,
have been described by McBirney and Williams (1965), Borgia and van Wyk de Vries
(2003) and by Funk et al. (2009). The oldest known rock type in the area is the Nicoya
Complex that ranges in age from Jurassic to Cretaceous (de Boer, 1979; Hoernle et al.,
2004). The Nicoya Complex is a suite of igneous rocks (gabbros, plagiogranites, and
basalts) and Mn-radiolarites that are exposed on the Nicoya Peninsula in Costa Rica and
are believed to extend into southern Nicaragua (Denyer and Baumgartner, 2006). Above
the Nicoya Complex lies a sequence of flysch deposits from the Rivas, Brito and
Masachapa formations that were deposited within the Nicaragua depression. These
formations range in age from Cretaceous to Miocene (Borgia and van Wyk de Vries,
2003). Above these units lies the El Salto Formation of Pliocene age and above this lie
the lake sediments deposited by Lake Nicaragua. The lake sediments are estimated to be
up to 1 km thick (Borgia and van Wyk de Vries, 2003).
2.4. Local Setting: Maderas Volcano
Maderas volcano is a small stratovolcano with a sub-conical shape (Grosse et al., 2009),
an estimated volume of 30 km3 (Carr et al., 2007b), a height of 1,394 m.a.s.l., and a
diameter of ~10 km (Borgia and van Wyk de Vries, 2003). In view of the significant
population and the known activity of Concepción, it is important to assess the potential of
activity at Maderas. No historic activity is recorded. Borgia et al. (2000) state that
Maderas has not erupted for at least 3,000 years. The absence of Holocene activity at
Maderas is consistent with its flat summit and extensive exposed faulting on the volcano.
Mathieu (2010) observes that Maderas’ fault structures would have been covered by
eruptive material faster than they could have formed if the volcano had been active
during their formation, as is believed to be the case at Concepción volcano where edifice
faults have been covered by recent eruptions (Delcamp et al., 2008).
The flanks of Maderas are largely deforested and contain more than 20 small towns and
communities (Figure 2.1). Much of the area below 200-300 m.a.s.l. has been altered for
annual cultivation and pasture (Aguirre, 2009). Above 400 m.a.s.l. the volcano is covered
6
by cloud forest. In this humid environment, vegetation is thick and lush and difficult to
navigate without a trail. In the summit crater of the volcano is a small crater lake called
Laguna de Maderas (Maderas Lagoon). As can be seen from the satellite photo (Figure
2.1) a large part of the volcano remains forested. The volcano is listed as a protected area
above elevations of 850 m.a.s.l. called Maderas Volcano Natural Reserve by Nicaragua’s
Ministry of the Environment and Natural Resources (Ministerio del Ambiente y los
Recursos Naturales or MARENA). The entire island of Ometepe has also been recently
declared a Biosphere Reserve as part of the Man and the Biosphere Program by the
United Nations Educational, Scientific and Cultural Organization (UNESCO) (UNESCO,
2010).
Figure 2.1: Locations of towns and communities around Maderas and extent of forestation on Maderas. The natural reserve represents all land above 850 m on Maderas volcano. The location of a 1996 lahar is also mapped. Image © 2011 Digital Globe, © 2011 TerraMetrics, © 2011 GeoEye, © 2011 Google.
7
Geological studies of Maderas are limited to investigations of structural features: van
Wyk de Vries and Borgia (1996), van Wyk de Vries and Merle (1996), van Wyk de Vries
and Matela (1998), Borgia et al. (2000), Delcamp et al. (2008), Byrne et al. (2009) and
Andrade and van Wyk de Vries (2010). These papers regard Maderas as an example of a
volcano with a ductile substratum that has undergone spreading. Some papers also
discuss the development of leaf graben structures around the base of the volcano. Van
Wyk de Vries and Borgia (1996) first called attention to Maderas’ spreading due to the
relatively weak lake sediments underlying the volcano. They used a number of physical
parameters to determine dimensionless pi numbers whose ratios were plotted and then
used to measure the “geometric capacity of the system to spread,” the rate of spreading,
and “the state of the elastic stresses within the volcanic edifice built by the last major
eruptive phase.” Their results indicate that Maderas is a fast-spreading volcano with low
collapse hazard and that the elastic stress should be almost completely relaxed within the
volcano. The paper also mentions that little or no evidence of hydrothermal features were
observed at Maderas and identifies a slump feature on the southwest side of the volcano.
Mathieu et al. (2011) describe deformation features on Maderas volcano with respect to a
135° dextral-striking transtensional fault zone using analog models. This fault zone
parallels the summit graben of the volcano. Their findings indicate that the regional stress
field (transtensional fault) and local stress field (spreading) support the formation of a
central conduit and near-radial lineaments around the base of the volcano that are found
in pairs. The 135°-striking fault zone on the volcano is supported by a 25-km-long and 5-
km wide fault zone described by Funk et al. (2009) that they call the San Ramon Fault
Zone to the SE of Maderas volcano in Lake Nicaragua. Their results suggest a half-
graben structure and this geometry lines up with the graben observed on Maderas
(N45°W).
A geologic map of Maderas volcano was published by the Czech Geologic Service
(Sebesta, 2001) in conjunction with the Nicaraguan Institute of Earth Studies (Instituto
Nicaragüense de Estudios Territoriales or INETER). This map is based on a map created
8
by van Wyk de Vries (1986). In this paper, the geologic map of Sebesta (2001) is updated
using new age dates and geochemical data.
9
3. Methodology
3.1. Field Methods
The goals of field research were to locate, map, and collect samples from lava flows from
a wide range of locations around Maderas representing the entire eruptive history of the
volcano. Sampling sites focused on lava flows that could be identified by field
observations and by lobate geomorphology with the help of Google Earth and digital
elevation models (DEMs). Lava flows were chosen because they represent material that
can be radiometrically dated. Samples selected for dating were chosen to reflect
stratigraphic or geomorphological positions that represent earliest and latest activity of
Maderas.
Twenty-one samples were collected from Maderas volcano from January to September
2010. All samples were believed to be from lava flows except for sample MADERAS
-009, which is a piece of lava rock taken from a debris flow. Sample locations were
obtained using a Global Positioning System (GPS) device. Sample locations can be seen
in Figure 3.1. In each location the freshest, most unaltered sample possible was sought,
however, in many locations it was impossible to find or obtain samples that were not
weathered to some degree.
3.2. Thin Sections
Ten samples were selected for thin section and petrographic study (MADERAS-002,
-003, -004, -007, -008, -011, -013, -015, -017, -018). These same samples were analyzed
for 40Ar/39Ar age dates (see section 3.4). Thin sections were prepared by the author at
Michigan Technological University.
3.3. Geochemical Analysis Methods
Geochemical analyses for this study were conducted at the Magma and Volcanoes
Laboratory (Laboratoire Magmas et Volcans) at Blaise Pascal University, Clermont-
Ferrand, France. Samples were crushed and pulverized at Michigan Technological
University and then sent to Blaise Pascal University for whole rock chemical analysis of
10
major elements by ICP-AES (inductively coupled plasma atomic emission spectroscopy).
Nineteen samples were selected for analysis from this study (Figure 3.1). Six additional
samples (11-A, 14, 17, 26-B, 39, and 41), collected from Maderas by Lucie Mathieu in
January and February of 2009 while conducting research for her Ph.D. (Mathieu, 2010),
were also prepared and analyzed (Figure 3.1). Thirty-four additional whole rock and trace
element analyses from Maderas volcano were used to characterize the volcano: eighteen
samples from Benjamin van Wyk de Vries (unpublished) and sixteen samples from Fara
Lindsay (Lindsay, 2009) (Figure 3.1). This makes a total of 59 whole rock analyses from
Maderas volcano. It should be noted that samples collected for Lindsay’s study are biased
toward more mafic samples in order to look at source processes.
Fifty-four whole rock and trace element analyses from Concepción volcano were
compared to Maderas: forty-two samples from van Wyk de Vries (1993), six samples
from Borgia and van Wyk de Vries (2003) and six samples from the geochemical
database of Central American volcanoes (http://www.rci.rutgers.edu/~carr/index.html)
maintained by Mike Carr (Carr and Rose, 1987). Tables of all of the Ometepe analyses
can be found in Appendix A.
Additional geochemical samples used for this study include 235 samples from
Nicaraguan volcanic front volcanoes and 336 samples from Costa Rican volcanic front
volcanoes. These analyses were also provided by the database of Central American
volcanoes maintained by Mike Carr (Carr and Rose, 1987).
3.4. 40Ar/39Ar Methods
Ten samples were selected for 40Ar/39Ar analysis. These samples were chosen based on
two main factors: lack of weathering and stratigraphic location. The goal was to obtain
high precision dates that would demonstrate the entire age of the volcano, from oldest to
youngest. The locations of samples analyzed for 40Ar/39Ar analysis can be seen in Figure
3.1 as well the location of a previously analyzed sample from Maderas by Carr et al.
(2007b). The following information was provided by Brian Jicha at the University of
Wisconsin-Madison regarding sample preparation and analysis:
11
Samples were prepared at the University of Wisconsin-Madison. Samples
were crushed, sieved to 250-350 µm, and phenocrysts were removed via
magnetic sorting or density separation using methylene iodide.
Microphenocrysts that survived mechanical separation or groundmass
which still showed evidence of alteration were ultimately removed by
hand picking under a binocular microscope. Phenocryst-free groundmass
separates were weighed and then wrapped in 99.99% copper foil packets
placed into in 2.5cm diameter aluminum disks with sanidine from the
28.201 Ma Fish Canyon tuff (Kuiper et al., 2008), which monitors neutron
fluence. Samples and standards were irradiated at the Oregon State
University TRIGA-type reactor in the Cadmium-Lined In-Core Irradiation
Tube (CLICIT) for 1 hour.
At the University of Wisconsin-Madison Rare Gas Geochronology
Laboratory, ~ 200 mg groundmass packets were incrementally heated in a
double-vacuum resistance furnace attached to a 300 cm3 gas clean-up line.
Prior to sample introduction, furnace blanks were measured at 100 °C
increments throughout the temperature range spanned by the incremental
heating experiment and interpolated. Following blank analyses, samples
were degassed at 550 °C for 60 minutes to potentially remove large
amounts of atmospheric argon. Fully automated experiments consisted of
9-10 steps from 650-1250 °C; each step included a two-minute increase to
the desired temperature that was maintained for 15 minutes, followed by
an additional 15 minutes for gas cleanup. The gas was cleaned during and
after the heating period with three SAES C50 getters, two of which were
operated at ~450 °C and the other at room temperature. Argon isotope
analyses were done using a MAP 215-50 mass spectrometer using a single
Balzers SEM-217 electron multiplier, and the isotopic data was reduced
using ArArCalc software version 2.5 (Koppers, 2002). The age
uncertainties reported for each individual sample are at the 95%
12
confidence level, and the decay constants used are those of Min et al.
(2000).
Figure 3.1: 40Ar/39Ar and geochemical sample locations by collector and rock type based on Le Bas et al. (1986). Note that some sample names are repeated (i.e. M1 and M1). Both van Wyk de Vries (unpublished) and Lindsay (2009) used the same naming system for their samples.
13
4. Results 4.1. Petrography
The hand samples and thin sections collected for this project reveal that lavas from
Maderas are largely porphyritic with the majority of samples having between 25-30%
plagioclase phenocrysts. A high abundance of phenocrysts is consistent with lavas found
elsewhere in Central America (Carr et al., 1982). All samples with thin sections contain
plagioclase, olivine, clinopyroxene, apatite and opaque phenocrysts. Some samples also
contain orthopyroxene, amphibole, and biotite. Zoning is common within the plagioclase
phenocrysts as has been observed at other Central American lavas as well (Carr et al.,
2007a). Table 4.1 shows the results of the petrographic analysis.
4.1.1. Basalts
Of the 59 sample analyses from Maderas used for this study, 24 are basalts. To account
for duplicate samples of the same rock unit based on the geologic map (see section 5.1)
or duplicate analyses, 46 samples are used to determine the percentage of each rock type.
The percentage of basalts is ~33% (15 of 46 samples). There are 3 thin sections of basalts
(MADERAS-004, -008, and -017). All three thin sections display high percentages of
plagioclase phenocrysts (25-45%) ranging in size from fine to medium grained and often
displaying twinning and/or zoning. Other phenocrysts include clinopyroxene (<1-5%),
olivine (~1%), and small percentages of opaques (<1%). Two of the samples also contain
small percentages of orthopyroxene (~1%).
4.1.2. Basaltic Andesites
Basaltic andesites represent ~30% or 14 of the 46 analyses. Of those there are 3 thin
sections of basaltic andesite (MADERAS-002, -011, and -018). Phenocrysts present in all
three thin sections include plagioclase (20-30%), olivine (~1%), clinopyroxene (<1-3%),
and opaques (<1%). Two of the thin sections contain orthopyroxene (<1-3%). Twinning
and zoning are common in the plagioclase phenocrysts. Phenocrysts are mostly fine
grained with plagioclase ranging in size from fine to medium grained.
14
4.1.3. Andesites and Dacites
Andesites/trachy-andesites represent ~28% or 13 of the 46 rock analyses and
trachydacites represent ~9% or 4 of the 46 analyses. Thin sections of two trachy-
andesites (MADERAS-013 and -015) and two trachydacites (MADERAS-003 and -007)
were investigated. All four thin sections contain phenocrysts of plagioclase,
orthopyroxene (<1-2%), clinopyroxene (<1-2%), olivine (<1%), and opaques (<1-1%).
MADERAS-013 and -015 also contain phenocrysts of biotite (<1%) and sample -013
also has phenocrysts of amphibole (<1%).
Phenocrysts range in size from medium- to fine-grained with the majority of phenocrysts
being fine grained. Zoning and twinning is common amongst plagioclase phenocrysts and
twinning is sometimes encountered amongst clinopyroxene grains. Plagioclase
phenocrysts are 20-30% of the rock in the trachy-andesites (MADERAS-013 and
MADERAS-015) while they make up only 3-5% in the trachydacites (MADERAS-003
and MADERAS-007). Sample MADERAS-007 is highly vesicular.
4.1.4. Comparison of Phenocryst Mineralogy
Phenocryst mineralogy for Maderas and Concepción volcanoes was compared to other
Central American volcanoes. A graphical summary of phenocryst mineralogy for Central
American volcanic rocks using data from Carr et al. (1982) was created (Figure 4.1). The
ranges of SiO2 contents found at Maderas and Concepción are plotted. Differences from
the other nearby volcanoes are minor. At Maderas olivine was found in the andesites (up
to 61.43% SiO2). At Concepción, orthopyroxene was not found above 62% SiO2 and
amphibole was seen only in dacites (van Wyk de Vries, 1993). It is concluded that the
mineralogy at Maderas is similar to other nearby volcanoes.
15
Tab
le 4
.1: R
esul
ts o
f thi
n se
ctio
n an
alys
is.
1. p
l=pl
agio
clas
e, o
l=ol
ivin
e, c
px=c
linop
yrox
ene,
opx
=orth
opyr
oxen
e, a
mph
=am
phib
ole)
2.
phe
nocr
ysts
size
s: f=
fine
grai
ned
(<1m
m),
m=m
ediu
m g
rain
ed (1
-5m
m)
3. a
ltera
tion
is b
ased
on
perc
enta
ges o
f sec
onda
ry m
iner
als:
0-2
5% =
low
, 25-
50%
= m
ed.,
and
>50%
= h
igh
Sam
ple
Num
ber
Roc
k Ty
pe
Phe
nocr
ysts
1 (Siz
e2 an
d W
hole
Roc
k P
erce
ntag
es)
Gro
undm
ass
Tex
ture
A
ltera
tion3
Ves
icle
s Z
eolit
es
pl
ol
cpx
opx
opaq
ues
biot
ite
amph
hi
gh
med
. lo
w
MA
DE
RA
S-0
02
bas
altic
an
desi
te
f-m
f-
m
f-m
f
in
erse
rtal
X
X
30-
35
<1
1-2
1
MA
DE
RA
S-0
03
trac
hyda
cite
f-
m
f f
f f
inte
rser
tal
X
3-5
<1
<1
<1
<1
MA
DE
RA
S-0
04
basa
lt f-
m
f f-
m
f-m
f
inte
rser
tal
X
35-
40
1 5
1 <<
1
MA
DE
RA
S-0
07
trac
hyda
cite
f-
m
f f
f f
inte
rser
tal,
trac
hytic
X
X
3 <<
1 1
<1
<<1
MA
DE
RA
S-0
08
basa
lt f-
m
f- m?
f-m
f
f
in
ters
erta
l
X
25-
30
1 <1
<1
<1
MA
DE
RA
S-0
11
basa
ltic
ande
site
f-m
f
f f
f
f in
ters
erta
l, po
ikal
itic
X
25-
30
<1
<1
<1
<1
<1
MA
DE
RA
S-0
13
trac
hy-
ande
site
f-m
f
f-m
f-
m
f f
f in
ters
erta
l
X
X
X
20
-25
<<
1 <1
1-
2 1
<<1
<<1
MA
DE
RA
S-0
15
trac
hy-
ande
site
f-m
f
f f
f f
in
ters
erta
l
X
25
-30
<<
1 2
2 1
<<1
MA
DE
RA
S-0
17
basa
lt f-
m
f f
f
inte
rser
tal
X
X
40
-45
<1
<1
<<1
MA
DE
RA
S-0
18
basa
ltic
ande
site
f-m
f
f-m
f-
m
f
in
ters
erta
l
X
X
25-
30
1 2-
3 2-
3 <1
16
Figure 4.1: Phenocryst mineralogy of Maderas and Concepción volcanoes. Values of wt. % SiO2 for each mineral are from Carr et al. (1982) and represent common phenocryst mineralogy for Central America. Solid lines indicate the mineral is usually present, dashed lines indicate the mineral is sometimes present. Symbols: ol = olivine, cp = clinopyroxene, op = orthopyroxene, hb = hornblende, bi = biotite, pl = plagioclase, qt = quarts, kf = potash feldspar, cu = cummingtonite, ma = magnetite, il = ilmenite, ap = apatite.
4.2. Geochemical Analysis Results
4.2.1. General Characteristics
Major element oxide analysis results can be found in Appendix A. The volcanic rock
classification of LeBas et al (1986) shows that Maderas rocks include basalts, basaltic
andesites, and the more silicic rocks are on both sides of the divide between andesites and
trachyandesites, while the highest silica rocks are trachydacites (Figure 4.2). This
distribution of rock types differs from Concepción, where most all of the rocks are basalt,
basaltic andesite, andesite and dacite (Figure 4.2). Figure 4.3 shows the same plot but
includes samples from volcanoes in Nicaragua and Costa Rica. The Maderas and
Concepción samples show the same range in composition (basalt to dacite) as other
Central American (CA) volcanoes based on silica content.
ol cp op hb bi pl qt kf cu ma il ap
Concepción Maderas
?
?
50 60 70 75 55 65 Wt. % SiO2
17
Picro-basalt
BasaltBasalticandesite
AndesiteDacite
Rhyolite
Trachyte
TrachydaciteTrachy-andesite
Basaltictrachy-andesiteTrachy-
basalt
Tephrite orBasanite
Phono-Tephrite
Tephri-phonolite
Phonolite
Foidite
35 40 45 50 55 60 65 70 750
2
4
6
8
10
12
14
16
Na2O+K2O
SiO2
LeBas et al 1986 NM100
Figure 4.2. Total alkalies vs. silica for Ometepe rocks.
Picro-basalt
BasaltBasalticandesite
AndesiteDacite
Rhyolite
Trachyte
TrachydaciteTrachy-andesite
Basaltictrachy-andesiteTrachy-
basalt
Tephrite orBasanite
Phono-Tephrite
Tephri-phonolite
Phonolite
Foidite
35 40 45 50 55 60 65 70 750
2
4
6
8
10
12
14
16
Na2O+K2O
SiO2
LeBas et al 1986 NM100
Figure 4.3. Total alkalies vs. silica for rocks from Central America.
4.2.2. Bulk Composition of Ometepe lavas
Figure 4.4 shows the silica distribution of Maderas rocks as represented by the whole
rock data in Appendix A. The 59 whole rock analyses describe a typical andesitic
volcano with a mean SiO2 percentage of 54.4 ± 4.1 %. The range is from 48 to 64 %. The
distribution is likely slightly skewed toward the mafic end because one of the
investigators (Lindsay, 2009)sampled mafic materials selectively for petrological reasons.
18
Figure 4.5 shows the silica distribution for Concepción volcano. Concepción has an
almost identical silica range and distribution as Maderas, with a mean at 55.2 ± 4.5 % and
a slightly larger range of 48 to 66 % SiO2.
Distribution plots from Maderas and Concepción can be compared with the distribution
plot for Nicaragua samples in Figure 4.6. Based on the samples collected, Nicaraguan
volcanic rocks (including Maderas and Concepción) have a mean of 53.7 ± 5.0 % and a
range of 47-68%. This is also nearly identical to Maderas and shows that the bulk
composition of Maderas is similar to other nearby volcanoes.
45 50 55 60 65 700
2
4
6
8
10
12
14
16
18
20
22
24
26
Frequency
S iO2
N=59 M =5.44E+1 SD=4.09E+0 SE=5.32E-1
Figure 4.4: Silica distribution for lavas from Maderas volcano.
45 50 55 60 65 700123456789
101112131415
Frequency
SiO2
N=54 M =5.52E+1 SD=4.49E+0 SE=6.11E-1
Figure 4.5: Silica distribution for Concepción volcano.
19
45 50 55 60 65 700
5
10
15
20
25
30
35
40
45
50
55
60
65
Frequency
S iO2
N=235 M =5.37E+1 SD=4.96E+0 SE=3.23E-1
Figure 4.6: Silica distribution for samples from Nicaragua.
4.2.3. Incompatible Elements
Maderas lavas differ from Concepción in one significant way. They are higher in
incompatible elements. Figure 4.3 shows that Maderas and Concepción display higher
amounts of alkalies than other Nicaraguan and Costa Rican volcanoes when plotted
against SiO2 and that Maderas displays higher amounts than Concepción. A plot of K2O
vs. SiO2 (Gill, 1981) highlights this trend with the Maderas samples exhibiting higher
concentrations of incompatible potassium (High-K) than most other Nicaraguan and
Costa Rican volcanoes (Figure 4.7). The Concepción samples are found along the high
end of the Medium-K rocks.
L o w -K
M ed iu m -K
H igh -K
A C ID
B A S IC
5 0 5 5 6 0 6 50
1
2
3
4
K2O
S iO2
A n d es ite typ es
Figure 4.7. K2O vs. SiO2 for Central American volcanic rocks.
20
Plots of incompatible elements vs. MgO for Maderas and Concepción can be seen in
Figure 4.8. For comparable MgO ranges, Maderas lavas are higher in K2O, Rb, Zr, Nb,
and Th than Concepción. This difference amounts to Maderas enrichments of about 20-
50%, but this enrichment is not shared by Ba. This enrichment may reveal a more
evolved magmatic system below Maderas than the system below Concepción but the
cause of Maderas’ incompatible element enrichment is beyond the scope of the study.
In Figure 4.9, incompatible elements at Maderas and Concepción are compared to other
volcanoes from Nicaragua and Costa Rica. For MgO ranges similar to Maderas and
Concepción (0-6 wt. %) Nicaraguan and Costa Rican volcanoes show similar ranges of
incompatible elements with some Costa Rican volcanoes displaying the highest
concentrations. Samples from Maderas and Concepción fall within this range. Above 6
wt. % MgO the Nicaraguan and Costa Rican volcanoes bifurcate with Costa Rican
volcanoes always displaying higher values.
0
1
2
3
4
5
K 2 O
Concepcion Maderas
0
1000
2000
3000
Ba
Concepcion Maderas
0
25
50
75
100
Rb
0
100
200
300
400
500
Zr
0 1 2 3 4 5 60
10
20
30
40
50
Nb
MgO0 1 2 3 4 5 6
0
5
10
15
20
Th
MgO Figure 4.8: Plots of incompatible elements vs. MgO with regression lines for Maderas and
Concepción volcanoes.
21
0
1
2
3
4
5
K 2 O
Nicaragua Concepcion Maderas Costa Rica
0
1000
2000
3000
Ba
0
100
200
Rb
0
100
200
300
400
500
Zr
0 1 2 3 4 5 6 7 8 9 10 11 120
10
20
30
40
50
60
70
Nb
MgO0 1 2 3 4 5 6 7 8 9 10 11 12
0
10
20
30
40
Th
MgO
Figure 4.9: Plot of incompatible trace elements vs. MgO comparing Maderas and Concepción to
other Central American volcanoes.
While new trace element data was not analyzed for the samples collected in this study
other than Ba and Sr, previous studies of trace elements from Central America show that
Nicaragua has a regional high for degree of melting and fluid from the subducted slab
based on Ba/La and La/Yb ratios (Bolge et al., 2009). However, this applies only to
western Nicaragua and as you move south these ratios decrease steadily towards Maderas
and Concepción to show some of the lowest values in slab signal and degree of melting in
Central America, other than in central Costa Rica. Trace element ratios also indicate that
while most of the magmas along the CAVF are derived from water-rich flux, at Maderas
and Concepción there is also a component of decompression melting due to the steep dip
of the slab (Carr et al., 2007b; Lindsay, 2009).
22
4.2.4. Fenner Diagrams
Fenner diagrams comparing Maderas and Concepción to other Nicaraguan and Costa
Rican volcanoes are presented below (Figure 4.10). The rocks from Maderas and
Concepción volcanoes display smaller ranges of MgO (0-6 wt. %) than all the
Nicaraguan and Costa Rican volcanoes (0-12 wt. %). However, within their range they
display similar values for the other element oxides indicating that they are typical Central
American volcanoes.
12
17
22
Al 2 O 3
Nicaragua Concepcion Maderas Costa Rica
45
50
55
60
65
SiO 2
0
10
20
FeO
0.0
0.5
1.0
1.5
2.0
TiO 2
0
2
4
6
Na 2 O
0
5
10
15
CaO
05100
2
4
K 2 O
MgO0510
0.0
0.5
1.0
P 2 O 5
MgO Figure 4.10. Fenner diagrams for Central American volcanic rocks. (All FeO as FeO*.)
23
4.2.5. Analogy to paired volcanoes of Halsor and Rose (1988)
Due to the close proximity of Maderas volcano to Concepción volcano, the two were
compared to superficially similar paired volcanoes in northern Central America (NCA
pairs) studied by Halsor and Rose (1988). The NCA pairs (Cerro Quemado-Santa Maria,
Tolimán-Atitlán, Acatenango-Fuego, and Santa Ana-Izalco) straddle the volcanic front
whereas Maderas and Concepción are arranged parallel to the front. Dollfus and de
Montserrat (1868) and others who have described volcanoes in Guatemala have observed
that volcanic front volcanoes seem to be migrating spatially to the south, as marked by
younger, more active southerly cones which are spatially near older northern vents. This
suggested that the volcanic front, and perhaps the trench and subduction zone, might be
migrating southward.
This has not been suggested for Nicaragua, however. In addition, in Northern Central
America there are silicic calderas located north of the VF (Rose et al., 1999) and so the
northerly position of the older vents suggests that the high incompatible element content
could be influenced by mixing with silicic magma bodies of the caldera. This is unlikely
to apply at Ometepe, where there is as yet no evidence of a silicic center. However,
Maderas does share characteristic incompatible element enrichments along with the older
cones of NCA (all except Ba, Figure 4.8). It is concluded that while there are some
similarities to NCA pairs, it is unlikely that they share completely similar explanations.
4.3. 40Ar/39Ar Results A summary of the results of the 40Ar/39Ar analyses can be found in Table 4.2. Of the ten
samples prepared for analysis, seven samples were analyzed. Two samples (MADERAS-
007 and -008) did not define an age plateau and are not included in the table. The
remaining five samples revealed ages that range from 70.4 ± 6.1 ka to 176.8 ± 6.1 ka. The
ages for samples MADERAS-002, -003, -011, and -013 are precise with uncertainties of
1.4%-8.6%. The age determined for sample MADERAS-004 is less precise with a
(±17%), which may be due to alteration. These ages are consistent with the previous age-
date obtained for Maderas of 76±6 ka (Carr et al., 2007b) which is also included in the
24
table. An example of an 40Ar/39Ar age determination can be seen in Figure 4.11. For
complete results of the 40Ar/39Ar age determinations see Appendix B.
85.2 ± 3.1 Ka
100
50
0
50
100
150
200
250
300
350
400
450
500
0 10 20 30 40 50 60 70 80 90 100
Cumulative 39Ar Released [ % ]
0.0000
0.0005
0.0010
0.0015
0.0020
0.0025
0.0030
0.0035
0.0040
0.0045
0 1 1 2 2 3 3 4 4 5 5 6 6 7 7
39Ar / 40Ar
Figure 4.11 Age plateau diagram (a) and inverse isochron diagram (b) for sample MADERAS-013.
(a)
(b)
85.1 ± 3.8 Ka
25
Tab
le 4
.2. S
umm
ary
of 40
Ar/
39A
r ex
peri
men
ts
K
/Ca
Tot
al fu
sion
Isoc
hron
Pla
teau
G
eolo
gic
S
ampl
e #
tota
l A
ge (k
a) ±
2σ
40A
r/36
Ar i
± 2σ
M
SW
D
Age
(ka)
± 2
σ N
39
Ar %
M
SW
D
Age
(ka)
± 2
σ U
nit1
MA
D00
2 0.
43
68.1
±
7.2
293.
4 ±
5.5
0.31
73
.2
± 9.
4 9
of
9 10
0.0
0.34
70
.4
± 6.
1 Q
poba
MA
D01
3 1.
88
85.1
±
4.7
295.
6 ±
2.4
0.28
85
.1
± 3.
8 10
of
10
10
0.0
0.25
85
.2
± 3.
1 Q
poa
MA
D00
4 0.
13
125.
8 ±
30.9
29
5.0
± 1.
7 0.
23
136.
5 ± 33
.4
9 of
10
95
.7
0.25
12
8.7
± 22
.2
Qpr
gb
MA
D00
3 1.
69
157.
7 ±
3.5
296.
3 ±
7.0
0.23
15
7.1
± 3.
7 9
of
9 10
0.0
0.21
15
7.5
± 2.
2 Q
pra
MA
D01
1 0.
37
175.
5 ±
8.6
295.
5 ±
5.2
0.21
17
6.8
± 9.
1 9
of
9 10
0.0
0.19
17
6.8
± 6.
1 Q
prba
M10
2 -
- -
- -
- -
- -
- -
- -
76.0
±
12.0
3 Q
al
Age
s cal
cula
ted
rela
tive
to 2
8.20
1 M
a fo
r the
Fish
Can
yon
sani
dine
(Kui
per e
t al.,
200
8) u
sing
deca
y co
nsta
nts o
f Min
et a
l. (2
001)
. A
ge in
bol
d is
pre
ferr
ed.
All
unce
rtain
ties a
re g
iven
at 9
5% c
onfid
ence
leve
l.
1 Geo
logi
c un
it re
fers
to F
igur
e 5.
1 2
For m
ore
info
rmat
ion
on sa
mpl
e M
10 se
e C
arr e
t al.
(200
7)
3 Pl
atea
u ag
e ha
s be
en m
odifi
ed fr
om C
arr e
t al.
(200
7) fr
om 7
6.0
± 6.
0 to
76.
0 ±
12.0
to a
ccou
nt fo
r the
diff
eren
ce in
unc
erta
inty
repo
rting
bet
wee
n th
e tw
o st
udie
s (2
σ fo
r thi
s stu
dy a
nd 1
σ fo
r Car
r et a
l.).
27
5. Discussion
5.1. Geological Map
As a framework for gaining the full significance of age dates, geochemical data, sample
locations and field observations, a geologic map of Maderas volcano was constructed
(Figure 5.1). Previous geologic maps by Sebesta (2001) and van Wyk de Vries (1986)
were consulted while constructing this map. For structural features the structural maps in
the articles found in Table 5.1 were consulted. Topographic maps of the island (INETER
and JICA, 2006b; INETER and JICA, 2006a), Google Earth images, and a 20m DEM
were also used in the mapping process. The new map is discussed below along with the
differences from previous maps.
Table 5.1: Articles featuring structural maps of Maderas
Article
van Wyk de Vries and Borgia (1996)
van Wyk de Vries and Merle (1996)
Borgia et al. (2000)
Kerle and van Wyk de Vries (2001)
Delcamp et al. (2008)
Byrne et al. (2009)
Mathieu et al. (2011)
5.1.1. Dominant structural feature: A cross-cutting graben
As discussed above, a graben striking 135° cuts across the center of the volcano. The
main faults are evidently normal. These faults bound an asymmetrical graben with over
100 meters of vertical displacement on the eastern fault and over 50 meters of vertical
displacement on the western fault. The graben created a topographic low along the
summit of the volcano. A cross section and summit profile can be seen in Figure 5.2.
When volcanism occurred after the formation of this graben, the erupted lava
accumulated and flowed along the strike of the graben creating a flatter top to the volcano
and less steep slopes to the north and south. The feature is clearly delineated by the
differential erosion where inside the graben the younger deposits are less deeply incised.
28
Fi
gure
5.1
: Geo
logi
c m
ap o
f Mad
eras
vol
cano
. SR
FZ =
San
Ram
on F
ault
Zone
. Loc
atio
n of
SR
FZ d
eter
min
ed b
y (F
unk
et a
l., 2
009)
.
29
Figure 5.2: a) Summit profile and cross-section of Maderas volcano. Vertical exaggeration is ~1.5x. Light grey lines represent a general orientation of volcanic deposits. The blue area represents alluvial deposits b) Location of A and A’ on Maderas volcano.
5.1.2. Existence of an older cone
Following the previous discussion of the cross-cutting graben, Maderas volcano has a flat
summit with relatively steep western and eastern flanks. A map of the slope of the
volcano (Figure 5.3) shows that the area west of the summit crater and east-northeast of
the summit graben have the steepest slopes on the volcano with an average gradient of
~24° on the east side and a gradient of ~25° on the west side. For comparison, the slopes
of Concepción volcano have a gradient of ~28°. This topography is interpreted to
represent an older cone that was eroded and breached by the graben. The east and west
flanks apparently represent the slopes of the cone before faulting and are composed of the
oldest exposed flows on the volcano. The depth of the erosional channels and gullies in
these areas suggest that there have not been any new lava flows or deposits on these
slopes for an extended period of time. This is consistent with the dense forest cover found
on these slopes that is nearly impossible to traverse without a trail.
5.1.3. Alluvial Deposits
Large alluvial deposits are found around the base of the volcano with the most
voluminous deposits on the east and west sides of the volcano (Figure 5.1). The majority
of these deposits are found downslope of the extensively eroded older cone. It is likely
a)
b)
A
A’
30
that the erosion of the older cone, at times in the form of lahars, is the origin of these
deposits. A gradational contact has been mapped between the old cone and the deposits.
Other depositional features are an alluvial fan on the south side of the island near the
town of Tichaná, streambeds where sediments have been deposited, and lacustrine
deposits from Lake Nicaragua on the isthmus between Maderas and Concepción volcano.
5.1.4. Lava Flows
Lava flows that have been emplaced on the volcano after the formation of the old cone
largely radiate out from the central crater (Figure 5.1). These lava flows can be broken up
into pre-graben flows and post-graben flows. Pre-graben flows are found on the east and
west side of the volcano emanating from the older cone. Where lava flows can be
observed on the lower slopes in these areas they have been traced up the flanks of the
volcano if possible. This indicates that the pre-graben flows are younger than the older
cone as their traces mantle the older cone.
Figure 5.3: Slope map of Maderas volcano in degrees.
31
Lava compositions from the pre-graben flows vary from basalt to dacite, which differs
from the map by Sebesta (2001) where all of the lava flows were mapped as andesite.
Some flows that were mapped do not have geochemical data associated with them and
have been mapped as having unknown compositions. There is some uncertainty about the
exact contacts between lava flows in some areas. Where uncertainty exists a dashed line
has been used.
Post-graben flows are found to the north and south of the volcano emanating from the
summit crater along the strike of the graben. As the graben formed it created a
topographic low to the north and south causing the flows to move in these directions. The
compositions of these flows based on geochemical data are basaltic to andesitic.
5.1.5. Central Crater and Vents
Knowledge about rock materials near Maderas’ summit is limited by strong weathering
and heavy vegetation cover in an area receiving orographic rainfall. The central vent of
Maderas volcano contains a small lake and is located roughly in the center of the volcano,
within the graben, and along its west side (Figure 5.1). On the west side of the central
crater is a debris avalanche deposit. The east side of the crater had thick vegetation but
possible lava flows are present.
Two other vents can be seen on the northeast side of the volcano. One vent is located in
an area known as Punta Gorda and the other is southeast of Punta Gorda near the town of
El Corozal. Punta Gorda can be divided into two areas, a northern area and a southern
area. The northern-most area at Punta Gorda has a semi-circular shape, a topographic
high towards the northern edge of the point and is cut by a fault. Near the northern coast
of this area and at the topographic highs there are many large boulders of lava. The
largest are ~1.5 m in diameter with an average diameter being ~40 cm. Mathieu (2010)
also found a phreatomagmatic deposit on the southwest side of this area; however, it is
possible it is associated with the more southern area on Punta Gorda.
The southern area on Punta Gorda has a semi-circular shape and a flat central crater with
a rim around it except for an area on the eastern side along the lakeshore. This rim is
32
highest on the southwest side (~100 m.a.s.l.). A phreatomagmatic deposit is located in
this same area as well as on the eastern side along with a lava flow (Mathieu, 2010). The
flat central crater is roughly 0.8 km in diameter.
Based on the description above, it is proposed that a lava flow descended from the
summit crater of the volcano and started to form a terrace over the lake in the area of
Punta Gorda. This terrace collapsed in the southern area of the point and reacted with
water creating a littoral maar, or rootless vent feature. Lava flows that appear to have
flowed down the side of the volcano to this littoral maar have been mapped in the area
upslope from Punta Gorda by Sebesta (2001) and were mapped in this study as well,
supporting this theory.
A similar situation is thought to have occurred near El Corozal to the southeast where
another semi-circular flat, central crater is located near phreatomagmatic deposits. A
lateral vent, located upslope at about 200 m.a.s.l, is thought to have erupted an andesitic
to dacitic lava near the lakeshore. When this flow reached the water, it reacted with it
forming another littoral maar, or rootless vent feature.
A second lateral vent is located on the northwestern slope of the volcano above the
community of El Tistero. This vent appears to have erupted several lava flows. Sebesta’s
map indicates that this vent is a maar feature, however no hydrothermal features were
found during field observations of this area. Also an investigation into the past lake levels
of Lake Nicaragua did not reveal much as little information is available regarding this
subject. One article did imply that during the mid to late Pleistocene the lake was larger,
reaching down into northern Costa Rica, which could indicate higher lake levels
(Bergoeing and Protti, 2006), however the vent sits at around 350 m.a.s.l. and it is highly
unlikely that lake levels ever reached that high. Also, the lack of hydrothermal deposits
makes it unlikely that water played a role in this vent.
One other possible vent located in this study is Punta el Delirio on the north-northwest
side of the volcano. However, too little information was collected during this study to
determine whether or not this is a littoral vent.
33
Mathieu et al. (2011) also proposed two more vents near the summit of the crater (one to
the southwest and one to the north) and one other vent south of Punta el Delirio. Van
Wyk de Vries and Borgia (1996) also proposed a vent at Punta El Delirio as well as more
vents in the Punta Gorda area. No evidence was found during this study to support the
presence of these vents.
5.2. Geochemical Data
As the stature of stratovolcanoes increases their silica content may also rise. To evaluate
the geochemical evolution of the volcano, plots of vent elevation versus silica content
were made (Figure 5.4). Excluding the two mapped lateral vents, we see a weak tendency
for trachy-andesites/trachydacites to be erupted from vents higher up on the volcano. It
should be noted that many flows are not plotted, as it is not possible to tell from which
height they were erupted due to their location beneath younger flows.
To determine if the lava flows at the volcano became more evolved over time a plot of
lava flow age vs. silica content was created using known age dates and stratigraphy
(Figure 5.5). Lava flows were first divided up by known age dates and by map unit (old
cone, pre-faulting flow or post-faulting flow, Figure 5.1). Within each unit, flows that
were known to be stratigraphically younger or older than the dated flows were added.
Remaining flows with geochemical data were then placed. In many cases uncertainty
exists about relative ages of these flows. This plot reveals no apparent correlation
between age and silica content. However, it does show that a range of lava compositions
(basalt, basaltic andesite, and andesite) have been erupted throughout the life of the
volcano.
34
0
200
400
600
800
1000
1200
1400
50 52 54 56 58 60 62 64wt.% SiO2
Figure 5.4. Plot of vent height vs. wt. % SiO2.
45
50
55
60
65
0 18
wt.
% S
iO2
Figure 5.5: Plot of wt. % SiO2 versus age of the lava flow. Age axis is not to scale. Grey symbols represent samples that have been radiometrically dated by 40Ar/39Ar with the determined ages labeled.
>150 ka ~150 to ~100 ka ~100 to ~60 ka
157.5 ± 2.2 ka
176.8 ± 6.1 ka
128.7 ± 22.2 ka
85.2 ± 3.1 ka
70.4 ± 6.1 ka
northwest lateral vent northeast
lateral vent
35
5.3. 40Ar/39Ar Age Dates
5.3.1. Phases of volcanism The age dates at Maderas range from 176.8 ± 6.13 ka to 70.4 ± 6.1 ka and based on
geomorphology and location of the age dates it is suggested that the volcano experienced
at least three separate periods of volcanism. The first period occurred with the building
up of the original cone of the volcano prior to ~176 ka and lasting up to ~150 ka. This is
based on the two age dates (MADERAS-011 and MADERAS-003) obtained from the old
cone unit that can be seen on the geologic map (Figure 5.1).
The second period of volcanism occurred after ~150 ka but prior to ~100 ka. These lava
flows occur on the west, east, and northeast flanks of the volcano. They cover the old
cone and it is possible to trace their outline up the flanks of the volcano so it is believed
that they are younger than the old cone. This is supported by the age date obtained from
sample MADERAS-004 on the west side of the volcano with an age of ~128 ka (Figure
5.1). It is likely that they are older than the central graben as the graben constrained
volcanism to move north and south of the crater after it formed and these flows have not
been constrained in that manner. However, there is no evidence to show that they could
not have been erupted at the same time as the formation of the graben.
The third phase of volcanism occurred after ~100 ka and after the formation of the central
graben. The direction of the flows of this volcanism to the northwest and southeast was
controlled by the graben structure. The location of the flow with the youngest obtained
age date of ~70 ka lies outside of and near to the graben structure. This supports a
younger age as it shows that enough lava had accumulated within the graben for it to
have flowed over the side of the structure.
5.3.2. Implications of ages for shorelines at Maderas and Concepción One difference between Maderas and Concepción volcanoes is the nature of their
shorelines. Maderas volcano exhibits a drowned shoreline whereas Concepcion’s
shorelines appear to be rising. At Concepcion the base of the volcano contains raised
beaches and deformed beds on its east and west sides (Borgia and van Wyk de Vries,
36
2003). The eastern side is characterized by diapiric rise while the western side is
characterized by outward thrusting (Borgia and van Wyk de Vries, 2003).
The difference in shorelines of the two volcanoes is likely due to the difference in ages
with Concepcion being younger than Maderas. Concepcion has historic activity (Diez et
al., 2006) as well as an age date of 19 ka (Siebert et al., 2010). At Concepcion the rise of
shorelines around its base is believed to be caused by loading of volcanic material which
causes spreading of the ductile lake sediments on which the volcano sits (Borgia and van
Wyk de Vries, 2003). The drowned shorelines of Maderas, which is no longer loading
volcanic material, imply that it is subsiding. This could be due to the reaction of the
underlying lake sediments to the overlying edifice over the last few tens of thousands of
years. The collapse of the magma chamber below the volcano is another possible
explanation for the apparent subsidence.
5.3.3. Comparison of age dates to other Central American volcanoes The duration and age of volcanic front volcanoes in Central America is not yet well
constrained. Very few volcanoes have been extensively sampled for age dates. Figure 5.6
is a plot of dated age samples from various volcanoes in Central America. Most
volcanoes have numerous recent eruptions that have been dated but few older dates
making it difficult to study the duration of volcanism.
Carr et al. (2007b) show that onset of active volcanoes of the volcanic front in Nicaragua
is generally less than ~400 ka. This is based on the oldest Nicaraguan volcanic front lava
sample, from Telica volcano, that has an age of 330 ± 20 ka. Costa Rican volcanism is
thought to begin ~600 ka. In Nicaragua the age of onset of volcanism is much less
constrained due to the location of the volcanoes within the Nicaraguan depression and the
covering of the earliest flows of the volcanoes by sediments (Carr et al., 2007b).
Guatemalan volcanoes display similar ages. Extensive age-date sampling at Santa Maria
revealed ages ranging from 103 ka to 35 ka (Escobar-Wolf et al., 2010) with another
eruption occurring in 1902. Volcanism at the Fuego-Acatenango volcanic complex
37
ranges in age from over 230 ka to the present and with an age of less than 30 ka for
Fuego volcano itself (Vallance et al., 2001b).
Figure 5.6: Ranges of age dates analyzed for Central American volcanoes. White symbols represent Guatemalan volcanoes, black symbol represent Nicaraguan volcanoes and grey symbols represent Costa Rican volcanoes. (Age dates from (Bardintzeff and Deniel, 1992; Vallance et al., 2001b; Carr et al., 2007b; Escobar-Wolf et al., 2010; Siebert et al., 2010)
In all of these cases it is difficult to know the duration of volcanism with only a few dated
samples. Most of Fuego’s young volcanism may have happened in the past 30 ka while it
is built on an edifice that is 230 ka or more (Vallance et al., 2001b). While Santa Maria is
mostly younger than 103 ka, it is built on cones that have ages ranging from 163-438 ka
(Singer et al., in press). Only a few volcanoes have more than a few dates, so the duration
of currently active cones is unconstrained and could be a few tens of thousands of years.
Do the maximum ages of cones like Telica suggest that the volcano is continuously active
for 300 ka or is the volcano’s current activity only the latest of several periods of
concentrated activity, each of which could be viewed as a separate volcano? For Maderas
itself are there two volcanoes or one? Does the lack of age-dated materials younger than
60ka mean that Maderas is extinct? The answers to these questions are unknown. But the
apparent lack of activity for 60 ka is surely significant to hazards potential and it
Santa Maria Fuego Pacaya Cosegüina San Cristóbal Telica Cerro Negro Momotombo Concepción Maderas Rincón de la Vieja Miravalles Tenorio Platanar Poás Barba Irazu
38
contrasts markedly with Concepción which is known to have had dangerous historic
activity.
5.4. An eruptive history of Maderas
Based on the geochemical and age date results gathered in this study and on the geologic
map, a brief history of Maderas volcano has been outlined. It has been divided into 5
phases, each of which is discussed below.
1. Construction of the older cone: The initial activity of Maderas is buried under the
current edifice and cannot be described. Therefore, the first phase of the volcano
discussed here is the construction of the cone. Based on the ages shown in Table 4.2, this
older cone was formed more than ~150 ka. The volcano began to build up an edifice
composed of alternating lava flows and pyroclastic deposits. It is likely that the west side
of the volcano received more pyroclastic material, as seen at Concepción (Borgia and van
Wyk de Vries, 2003), as the prevailing trade wind direction is east to west and this is
likely to have been true throughout the life of the volcano. Traverses into some of the
deepest eroded channels on the volcano revealed both lava flows and pyroclastic
deposits. Mathieu (2010) describes some of these deposits. The locations of these deep
gullies can be found on the steepest slopes of the volcano, which, explained above, are
likely to be remnants of the original cone. It is likely that the older cone formerly reached
an elevation similar to that of Concepción (1600 m.a.s.l. compared to Maderas’ current
elevation of 1394 m.a.s.l.).
The reason for the steeper slopes on Maderas’ older cone is unknown. Continual erosion
over an extended period of time could result in the observed steeper slopes. Additionally,
the formation of the graben could have caused a slight upward tilting of the slopes
making them steeper (Figure 5.2). Another possibility could be the eruption of more
silicic material from higher up on the edifice which could result in a thick hard core to the
volcano and more resistant lava flows near the summit which would be slower to erode
and could cause steepening of the slopes of the underlying units. However, the
geochemical data does not support this as seen in Figure 5.4 where there is not a strong
39
correlation between vent height and more silicic lava composition. The most silicic rocks
found at Maderas were actually found near the base of the volcano. It is possible that
even though there is not a correlation between composition and vent elevation, there
could be a tendency for thicker and more erosionally resistant units near the central vent.
This could partly explain why erosion seems to enhance steepness.
2. Pre-graben volcanism: Due to the observed traces of lava flows over the old cone,
these flows are thought to have been emplaced after formation of the old cone between
~150 ka and ~100 ka based on obtained age dates. These flows can be seen on the
eastern, northeastern and western sides of Maderas. It is proposed that during this time
period lava flows on the northeast side of the volcano, one of which is from a lateral vent,
flowed out into the lake and reacted with lake water to form littoral maars creating the
point at Punta Gorda and a crater-like feature near the town of El Corozal Nuevo.
3. Faulting and formation of the graben: Maderas was affected by faulting in a general
NW-SE direction roughly parallel to the Nicaraguan depression and the CAVF. These
faults formed an asymmetrical graben through the center of the volcano with the eastern
fault having dropped down more than the western fault and leaving behind a larger fault
scarp. This graben caused the top of the volcano to become flattened and created an
asymmetrical shape to the profile of the volcano. The age of the formation of the graben
is not well constrained. It is thought to have started after or possibly concurrently with the
eruption of the pre-graben flows. The initial faulting of the graben is estimated to have
begun ~100 ka.
4. Post-graben volcanism and lateral vent on the northwest side of the volcano: After
the formation of the graben Maderas continued to erupt. It is thought that little or no
eruptive activity occurred during the formation of the graben as the faults do not appear
to have been covered up by eruptive material. The formation of the graben in the center
of the volcano created a topographic low and constrained the movement of lava along this
low, covering up the older, steeper parts of the cone that had been dropped down. One
flow, to the southeast of the volcano appears to have been strongly constrained by the
40
faulting and flowed down a channel-like feature. The age range of these lavas is
estimated at ~80 ka to ~60 ka.
An active vent was present on the northwest flanks of the volcano that erupted various
lava flows. Four of the six analyses from these flows are andesitic, one is basaltic
andesite and one is basalt. An age date for MADERAS-015, a lava flow from this vent,
would help us constrain the age of the vent. The graben that runs through the volcano
does not appear to cut through this lateral vent and, therefore, it is proposed that it was
erupted after the formation of the graben.
5. Alluvial deposits: Throughout the life of the volcano, deep gullies formed and the
slopes of the volcano were eroded. Volcanic sediments accumulated around the base of
the volcano in the form of lahars and fluvial deposits. These deposits are more prevalent
below the old cone. There is also an alluvial fan located at the base of a large gully on the
southeast side of the volcano.
5.5. Implications for geologic hazards
5.5.1. History of geologic hazards
According to Bundschuh et al. (2007), Central America is one of the regions in the world
most prone to geology-related natural disasters due its tectonic setting and climate.
Nicaragua, located in the center of Central America has experienced all of the following
geology-related hazards in the past two decades: earthquakes (Lesage et al., 2007),
tsunamis (Molina, 1997; Fernández and Ortiz, 2007), landslides or lahars (Kerle et al.,
2003; Rodríguez, 2007), hurricanes (Kerle et al., 2003), and volcanic eruptions (Alvarado
et al., 2007). Freundt et al. (2006) also list a number of volcano-related hazards that have
occurred in Nicaragua.
As a small island located in Nicaragua, Ometepe is vulnerable to hazards in different
ways than the rest of the country. Pelling and Uitto (2001) list and describe a number of
intrinsic vulnerabilities related to small island developing states (SIDS). While Ometepe
is not its own nation, many of these vulnerabilities still apply. These vulnerabilities are
41
small size, insularity and remoteness, environmental factors, disaster mitigation
capability, demographic factors, and economic factors.
Small size relates to limited natural resources, land use competition, and other spatial
issues found on small islands. Insularity and remoteness relates to the higher costs of
importing or exporting goods to and from the island, time delays in receiving goods, and
possible reduced flow of information to the island. Environmental factors relate to
exposure from large shorelines and small interiors. Demographic factors relate to smaller
populations and therefore a smaller human resource base, populations located near
shores, possible rapid changes in populations, and single urban centers. Economic factors
relate to small economies, specialized products, and dependence on external finance.
(Pelling and Uitto, 2001). On Ometepe, tourism is a large part of the economy and
hazards on the island could greatly influence its numbers. For example, during the time
the author lived on the island, Concepción volcano experienced small explosions over the
week of Semana Santa, a time of celebration in Nicaragua when many tourists visit the
island. Due to these small eruptions of Concepción, tourism on the island greatly
decreased and many businesses suffered because of it. Therefore it can be seen that when
small islands are confronted with geologic-hazards they face many obstacles.
Ometepe itself has experienced and remains vulnerable to all of the geologic hazards
mentioned above. Concepción volcano has erupted frequently in the past century. Diez et
al. (2006) prepared a table showing reported historical eruptions of Concepción volcano.
While the most recent eruptions have all been VEI =1 or VEI=2, earlier accounts indicate
that more violent eruptions have occurred. The most vulnerable populations for volcanic
eruptions of Ometepe are those living near Concepción and especially those living on the
west side of the volcano as prevailing trade winds move in that direction and will carry
ash and other pyroclastic material that way. Maderas volcano, to the south of
Concepción, is not known to have erupted in historic times. Since debris from
Concepción is blown to the west it is also relatively safe to live around Maderas when
looking at volcanic hazards from Concepción.
42
The island has experienced and remains at risk for earthquakes as well. The location of
Ometepe along the CAVF and near the subduction zone of the Cocos plate moving
beneath the Caribbean plate means that it is located in a very seismically active region of
the world. Funk et al (2009) prepared a figure (Figure 2) showing the locations of
numerous earthquakes from 1995-2003 in Nicaragua. They do not include the magnitudes
of these earthquakes; however, it is possible to see that many earthquakes have occurred
near Ometepe. They also interpreted a fault along the border of the Nicaraguan
depression on the west side of Lake Nicaragua and another one to the south of Maderas
volcano within Lake Nicaragua. French et al (2010) discuss an Mw 5.3 fore shock and Mw
6.3 main shock that occurred in Lake Nicaragua near Maderas in 2005.
Also, this study, as well as others (van Wyk de Vries and Borgia, 1996; Mathieu et al.,
2011), show that Maderas itself is crossed with a number of faults. Wells and
Coppersmith (1994) plot the surface rupture lengths of faults against moment magnitudes
the results of which suggest that the faults that cut across Ometepe (with the longest
surface rupture length being about 5 km) would have been formed by earthquakes with
magnitudes of about M5.5 or smaller. It is likely that continued faulting of the volcano
would create earthquakes of similar magnitudes.
Landslides and lahars are also known to occur on the island. On September 27, 1996 a
lahar (Figure 2.1) destroyed the town of El Corozal on the northeast flanks of Maderas
volcano, killing six people, destroying 36 houses and causing the people of the town to be
moved to a new location (Smithsonian Institution, 1996). Other deposits around the
volcano also show that lahars and landslides have occurred in other areas as well. A
report on lahar hazards at Concepción volcano was published in 2001 (Vallance et al.,
2001a). A lahar hazard map from this paper shows that large areas around Concepción
are at risk from lahars.
While no tsunamis have been documented on Ometepe, they are still a threat to the island
and possible tsunami triggers in Lake Nicaragua have been identified such as the collapse
of Mombacho volcano on the northwest shore of lake Nicaragua (Freundt et al., 2007). A
43
collapse of either volcano on Ometepe would not only cause tsunami hazards for the
residents of Ometepe but for those living around the shores of Lake Nicaragua as well.
5.5.2. Implications for Future Hazards
The new age dates imply that the volcano has likely not been active for tens of thousands
of years with the youngest determined age date being 70.4 ± 6.1 ka. It also implies that
the volcano has remained relatively stable over the past 170 ka years in that it has not had
explosive behavior or collapsed. The stability of the volcano is supported by work from
van Wyk de Vries and Borgia (1996) who looked at a number of different ratios between
characteristic geometric parameters to measure stability, how high a volcano can grow
before the failure of the brittle substratum, the mode of deformation of the substratum,
the buoyancy response of the substratum, and rate of deformation. The results of these
ratios imply that Maderas has considerable potential for spreading and low explosive and
collapse hazards. The lack of hydrothermal activity on the volcano (van Wyk de Vries
and Borgia, 1996) also makes it more stable as hydrothermal activity has been linked
with volcanic collapse (Lopez and Williams, 1993; Reid et al., 2001).
The apparent lack of activity at Maderas for ~60 ka implies that the risk for a future
eruption is low, however, it cannot be completely ruled out. Santa Maria volcano in
Guatemala erupted in 1902 after a repose that may have lasted ~30 ka (Escobar-Wolf et
al., 2010). However, there are often signs of unrest before a volcano erupts, especially
after long reposes. Before the Santa Maria eruption there was a marked seismic warning
lasting for months (Anderson, 1908). It is also likely that precursive deformation or
increased seismicity associated with movement of magma below the volcano would be
detected by people around Maderas. While Maderas is not being closely monitored for
deformation, a seismic station is located on its southwest side and there are two other
seismic stations on the island near Concepción. These stations will help scientists monitor
seismic activity on the island and should be able to recognize increased seismicity if it
occurs.
44
Lahars and landslides remain a concern for the inhabitants living on the flanks of
Maderas. As seen in the geologic map (Figure 5.1) much of the base of the volcano is
covered in alluvial deposits. It is likely that some of these have been deposited in the
form of lahars during extreme rainfall events. Therefore, there is a continued risk in these
areas for more lahars to occur as climate change may bring about more extreme weather
events (McBean, 2004). The older cone is the most likely source of these deposits as they
are largely located downslope of the older cone.
The older cone is also the most likely source for landslides or small-scale collapses on the
volcano. The average gradient of the older cone is about 25° but some slopes have
inclines of up to 77° (Figure 5.3). These steeper slopes are more unstable than other areas
of the volcano. Failure of these slopes could result in landslides. A small-scale collapse
was observed on one of these very steep slopes at Maderas by the author in 2009. Areas
located downslope of these steeper slopes have a higher a risk of landslides than other
areas on the volcano.
The experiences of Casita volcano in Nicaragua, which collapsed in 1998 during
Hurricane Mitch and produced a deadly debris flow (Kerle and van Wyk de Vries, 2001)
and of Toliman volcano in Guatemala, which collapsed in 2005 during Hurricane Stan
(Sheridan et al., 2007), are examples of this type of hazard. They suggest the
investigation of possible hydrothermal alteration in the older cone might be useful, and
they also point to the trigger mechanism of heavy rainfall loading from tropical
hurricanes. On Maderas, van Wyk de Vries and Borgia (1996) found that there is a lack
of hydrothermal features on the volcano because their formation is hindered by the
underlying lake sediments that seal fractures caused by spreading and do not allow a
hydrothermal system to rise into the volcano. This lack of alteration should make
Maderas more stable and less prone to large collapses caused by extreme rainfall events.
Earthquakes also remain a concern for the communities on the volcano due to Maderas’
location along the CAVF and near the subduction zone of the Cocos plate beneath the
Caribbean plate. Continued spreading of the volcano could also lead to more seismic
events.
45
Disaster preparedness on the island was taking place during the author’s residence in
Mérida. Care, International began a project on the island working with communities on
disasters (http://www.care.org/careswork/projects/NIC170.asp). One of their main
focuses on the island is Concepción as it is an active volcano. However a number of
workshops were given in all communities and schools on the island about the types of
hazards that can occur in each community, what to do in an emergency and signs for
evacuation routes were put up. (For those living on the Maderas side of Ometepe, the
community of San Ramon was chosen as a safe zone in case of a large eruption from
Concepción.) Community leaders were used and committees for each community were
formed, creating a chain of command for what to do in case of an emergency. This is a
positive step toward disaster preparation on the island, and hopefully community
workshops and school activities will continue to be carried out after Care, International
leaves. The choice of San Ramon as a safe location is supported by this study, which
shows that volcanic hazards at Maderas are far less likely than at Concepción.
47
6. Future Work Regarding hazards, seismic monitoring of Maderas volcano should continue. As stated
above, it is unlikely that Maderas will become active again after ~60 ka of inactivity,
however it is not impossible. A look at lahar hazards on Maderas should also be
conducted. A study by the U.S. Geological Survey has been completed for Concepción
volcano (Vallance et al., 2001a). While, Concepción is more prone to lahars than
Maderas, a study of lahars should also be done for Maderas volcano. It is the author’s
understanding that a map of landslide/lahar hazards for Maderas is currently being
conducted by INETER.
Regarding INETER, an important aspect of this study will be to impart the information
gained to INETER. Collaboration is important among scientists, and it is especially
important to work with scientists in countries with fewer resources. It would also be
important to pass this information along to local tour guides who often state that the last
eruption at Maderas was ~800 to 1000 years ago. The author was unable to determine
where this date came from when talking to local tour guides
Finally community outreach programs should continue each year in all of the
communities of Ometepe regarding geologic hazards. It is important to remind the
inhabitants of the risks posed by the volcanoes and to discuss evacuation routes and what
to do in case a natural disaster occurs.
49
7. Conclusions The main conclusions of the study are that Maderas volcano is similar to other Central
American volcanoes in regard to petrology, geochemistry, and age. Maderas is a typical
volcanic front volcano with lava compositions ranging from basalt to trachydacite. The
ages determined in this study for Maderas suggest that the volcano has not erupted for ~
60 ka.
The ages also indicate that Maderas underwent at least three phases of volcanism: the
construction of the initial cone prior to ~150 ka, pre-graben volcanism prior to ~100ka
and post-graben volcanism that occurred between ~100ka and ~60 ka. These phases are
separated by the formation of a central graben through the volcano that constrained the
movement of the last phase of volcanism within its boundaries.
These findings indicate that volcanic eruptions are not considered a likely hazard for
Maderas volcano. However, earthquakes and lahars are considered as significant hazards
that could occur. Tropical storms, especially those with high rainfall rates could lead to
dangerous debris flows beneath Maderas’ steep flanks. Continued seismic monitoring
should take place on the island as well as continued community outreach and education
about possible disasters, emergency plans, and evacuation routes.
51
8 References Aguirre, J.C., 2009. Suelos, capacidad de uso de la tierra y conflictos de uso en el
municipio Altagracia, Asociacion de Municipios de Rivas, Rivas, Nicaragua.
Alvarado, G.E., Soto, G.J., Pullinger, C.R., Escobar, R., Bonis, S., Escobar, D. and Navarro, M., 2007. Volcanic activity, hazards, and monitoring. In: J. Bundschuh and G.E. Alvarado (Editors), Central America: Geology, Resources, Hazards. Taylor & Francis, London, UK, pp. 1155-1188.
Anderson, T., 1908. The volcanoes of Guatemala. The Geographical Journal, 31(5): 473-485.
Andrade, S.D. and van Wyk de Vries, B., 2010. Structural analysis of the early stages of catastrophic stratovolcano flank-collapse using analogue models. Bulletin of Volcanology, 72: 771-789.
Bardintzeff, J.-M. and Deniel, C., 1992. Magmatic evolution of Pacaya and Cerro Chiquito volcanological complex, Guatemala. Bulletin of Volcanology, 54: 267-283.
Bergoeing, J.P. and Protti, R., 2006. Geomorfología paleo-lacustre del sur del Lago de Nicaragua. Revista Geográfica, 139: 27-38.
Bolge, L.L., Carr, M.J., Milidakis, K.I., Lindsay, F.N. and Feigenson, M.D., 2009. Correlating geochemistry, tectonics, and volcanic volume along the Central American volcanic front. Geochemistry Geophysics Geosystems, 10(12).
Borgia, A., Delaney, P.T. and Denlinger, R.P., 2000. Spreading volcanoes. Annual Review of Earth and Planetary Sciences, 28: 539-570.
Borgia, A. and van Wyk de Vries, B., 2003. The volcano-tectonic evolution of Concepción, Nicaragua. Bulletin of Volcanology, 65: 248-266.
Bundschuh, J., Winograd, M., Day, M. and Alvarado, G.E., 2007. Geographical, social, economic, and environmental framework and developments. In: J. Bundschuh and G. Alvarado (Editors), Central America: Geology, Resources and Hazards. Taylor & Francis, London, UK, pp. 1-52.
Byrne, P.K., van Wyk de Vries, B., Murray, J.B. and Troll, V.R., 2009. The geometry of volcano flank terraces on Mars. Earth and Planetary Science Letters, 281: 1-13.
Carr, M.J., 1984. Symmetrical and segmented variation of physical and geochemical characteristics of the Central American volcanic front. Journal of Volcanology and Geothermal Research, 20: 231-252.
52
Carr, M.J., Feigenson, M.D., Patino, L.C. and Walker, J.A., 2003. Volcanism and geochemistry in Central America: Progress and problems. Geophysical Monograph, 138: 153-174.
Carr, M.J., Patino, L.C. and Feigenson, M.D., 2007a. Chapter 22: Petrology and geochemistry of lavas. In: J. Bundschuh and G.E. Alvarado (Editors), Central America: Geology, Resources and Hazards. Taylor & Francis, London, UK, pp. 565-590.
Carr, M.J. and Rose, W.I., 1987. CENTAM -- A data base of Central American volcanic rocks. Journal of Volcanology and Geothermal Research, 33(1-3): 239-240.
Carr, M.J., Rose, W.I. and Stoiber, R.E., 1982. Central America. In: R.S. Thorpe (Editor), Andesites: Orogenic Andesites and Related Rocks. John Wiley & Sons Ltd., New York, New York, pp. 149-166.
Carr, M.J., Saginor, I., Alvarado, G.E., Bolge, L.L., Lindsay, F.N., Milidakis, K., Turrin, B.D., Feigenson, M.D. and Swisher, C.C., 2007b. Element fluxes from the volcanic front of Nicaragua and Costa Rica. Geochemistry Geophysics Geosystems, 8(6).
de Boer, J., 1979. The outer arc of the Costa Rican orogen (oceanic basement complexes of the Nicoya and Santa Elena Peninsulas). Tectonophysics, 56(3-4): 221-259.
Delcamp, A., van Wyk de Vries, B. and James, M.R., 2008. The influence of edifice slope and substrata on volcano spreading. Journal of Volcanology and Geothermal Research, 177: 925-943.
DeMets, C., 2001. A new estimate for present-day Cocos-Caribbean plate motion: Implications for slip along the Central American volcanic arc. Geophysical Research Letters, 28(21): 4043-4046.
Denyer, P. and Baumgartner, P.O., 2006. Emplacement of Jurassic-Lower Cretaceous radiolarites of the Nicoya Complex (Costa Rica). Geologica Acta, 4(1-2): 203-218.
Diez, M., Connor, C., Navarro, M., Strauch, W., Tenorio, V., Tenorio, L. and Aviles, R., 2006. Volcanic hazards at Concepcion volcano, Nicaragua and recommendations for hazard mitigation, prepared for US Southern Command.
Dollfus, A. and de Montserrat, E., 1868. Voyage geologique dans les republiques de Guatemala et El Salvator. Imperiale, Paris, 539 pp.
Escobar-Wolf, R.P., Diehl, J.F., Singer, B.S. and Rose, W.I., 2010. 40Ar/39Ar and paleomagnetic constraints on the evolution of Volcán de Santa María, Guatemala. GSA Bulletin, 122(5-6): 757-771.
53
Fernández, M. and Ortiz, M., 2007. Earthquake triggered tsunamis. In: J. Bundschuh and G. Alvarado (Editors), Central America: Geology, Resources and Hazards. Taylor & Francis, London, UK, pp. 1257-1265.
French, S.W., Warren, L.M., Fischer, K.M., Abers, G.A., Strauch, W., Protti, J.M. and Gonzalez, V., 2010. Constraints on upper plate deformation in the Nicaraguan subduction zone from earthquake relocation and directivity analysis. Geochemistry Geophysics Geosystems, 11(3).
Freundt, A., Kutterolf, S., Schmincke, H.-U., Hansteen, T., Wehrmann, H., Pérez, W., Strauch, W. and Navarro, M., 2006. Volcanic Hazards in Nicaragua: Past, present, and future. In: W.I. Rose, G.J.S. Bluth, M.J. Carr, J.W. Ewert, L.C. Patino and J.W. Vallance (Editors), Volcanic Hazards in Central America. The Geological Society of America, Boulder, CO, pp. 141-165.
Freundt, A., Strauch, W., Kutterolf, S. and Schmincke, H.-U., 2007. Volcanogenic tsunamis in lakes: Examples from Nicaragua and general implications. Pure and Applied Geophysics, 164: 527-545.
Funk, J., Mann, P., McIntosh, K. and Stephens, J., 2009. Cenozoic tectonics of the Nicaraguan depression, Nicaragua, and Median Trough, El Salvador, based on seismic-reflection profiling and remote-sensing data. GSA Bulletin, 121(11/12): 1491-1521.
GADM, 2011. GADM database of Global Administrative Areas. http://www.gadm.org/
Gill, J.B., 1981. Orogenic andesites and plate tectonics. Springer-Verlag, Berlin 390 pp.
Goffin, C., Herrera, M.-A.B., Furlan, D.A.P. and Oritiz, J.M.R., 2006. VIII Censo de Población y IV de Vivienda: Población Municipios, Gobierno de Nicaragua, Managua, Nicaragua.
Grosse, P., van Wyk de Vries, B., Petrinovic, I.A., Euillades, P.A. and Alvarado, G.E., 2009. Morphometry and evolution of arc volcanoes. Geology, 37(7): 651-654.
Halsor, S.P. and Rose, W.I., 1988. Common characteristics of paired volcanoes in northern Central America. Journal of Geophysical Research, 93(B5): 4467-4476.
Hoernle, K., Hauff, F. and van den Bogaard, P., 2004. 70 m.y. history (139-69 Ma) for the caribbean large igneous province. Geology, 32: 697-700.
INETER and JICA, 2006a. La Palma, Nicaragua, 3150 III, E751. INETER, Managua, Nicaragua.
INETER and JICA, 2006b. San José del Sur, Nicaragua 3050 II, E751. INETER, Managua, Nicaragua.
54
Kerle, N. and van Wyk de Vries, B., 2001. The 1998 debris avalanche at Casita volcano Nicaragua - investigation of structural deformation as the cause of slope instability using remote sensing. Journal of Volcanology and Geothermal Research, 105(1-2): 49-63.
Kerle, N., van Wyk de Vries, B. and Oppenheimer, C., 2003. New insight into the factors leading to the 1998 flank collapse and lahar disaster at Casita volcano, Nicaragua. Bulletin of Volcanology, 64(331-345).
Koppers, A.P., 2002. ArArALC-software for 40Ar/39Ar age calculations. Computers and Geosciences, 28(5): 605-619.
Kuiper, K.F., Deino, A., Hilgen, F.J., Krijgsman, W., Renne, P.R. and Wijbrans, J.R., 2008. Synchronizing Rock Clocks of Earth History. Science, 320(87): 500-504.
Le Bas, M.J., Le Maitre, R.W., Streckeisen, A. and Zanettin, B., 1986. A chemical classification of volcanic rocks based on the total alkali-silica diagram. Journal of Petrology, 27(3): 745-750.
Lesage, P., Mora, M., Strauch, W., Escobar, D., Matías, O., Tenorio, V., Talavera, E., Rodríguez, A. and Alvarado, G.E., 2007. Volcano seismology. In: J. Bundschuh and G.E. Alvarado (Editors), Central America: Geology, Resources, Hazards. Taylor & Francis, London, UK, pp. 1189-1215.
Lindsay, F.N., 2009. Geochemistry of lavas from southeastern Nicaragua and of mantle xenolyths from Cerro Mercedes, Costa Rica, Rutgers The State University of New Jersey-New Brunswick, New Brunswick.
Lopez, D.L. and Williams, S.N., 1993. Catastrophic volcanic collapse: relation to hydrothermal processes. Science, 260(5115): 1794-1796.
Mathieu, L., 2010. The impact of strike-slip movements on the structure of volcanoes: a case study of Guadeloupe, Maderas and Mt. Cameroon volcanoes, Trinity College, Dublin, Irelend, 152 pp.
Mathieu, L., van Wyk de Vries, B., Pilato, M. and Troll, V.R., 2011. The interaction between volcanoes and strike-slip, transtensional and transpressional fault zones: Analogue models and natural examples. Journal of Structural Geology, 33: 898-906.
McBean, G., 2004. Climate change and extreme weather: A basis for action. Natural Hazards, 31: 177-190.
McBirney, A.R. and Williams, H., 1965. Volcanic History of Nicaragua. University of California Press, Berkeley and Los Angeles, California, 73 pp.
55
Min, K., Mundil, R., Renne, P.R. and Ludwig, K.R., 2000. A test for systematic erros in 40Ar/39Ar geochronology through comparison with U/Pb analysis of a 1.1-Ga rhyolite. Geochimica et Cosmochimica Acta, 64: 73-98.
Molina, E., 1997. Tsunami catalogue for Central America 1539-1996. II 1-04, Institute of Solid Earth Physics, University of Bergen, Bergen, Norway.
Pelling, M. and Uitto, J.I., 2001. Small island developing states: natural disaster vulnerability and global change. Environmental Hazards, 3: 49-62.
Reid, M.E., Sisson, T.W. and Brien, D.L., 2001. Volcano collapse promoted by hydrothermal alteration and edifice shape, Mount Ranier, Washington. Geology, 29(9): 779-782.
Rodríguez, C.E., 2007. Earthquake-induced landslides. In: J. Bundschuh and G.E. Alvarado (Editors), Central America: Geology, Resources, Hazards. Taylor & Francis, London, UK, pp. 1217-1255.
Rose, W.I., Conway, F.M., Pullinger, C.R., Deino, A. and McIntosh, W.C., 1999. An improved age framework for late Quaterary silicic eruption in northern Central America. Bulletin of Volcanology, 61: 106-120.
Sebesta, J., 2001. Análisis de origen dinámico del relieve, Isla de Ometepe. Czech Geologic Service, Prague, Czech Republic.
Sheridan, M.F., Connor, C., Connor, L., Stinton, A., Galacia, O.R. and Barrios, G., 2007. October 2005 debris flows at Panabaj, Guatemala: Hazard assessment. Eos Transactions AGU, 88(23): Joint Assembly Supplement, Abstract #V33A-07.
Siebert, L., Simkin, T. and Kimbrly, P., 2010. Volcanoes of the World. University of California Press, Smithsonian Institution, Berkeley and Los Angeles, California.
Singer, B.S., Smith, K.E., Jicha, B.R., Beard, B.L., Johnson, C.M. and Rogers, N.W., in press. Tracking open-system differentiation growth of Santa Maria volcano, Guatemala. Journal of Petrology.
Smithsonian Institution, 1996. Maderas. Bulletin of the Global Volcanism Network, 21(09).
Swain, F.M., 1966. Bottom sediments of Lake Nicaragua and Lake Managua, western Nicaragua. Journal of Sedimentary Petrology, 36(2): 522-540.
Syracuse, E.M. and Abers, G.A., 2006. Global compilation of variations in slab depth beneath arc volcanoes and implications. Geochemistry Geophysics Geosystems, 7(5).
UNESCO, 2010. Thirteen new biosphere reserves. A World of Science, 8(3): 12-13.
56
Vallance, J.W., Schilling, S.P., Devoli, G. and Howell, M.M., 2001a. Lahar hazards at Concepción volcano, Nicaragua. Open-File Report 01-457, U.S. Geological Survey, Vancouver, Washington U.S.A.
Vallance, J.W., Schilling, S.P., Matías, O., Rose, W.I. and Howell, M.M., 2001b. Volcano Hazards at Fuego and Acatenango, Guatemala. In: U.S.G. Survey (Editor), Vancouver, Washington, U.S.A.
van Wyk de Vries, B., 1986. Mapa Geologico Isla de Ometepe. Instituto Nicaraguense de Estudios (INETER), Managua, Nicaragua.
van Wyk de Vries, B., 1993. Tectonics and Magma Evolution of Nicaraguan Volcanic Systems, The Open University, Milton Keynes, UK, 238 pp.
van Wyk de Vries, B. and Borgia, A., 1996. The role of basement in volcano deformation. Geological Society Special Publication, 110: 95-110.
van Wyk de Vries, B. and Matela, R., 1998. Styles of volcano-induced deformation: numberical models of substratum flexure, spreading and extrusion. Journal of Volcanology and Geothermal Research, 81: 1-18.
van Wyk de Vries, B. and Merle, O., 1996. The effect of volcanic constructs on rift fault patterns. Geology, 24(7): 643-646.
Wells, D.L. and Copersmith, K.J., 1994. New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement. Bulletin of the Seismological Society of America, 84(4): 974-1002.
Wilder, P.R., 2010. Concepción está en plena erupción, La Prensa, Managua, Nicaragua.
57 9 A
ppen
dice
s
9.1
App
endi
x A
: Geo
chem
ical
Dat
a
Tab
le 9
.1: W
hole
-roc
k ch
emic
al a
naly
sis fo
r sa
mpl
es c
olle
cted
dur
ing
this
stud
y. A
ll va
lues
are
in w
t. %
. All
Fe a
s Fe 2
O3.
Sam
ple
Nam
e M
ader
as-
001
Mad
eras
-00
2 M
ader
as-
003
Mad
eras
-00
4 M
ader
as-
005
Mad
eras
-00
6 M
ader
as-
007
Mad
eras
-00
8 M
ader
as-
009
Mad
eras
-01
1 M
ader
as-
012
Mad
eras
-01
3
SiO
2 53
.33
53.3
0 61
.23
49.5
1 55
.42
55.9
1 61
.43
50.2
2 58
.12
53.0
2 51
.74
57.6
2
TiO
2 0.
97
1.01
0.
96
1.07
1.
18
0.90
0.
94
1.15
0.
90
1.02
1.
08
0.97
Al 2O
3 18
.45
18.9
5 15
.26
17.1
7 17
.00
16.9
9 16
.12
18.4
0 17
.36
19.4
6 18
.17
17.3
8
Fe 2
O3
9.21
9.
84
8.44
12
.42
9.81
8.
78
7.13
11
.72
7.43
10
.12
10.1
4 7.
69
MnO
0.
17
0.17
0.
16
0.19
0.
20
0.16
0.
20
0.19
0.
14
0.15
0.
17
0.16
MgO
3.
34
2.92
1.
11
5.36
2.
42
3.41
1.
30
4.48
2.
22
2.30
3.
74
2.31
CaO
8.
53
8.04
2.
91
10.4
8 6.
33
7.14
3.
50
9.43
4.
80
8.58
9.
07
4.58
Na 2
O
3.28
3.
79
4.38
2.
26
3.92
3.
39
5.33
3.
00
3.82
3.
38
3.31
3.
92
K2O
1.
71
1.96
3.
62
1.03
2.
18
2.44
3.
37
1.17
2.
74
1.81
1.
63
3.01
P2O
5 0.
42
0.39
0.
32
0.26
0.
59
0.38
0.
22
0.34
0.
43
0.37
0.
39
0.40
H2O
+ 0.
00
0.26
1.
00
0.29
0.
26
0.26
0.
21
0.21
0.
45
0.16
0.
21
0.46
H2O
- -0
.51
-0.7
7 0.
00
-0.6
4 -0
.03
-0.0
8 -0
.01
-0.0
5 0.
82
-0.6
5 -0
.27
0.86
Ba
0.
054
0.06
0 0.
086
0.03
3 0.
072
0.06
3 0.
073
0.04
1 0.
066
0.04
4 0.
037
0.06
5
Sr
0.05
9 0.
061
0.03
1 0.
050
0.05
2 0.
052
0.03
7 0.
057
0.04
4 0.
051
0.05
2 0.
043
Tot
al %
99
.01
100.
00
99.5
0 99
.49
99.4
0 99
.80
99.8
6 10
0.37
99
.35
99.8
3 99
.47
99.4
7
58
Tab
le 9
.1: C
ontin
ued.
Sam
ple
Nam
e M
ader
as-
014
Mad
eras
-01
5 M
ader
as-
016
Mad
eras
-01
7 M
ader
as-
018
Mad
eras
-02
0 M
ader
as-
021
11-A
14
C
17
26 B
39
41
SiO
2 51
.03
58.1
3 57
.37
50.9
6 52
.58
59.0
7 49
.91
53.3
4 49
.34
53.5
6 55
.66
54.6
2 55
.20
TiO
2 1.
10
0.99
0.
93
1.07
1.
09
1.11
1.
15
1.20
1.
17
1.03
1.
19
1.10
1.
23
Al 2O
3 19
.77
17.3
0 17
.95
19.3
0 16
.42
16.2
7 19
.01
18.3
9 16
.69
19.2
9 17
.49
17.2
7 15
.37
Fe 2
O3
10.2
5 7.
99
7.28
10
.38
9.01
8.
18
10.7
3 10
.19
11.4
0 9.
24
8.89
10
.65
11.1
6
MnO
0.
17
0.18
0.
17
0.16
0.
21
0.19
0.
17
0.19
0.
16
0.14
0.
18
0.17
0.
17
MgO
3.
11
2.33
2.
11
3.07
2.
88
1.96
3.
98
2.48
4.
57
2.27
2.
08
2.85
2.
21
CaO
9.
77
4.99
5.
33
9.84
6.
57
4.92
10
.24
7.96
9.
97
8.61
6.
26
6.04
5.
27
Na 2
O
2.71
4.
05
4.40
2.
89
7.53
4.
13
2.79
3.
36
2.42
3.
18
4.18
3.
75
3.56
K2O
1.
22
2.92
2.
91
1.34
2.
23
3.10
1.
26
2.07
1.
16
1.88
2.
35
2.24
2.
53
P2O
5 0.
33
0.32
0.
36
0.32
0.
42
0.61
0.
39
0.54
0.
44
0.36
0.
63
0.45
0.
62
H2O
+ 0.
12
0.10
0.
14
0.11
0.
18
0.15
0.
17
0.39
1.
42
0.28
0.
26
0.45
0.
31
H2O
- 0.
03
0.28
0.
15
-0.2
3 0.
06
-0.0
5 -0
.28
-0.1
5 0.
61
-0.3
6 -0
.16
0.23
-0
.45
Ba
0.
043
0.05
6 0.
059
0.04
0 0.
049
0.04
9 0.
027
0.03
7 0.
023
0.04
8 0.
073
0.09
0 0.
063
Sr
0.05
2 0.
044
0.04
5 0.
051
0.04
5 0.
045
0.06
2 0.
059
0.05
9 0.
051
0.05
5 0.
044
0.03
9
Tot
al %
99
.70
99.6
8 99
.19
99.3
0 99
.27
99.7
5 99
.61
100.
04
99.4
3 99
.58
99.1
4 99
.96
97.2
7
59
Tab
le 9
.2: G
eoch
emic
al in
form
atio
n fr
om M
ader
as v
olca
no (L
inds
ay 2
009)
. Ele
men
t oxi
des a
re in
wt.
% a
nd e
lem
ents
are
in p
pm. A
ll Fe
as F
e 2O
3.
Sam
ple
M1
M2
M3
M4
M5
M5d
up
M6
M7
M8
M8a
M
9 M
9S0
M10
M
11
M11
a M
12
SiO
2 60
.75
61.7
4 50
.37
51.7
3 50
.69
50.6
9 51
.22
50.7
9 51
.56
51.5
6 51
.2
51.2
51
.7
50.2
1 50
.21
48.1
2
TiO
2 1.
07
1.09
1.
1 1.
07
1.07
1.
07
1.07
1.
04
0.99
0.
99
0.98
0.
98
0.56
0.
88
0.88
1.
18
Al 2O
3 16
.46
17.3
2 18
.66
18.2
9 18
.39
18.3
9 18
.26
18.4
1 18
.06
18.0
6 18
.22
18.2
2 20
.8
17.7
8 17
.78
18.6
5
Fe 2
O3
6.81
7.
26
10.0
3 9.
79
9.81
9.
81
9.97
9.
69
9.82
9.
82
9.67
9.
67
8.28
9.
36
9.36
10
.8
MnO
0.
17
0.17
0.
18
0.17
0.
17
0.17
0.
17
0.17
0.
17
0.17
0.
17
0.17
0.
15
0.15
0.
15
0.17
MgO
1.
91
1.95
4.
56
4.18
4.
49
4.49
4.
51
4.54
4.
76
4.76
4.
68
4.68
4.
16
5.82
5.
82
5.29
CaO
4.
56
4.4
9.54
9.
3 9.
52
9.52
9.
53
9.63
9.
48
9.48
9.
65
9.65
10
.13
10.6
5 10
.65
10.8
5
Na 2
O
4.29
4.
34
2.76
2.
84
2.69
2.
69
2.62
2.
49
2.38
2.
38
2.48
2.
48
2.35
2.
56
2.56
2.
25
K2O
2.
83
2.8
1.07
1.
22
1.15
1.
15
1.21
1.
33
1.22
1.
22
1.17
1.
17
0.43
1.
21
1.21
0.
96
P2O
5 0.
46
0.44
0.
32
0.3
0.3
0.3
0.31
0.
3 0.
27
0.27
0.
27
0.27
0.
13
0.23
0.
23
0.3
Sc
15.7
4 17
.13
30.7
9 28
.46
24.0
1 25
.92
26.3
8 26
.5
24.9
9 25
.21
28.7
7 27
.97
24.3
2 26
.35
21.8
8 29
.24
V
77.9
4 85
.36
307.
22
292.
56
260.
76
270
274.
65
261.
13
290.
99
233.
95
282.
93
273.
38
210.
24
243.
95
212.
44
322.
24
Cr
2.12
1.
6 26
.01
26.1
7 23
.11
24.1
2 23
.63
23.5
4 23
.36
19.4
3 23
.5
22.9
1 12
.23
50.4
4 41
.89
10.9
9
Co
9.11
10
.22
29.7
7 27
.16
24.7
8 24
.78
26.7
8 26
.89
27.0
5 23
.54
27.6
4 28
.08
21.6
6 30
.79
25.9
34
.61
Ni
0.54
0.
3 14
.9
11.9
11
.46
13
12.5
2 12
.58
15.1
4 13
.13
16.3
1 14
.71
10.7
4 27
.81
22.4
4 19
.68
Cu
20.1
22
.36
137.
25
95.3
10
8 10
7.23
12
8.9
125.
73
110.
05
96.9
1 12
8.45
12
2.59
98
.76
135.
76
119.
45
149.
06
Zn
82.2
3 84
.37
79.7
4 77
.02
67.9
1 72
.76
75.2
8 69
.61
74.0
5 67
.3
76.5
8 72
.88
71.4
4 68
.21
58.9
5 80
.33
Rb
66.6
5 57
.68
15.6
23
.88
21.9
5 22
.55
22.5
7 25
.01
20.3
2 22
.02
25.9
7 25
.65
37.2
5 20
.4
17.9
7 18
.64
Sr
431.
69
416.
37
561.
03
530.
19
511.
27
504.
01
497.
51
499.
01
444.
01
448.
53
484.
54
494
484.
98
429.
25
424.
84
543.
3
Y
36.3
4 43
.71
21.8
7 21
.22
19
18.4
7 19
.03
19.6
4 16
.72
18.2
1 19
.02
18.5
22
.81
18.2
3 17
.43
19.9
8
Zr
299.
98
314.
27
144.
03
125.
57
118
119.
92
117.
99
118.
18
118.
94
119.
72
121.
21
120.
68
176.
78
119.
14
109.
83
123.
06
Nb
29.6
6 29
.69
12.8
5 12
.36
11.6
7 11
.84
11.2
1 11
.4
11.0
6 11
.7
11.7
5 11
.6
15.8
1 9.
46
9.16
13
.06
Mo
1.59
2.
63
1.1
1.02
1.
06
1.01
1.
05
0.99
1.
04
1.1
1.17
1.
11
1.59
0.
94
0.91
0.
92
Cs
0.76
0.
82
0.27
0.
24
0.45
0.
48
0.45
0.
51
0.5
0.54
0.
58
0.57
0.
87
0.48
0.
44
0.15
Ba
1160
12
00
624
586
538
536
562
550
521
549
551
544
759
471
487
503
Hf
4.02
4.
21
1.92
1.
75
1.65
1.
66
1.63
1.
6 1.
66
1.83
1.
74
1.69
2.
27
1.62
1.
66
1.7
Ta
1.42
1.
54
0.59
0.
6 0.
54
0.59
0.
59
0.55
0.
56
0.6
0.65
0.
57
0.8
0.47
0.
47
0.59
W
0.72
0.
89
0.28
0.
29
0.29
0.
3 0.
27
0.29
0.
28
0.32
0.
33
0.3
0.41
0.
23
0.26
0.
23
Tl
5.6
5.53
1.
54
1.98
2.
29
2.47
2.
54
2.92
3.
16
3.45
3.
44
3.48
5.
08
2.15
2.
05
0.98
Pb
8.44
5.
6 2.
27
2.47
2.
51
2.42
2.
53
2.47
2.
54
2.82
3.
32
2.75
3.
78
2.57
2.
74
2.1
Th
5.86
5.
64
2.33
2.
02
1.95
2.
07
1.86
1.
9 1.
8 2.
48
2.38
2.
11
3.16
1.
86
2.09
1.
85
U
3.53
3.
66
1.41
1.
38
1.3
1.43
1.
21
1.18
1.
23
1.63
1.
55
1.38
2.
08
1.3
1.45
1.
07
60
Tab
le 9
.3: R
are
eart
h el
emen
t ana
lyse
s of M
ader
as v
olca
no fr
om L
inds
ay (2
009)
. Ele
men
ts a
re in
ppm
.
Sam
ple
M1
M2
M3
M4
M5
M5
dup
M6
M7
M8
M8a
M
9 M
9S0
M10
M
11
M11
a M
12
La
35.9
7 48
.3
19.0
4 18
.14
15.9
8 16
.42
16.5
4 16
.7
15.5
2 17
.55
17.0
8 17
23
.17
14.3
5 14
.23
16.8
1
Ce
73.7
1 75
.13
38.5
6 35
.13
33.2
3 33
.88
34.7
34
.33
31.7
8 34
.5
35.1
8 35
.34
45.1
5 28
.56
29.3
4 34
.58
Pr
8.64
10
.28
5.22
5.
06
4.16
4.
24
4.44
4.
37
4.04
4.
68
4.57
4.
49
5.61
3.
89
4.05
4.
51
Nd
35.8
6 47
.1
24.3
6 22
.52
19.7
19
.97
19.0
5 19
.11
17.7
8 20
.01
19.7
2 20
.23
26.8
9 17
.69
17.5
7 20
.72
Sm
7.
63
9.4
5.04
4.
72
4.26
4.
24
4.43
4.
15
3.87
4.
23
4.42
4.
15
5.45
4.
1 3.
84
4.51
Eu
1.95
2.
11
1.43
1.
47
1.24
1.
26
1.24
1.
28
1.15
1.
28
1.3
1.25
1.
45
1.13
1.
08
1.28
Gd
7.09
8.
54
4.78
4.
74
4.19
4.
03
4.27
4.
28
3.84
4.
12
4.26
4.
14
5.07
3.
78
4 4.
57
Tb
1.03
1.
23
0.7
0.68
0.
62
0.61
0.
6 0.
65
0.6
0.65
0.
66
0.63
0.
74
0.59
0.
6 0.
63
Dy
5.84
6.
95
3.94
3.
74
3.31
3.
44
3.55
3.
56
3.34
3.
62
3.6
3.46
4
3.24
3.
36
3.69
Ho
1.21
1.
46
0.8
0.73
0.
74
0.7
0.73
0.
69
0.65
0.
71
0.72
0.
67
0.84
0.
64
0.68
0.
74
Er
3.91
4.
11
2.34
2.
31
1.96
2.
07
2.07
2.
1 1.
87
2.14
2.
15
2.14
2.
45
1.95
1.
95
2.22
Tm
0.
54.
0.63
0.
32
0.32
0.
3 0.
31
0.29
0.
3 0.
28
0.32
0.
31
0.3
0.37
0.
29
0.3
0.3
Yb
3.42
3.
87
2.21
2.
07
1.86
2.
03
1.93
1.
99
1.83
2.
13
2.06
2.
01
2.36
1.
95
2.01
1.
86
Lu
0.56
0.
61
0.34
0.
3 0.
28
0.29
0.
27
0.29
0.
27
0.3
0.31
0.
29
0.35
0.
27
0.28
0.
29
61 T
able
9.4
: Who
le r
ock
and
trac
e el
emen
t ana
lyse
s of M
ader
as v
olca
no fr
om v
an W
yk d
e V
ries
(unp
ublis
hed)
. Ele
men
t oxi
des a
re in
wt.
%. E
lem
ents
ar
e in
ppm
. All
Fe a
s Fe 2
O3.
Sam
ple
M1
M2
M2A
M
3 M
4 M
5 M
6 M
7 M
8 M
9 M
10
M11
M
13X
M
14
M15
M
16
M17
M
18
SiO
2 52
.02
63.3
2 62
.98
60.2
3 63
.15
52.8
7 50
.36
57.0
1 57
.34
52.6
9 54
.11
50.5
6 51
.7
57.4
6 57
.22
57.7
9 56
.25
59.2
3 T
iO2
1.01
0.
88
0.87
1.
13
0.09
1.
4 1.
11
0.97
0.
96
1.4
1.03
1.
2 1.
07
1.15
0.
93
0.91
1.
18
1.13
A
l 2O3
19.1
9 16
.97
16.8
8 16
.97
16.7
8 19
.35
17.7
7 18
.7
19.0
8 18
.28
18.3
4 16
.61
18.2
2 17
.03
17.2
2 16
.94
16.9
8 17
.52
Fe 2
O3
9.32
5.
26
5.19
7.
14
5.31
8.
96
10.5
2 7.
1 6.
86
9.8
8.32
9.
77
10.0
5 7.
83
7.64
7.
26
8.24
7.
11
MnO
0.
17
0.13
0.
12
0.19
0.
16
0.16
0.
18
0.15
0.
15
0.17
0.
16
0.17
0.
18
0.2
0.17
0.
16
0.2
0.19
M
gO
4.31
1
1.1
1.85
0.
1 2.
66
5.53
2.
07
2.11
3.
91
3.82
5.
28
4.08
2.
46
3.27
2.
64
2.36
1.
87
CaO
9.
71
3.51
3.
42
4.94
3.
52
8.88
10
.44
7 7.
03
9.39
8.
72
10.0
5 8.
41
5.83
6.
94
6.32
6.
24
5.29
N
a 2O
3.
1 4.
3 4.
43
4.4
4.86
3.
62
2.93
3.
86
3.97
3.
28
3.31
2.
47
2.68
3.
96
3.45
3.
55
3.93
5.
27
K2O
1.
14
3.5
3.49
2.
82
3.73
2.
02
1.27
2.
33
2.22
1.
57
1.83
1.
45
1.6
2.51
2.
72
2.63
2.
37
2.56
P
2O5
0.24
0.
29
0.27
0.
53
0.31
0.
52
0.3
0.44
0.
41
0.39
0.
38
0.32
0.
32
0.44
0.
35
0.35
0.
55
0.57
V
252
55
78
125
63
214
246
123
127
210
173
252
233
122
129
151
152
79
Cr
210
53
51
56
53
127
202
58
108
305
181
336
75
57
59
81
58
56
Co
30
21
22
24
21
28
30
25
24
29
29
30
41
26
25
25
27
25
Ni
16
13
13
14
13
15
16
14
14
16
16
16
17
14
14
14
15
14
Cu
136
13
14
16
14
64
113
44
49
89
59
107
121
49
57
66
58
20
Zn
81
79
84
90
85
75
65
74
70
89
74
85
89
77
70
68
98
101
Ga
17
18
15
19
16
19
16
19
17
17
19
12
19
17
16
17
20
19
Rb
22
88
87
68
88
45
30
53
52
31
41
30
37
56
61
63
51
54
Sr
515
360
355
440
350
603
508
546
537
524
498
494
482
435
482
470
509
503
Y
21
100
91
46
51
39
25
31
32
32
28
24
38
50
30
34
41
43
Zr
131
386
386
306
393
261
157
246
234
209
184
175
207
274
260
265
253
283
Nb
11.4
33
34
26
.2
34.8
23
.4
14.9
22
.4
21.8
20
.9
16.3
19
.7
17.3
25
.4
22.5
24
.2
23.7
28
.5
Mo
3 3
3 3
4 4
4 3
4 4
4 4
2 3
4 3
4 3
Ba
918
1706
17
50
1759
19
13
1412
94
2 11
50
1523
11
41
1375
98
9 12
97
1504
14
59
1560
15
51
1557
P
b 5
12
10
10
14
5 6
6 9
5 10
5
6 8
9 8
11
10
Th
4 11
10
9
12
4 6
6 4
5 4
4 4
7 8
6 5
7
U
5 5
5 5
5 6
5 5
5 5
6 5
3 5
5 5
5 5
62 Tab
le 9
.5: W
hole
roc
k an
d tr
ace
elem
ent d
ata
for
Con
cepc
ión
volc
ano
from
van
Wyk
de
Vri
es (1
993)
. Oxi
des a
re in
wt.
%. T
race
ele
men
ts a
re in
ppm
. A
ll Fe
as F
e 2O
3.
Sam
ple
CL1
C
L2
CL3
C
L4
CL5
C
L6
CL7
C
L8
CL9
C
L10
CL1
1 C
L13
CL1
4 C
L15
CL1
6
SiO
2 59
.48
59.2
5 53
.21
53.9
1 48
.05
53.5
2 52
.94
52.5
2 60
.62
59.4
1 61
.26
56.6
9 60
.65
54.5
5 54
.39
TiO
2 0.
91
0.94
0.
96
0.99
1.
25
1.11
1.
02
0.99
0.
80
0.92
0.
85
0.89
0.
93
0.95
0.
93
Al2
O3
17.4
2 17
.09
19.1
2 19
.00
20.5
7 18
.67
19.4
8 18
.93
17.1
9 17
.17
17.3
8 16
.95
17.2
6 19
.07
19.7
2 F
e2O
3 6.
68
6.77
7.
90
7.92
10
.32
9.15
8.
36
8.65
5.
93
6.77
6.
10
6.94
6.
29
7.58
7.
71
MnO
0.
18
0.18
0.
16
0.17
0.
18
0.20
0.
17
0.19
0.
16
0.19
0.
17
0.19
0.
18
0.17
0.
17
MgO
2.
57
2.52
3.
24
3.37
3.
42
3.35
3.
15
3.79
2.
14
2.48
2.
17
2.27
2.
34
2.92
2.
64
CaO
5.
49
5.47
8.
58
8.49
9.
17
7.98
8.
90
8.78
5.
49
5.51
5.
67
5.40
5.
44
8.36
8.
56
Na2
O
4.84
4.
70
3.96
3.
57
3.07
4.
28
3.82
4.
06
4.43
5.
13
4.02
4.
80
4.63
4.
11
3.96
K
2O
2.10
2.
12
1.52
1.
50
0.79
1.
44
1.29
1.
21
2.15
2.
10
2.11
2.
18
2.13
1.
31
1.16
P
2O5
0.44
0.
46
0.28
0.
37
0.47
0.
38
0.31
0.
42
0.37
0.
44
0.35
0.
48
0.45
0.
42
0.37
LO
I 0.
60
0.02
0.
04
0.11
2.
37
0.01
0.
07
0.19
0.
12
0.09
0.
09
0.18
0.
01
-0.1
4 0.
02
V
93
75
199
183
17
4 18
4 19
9 98
14
5 98
10
2 95
16
7 17
9 C
r 54
56
10
6 18
7
88
131
98
55
56
56
57
56
62
117
Co
25
25
28
28
29
28
28
24
25
24
25
24
27
27
N
i 14
14
15
15
15
15
15
14
14
13
14
13
14
15
Cu
27
34
104
84
83
76
41
25
37
24
33
21
47
60
Z
n 94
95
89
89
85
85
78
81
94
82
96
88
82
80
Ga
21
18
19
19
17
17
18
21
14
17
18
18
19
20
A
s 5
5 5
6
5 5
5 5
5 5
6 5
5 5
Rb
48
48
36
34
31
26
23
46
46
47
49
48
27
23
S
r 46
1 45
5 59
7 58
9
539
570
571
458
458
457
471
454
627
623
Y
39
40
27
28
33
27
27
36
69
34
41
37
28
25
Z
r 20
6 20
7 14
7 14
7
144
135
122
214
204
205
217
208
135
119
Nb
16
17
11
12
12
11
10
17
15
17
17
16
11
10
M
o 3
3 3
3
3 3
3 3
3 3
3 4
3 4
Ba
1488
15
33
1402
98
2
889
1188
14
16
1640
14
52
1523
14
63
1433
12
54
924
Pb
9 12
6
6
5 10
5
9 8
8 9
13
7 7
Th
4 5
4 4
4
4 4
5 4
5 5
5 4
4
U
5 5
5 5
6
5 5
5 5
5 5
5 6
5
63
Tab
le 9
.5: C
ontin
ued.
Sam
ple
CL1
7 C
L19
CL2
0 C
L21
CL2
3 C
L25A
C
L25A
C
L25
CL2
6 C
L27
CL2
8 C
L29A
C
L29B
C
L30
CL3
1
SiO
2 56
.01
61.5
9 62
.02
61.5
3 54
.87
53.5
7 53
.95
56.5
4 54
.64
58.6
6 62
.87
52.0
3 52
.02
51.6
8 57
.74
TiO
2 1.
02
0.83
0.
87
0.84
0.
99
0.97
0.
98
0.99
0.
93
0.92
0.
83
1.25
1.
14
1.13
0.
97
Al2
O3
18.8
5 16
.75
16.6
2 16
.84
19.3
8 18
.77
18.9
0 18
.94
19.0
6 16
.93
16.8
4 19
.36
19.5
0 19
.30
19.9
6 F
e2O
3 7.
68
6.11
6.
12
5.45
7.
72
7.91
7.
97
7.26
8.
05
7.68
5.
64
9.79
9.
96
9.82
8.
11
MnO
0.
17
0.18
0.
18
0.17
0.
17
0.18
0.
18
0.18
0.
16
0.18
0.
18
0.19
0.
18
0.18
0.
18
MgO
2.
44
1.79
1.
97
2.29
2.
89
3.37
3.
39
2.69
2.
72
2.10
1.
72
3.75
3.
87
3.94
2.
18
CaO
8.
05
4.57
4.
57
4.75
8.
41
8.62
8.
68
7.66
8.
47
6.47
4.
57
9.53
9.
59
9.50
6.
56
Na2
O
4.02
5.
11
4.76
5.
31
4.16
4.
38
4.41
4.
03
3.79
4.
14
4.72
2.
79
2.87
2.
68
4.20
K
2O
1.61
2.
45
2.42
1.
99
1.36
1.
55
1.56
1.
55
1.67
1.
73
2.15
1.
04
1.05
1.
00
1.97
P
2O5
0.43
0.
47
0.42
0.
41
0.40
0.
39
0.39
0.
37
0.39
0.
39
0.29
0.
22
0.35
0.
34
0.43
LO
I 0.
25
0.17
0.
22
0.14
0.
02
0.20
0.
08
0.38
0.
22
0.70
0.
13
0.37
0.
50
0.44
0.
21
V
141
97
77
50
146
230
230
128
173
145
98
253
286
264
127
Cr
121
55
56
55
167
148
148
129
97
59
54
100
169
74
58
Co
27
24
24
23
27
28
28
27
28
33
29
42
43
42
34
Ni
15
14
14
13
14
15
15
14
15
8 7
13
13
13
9 C
u 72
18
17
10
67
92
92
61
10
6 25
8
112
189
110
35
Zn
77
86
96
89
88
86
86
88
82
81
83
94
99
98
83
Ga
19
19
18
20
17
20
20
16
19
18
20
21
18
21
21
As
6 5
5 5
5 6
6 5
6 4
4 5
5 5
4 R
b 34
54
57
44
26
35
35
33
34
32
45
26
23
23
37
S
r 57
5 45
2 45
1 45
6 60
6 58
5 58
5 57
8 63
1 53
7 49
0 66
3 54
4 64
4 55
0 Y
31
43
42
38
28
26
26
31
29
32
39
29
24
27
38
Z
r 16
7 23
6 23
4 20
2 13
4 15
0 15
0 16
7 14
9 16
1 21
3 13
0 88
12
4 20
1 N
b 14
18
18
17
11
12
12
13
12
14
18
12
8
11
18
Mo
3 5
3 5
3 3
3 3
3 3
3 2
3 3
3 B
a 11
60
1588
15
86
1823
12
72
1527
15
27
1475
10
78
1206
13
28
708
751
876
1372
P
b 6
10
7 12
6
11
11
5 7
6 11
5
5 8
6 T
h 4
4 5
6 4
4 4
4 4
2 4
3 3
3 4
U
5 5
5 5
5 6
6 5
6 3
3 3
3 3
3
64
Tab
le 9
.5: C
ontin
ued.
Sam
ple
CL3
3 C
L35
CL3
6 C
L37A
C
L38
CL3
9 C
L40
CL4
2 C
L41
CL4
3 C
L44
CL4
5
SiO
2 63
.10
53.1
8 53
.72
51.0
2 51
.16
47.8
6 48
.27
47.9
3 47
.34
51.3
5 55
.59
53.5
2
TiO
2 0.
86
1.03
0.
96
1.03
1.
22
0.89
0.
90
0.89
0.
83
0.92
1.
11
1.07
Al2
O3
16.3
6 19
.43
19.3
8 19
.97
18.2
3 21
.42
21.3
4 20
.91
20.6
3 20
.39
17.1
2 18
.29
Fe2
O3
5.96
8.
98
8.37
8.
49
10.9
1 10
.26
9.75
10
.11
10.4
0 9.
24
9.03
9.
23
MnO
0.
18
0.17
0.
16
0.15
0.
20
0.15
0.
16
0.15
0.
15
0.15
0.
17
0.18
MgO
1.
75
2.45
2.
42
3.13
4.
54
3.52
3.
77
3.92
3.
75
2.90
2.
67
3.87
CaO
4.
40
8.85
8.
92
9.20
9.
51
12.2
2 12
.71
12.3
7 12
.38
10.0
6 7.
77
8.32
Na2
O
4.59
3.
37
3.66
3.
24
3.24
1.
90
2.01
2.
22
2.30
2.
85
4.05
3.
37
K2O
2.
27
1.56
1.
65
1.36
0.
95
0.47
0.
54
0.57
0.
58
0.97
1.
63
1.47
P2O
5 0.
29
0.38
0.
46
0.42
0.
37
0.08
0.
04
0.07
0.
14
0.17
0.
41
0.41
LOI
0.61
0.
15
0.21
0.
29
-0.2
2 1.
20
0.93
0.
35
0.01
0.
55
0.01
0.
51
V
79
175
161
225
211
242
254
185
269
Cr
56
62
62
134
131
161
144
84
62
13
Co
29
37
35
40
40
40
40
37
37
Ni
7 9
11
13
22
12
13
9 11
19
Cu
16
95
59
133
117
122
126
88
107
Zn
91
79
78
76
77
74
71
77
84
Ga
17
22
21
18
17
18
22
19
20
As
4 4
4
4
4 4
4 4
4
Rb
51
30
32
10
10
11
12
20
32
Sr
475
750
738
690
654
662
681
689
595
Y
38
28
27
17
18
17
18
23
30
Zr
217
144
140
74
72
71
71
108
170
Nb
18
14
14
7 7
7 8
9 15
Mo
3 2
3
3
3 3
3 3
3
Ba
1362
93
4 91
6
71
5 46
2 71
7 61
1 59
5 12
39
872
Pb
9 8
7
6
5 5
5 8
8
Th
5 2
3
2
2 2
3 2
3
U
3 3
3
3
3 3
3 3
3
65
Tab
le 9
.6: R
are
eart
h el
emen
ts a
t Con
cepc
ión
volc
ano
from
van
Wyk
de
Vri
es (1
993)
. Ele
men
ts a
re in
ppm
.
Sam
ple
Nam
e C
L7
CL1
1 C
L26
CL2
9A
CL2
9B
CL3
1 C
L36
La
21.4
0 29
.50
23.2
0 18
.60
9.70
29
.10
25.7
0
Ce
44.1
0 59
.10
47.7
0 37
.40
22.6
0 60
.50
50.3
0
Nd
26.3
0 34
.10
29.1
0 24
.10
15.5
0 35
.80
29.1
0
Sm
5.
80
7.37
6.
47
5.63
3.
76
8.01
6.
31
Eu
1.71
1.
89
1.82
1.
72
1.17
2.
12
1.84
Tb
0.79
1.
00
0.82
0.
76
0.68
1.
08
0.78
Yb
2.40
3.
22
2.41
2.
23
1.97
3.
34
2.22
Lu
0.41
0.
54
0.41
0.
38
0.29
0.
55
0.37
Th
2.27
3.
89
2.51
1.
87
0.87
3.
05
2.44
U
1.31
2.
59
1.74
1.
21
0.83
1.
97
1.71
Ta
0.64
0.
97
0.59
0.
47
0.33
0.
95
0.66
Hf
3.05
4.
82
3.32
2.
65
1.71
4.
49
3.00
Rb
30.0
0 52
.00
38.0
0 29
.00
46
.00
33.0
0
Cs
0.53
1.
04
0.78
0.
63
0.80
0.
36
0.39
Co
22.8
0 11
.30
19.2
0 26
.10
26.2
0 15
.60
20.2
0
Sc
25.3
0 16
.40
22.1
0 27
.90
27.7
0 18
.80
21.7
0
Cr
10.0
0 5.
00
11.0
0 14
.00
6.
00
13.0
0
66 Tab
le 9
.7: W
hole
roc
k an
d tr
ace
elem
ent a
naly
ses f
rom
Con
cepc
ión
volc
ano
from
Bor
gia
and
van
Wyk
de
Vri
es (2
003)
and
from
Car
r an
d R
ose
(198
7).
Ele
men
t oxi
des a
re in
wt.
% a
nd e
lem
ents
are
in p
pm. A
ll Fe
as F
e 2O
3.
Sam
ple
C1
C2
C3
N14
6 N
148
C-9
2-2
C2
C1b
C
5a
C7a
C
1b
GA
B1
SiO
2 55
.78
55.4
3 56
.77
55.9
6 51
.9
58.7
5 49
.09
65.7
1 61
.71
52.7
8 54
.61
48.7
T
iO2
1 0.
98
1.1
1.14
1.
13
0.71
1.
319
0.47
8 0.
873
0.99
9 0.
895
1.02
1 A
l 2O3
17.6
3 17
.92
16.9
5 17
.66
19.0
3 16
.58
18.5
2 16
.29
16.6
20
.05
17.7
1 21
.67
Fe 2
O3
9.03
8.
68
8.57
2.
25
3.85
11.1
3.
87
6.35
8.
88
8.83
9.
31
Fe 2
O3
9.03
8.
68
8.57
8.
62
9.81
8.
89
11.1
3.
87
6.35
8.
88
8.83
9.
31
MnO
0.
2 0.
2 0.
18
0.17
0.
16
0.17
0.
24
0.18
0.
18
0.17
0.
201
0.15
1 M
gO
3.31
3.
28
2.7
2.9
3.94
3.
72
5.64
1.
11
1.88
2.
83
3.97
3.
89
CaO
7.
73
7.71
6.
49
6.88
9.
02
7.11
11
.09
3.12
4.
46
8.4
8.43
12
.41
Na 2
O
4.11
3.
74
3.49
4.
06
2.88
3.
17
2.99
5.
04
4.79
2.
98
3.54
2.
53
K2O
1.
22
1.2
1.94
1.
65
1.2
1.7
0.64
2.
6 2.
54
1.46
1.
33
0.57
P
2O5
0.38
0.
37
0.49
0.
58
0.37
0.
23
0.10
4 0.
185
0.41
1 0.
394
3.66
0.
292
Sc
19.8
8 19
.03
19.7
7 20
.43
27.2
1 23
.51
V
165.
13
174.
51
183.
96
130.
4 22
9.5
237
Cr
2.54
2.
43
2.92
15
.96
15.5
9 20
.4
Co
17.4
5 18
.45
17.2
6
Ni
2.49
2.
42
1.91
12
.04
12.3
4 18
.6
16
4 3
7 13
11
C
u 51
.08
47.8
7 96
.85
32.6
3 91
.07
84.4
Z
n 81
.04
88.2
7 87
.43
R
b 23
.19
20.3
4 34
.99
35.5
26
.5
37.5
31
51
58
32
26
13
S
r 54
7.48
57
2.52
45
0.12
60
7.3
577.
9 58
9.1
783
425
463
616
611
730
Y
25.4
6 24
.63
29.6
7 40
.21
28.9
9
20
30
43
31
28
17
Zr
122.
19
127.
26
184.
94
159.
1 13
6.2
119.
8 72
24
3 24
1 15
3 12
3 65
N
b 11
.11
11.7
6 15
.18
10.7
10
.3
M
o 1.
02
1.1
1.67
Cs
0.34
0.
44
0.82
0.
822
0.69
Ba
657.
21
674.
18
973.
89
986.
6 78
9.4
990.
3
67
Tab
le 9
.8: R
are
eart
h el
emen
t ana
lysi
s fro
m C
once
pció
n vo
lcan
o fr
om C
arr
and
Ros
e (1
987)
.
Sam
ple
C1
C2
C3
N14
6 N
148
La
17.8
9 18
.42
25.9
5 27
.04
22.0
5
Ce
37.3
4 39
.14
53.4
1 56
.17
44.6
8
Pr
5.13
5.
14
6.92
Nd
24.0
5 24
.09
29.4
8 34
.83
26.4
5
Sm
5.
32
5.27
6.
44
7.35
5.
73
Eu
1.66
1.
67
1.87
2.
26
1.69
Gd
5.23
5.
33
6.34
7.
56
5.71
Tb
0.79
0.
78
0.95
Dy
4.51
4.
38
5.01
6.
45
5.14
Ho
0.92
0.
91
1.08
Er
2.64
2.
65
3.06
3.
57
2.69
Tm
0.
39
0.39
0.
47
Yb
2.63
2.
5 3.
18
3.69
2.
33
Lu
0.39
0.
38
0.46
Hf
1.8
1.75
2.
5
Ta
0.55
0.
58
0.77
W
0.23
0.
21
0.36
Tl
0.08
0.
09
0.17
Pb
2.87
2.
7 4.
16
4.47
9 3.
98
Th
1.8
1.87
3.
08
2.48
2 2.
158
U
1.13
1.
15
1.87
1.
835
1.49
7
68 9.2
App
endi
x B
: 40A
r/39Ar
Res
ults
9.2.
1 Sa
mpl
e M
AD
ER
AS-
002
Tab
le 9
.9: I
ncre
men
tal h
eatin
g su
mm
ary
for
MA
DE
RA
S-00
2
Incr
emen
tal
Hea
ting
36
Ar(
a)
37A
r(ca
) 38
Ar(
cl)
39A
r(k)
40
Ar(
r)
Age
±
2σ
40A
r(r)
39
Ar(
k)
K/C
a ±
2σ
(Ka)
(%
) (%
)
BH
5976
67
5 °C
0.
0001
72
0.02
9115
0.
0000
11
0.02
8409
0.
0016
84
28.5
±
75.9
3.
20
2.11
0.
420
± 0.
024
BH
5977
72
0 °C
0.
0000
73
0.01
8225
0.
0000
00
0.01
9890
0.
0020
89
50.4
±
117.
5 8.
85
1.48
0.
469
± 0.
030
BH
5978
73
5 °C
0.
0000
47
0.01
5139
0.
0000
00
0.01
7814
0.
0018
48
49.8
±
152.
4 11
.66
1.32
0.
506
± 0.
033
BH
5979
80
0 °C
0.
0002
51
0.09
3700
0.
0000
00
0.10
8512
0.
0148
28
65.6
±
22.1
16
.67
8.06
0.
498
± 0.
027
BH
5980
87
0 °C
0.
0006
26
0.26
7650
0.
0000
00
0.34
0424
0.
0522
17
73.6
±
10.8
22
.01
25.2
8 0.
547
± 0.
028
BH
5981
94
0 °C
0.
0005
68
0.22
1664
0.
0000
80
0.31
4617
0.
0475
40
72.5
±
10.0
22
.09
23.3
6 0.
610
± 0.
031
BH
5982
10
25 °
C
0.00
0905
0.
2270
12
0.00
0104
0.
2236
59
0.03
0329
65
.1
± 16
.8
10.1
9 16
.61
0.42
4 ±
0.02
2 B
H59
83
1125
°C
0.
0009
09
0.18
7692
0.
0002
59
0.18
5675
0.
0255
72
66.1
±
24.4
8.
69
13.7
9 0.
425
± 0.
022
BH
5984
12
25 °
C
0.00
1435
0.
2968
03
0.00
0400
0.
1078
37
0.01
4919
66
.4
± 31
.8
3.40
8.
01
0.15
6 ±
0.00
8
Σ 0.
0049
85
1.35
7000
0.
0008
55
1.34
6837
0.
1910
27
T
able
9.9
: Con
tinue
d
Info
rmat
ion
on A
naly
sis
R
esul
ts
40(r
)/39
(k)
± 2σ
A
ge
± 2σ
MSWD
39A
r(k)
K
/Ca
± 2σ
(Ka)
(%
,n)
Sam
ple
= M
AD
002
A
ge P
late
au
0.14
66
± 0.
0126
70
.4
± 6.
1 0.
34
100.
00
0.29
3 ±
0.11
4 M
ater
ial =
gro
undm
ass
±
8.62
%
± 8.
62%
9
Loca
tion
= U
W93
C42
Min
imal
Ext
erna
l Err
or
± 6.
7 2.
31
Sta
tistic
al T
Rat
io
Ana
lyst
= B
rian
Jich
a
Ana
lytic
al E
rror
±
6.1
1.00
00
Err
or M
agni
ficat
ion
Pro
ject
= U
W93
C
M
ass
Dis
crim
inat
ion
Law
= L
IN
T
otal
Fus
ion
Age
0.
1418
±
0.01
49
68.1
±
7.2
9
0.42
7 ±
0.00
9 Ir
radi
atio
n =
UW
93
±
10.5
1%
± 10
.51%
J =
0.00
0262
30 ±
0.0
0000
013
M
inim
al E
xter
nal E
rror
±
7.6
FC
S =
28.
201
± 0.
023
Ma
A
naly
tical
Err
or
± 7.
2
69
Table 9.10: Normal isochron table for MADERAS-002
Normal Isochron 39(k)/36(a) ± 2σ 40(a+r)/36(a) ± 2σ
r.i.
BH5976 675 °C 164.9 ± 14.5 305.3 ± 26.9 0.9972
BH5977 720 °C 273.1 ± 61.7 324.2 ± 73.3 0.9992
BH5978 735 °C 375.8 ± 151.7 334.5 ± 135.0 0.9997
BH5979 800 °C 432.7 ± 29.2 354.6 ± 23.9 0.9981
BH5980 870 °C 543.8 ± 22.5 378.9 ± 15.7 0.9983
BH5981 940 °C 554.3 ± 21.6 379.3 ± 14.8 0.9985
BH5982 1025 °C 247.3 ± 7.2 329.0 ± 9.6 0.9891
BH5983 1125 °C 204.3 ± 7.2 323.6 ± 11.3 0.9943
BH5984 1225 °C 75.1 ± 1.3 305.9 ± 5.1 0.9810
Table 9.10:Continued
Results 40(a)/36(a) ± 2σ 40(r)/39(k) ± 2σ Age ± 2σ
MS
WD
(Ka)
Normal Isochron 293.3429 ± 5.4894 0.1524 ± 0.0199 73.2 ± 9.5 0.32 ± 1.87% ± 13.03% ± 13.03%
Minimal External Error ± 10.0 Analytical Error ± 9.5
Statistics Statistical F ratio 2.01 Convergence 0.0000000004
Error Magnification 1.0000 Number of Iterations 12
Number of Data Points 9 Calculated Line Weighted York-2
Table 9.11: Inverse isochron table for MADERAS-002
Inverse Isochron 39(k)/40(a+r) ± 2σ 36(a)/40(a+r) ± 2σ
r.i.
BH5976 675 °C 0.540065 ± 0.003590 0.003276 ± 0.000289 0.0403
BH5977 720 °C 0.842375 ± 0.007590 0.003085 ± 0.000697 0.0201
BH5978 735 °C 1.123452 ± 0.011730 0.002990 ± 0.001207 0.0174
BH5979 800 °C 1.220118 ± 0.005072 0.002820 ± 0.000190 0.0084
BH5980 870 °C 1.435059 ± 0.003509 0.002639 ± 0.000109 0.0239
BH5981 940 °C 1.461635 ± 0.003123 0.002637 ± 0.000103 0.0210
BH5982 1025 °C 0.751508 ± 0.003242 0.003039 ± 0.000089 0.1009
BH5983 1125 °C 0.631266 ± 0.002357 0.003090 ± 0.000108 0.0367
BH5984 1225 °C 0.245667 ± 0.000813 0.003269 ± 0.000055 0.0251
Table 9.11: Continued
Results 40(a)/36(a) ± 2σ 40(r)/39(k) ± 2σ Age ± 2σ
MS
WD
(Ka)
Inverse Isochron 293.3914
± 2.7383 0.1525 ± 0.0098 73.2 ± 4.7 0.31
± 0.93% ± 6.45% ± 6.45%
Minimal External Error ± 5.5 Analytical Error ± 4.7
Statistics Statistical F ratio 2.01 Convergence 0.0000000087
Error Magnification 1.0000 Number of Iterations 4 Number of Data Points 9 Calculated Line Weighted York-2
70
Tab
le 9
.12:
Rel
ativ
e ab
unda
nces
for
MA
DE
RA
S-00
2
Rel
ativ
e A
bund
ance
s
36A
r %
1σ
37A
r %
1σ
38A
r %
1σ
39A
r %
1σ
40A
r %
1σ
Age
±
2σ
40A
r(r)
39
Ar(
k)
K/C
a ±
2σ
(Ka)
(%
) (%
)
BH
5976
67
5 °C
0.
0001
800
4.21
3 0.
0291
148
2.86
0 0.
0003
860
6.36
4 0.
0284
290
0.22
7 0.
0526
036
0.24
3 28
.5
± 75
.9
3.20
2.
11
0.42
0 ±
0.02
4
BH
5977
72
0 °C
0.
0000
776
10.5
99
0.01
8224
6 3.
199
0.00
0243
6 5.
287
0.01
9902
1 0.
317
0.02
3611
6 0.
320
50.4
±
117.
5 8.
85
1.48
0.
469
± 0.
030
BH
5978
73
5 °C
0.
0000
514
18.6
09
0.01
5139
1 3.
280
0.00
0200
6 8.
877
0.01
7823
7 0.
299
0.01
5856
1 0.
428
49.8
±
152.
4 11
.66
1.32
0.
506
± 0.
033
BH
5979
80
0 °C
0.
0002
755
3.05
7 0.
0936
999
2.68
9 0.
0012
961
1.81
0 0.
1085
748
0.19
3 0.
0889
355
0.07
7 65
.6
± 22
.1
16.6
7 8.
06
0.49
8 ±
0.02
7
BH
5980
87
0 °C
0.
0006
967
1.84
2 0.
2676
503
2.55
3 0.
0039
962
1.15
0 0.
3406
039
0.09
4 0.
2372
194
0.07
8 73
.6
± 10
.8
22.0
1 25
.28
0.54
7 ±
0.02
8
BH
5981
94
0 °C
0.
0006
261
1.74
7 0.
2216
639
2.55
1 0.
0039
802
1.62
7 0.
3147
667
0.08
4 0.
2152
504
0.06
6 72
.5
± 10
.0
22.0
9 23
.36
0.61
0 ±
0.03
1
BH
5982
10
25 °
C
0.00
0964
4 1.
351
0.22
7012
0 2.
556
0.00
2970
5 1.
503
0.22
3812
1 0.
121
0.29
7613
8 0.
178
65.1
±
16.8
10
.19
16.6
1 0.
424
± 0.
022
BH
5983
11
25 °
C
0.00
0958
4 1.
654
0.18
7691
9 2.
559
0.00
2668
6 1.
169
0.18
5801
0 0.
151
0.29
4130
7 0.
110
66.1
±
24.4
8.
69
13.7
9 0.
425
± 0.
022
BH
5984
12
25 °
C
0.00
1513
3 0.
784
0.29
6803
2 2.
583
0.00
1968
6 1.
200
0.10
8036
7 0.
154
0.43
8956
2 0.
059
66.4
±
31.8
3.
40
8.01
0.
156
± 0.
008
Σ 0.
0053
435
0.63
0 1.
3569
996
1.04
7 0.
0177
104
0.60
5 1.
3477
499
0.04
7 1.
6641
773
0.04
4
T
able
9.1
2: C
ontin
ued
Info
rmat
ion
on A
naly
sis
and
Con
stan
ts U
sed
in C
alcu
latio
ns
Sam
ple
= M
AD
002
Ext
ract
ion
Met
hod
= U
ndef
ined
M
ater
ial =
gro
undm
ass
Hea
ting
= 90
0 se
c L
ocat
ion
= U
W93
C42
Is
olat
ion
= 15
.00
min
A
naly
st =
Bria
n Ji
cha
Inst
rum
ent =
MA
P21
5 P
roje
ct =
UW
93C
L
ithol
ogy
= U
ndef
ined
M
ass
Dis
crim
inat
ion
Law
= L
IN
Lat
-Lon
= U
ndef
ined
- U
ndef
ined
Ir
radi
atio
n =
UW
93
Age
Equ
atio
ns =
Con
vent
iona
l J
= 0
.000
2623
0 ±
0.00
0000
13
Neg
ativ
e In
tens
ities
= F
orce
d Z
ero
FC
S =
28.
201
± 0.
023
Ma
Dec
ay C
onst
ant 4
0K =
5.4
63 ±
0.1
07 E
-10
1/a
IGS
N =
Und
efin
ed
Dec
ay C
onst
ant 3
9Ar =
2.9
40 ±
0.0
29 E
-07
1/h
Pre
ferr
ed A
ge =
Und
efin
ed
Dec
ay C
onst
ant 3
7Ar =
8.2
30 ±
0.0
82 E
-04
1/h
Cla
ssifi
catio
n =
Und
efin
ed
No
36C
l Cor
rect
ion
Exp
erim
ent T
ype
= U
ndef
ined
N
o 36
Cl C
orre
ctio
n
71
Tab
le 9
.12:
Con
tinue
d
Res
ults
40
(r)/
39(k
) ±
2σ
Age
±
2σ
MSWD
39A
r(k)
K
/Ca
± 2σ
(K
a)
(%,n
)
Age
P
late
au
0.14
66
± 0.
0126
70
.4
± 6.
1 0.
34
100.
00
0.29
3 ±
0.11
4 ±
8.62
%
± 8.
62%
9
Min
imal
Ext
erna
l Err
or
± 6.
7 2.
31
Sta
tistic
al T
Rat
io
Ana
lytic
al E
rror
±
6.1
1.00
00
Err
or M
agni
ficat
ion
Tot
al
Fus
ion
Age
0.
1418
±
0.01
49
68.1
±
7.2
9
0.42
7 ±
0.00
9 ±
10.5
1%
± 10
.51%
Min
imal
Ext
erna
l Err
or
± 7.
6
A
naly
tical
Err
or
± 7.
2
Nor
mal
Is
ochr
on
0.15
24
± 0.
0199
73
.2
± 9.
5 0.
32
100.
00
± 13
.03%
±
13.0
3%
9
Min
imal
Ext
erna
l Err
or
± 10
.0
2.01
S
tatis
tical
F ra
tio
Ana
lytic
al E
rror
±
9.5
1.00
00
Err
or M
agni
ficat
ion
Inve
rse
Isoc
hron
0.
1525
±
0.00
98
73.2
±
4.7
0.31
10
0.00
±
6.45
%
± 6.
45%
9
Min
imal
Ext
erna
l Err
or
± 5.
5 2.
01
Sta
tistic
al F
ratio
A
naly
tical
Err
or
± 4.
7 1.
0000
E
rror
Mag
nific
atio
n
T
able
9.1
3: D
egas
sing
patt
erns
for
MA
DE
RA
S-00
2
Deg
assi
ng
Pat
tern
s
36A
r(a)
%
1σ
36A
r(c)
%
1σ
36A
r(ca
) %
1σ
36A
r(cl
) %
1σ
37A
r(ca
) %
1σ
38A
r(a)
%
1σ
38A
r(c)
%
1σ
BH
5976
6
75 °
C
0.
0001
72
4.4
0
0.00
0000
0
.00
0.
0000
08
2.8
6
0.00
0000
0
.00
0.
0291
15
2.8
6
0.00
0032
4
.40
0.
0000
00
0.0
0
BH
5977
7
20 °
C
0.
0000
73
11.
30
0.
0000
00
0.0
0
0.00
0005
3
.20
0.
0000
00
0.0
0
0.01
8225
3
.20
0.
0000
14
11.
30
0.
0000
00
0.0
0
BH
5978
7
35 °
C
0.
0000
47
20.
18
0.
0000
00
0.0
0
0.00
0004
3
.28
0.
0000
00
0.0
0
0.01
5139
3
.28
0.
0000
09
20.
18
0.
0000
00
0.0
0
BH
5979
8
00 °
C
0.
0002
51
3.3
7
0.00
0000
0
.00
0.
0000
25
2.6
9
0.00
0000
0
.00
0.
0937
00
2.6
9
0.00
0047
3
.37
0.
0000
00
0.0
0
BH
5980
8
70 °
C
0.
0006
26
2.0
7
0.00
0000
0
.00
0.
0000
71
2.5
5
0.00
0000
0
.00
0.
2676
50
2.5
5
0.00
0117
2
.07
0.
0000
00
0.0
0
BH
5981
9
40 °
C
0.
0005
68
1.9
4
0.00
0000
0
.00
0.
0000
59
2.5
5
0.00
0000
0
.00
0.
2216
64
2.5
5
0.00
0106
1
.94
0.
0000
00
0.0
0
BH
5982
10
25 °
C
0.
0009
05
1.4
5
0.00
0000
0
.00
0.
0000
60
2.5
6
0.00
0000
0
.00
0.
2270
12
2.5
6
0.00
0169
1
.45
0.
0000
00
0.0
0
BH
5983
11
25 °
C
0.
0009
09
1.7
5
0.00
0000
0
.00
0.
0000
50
2.5
6
0.00
0000
0
.00
0.
1876
92
2.5
6
0.00
0170
1
.75
0.
0000
00
0.0
0
BH
5984
12
25 °
C
0.
0014
35
0.8
4
0.00
0000
0
.00
0.
0000
78
2.5
8
0.00
0000
0
.00
0.
2968
03
2.5
8
0.00
0268
0
.84
0.
0000
00
0.0
0
Σ
0.00
4985
0
.68
0.
0000
00
0.0
0
0.00
0358
1
.05
0.
0000
00
0.0
0
1.35
7000
1
.05
0.
0009
32
0.6
8
0.00
0000
0
.00
Σ
0.00
5344
0
.64
1.
3570
00
1.0
5
72
Tab
le 9
.13:
Con
tinue
d
38A
r(k)
%
1σ
38A
r(ca
) %
1σ
38A
r(cl
) %
1σ
39A
r(k)
%
1σ
39A
r(ca
) %
1σ
40A
r(r)
%
1σ
40A
r(a)
%
1σ
40A
r(c)
%
1σ
40A
r(k)
%
1σ
0.00
0343
0
.23
0.
0000
00
0.0
0
0.00
0011
22
0.28
0.02
8409
0
.23
0.
0000
20
2.8
6
0.00
1684
13
3.38
0.05
0920
4
.40
0.
0000
00
0.0
0
0.00
0000
0
.00
0.00
0240
0
.32
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0198
90
0.3
2
0.00
0012
3
.20
0.
0020
89
116.
47
0.
0215
22
11.
30
0.
0000
00
0.0
0
0.00
0000
0
.00
0.00
0215
0
.30
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0178
14
0.3
0
0.00
0010
3
.28
0.
0018
48
152.
97
0.
0140
08
20.
18
0.
0000
00
0.0
0
0.00
0000
0
.00
0.00
1309
0
.19
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
1085
12
0.1
9
0.00
0063
2
.69
0.
0148
28
16.
84
0.
0741
07
3.3
7
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
4106
0
.09
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
3404
24
0.0
9
0.00
0180
2
.55
0.
0522
17
7.3
4
0.18
5002
2
.07
0.
0000
00
0.0
0
0.00
0000
0
.00
0.00
3794
0
.08
0.
0000
00
0.0
0
0.00
0080
8
1.23
0.31
4617
0
.08
0.
0001
49
2.5
5
0.04
7540
6
.87
0.
1677
11
1.9
4
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
2697
0
.12
0.
0000
00
0.0
0
0.00
0104
4
3.06
0.22
3659
0
.12
0.
0001
53
2.5
6
0.03
0329
1
2.90
0.26
7285
1
.45
0.
0000
00
0.0
0
0.00
0000
0
.00
0.00
2239
0
.15
0.
0000
00
0.0
0
0.00
0259
1
2.15
0.18
5675
0
.15
0.
0001
26
2.5
6
0.02
5572
1
8.42
0.26
8559
1
.75
0.
0000
00
0.0
0
0.00
0000
0
.00
0.00
1301
0
.15
0.
0000
00
0.0
0
0.00
0400
5
.96
0.
1078
37
0.1
5
0.00
0200
2
.58
0.
0149
19
23.
90
0.
4240
37
0.8
4
0.00
0000
0
.00
0.
0000
00
0.0
0
0.01
6243
0
.05
0.
0000
00
0.0
0
0.00
0855
1
0.72
1.34
6837
0
.05
0.
0009
13
1.0
5
0.19
1027
5
.26
1.
4731
50
0.6
8
0.00
0000
0
.00
0.
0000
00
0.0
0
0.
0180
29
0.5
1
1.34
7750
0
.05
1.
6641
77
0.8
5
T
able
9.1
4: A
dditi
onal
par
amet
ers f
or M
AD
ER
AS-
002
Add
ition
al
Par
amet
ers
40
(r)/3
9(k)
1σ
40
(r+a
) 1σ
40
Ar/
39A
r 1σ
37
Ar/
39A
r 1σ
36
Ar/
39A
r 1σ
T
ime
(day
s)
37A
r (d
ecay
) 39
Ar
(dec
ay)
40A
r (m
oles
)
BH
5976
6
75 °
C
0.05
9268
0.
0790
5 0.
0526
04
0.
0001
3 1
.850
353
0.
0061
5 1
.024
124
0.
0293
8 0
.006
332
0.00
027
128
.020
12
.541
7772
9 1.
0009
0387
3.
105E
-16
BH
5977
7
20 °
C
0.10
5044
0.
1223
5 0.
0236
12
0.
0000
8 1
.186
388
0.
0053
4 0
.915
713
0.
0294
3 0
.003
901
0.00
041
128
.055
12
.550
3818
1 1.
0009
0411
1.
394E
-16
BH
5978
7
35 °
C
0.10
3769
0.
1587
3 0.
0158
56
0.
0000
7 0
.889
605
0.
0046
4 0
.849
381
0.
0279
7 0
.002
884
0.00
054
128
.094
12
.560
1981
7 1.
0009
0439
9.
358E
-17
BH
5979
8
00 °
C
0.13
6653
0.
0230
2 0.
0889
36
0.
0000
7 0
.819
117
0.
0017
0 0
.862
999
0.
0232
7 0
.002
538
0.00
008
128
.132
12
.569
5049
5 1.
0009
0465
5.
249E
-16
BH
5980
8
70 °
C
0.15
3389
0.
0112
7 0.
2372
19
0.
0001
8 0
.696
467
0.
0008
5 0
.785
811
0.
0200
8 0
.002
046
0.00
004
128
.167
12
.578
1284
9 1.
0009
0490
1.
400E
-15
BH
5981
9
40 °
C
0.15
1103
0.
0103
8 0.
2152
50
0.
0001
4 0
.683
841
0.
0007
3 0
.704
217
0.
0179
7 0
.001
989
0.00
003
128
.202
12
.586
9306
0 1.
0009
0515
1.
270E
-15
BH
5982
10
25 °
C
0.13
5605
0.
0174
9 0.
2976
14
0.
0005
3 1
.329
749
0.
0028
7 1
.014
297
0.
0259
6 0
.004
309
0.00
006
128
.237
12
.595
5661
0 1.
0009
0540
1.
757E
-15
BH
5983
11
25 °
C
0.13
7724
0.
0253
7 0.
2941
31
0.
0003
2 1
.583
042
0.
0029
5 1
.010
177
0.
0258
9 0
.005
158
0.00
009
128
.272
12
.604
3804
1 1.
0009
0565
1.
736E
-15
BH
5984
12
25 °
C
0.13
8352
0.
0330
7 0.
4389
56
0.
0002
6 4
.063
029
0.
0067
1 2
.747
244
0.
0710
9 0
.014
008
0.00
011
128
.307
12
.613
0278
8 1.
0009
0589
2.
591E
-15
73
Tab
le 9
.15:
Pro
cedu
re b
lank
s for
MA
DE
RA
S-00
2
Pro
cedu
re
Bla
nks
36A
r 1σ
37
Ar
1σ
38A
r 1σ
39
Ar
1σ
40A
r 1σ
BH
5976
6
75 °
C
0.0
0005
6 0
.000
007
0.0
0000
9 0
.000
016
0.0
0002
7 0
.000
012
0.0
0001
6 0
.000
010
0.0
1622
1 0
.000
050
BH
5977
7
20 °
C
0.0
0005
8 0
.000
007
0.0
0001
3 0
.000
016
0.0
0002
5 0
.000
012
0.0
0000
4 0
.000
010
0.0
1721
5 0
.000
050
BH
5978
7
35 °
C
0.0
0005
9 0
.000
007
0.0
0001
4 0
.000
016
0.0
0002
4 0
.000
012
0.0
0000
3 0
.000
010
0.0
1743
5 0
.000
050
BH
5979
8
00 °
C
0.0
0006
2 0
.000
007
0.0
0002
0 0
.000
016
0.0
0002
1 0
.000
012
0.0
0001
6 0
.000
010
0.0
1797
4 0
.000
050
BH
5980
8
70 °
C
0.0
0006
6 0
.000
007
0.0
0002
5 0
.000
016
0.0
0001
8 0
.000
012
0.0
0003
4 0
.000
010
0.0
1819
4 0
.000
050
BH
5981
9
40 °
C
0.0
0006
9 0
.000
007
0.0
0003
1 0
.000
016
0.0
0001
6 0
.000
012
0.0
0004
2 0
.000
010
0.0
1847
3 0
.000
050
BH
5982
10
25 °
C
0.0
0007
3 0
.000
007
0.0
0003
8 0
.000
016
0.0
0001
2 0
.000
012
0.0
0003
0 0
.000
010
0.0
1928
0 0
.000
050
BH
5983
11
25 °
C
0.0
0007
8 0
.000
007
0.0
0004
6 0
.000
016
0.0
0000
8 0
.000
012
0.0
0000
9 0
.000
010
0.0
2104
7 0
.000
050
BH
5984
12
25 °
C
0.0
0008
3 0
.000
007
0.0
0005
4 0
.000
016
0.0
0000
4 0
.000
012
0.0
0005
4 0
.000
010
0.0
2329
6 0
.000
050
T
able
9.1
6: In
terc
ept v
alue
s for
MA
DE
RA
S-00
2
Inte
rcep
t V
alue
s 36
Ar
1σ
r2
37
Ar
1σ
r2
38
Ar
1σ
r2
BH
5976
6
75 °
C
0.00
0240
0.
0000
02
0.90
80
LIN
7
of 8
0.
0023
66
0.00
0027
0.
9335
LI
N
8 of
8
0.00
0417
0.
0000
22
0.41
28
LIN
8
of 8
B
H59
77
720
°C
0.
0001
38
0.00
0004
0.
1250
E
XP
8
of 8
0.
0014
87
0.00
0024
0.
7950
E
XP
8
of 8
0.
0002
71
0.00
0006
0.
8349
E
XP
8
of 8
B
H59
78
735
°C
0.
0001
12
0.00
0006
0.
0801
LI
N
7 of
8
0.00
1238
0.
0000
20
0.57
45
EX
P
8 of
8
0.00
0227
0.
0000
14
0.23
83
EX
P
8 of
8
BH
5979
8
00 °
C
0.00
0343
0.
0000
04
0.84
05
EX
P
8 of
8
0.00
7588
0.
0000
67
0.95
94
EX
P
8 of
8
0.00
1331
0.
0000
21
0.86
01
EX
P
8 of
8
BH
5980
8
70 °
C
0.00
0777
0.
0000
11
0.83
35
LIN
8
of 8
0.
0216
29
0.00
0067
0.
9946
E
XP
7
of 8
0.
0040
55
0.00
0045
0.
9149
E
XP
8
of 8
B
H59
81
940
°C
0.
0007
08
0.00
0008
0.
8974
E
XP
7
of 8
0.
0179
11
0.00
0049
0.
9943
E
XP
8
of 8
0.
0040
36
0.00
0064
0.
8528
E
XP
8
of 8
B
H59
82
1025
°C
0.
0010
57
0.00
0011
0.
8942
LI
N
8 of
8
0.01
8336
0.
0000
58
0.99
32
EX
P
8 of
8
0.00
3013
0.
0000
44
0.82
56
EX
P
8 of
8
BH
5983
11
25 °
C
0.00
1056
0.
0000
14
0.87
12
LIN
8
of 8
0.
0151
64
0.00
0049
0.
9931
E
XP
8
of 8
0.
0027
04
0.00
0029
0.
9051
E
XP
8
of 8
B
H59
84
1225
°C
0.
0016
27
0.00
0009
0.
9759
LI
N
8 of
8
0.02
3945
0.
0001
16
0.98
47
EX
P
8 of
8
0.00
1992
0.
0000
21
0.85
77
EX
P
8 of
8
74
Tab
le 9
.16:
Con
tinue
d
39A
r 1σ
r2
40A
r 1σ
r2
0.0
2856
4 0
.000
063
0.99
52
LIN
8
of 8
0
.068
824
0.0
0011
8 0.
9923
E
XP
8
of 8
0
.019
989
0.0
0006
2 0.
9874
E
XP
8
of 8
0
.040
826
0.0
0005
7 0.
9797
E
XP
8
of 8
0
.017
902
0.0
0005
2 0.
9958
LI
N
4 of
8
0.0
3329
1 0
.000
046
0.95
61
EX
P
7 of
8
0.1
0904
4 0
.000
208
0.99
72
EX
P
8 of
8
0.1
0691
0 0
.000
046
0.99
96
EX
P
5 of
8
0.3
4206
1 0
.000
306
0.99
93
EX
P
8 of
8
0.2
5541
3 0
.000
177
0.99
92
EX
P
7 of
8
0.3
1612
3 0
.000
247
0.99
95
EX
P
8 of
8
0.2
3372
4 0
.000
133
0.99
92
EX
P
8 of
8
0.2
2477
6 0
.000
264
0.99
88
EX
P
8 of
8
0.3
1689
4 0
.000
528
0.99
56
EX
P
8 of
8
0.1
8658
6 0
.000
276
0.99
81
EX
P
8 of
8
0.3
1517
8 0
.000
319
0.99
84
EX
P
8 of
8
0.1
0854
2 0
.000
164
0.99
77
EX
P
8 of
8
0.4
6225
2 0
.000
254
0.99
97
EX
P
8 of
8
T
able
9.1
7: S
ampl
e pa
ram
eter
s for
MA
DE
RA
S-00
2
Sam
ple
Par
amet
ers
Sam
ple
Mat
eria
l Lo
catio
n A
naly
st
Temp
Sta
ndar
d %
1σ
J %
1σ
(in M
a)
BH
5976
6
75 °
C
MA
D00
2 gr
ound
mas
s U
W93
C42
B
rian
Jich
a 67
5 28
.201
0.
08
0.00
0262
3 0.
05
BH
5977
7
20 °
C
MA
D00
2 gr
ound
mas
s U
W93
C42
B
rian
Jich
a 72
0 28
.201
0.
08
0.00
0262
3 0.
05
BH
5978
7
35 °
C
MA
D00
2 gr
ound
mas
s U
W93
C42
B
rian
Jich
a 73
5 28
.201
0.
08
0.00
0262
3 0.
05
BH
5979
8
00 °
C
MA
D00
2 gr
ound
mas
s U
W93
C42
B
rian
Jich
a 80
0 28
.201
0.
08
0.00
0262
3 0.
05
BH
5980
8
70 °
C
MA
D00
2 gr
ound
mas
s U
W93
C42
B
rian
Jich
a 87
0 28
.201
0.
08
0.00
0262
3 0.
05
BH
5981
9
40 °
C
MA
D00
2 gr
ound
mas
s U
W93
C42
B
rian
Jich
a 94
0 28
.201
0.
08
0.00
0262
3 0.
05
BH
5982
10
25 °
C
MA
D00
2 gr
ound
mas
s U
W93
C42
B
rian
Jich
a 10
25
28.2
01
0.08
0.
0002
623
0.05
B
H59
83
1125
°C
M
AD
002
grou
ndm
ass
UW
93C
42
Bria
n Ji
cha
1125
28
.201
0.
08
0.00
0262
3 0.
05
BH
5984
12
25 °
C
MA
D00
2 gr
ound
mas
s U
W93
C42
B
rian
Jich
a 12
25
28.2
01
0.08
0.
0002
623
0.05
75
Table 9.17: Continued
MDF %1σ Volume Ratio Sensitivity D
ay
Mon
th
Yea
r
Hou
r
Min
Res
ist
Irradiation Project Experiment
Nm
b Standard Name
(mol/volt)
1.005096 0.03 1 5.902E-15 20 OCT 2011 17 40 001 UW93 UW93C UW93C42 01 FCS
1.005096 0.03 1 5.902E-15 20 OCT 2011 18 30 001 UW93 UW93C UW93C42 01 FCS
1.005096 0.03 1 5.902E-15 20 OCT 2011 19 27 001 UW93 UW93C UW93C42 01 FCS
1.005096 0.03 1 5.902E-15 20 OCT 2011 20 21 001 UW93 UW93C UW93C42 01 FCS
1.005096 0.03 1 5.902E-15 20 OCT 2011 21 11 001 UW93 UW93C UW93C42 01 FCS
1.005096 0.03 1 5.902E-15 20 OCT 2011 22 02 001 UW93 UW93C UW93C42 01 FCS
1.005096 0.03 1 5.902E-15 20 OCT 2011 22 52 001 UW93 UW93C UW93C42 01 FCS
1.005096 0.03 1 5.902E-15 20 OCT 2011 23 43 001 UW93 UW93C UW93C42 01 FCS
1.005096 0.03 1 5.902E-15 21 OCT 2011 00 33 001 UW93 UW93C UW93C42 01 FCS
Table 9.18: Irradiation constants for MADERAS-002
Irradiation Constants 40/36(a) %1
σ 40/36
(c) %1σ 38/36
(a) %1σ
38/36(c)
%1σ
39/37(ca) %1σ
38/37(ca)
%1σ
36/37(ca) %1σ
BH5976 675 °C 295.5 0 0.018 35 0.1869 0 1.493 3 0.000673 0 0 0 0.000264 0
BH5977 720 °C 295.5 0 0.018 35 0.1869 0 1.493 3 0.000673 0 0 0 0.000264 0
BH5978 735 °C 295.5 0 0.018 35 0.1869 0 1.493 3 0.000673 0 0 0 0.000264 0
BH5979 800 °C 295.5 0 0.018 35 0.1869 0 1.493 3 0.000673 0 0 0 0.000264 0
BH5980 870 °C 295.5 0 0.018 35 0.1869 0 1.493 3 0.000673 0 0 0 0.000264 0
BH5981 940 °C 295.5 0 0.018 35 0.1869 0 1.493 3 0.000673 0 0 0 0.000264 0
BH5982 1025 °C 295.5 0 0.018 35 0.1869 0 1.493 3 0.000673 0 0 0 0.000264 0
BH5983 1125 °C 295.5 0 0.018 35 0.1869 0 1.493 3 0.000673 0 0 0 0.000264 0
BH5984 1225 °C 295.5 0 0.018 35 0.1869 0 1.493 3 0.000673 0 0 0 0.000264 0
Table 9.18: Continued
40/39(k) %1σ 38/39(k) %1σ 36/38(cl) %1σ K/Ca %1σ K/Cl %1σ Ca/Cl %1σ
0 0 0.01206 0 0 0 0.43 0 0 0 0 0 0 0 0.01206 0 0 0 0.43 0 0 0 0 0 0 0 0.01206 0 0 0 0.43 0 0 0 0 0 0 0 0.01206 0 0 0 0.43 0 0 0 0 0 0 0 0.01206 0 0 0 0.43 0 0 0 0 0 0 0 0.01206 0 0 0 0.43 0 0 0 0 0 0 0 0.01206 0 0 0 0.43 0 0 0 0 0 0 0 0.01206 0 0 0 0.43 0 0 0 0 0 0 0 0.01206 0 0 0 0.43 0 0 0 0 0
76
70.4 ± 6.1 Ka
200
150
100
50
0
50
100
150
200
0 10 20 30 40 50 60 70 80 90 100
Cumulative 39Ar Released [ % ]
UW93C42.AGE >>> MAD002 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU70.4 ± 6.1TOTAL FUSION 68.1 ± 7.2NORMAL ISOCHRON 73.2 ± 9.5INVERSE ISOCHRON73.2 ± 4.7
MSWD0.34
Sample Info
groundmassUW93C42Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000013
Figure 9.1: Age plateau for MADERAS-002
0.293 ± 0.114
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0 10 20 30 40 50 60 70 80 90 100
Cumulative 39Ar Released [ % ]
UW93C42.AGE >>> MAD002 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU70.4 ± 6.1TOTAL FUSION 68.1 ± 7.2NORMAL ISOCHRON 73.2 ± 9.5INVERSE ISOCHRON73.2 ± 4.7
Sample Info
groundmassUW93C42Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000013
Figure 9.2: K-Ca plateau for MADERAS-002
77
0
50
100
150
200
250
300
350
400
450
500
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700
39Ar / 36Ar
UW93C42.AGE >>> MAD002 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU70.4 ± 6.1TOTAL FUSION 68.1 ± 7.2NORMAL ISOCHRON 73.2 ± 9.5INVERSE ISOCHRON73.2 ± 4.7
MSWD0.32
40AR/36AR INTERCEPT293.3 ± 5.5
Sample Info
groundmassUW93C42Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000013
Figure 9.3: Normal isochron for MADERAS-002
0.0000
0.0005
0.0010
0.0015
0.0020
0.0025
0.0030
0.0035
0.0040
0.0045
0 1 2 3 4 5 6 7 8 9
39Ar / 40Ar
UW93C42.AGE >>> MAD002 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU70.4 ± 6.1TOTAL FUSION 68.1 ± 7.2NORMAL ISOCHRON 73.2 ± 9.5INVERSE ISOCHRON73.2 ± 4.7
MSWD0.31
40AR/36AR INTERCEPT293.4 ± 2.7
Sample Info
groundmassUW93C42Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000013
Figure 9.4: Inverse isochron for MADERAS-002
78 9.2.
2 Sa
mpl
e M
AD
ER
AS-
003
Tab
le 9
.19:
Incr
emen
tal h
eatin
g su
mm
ary
for
MA
DE
RA
S-00
3
Incr
emen
tal
Hea
ting
36
Ar(
a)
37A
r(ca
) 38
Ar(
cl)
39A
r(k)
40
Ar(
r)
Age
±
2σ
40A
r(r)
39
Ar(
k)
K/C
a ±
2σ
(Ka)
(%
) (%
) B
H59
51
720
°C
0.
0006
00
0.01
3712
0.
0000
00
0.04
8528
0.
0174
58
172.
7 ±
62.3
8
.97
2.2
5 1.
52
± 0.
09
BH
5952
7
85 °
C
0.00
0519
0.
0527
41
0.00
0000
0.
2231
42
0.07
2619
15
6.2
± 8.
4 3
2.12
1
0.36
1.
82
± 0.
10
BH
5953
8
45 °
C
0.00
0467
0.
1038
17
0.00
0000
0.
5811
65
0.19
1857
15
8.5
± 3.
1 5
8.16
2
6.98
2.
41
± 0.
12
BH
5954
9
00 °
C
0.00
0320
0.
0937
38
0.00
0000
0.
5546
42
0.18
0650
15
6.4
± 3.
6 6
5.61
2
5.75
2.
54
± 0.
13
BH
5955
9
60 °
C
0.00
0246
0.
0830
57
0.00
0000
0.
3827
87
0.12
5462
15
7.4
± 6.
3 6
3.33
1
7.77
1.
98
± 0.
10
BH
5956
10
25 °
C
0.00
0205
0.
0516
85
0.00
0145
0.
1514
95
0.04
9685
15
7.5
± 15
.8
45.
05
7.0
3 1.
26
± 0.
07
BH
5957
10
95 °
C
0.00
0255
0.
0591
00
0.00
0223
0.
1198
77
0.03
9421
15
7.9
± 22
.6
34.
37
5.5
7 0.
87
± 0.
05
BH
5958
11
60 °
C
0.00
0219
0.
0379
67
0.00
0234
0.
0416
92
0.01
2185
14
0.3
± 56
.5
15.
82
1.9
4 0.
47
± 0.
03
BH
5959
12
25 °
C
0.00
0323
0.
0536
65
0.00
0233
0.
0507
65
0.01
8094
17
1.1
± 69
.0
15.
94
2.3
6 0.
41
± 0.
02
Σ 0.
0031
54
0.54
9483
0.
0008
36
2.15
4093
0.
7074
30
T
able
9.1
9: C
ontin
ued
Info
rmat
ion
on A
naly
sis
R
esul
ts
40(r
)/39
(k)
± 2σ
A
ge
± 2σ
MSWD
39A
r(k)
K
/Ca
± 2σ
(Ka)
(%
,n)
Sam
ple
= M
AD
003
A
ge P
late
au
0.32
80
± 0.
0044
15
7.5
± 2.
2 0.
21
100.
00
0.67
±
0.34
M
ater
ial =
gro
undm
ass
±
1.34
%
± 1.
37%
9
Loc
atio
n =
UW
93C
43
M
inim
al E
xter
nal E
rror
±
6.5
2.31
S
tatis
tical
T R
atio
A
naly
st =
Bria
n Ji
cha
A
naly
tical
Err
or
± 2.
1 1.
0000
E
rror
Mag
nific
atio
n P
roje
ct =
UW
93C
Mas
s D
iscr
imin
atio
n La
w =
LIN
Tot
al F
usio
n A
ge
0.32
84
± 0.
0073
15
7.7
± 3.
5
9 1.
69
± 0.
03
Irra
diat
ion
= U
W93
± 2.
22%
±
2.23
%
J =
0.0
0026
230
± 0.
0000
0037
Min
imal
Ext
erna
l Err
or
± 7.
1
F
CS
= 2
8.20
1 ±
0.02
3 M
a
Ana
lytic
al E
rror
±
3.5
79
Table 9.20: Normal isochron table for MADERAS-003
Normal Isochron
39(k)/36(a) ± 2σ 40(a+r)/36(a) ± 2σ
r.i.
BH5951 720 °C 80.9 ± 2.9 324.6 ± 11.5 0.9888 BH5952 785 °C 429.6 ± 10.9 435.3 ± 11.1 0.9959 BH5953 845 °C 1244.2 ± 32.6 706.2 ± 18.7 0.9901 BH5954 900 °C 1730.8 ± 72.8 859.2 ± 36.3 0.9945 BH5955 960 °C 1557.2 ± 106.5 805.9 ± 55.2 0.9970 BH5956 1025 °C 738.8 ± 60.1 537.8 ± 43.8 0.9963 BH5957 1095 °C 470.6 ± 34.9 450.3 ± 33.5 0.9940 BH5958 1160 °C 190.1 ± 14.3 351.1 ± 26.5 0.9919 BH5959 1225 °C 157.2 ± 12.0 351.5 ± 26.8 0.9941
Table 9.20: Continued
Results 40(a)/36(a) ± 2σ 40(r)/39(k) ± 2σ Age ± 2σ
MS
WD
(Ka)
Normal Isochron
296.2474 ± 7.0069 0.3273 ± 0.0074 157.1 ± 3.6 0.23 ± 2.37% ± 2.26% ± 2.28%
Minimal External Error ± 7.1 Analytical Error ± 3.6
Statistics Statistical F ratio 2.01 Convergence 0.0000000032 Error Magnification 1.0000 Number of Iterations 33
Number of Data Points 9 Calculated Line Weighted York-2
Table 9.21: Inverse isochron table for MADERAS-003
Inverse Isochron
39(k)/40(a+r) ± 2σ 36(a)/40(a+r) ± 2σ
r.i.
BH5951 720 °C 0.249345 ± 0.001322 0.003081 ± 0.000109 0.0836 BH5952 785 °C 0.986861 ± 0.002273 0.002297 ± 0.000058 0.0690 BH5953 845 °C 1.761703 ± 0.006518 0.001416 ± 0.000037 0.1296 BH5954 900 °C 2.014361 ± 0.008884 0.001164 ± 0.000049 0.0821 BH5955 960 °C 1.932287 ± 0.010225 0.001241 ± 0.000085 0.0510 BH5956 1025 °C 1.373782 ± 0.009596 0.001859 ± 0.000152 0.0709 BH5957 1095 °C 1.045234 ± 0.008486 0.002221 ± 0.000165 0.0709 BH5958 1160 °C 0.541437 ± 0.005205 0.002849 ± 0.000215 0.0757 BH5959 1225 °C 0.447222 ± 0.003694 0.002845 ± 0.000217 0.0478
Table 9.21 Continued
Results 40(a)/36(a) ± 2σ 40(r)/39(k) ± 2σ Age ± 2σ
MS
WD
(Ka)
Inverse Isochron
296.3144 ± 3.5081 0.3273 ± 0.0037 157.1 ± 1.8 0.23 ± 1.18% ± 1.13% ± 1.17%
Minimal External Error ± 6.4 Analytical Error ± 1.8
Statistics Statistical F ratio 2.01 Convergence 0.0000002122 Error Magnification 1.0000 Number of Iterations 4
Number of Data Points 9 Calculated Line Weighted York-2
80
Tab
le 9
.22:
Rel
ativ
e ab
unda
nces
for
MA
DE
RA
S-00
3
Rel
ativ
e A
bund
ance
s
36A
r %
1σ
37A
r %
1σ
38A
r %
1σ
39A
r %
1σ
40A
r %
1σ
Age
±
2σ
40A
r(r)
39
Ar(
k)
K/C
a ±
2σ
(Ka)
(%
) (%
)
BH
5951
7
20 °
C
0.00
0603
2 1.
752
0.0
1371
25
2.94
9 0
.000
6735
2.
479
0.0
4853
73
0.17
6 0
.194
6222
0.
198
172.
7 ±
62.3
8
.97
2.2
5 1.
52
± 0.
09
BH
5952
7
85 °
C
0.00
0533
4 1.
233
0.0
5274
15
2.69
5 0
.002
5639
1.
531
0.2
2317
77
0.05
6 0
.226
1132
0.
100
156.
2 ±
8.4
32.
12
10.
36
1.82
±
0.10
BH
5953
8
45 °
C
0.00
0494
5 1.
228
0.1
0381
74
2.56
1 0
.006
4066
1.
048
0.5
8123
52
0.05
1 0
.329
8885
0.
178
158.
5 ±
3.1
58.
16
26.
98
2.41
±
0.12
BH
5954
9
00 °
C
0.00
0345
2 1.
942
0.0
9373
75
2.55
2 0
.006
4551
0.
810
0.5
5470
46
0.10
2 0
.275
3436
0.
195
156.
4 ±
3.6
65.
61
25.
75
2.54
±
0.13
BH
5955
9
60 °
C
0.00
0267
7 3.
131
0.0
8305
72
2.55
4 0
.004
5456
0.
819
0.3
8284
30
0.15
4 0
.198
1005
0.
215
157.
4 ±
6.3
63.
33
17.
77
1.98
±
0.10
BH
5956
10
25 °
C
0.00
0218
7 3.
806
0.0
5168
48
2.62
8 0
.002
0108
1.
065
0.1
5152
98
0.14
5 0
.110
2759
0.
318
157.
5 ±
15.8
4
5.05
7
.03
1.26
±
0.07
BH
5957
10
95 °
C
0.00
0270
3 3.
488
0.0
5910
04
2.61
5 0
.001
7164
0.
997
0.1
1991
72
0.24
0 0
.114
6896
0.
327
157.
9 ±
22.6
3
4.37
5
.57
0.87
±
0.05
BH
5958
11
60 °
C
0.00
0229
4 3.
593
0.0
3796
72
2.64
3 0
.000
7777
2.
929
0.0
4171
72
0.30
6 0
.077
0018
0.
371
140.
3 ±
56.5
1
5.82
1
.94
0.47
±
0.03
BH
5959
12
25 °
C
0.00
0337
1 3.
645
0.0
5366
45
2.78
1 0
.000
9057
2.
412
0.0
5080
13
0.30
8 0
.113
5123
0.
274
171.
1 ±
69.0
1
5.94
2
.36
0.41
±
0.02
Σ 0.
0032
994
0.79
3 0
.549
4829
0.
945
0.0
2605
53
0.42
4 2
.154
4632
0.
045
1.6
3954
76
0.07
4
T
able
9.2
2: C
ontin
ued
Info
rmat
ion
on A
naly
sis
and
Con
stan
ts U
sed
in C
alcu
latio
ns
Sam
ple
= M
AD
003
Ext
ract
ion
Met
hod
= U
ndef
ined
M
ater
ial =
gro
undm
ass
Hea
ting
= 90
0 se
c L
ocat
ion
= U
W93
C43
Is
olat
ion
= 15
.00
min
A
naly
st =
Bria
n Ji
cha
Inst
rum
ent =
MA
P21
5 P
roje
ct =
UW
93C
L
ithol
ogy
= U
ndef
ined
M
ass
Dis
crim
inat
ion
Law
= L
IN
Lat
-Lon
= U
ndef
ined
- U
ndef
ined
Ir
radi
atio
n =
UW
93
Age
Equ
atio
ns =
Con
vent
iona
l J
= 0
.000
2623
0 ±
0.00
0000
37
Neg
ativ
e In
tens
ities
= F
orce
d Z
ero
FC
S =
28.
201
± 0.
023
Ma
Dec
ay C
onst
ant 4
0K =
5.4
63 ±
0.1
07 E
-10
1/a
IGS
N =
Und
efin
ed
Dec
ay C
onst
ant 3
9Ar =
2.9
40 ±
0.0
29 E
-07
1/h
Pre
ferr
ed A
ge =
Und
efin
ed
Dec
ay C
onst
ant 3
7Ar =
8.2
30 ±
0.0
82 E
-04
1/h
Cla
ssifi
catio
n =
Und
efin
ed
No
36C
l Cor
rect
ion
Exp
erim
ent T
ype
= U
ndef
ined
N
o 36
Cl C
orre
ctio
n
81
Tab
le 9
.22:
Con
tinue
d
Res
ults
40
(r)/
39(k
) ±
2σ
Age
±
2σ
MSWD
39A
r(k)
K
/Ca
± 2σ
(K
a)
(%,n
)
Age
Pla
teau
0.
3280
±
0.00
44
157.
5 ±
2.2
0.21
10
0.00
0.
67
± 0.
34
± 1.
34%
±
1.37
%
9
Min
imal
Ext
erna
l Err
or
± 6.
5 2.
31
Sta
tistic
al T
Rat
io
Ana
lytic
al E
rror
±
2.1
1.00
00
Err
or M
agni
ficat
ion
Tot
al F
usio
n A
ge
0.32
84
± 0.
0073
15
7.7
± 3.
5
9 1.
69
± 0.
03
± 2.
22%
±
2.23
%
Min
imal
Ext
erna
l Err
or
± 7.
1
Ana
lytic
al E
rror
±
3.5
Nor
mal
Is
ochr
on
0.32
73
± 0.
0074
15
7.1
± 3.
6 0.
23
100.
00
± 2.
26%
±
2.28
%
9
Min
imal
Ext
erna
l Err
or
± 7.
1 2.
01
Sta
tistic
al F
ratio
Ana
lytic
al E
rror
±
3.6
1.00
00
Err
or M
agni
ficat
ion
Inve
rse
Isoc
hron
0.
3273
±
0.00
37
157.
1 ±
1.8
0.23
10
0.00
±
1.13
%
± 1.
17%
9
Min
imal
Ext
erna
l Err
or
± 6.
4 2.
01
Sta
tistic
al F
ratio
Ana
lytic
al E
rror
±
1.8
1.00
00
Err
or M
agni
ficat
ion
T
able
9.2
3: D
egas
sing
pat
tern
s for
MA
DE
RA
S-00
3
Deg
assi
ng
Pat
tern
s
36A
r(a)
%
1σ
36A
r(c)
%
1σ
36A
r(ca
) %
1σ
36A
r(cl
) %
1σ
37A
r(ca
) %
1σ
38A
r(a)
%
1σ
38A
r(c)
%
1σ
38A
r(k)
%
1σ
BH
5951
7
20 °
C
0.
0006
00
1.7
6
0.00
0000
0
.00
0.
0000
04
2.9
5
0.00
0000
0
.00
0.
0137
12
2.9
5
0.00
0112
1
.76
0.
0000
00
0.0
0
0.00
0585
0
.18
BH
5952
7
85 °
C
0.
0005
19
1.2
7
0.00
0000
0
.00
0.
0000
14
2.7
0
0.00
0000
0
.00
0.
0527
41
2.7
0
0.00
0097
1
.27
0.
0000
00
0.0
0
0.00
2691
0
.06
BH
5953
8
45 °
C
0.
0004
67
1.3
1
0.00
0000
0
.00
0.
0000
27
2.5
6
0.00
0000
0
.00
0.
1038
17
2.5
6
0.00
0087
1
.31
0.
0000
00
0.0
0
0.00
7009
0
.05
BH
5954
9
00 °
C
0.
0003
20
2.1
0
0.00
0000
0
.00
0.
0000
25
2.5
5
0.00
0000
0
.00
0.
0937
38
2.5
5
0.00
0060
2
.10
0.
0000
00
0.0
0
0.00
6689
0
.10
BH
5955
9
60 °
C
0.
0002
46
3.4
2
0.00
0000
0
.00
0.
0000
22
2.5
5
0.00
0000
0
.00
0.
0830
57
2.5
5
0.00
0046
3
.42
0.
0000
00
0.0
0
0.00
4616
0
.15
BH
5956
10
25 °
C
0.
0002
05
4.0
6
0.00
0000
0
.00
0.
0000
14
2.6
3
0.00
0000
0
.00
0.
0516
85
2.6
3
0.00
0038
4
.06
0.
0000
00
0.0
0
0.00
1827
0
.15
BH
5957
10
95 °
C
0.
0002
55
3.7
0
0.00
0000
0
.00
0.
0000
16
2.6
1
0.00
0000
0
.00
0.
0591
00
2.6
1
0.00
0048
3
.70
0.
0000
00
0.0
0
0.00
1446
0
.24
BH
5958
11
60 °
C
0.
0002
19
3.7
6
0.00
0000
0
.00
0.
0000
10
2.6
4
0.00
0000
0
.00
0.
0379
67
2.6
4
0.00
0041
3
.76
0.
0000
00
0.0
0
0.00
0503
0
.31
BH
5959
12
25 °
C
0.
0003
23
3.8
1
0.00
0000
0
.00
0.
0000
14
2.7
8
0.00
0000
0
.00
0.
0536
65
2.7
8
0.00
0060
3
.81
0.
0000
00
0.0
0
0.00
0612
0
.31
Σ
0.00
3154
0
.83
0.
0000
00
0.0
0
0.00
0145
0
.94
0.
0000
00
0.0
0
0.54
9483
0
.94
0.
0005
90
0.8
3
0.00
0000
0
.00
0.
0259
78
0.0
5
Σ
0.00
3299
0
.79
0.
5494
83
0.9
4
82
Tab
le 9
.23:
Con
tinue
d
38A
r(ca
) %
1σ
38A
r(cl
) %
1σ
39A
r(k)
%
1σ
39A
r(ca
) %
1σ
40A
r(r)
%
1σ
40A
r(a)
%
1σ
40A
r(c)
%
1σ
40A
r(k)
%
1σ
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0485
28
0.1
8
0.00
0009
2
.95
0.
0174
58
18.
02
0.
1771
64
1.7
6
0.00
0000
0
.00
0.
0000
00
0.0
0
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
2231
42
0.0
6
0.00
0035
2
.70
0.
0726
19
2.7
0
0.15
3494
1
.27
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
5811
65
0.0
5
0.00
0070
2
.56
0.
1918
57
0.9
9
0.13
8032
1
.31
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
5546
42
0.1
0
0.00
0063
2
.55
0.
1806
50
1.1
4
0.09
4694
2
.10
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
3827
87
0.1
5
0.00
0056
2
.55
0.
1254
62
2.0
1
0.07
2638
3
.42
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0145
1
4.87
0.15
1495
0
.15
0.
0000
35
2.6
3
0.04
9685
5
.00
0.
0605
91
4.0
6
0.00
0000
0
.00
0.
0000
00
0.0
0
0.
0000
00
0.0
0
0.00
0223
7
.87
0.
1198
77
0.2
4
0.00
0040
2
.61
0.
0394
21
7.1
4
0.07
5268
3
.70
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0234
9
.78
0.
0416
92
0.3
1
0.00
0026
2
.64
0.
0121
85
20.
13
0.
0648
17
3.7
6
0.00
0000
0
.00
0.
0000
00
0.0
0
0.
0000
00
0.0
0
0.00
0233
9
.46
0.
0507
65
0.3
1
0.00
0036
2
.78
0.
0180
94
20.
15
0.
0954
19
3.8
1
0.00
0000
0
.00
0.
0000
00
0.0
0
0.
0000
00
0.0
0
0.00
0836
5
.06
2.
1540
93
0.0
5
0.00
0370
0
.94
0.
7074
30
1.1
1
0.93
2117
0
.83
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0274
03
0.1
6
2.15
4463
0
.05
1.
6395
48
0.6
7
T
able
9.2
4: A
dditi
onal
par
amet
ers f
or M
AD
ER
AS-
003
Add
ition
al
Par
amet
ers
40
(r)/3
9(k)
1σ
40
(r+a
) 1σ
40
Ar/
39A
r 1σ
37
Ar/
39A
r 1σ
36
Ar/
39A
r 1σ
T
ime
(day
s)
37A
r (d
ecay
) 39
Ar
(dec
ay)
40A
r (m
oles
)
BH
5951
7
20 °
C
0.3
5975
7 0.
0648
3 0
.194
622
0.00
039
4.0
0974
8 0.
0106
3 0
.282
514
0.00
834
0.0
1242
7
0.00
022
127
.142
12
.326
2038
2 1.
0008
9767
1.
149E
-15
BH
5952
7
85 °
C
0.3
2543
9 0.
0087
8 0
.226
113
0.00
023
1.0
1315
3 0.
0011
7 0
.236
321
0.00
637
0.0
0239
0
0.00
003
127
.178
12
.334
8296
4 1.
0008
9792
1.
335E
-15
BH
5953
8
45 °
C
0.3
3012
4 0.
0032
7 0
.329
888
0.00
059
0.5
6756
4 0.
0010
5 0
.178
615
0.00
458
0.0
0085
1
0.00
001
127
.213
12
.343
2921
7 1.
0008
9816
1.
947E
-15
BH
5954
9
00 °
C
0.3
2570
6 0.
0037
3 0
.275
344
0.00
054
0.4
9637
9 0.
0010
9 0
.168
986
0.00
432
0.0
0062
2
0.00
001
127
.247
12
.351
7605
2 1.
0008
9841
1.
625E
-15
BH
5955
9
60 °
C
0.3
2776
0 0.
0066
0 0
.198
101
0.00
043
0.5
1744
6 0.
0013
7 0
.216
948
0.00
555
0.0
0069
9
0.00
002
127
.283
12
.360
4042
2 1.
0008
9866
1.
169E
-15
BH
5956
10
25 °
C
0.3
2796
1 0.
0164
2 0
.110
276
0.00
035
0.7
2775
0 0.
0025
4 0
.341
087
0.00
898
0.0
0144
3
0.00
005
127
.317
12
.368
8843
0 1.
0008
9890
6.
508E
-16
BH
5957
10
95 °
C
0.3
2884
5 0.
0234
9 0
.114
690
0.00
038
0.9
5640
7 0.
0038
8 0
.492
844
0.01
294
0.0
0225
4
0.00
008
127
.352
12
.377
3702
0 1.
0008
9915
6.
769E
-16
BH
5958
11
60 °
C
0.2
9226
1 0.
0588
4 0
.077
002
0.00
029
1.8
4580
7 0.
0088
7 0
.910
109
0.02
422
0.0
0549
8
0.00
020
127
.388
12
.386
0318
2 1.
0008
9940
4.
545E
-16
BH
5959
12
25 °
C
0.3
5641
7 0.
0718
3 0
.113
512
0.00
031
2.2
3443
8 0.
0092
3 1
.056
362
0.02
955
0.0
0663
5
0.00
024
127
.422
12
.394
5294
9 1.
0008
9964
6.
699E
-16
83
Tab
le 9
.25:
Pro
cedu
re b
lank
s for
MA
DE
RA
S-00
3
Pro
cedu
re
Bla
nks
36A
r 1σ
37
Ar
1σ
38A
r 1σ
39
Ar
1σ
40A
r 1σ
BH
5951
7
20 °
C
0.0
0006
3 0
.000
005
0.0
0001
1 0
.000
012
0.0
0000
5 0
.000
012
0.0
0000
0 0
.000
009
0.0
1918
6 0
.000
192
BH
5952
7
85 °
C
0.0
0006
6 0
.000
005
0.0
0001
1 0
.000
012
0.0
0000
5 0
.000
012
0.0
0000
4 0
.000
009
0.0
1840
8 0
.000
184
BH
5953
8
45 °
C
0.0
0007
0 0
.000
005
0.0
0001
2 0
.000
012
0.0
0000
5 0
.000
012
0.0
0000
8 0
.000
009
0.0
1894
3 0
.000
189
BH
5954
9
00 °
C
0.0
0007
4 0
.000
005
0.0
0001
5 0
.000
012
0.0
0000
6 0
.000
012
0.0
0001
1 0
.000
009
0.0
2018
0 0
.000
202
BH
5955
9
60 °
C
0.0
0008
0 0
.000
005
0.0
0002
3 0
.000
012
0.0
0000
7 0
.000
012
0.0
0001
5 0
.000
009
0.0
2201
2 0
.000
220
BH
5956
10
25 °
C
0.0
0008
7 0
.000
005
0.0
0003
8 0
.000
012
0.0
0000
9 0
.000
012
0.0
0001
9 0
.000
009
0.0
2416
5 0
.000
242
BH
5957
10
95 °
C
0.0
0009
5 0
.000
005
0.0
0006
7 0
.000
012
0.0
0001
2 0
.000
012
0.0
0002
3 0
.000
009
0.0
2617
6 0
.000
262
BH
5958
11
60 °
C
0.0
0010
4 0
.000
005
0.0
0010
7 0
.000
012
0.0
0001
5 0
.000
012
0.0
0002
7 0
.000
009
0.0
2727
6 0
.000
273
BH
5959
12
25 °
C
0.0
0011
4 0
.000
006
0.0
0016
3 0
.000
012
0.0
0001
9 0
.000
012
0.0
0003
0 0
.000
009
0.0
2717
6 0
.000
272
T
able
9.2
6: In
terc
ept v
alue
s for
MA
DE
RA
S-00
3
Inte
rcep
t V
alue
s 36
Ar
1σ
r2
37
Ar
1σ
r2
38
Ar
1σ
r2
BH
5951
7
20 °
C
0.00
0679
0.
0000
09
0.89
06
EX
P
7 of
8
0.00
1142
0.
0000
13
0.93
99
LIN
7
of 8
0.
0006
86
0.00
0012
0.
7761
E
XP
8
of 8
B
H59
52
785
°C
0.
0006
11
0.00
0004
0.
9519
P
AR
7
of 8
0.
0043
57
0.00
0041
0.
9392
E
XP
8
of 8
0.
0025
97
0.00
0038
0.
8565
E
XP
8
of 8
B
H59
53
845
°C
0.
0005
76
0.00
0003
0.
9441
LI
N
6 of
8
0.00
8561
0.
0000
40
0.98
45
EX
P
8 of
8
0.00
6482
0.
0000
67
0.91
38
EX
P
8 of
8
BH
5954
9
00 °
C
0.00
0427
0.
0000
04
0.40
70
EX
P
8 of
8
0.00
7728
0.
0000
32
0.99
03
EX
P
8 of
8
0.00
6532
0.
0000
51
0.96
60
EX
P
8 of
8
BH
5955
9
60 °
C
0.00
0353
0.
0000
07
A
VE
7
of 8
0.
0068
52
0.00
0028
0.
9888
E
XP
8
of 8
0.
0046
03
0.00
0036
0.
9412
E
XP
8
of 8
B
H59
56
1025
°C
0.
0003
10
0.00
0007
0.
6817
E
XP
8
of 8
0.
0042
85
0.00
0030
0.
9692
E
XP
8
of 8
0.
0020
42
0.00
0018
0.
9719
LI
N
7 of
8
BH
5957
10
95 °
C
0.00
0371
0.
0000
08
0.58
54
LIN
8
of 8
0.
0049
20
0.00
0032
0.
9760
E
XP
8
of 8
0.
0017
47
0.00
0012
0.
9800
E
XP
7
of 8
B
H59
58
1160
°C
0.
0003
38
0.00
0007
0.
8210
E
XP
8
of 8
0.
0032
23
0.00
0022
0.
9778
E
XP
8
of 8
0.
0008
01
0.00
0020
0.
7901
E
XP
8
of 8
B
H59
59
1225
°C
0.
0004
58
0.00
0011
0.
5925
E
XP
8
of 8
0.
0045
64
0.00
0051
0.
9268
E
XP
8
of 8
0.
0009
35
0.00
0019
0.
8804
LI
N
7 of
8
84
Table 9.26: Continued
39Ar 1σ r2 40Ar 1σ r2
0.048759 0.000085 0.9970 EXP 8 of 8 0.213808 0.000335 0.9977 PAR 8 of 8 0.224200 0.000117 0.9998 EXP 8 of 8 0.244521 0.000133 0.9997 LIN 6 of 8 0.583894 0.000271 0.9999 EXP 8 of 8 0.348832 0.000556 0.9955 EXP 8 of 8 0.557246 0.000558 0.9993 EXP 8 of 8 0.295523 0.000499 0.9943 EXP 6 of 8 0.384604 0.000588 0.9982 EXP 6 of 8 0.220112 0.000364 0.9937 EXP 8 of 8 0.152239 0.000219 0.9990 EXP 7 of 8 0.134441 0.000254 0.9954 EXP 7 of 8 0.120487 0.000288 0.9967 EXP 8 of 8 0.140865 0.000269 0.9961 EXP 8 of 8 0.041934 0.000128 0.9927 EXP 8 of 8 0.104278 0.000084 0.9996 PAR 6 of 8 0.051063 0.000157 0.9924 EXP 8 of 8 0.140689 0.000152 0.9991 LIN 6 of 8
Table 9.27: Sample parameters for MADERAS-003
Sample Parameters Sample Material Location Analyst
Tem
p
Standard %1σ J %1σ (in Ma)
BH5951 720 °C MAD003 groundmass UW93C43 Brian Jicha 720 28.201 0.08 0.0002623 0.14
BH5952 785 °C MAD003 groundmass UW93C43 Brian Jicha 785 28.201 0.08 0.0002623 0.14
BH5953 845 °C MAD003 groundmass UW93C43 Brian Jicha 845 28.201 0.08 0.0002623 0.14
BH5954 900 °C MAD003 groundmass UW93C43 Brian Jicha 900 28.201 0.08 0.0002623 0.14
BH5955 960 °C MAD003 groundmass UW93C43 Brian Jicha 960 28.201 0.08 0.0002623 0.14
BH5956 1025 °C MAD003 groundmass UW93C43 Brian Jicha 1025 28.201 0.08 0.0002623 0.14
BH5957 1095 °C MAD003 groundmass UW93C43 Brian Jicha 1095 28.201 0.08 0.0002623 0.14
BH5958 1160 °C MAD003 groundmass UW93C43 Brian Jicha 1160 28.201 0.08 0.0002623 0.14
BH5959 1225 °C MAD003 groundmass UW93C43 Brian Jicha 1225 28.201 0.08 0.0002623 0.14
Table 9.27: Continued
MDF %1σ Vol.
Ratio Sensitivity
Day
Mon
th
Yea
r
Hou
r
Min
Res
ist
Irradiation Project Experiment
Nm
b Standard
Name (mol/volt)
1.005474 0.02 1 5.902E-15 19 OCT 2011 20 36 001 UW93 UW93C UW93C43 01 FCS
1.005474 0.02 1 5.902E-15 19 OCT 2011 21 27 001 UW93 UW93C UW93C43 01 FCS
1.005474 0.02 1 5.902E-15 19 OCT 2011 22 17 001 UW93 UW93C UW93C43 01 FCS
1.005474 0.02 1 5.902E-15 19 OCT 2011 23 07 001 UW93 UW93C UW93C43 01 FCS
1.005474 0.02 1 5.902E-15 19 OCT 2011 23 58 001 UW93 UW93C UW93C43 01 FCS
1.005474 0.02 1 5.902E-15 20 OCT 2011 00 48 001 UW93 UW93C UW93C43 01 FCS
1.005474 0.02 1 5.902E-15 20 OCT 2011 01 38 001 UW93 UW93C UW93C43 01 FCS
1.005474 0.02 1 5.902E-15 20 OCT 2011 02 29 001 UW93 UW93C UW93C43 01 FCS
1.005474 0.02 1 5.902E-15 20 OCT 2011 03 19 001 UW93 UW93C UW93C43 01 FCS
85
Tab
le 9
.28:
Irra
diat
ion
cons
tant
s for
MA
DE
RA
S-00
3
Irra
diat
ion
Con
stan
ts
40/3
6(a)
%
1σ
40/3
6(c)
%
1σ
38/3
6(a)
%
1σ
38/3
6(c)
%
1σ
39/3
7(ca
) %
1σ
38/3
7 (c
a)
%1σ
36
/37(
ca)
%1σ
40
/39
(k)
%1σ
BH
5951
7
20 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5952
7
85 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5953
8
45 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5954
9
00 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5955
9
60 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5956
10
25 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5957
10
95 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5958
11
60 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5959
12
25 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
T
able
9.2
8: C
ontin
ued
38/3
9(k)
%
1σ
36/3
8(cl
) %
1σ
K/C
a %
1σ
K/C
l %
1σ
Ca/
Cl
%1σ
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0
86
157.5 ± 2.2 Ka
60
80
100
120
140
160
180
200
220
240
260
280
300
320
340
0 10 20 30 40 50 60 70 80 90 100
Cumulative 39Ar Released [ % ]
UW93C43.AGE >>> MAD003 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU157.5 ± 2.2TOTAL FUSION 157.7 ± 3.5NORMAL ISOCHRON 157.1 ± 3.6INVERSE ISOCHRON157.1 ± 1.8
MSWD0.21
Sample Info
groundmassUW93C43Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000037
Figure 9.5: Age plateau for MADERAS-003
0.67 ± 0.34
0.0
0.3
0.6
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
3.3
3.6
3.9
0 10 20 30 40 50 60 70 80 90 100Cumulative 39Ar Released [ % ]
UW93C43.AGE >>> MAD003 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU157.5 ± 2.2TOTAL FUSION 157.7 ± 3.5NORMAL ISOCHRON 157.1 ± 3.6INVERSE ISOCHRON157.1 ± 1.8
Sample Info
groundmassUW93C43Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000037
Figure 9.6: K-Ca plateau for MADERAS-003
87
0
100
200
300
400
500
600
700
800
900
1000
1100
0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200
39Ar / 36Ar
UW93C43.AGE >>> MAD003 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU157.5 ± 2.2TOTAL FUSION 157.7 ± 3.5NORMAL ISOCHRON 157.1 ± 3.6INVERSE ISOCHRON157.1 ± 1.8
MSWD0.23
40AR/36AR INTERCEPT296.2 ± 7.0
Sample Info
groundmassUW93C43Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000037
Figure 9.7: Normal isochron for MADERAS-003
0.0000
0.0005
0.0010
0.0015
0.0020
0.0025
0.0030
0.0035
0.0040
0.0045
0.0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3 3.6 3.9
39Ar / 40Ar
UW93C43.AGE >>> MAD003 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU157.5 ± 2.2TOTAL FUSION 157.7 ± 3.5NORMAL ISOCHRON 157.1 ± 3.6INVERSE ISOCHRON157.1 ± 1.8
MSWD0.23
40AR/36AR INTERCEPT296.3 ± 3.5
Sample Info
groundmassUW93C43Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000037
Figure 9.8: Inverse isochron for MADERAS-003
88 9.2.
3 Sa
mpl
e M
AD
ER
AS-
004
Tab
le 9
.29:
Incr
emen
tal h
eatin
g su
mm
ary
for
MA
DE
RA
S-00
4
Incr
emen
tal
Hea
ting
36
Ar(
a)
37A
r(ca
) 38
Ar(
cl)
39A
r(k)
40
Ar(
r)
Age
±
2σ
40A
r(r)
39
Ar(
k)
K/C
a ±
2σ
(Ka)
(%
) (%
)
BH
5991
6
75 °
C
0.0
0377
7 0
.046
903
0.0
0008
2 0
.023
839
0.
0029
37
59.1
±
225.
5 0
.26
4.9
7 0.
219
± 0.
012
BH
5992
7
20 °
C
0.0
0168
8 0
.031
165
0.0
0007
4 0
.012
243
0.
0077
36
303.
4 ±
436.
5 1
.53
2.5
5 0.
169
± 0.
009
BH
5993
7
85 °
C
0.0
0308
1 0
.138
734
0.0
0005
1 0
.047
412
0.
0160
62
162.
7 ±
147.
7 1
.73
9.8
8 0.
147
± 0.
008
BH
5994
8
30 °
C
0.0
0158
7 0
.078
312
0.0
0000
0 0
.032
112
0.
0092
96
139.
0 ±
160.
0 1
.94
6.6
9 0.
176
± 0.
009
BH
5995
8
75 °
C
0.0
0177
9 0
.137
666
0.0
0000
0 0
.062
204
0.
0182
94
141.
2 ±
66.9
3
.36
12.
96
0.19
4 ±
0.01
0 B
H59
96
925
°C
0
.001
863
0.2
0354
8 0
.000
000
0.0
9410
3
0.02
5853
13
1.9
± 46
.6
4.4
9 1
9.60
0.
199
± 0.
010
BH
5997
9
80 °
C
0.0
0183
4 0
.238
072
0.0
0006
5 0
.090
463
0.
0241
65
128.
3 ±
31.5
4
.27
18.
85
0.16
3 ±
0.00
8 B
H59
98
1050
°C
0
.002
292
0.2
2561
2 0
.000
094
0.0
5642
3
0.01
3410
11
4.1
± 92
.0
1.9
4 1
1.75
0.
108
± 0.
006
BH
5999
11
40 °
C
0.0
0469
8 0
.198
125
0.0
0020
8 0
.040
385
0.
0079
86
94.9
±
95.6
0
.57
8.4
1 0.
088
± 0.
005
BH
6000
12
25 °
C
0
.004
005
0.3
1239
1 0
.000
229
0.0
2083
8
0.00
0000
0.
0 ±
0.0
0.0
0 4
.34
0.02
9 ±
0.00
1
Σ 0
.026
603
1.6
1052
7 0
.000
802
0.4
8002
2
0.12
5738
T
able
9.2
9: C
ontin
ued
Info
rmat
ion
on A
naly
sis
R
esul
ts
40(r
)/39
(k)
± 2σ
A
ge
± 2σ
MSWD
39A
r(k)
K
/Ca
± 2σ
(Ka)
(%
,n)
Sam
ple
= M
AD
004
A
ge P
late
au
0.26
80
± 0.
0462
12
8.7
± 22
.2
0.25
95
.66
0.13
6 ±
0.03
1 M
ater
ial =
gro
undm
ass
±
17.2
5%
± 17
.25%
9
Loc
atio
n =
UW
93C
44
M
inim
al E
xter
nal E
rror
±
22.8
2.
31
Sta
tistic
al T
Rat
io
Ana
lyst
= B
rian
Jich
a
Ana
lytic
al E
rror
±
22.2
1.
0000
E
rror
Mag
nific
atio
n P
roje
ct =
UW
93C
M
ass
Dis
crim
inat
ion
Law
= L
IN
T
otal
Fus
ion
Age
0.
2619
±
0.06
43
125.
8 ±
30.9
10
0.12
8 ±
0.00
2 Ir
radi
atio
n =
UW
93
±
24.5
3%
± 24
.53%
J =
0.0
0026
230
± 0.
0000
0013
Min
imal
Ext
erna
l Err
or
± 31
.2
FC
S =
28.
201
± 0.
023
Ma
A
naly
tical
Err
or
± 30
.9
89
Table 9.30: Normal isochron table for MADERAS-004
Normal Isochron
39(k)/36(a) ± 2σ 40(a+r)/36(a) ± 2σ
r.i.
BH5991 675 °C 6.3 ± 0.1 296.3 ± 3.0 0.7818
BH5992 720 °C 7.3 ± 0.2 300.1 ± 6.7 0.9415
BH5993 785 °C 15.4 ± 0.3 300.7 ± 4.8 0.9593
BH5994 830 °C 20.2 ± 0.5 301.4 ± 6.9 0.9740
BH5995 875 °C 35.0 ± 0.6 305.8 ± 5.0 0.9836
BH5996 925 °C 50.5 ± 0.8 309.4 ± 5.1 0.9831
BH5997 980 °C 49.3 ± 0.5 308.7 ± 3.4 0.9407
BH5998 1050 °C 24.6 ± 0.4 301.3 ± 4.8 0.9842
BH5999 1140 °C 8.6 ± 0.1 297.2 ± 1.7 0.5689
BH6000 1225 °C 5.2 ± 0.1 295.5 ± 2.8 0.8536
Table 9.30: Continued
Results 40(a)/36(a) ± 2σ 40(r)/39(k) ± 2σ Age ± 2σ
MS
WD
(Ka)
Normal Isochron
294.9624 ± 1.7393 0.2843 ± 0.0705 136.5 ± 33.8 0.23 ± 0.59% ± 24.79% ± 24.79%
Minimal External Error ± 34.3 Analytical Error ± 33.8
Statistics Statistical F ratio 2.01 Convergence 0.0000000009
Error Magnification 1.0000 Number of Iterations 6
Number of Data Points 9 Calculated Line Weighted York-2
Table 9.31: Inverse isochron table for MADERAS-004
Inverse Isochron
39(k)/40(a+r) ± 2σ 36(a)/40(a+r) ± 2σ
r.i.
BH5991 675 °C 0.021303 ± 0.000163 0.003375 ± 0.000034 0.0568
BH5992 720 °C 0.024171 ± 0.000190 0.003332 ± 0.000074 0.0420
BH5993 785 °C 0.051181 ± 0.000239 0.003325 ± 0.000053 0.0275
BH5994 830 °C 0.067141 ± 0.000349 0.003318 ± 0.000076 0.1212
BH5995 875 °C 0.114360 ± 0.000340 0.003270 ± 0.000054 0.1357
BH5996 925 °C 0.163266 ± 0.000496 0.003232 ± 0.000054 0.1112
BH5997 980 °C 0.159823 ± 0.000607 0.003240 ± 0.000035 0.1254
BH5998 1050 °C 0.081680 ± 0.000233 0.003318 ± 0.000053 0.0548
BH5999 1140 °C 0.028927 ± 0.000233 0.003365 ± 0.000019 0.0265
BH6000 1225 °C 0.017609 ± 0.000098 0.003384 ± 0.000032 0.0424
Table 9.31: Continued
Results 40(a)/36(a) ± 2σ 40(r)/39(k) ± 2σ Age ± 2σ
MS
WD
(Ka)
Inverse Isochron
294.9699 ± 0.8699 0.2842 ± 0.0348 136.5 ± 16.7 0.23 ± 0.29% ± 12.25% ± 12.25%
Minimal External Error ± 17.5 Analytical Error ± 16.7
Statistics Statistical F ratio 2.01 Convergence 0.0000000311
Error Magnification 1.0000 Number of Iterations 4
Number of Data Points 9 Calculated Line Weighted York-2
90
Tab
le 9
.32:
Rel
ativ
e ab
unda
nces
for
MA
DE
RA
S-00
4
Rel
ativ
e A
bund
ance
s
36A
r %
1σ
37A
r %
1σ
38A
r %
1σ
39A
r %
1σ
40A
r %
1σ
Age
±
2σ
40A
r(r)
39
Ar(
k)
K/C
a ±
2σ
(Ka)
(%
) (%
)
BH
5991
67
5°C
0.
0037
895
0.48
9 0.
0469
027
2.64
7 0.
0010
750
2.77
4 0.
0238
708
0.36
8 1.
1190
795
0.10
4 59
.1
± 22
5.5
0.26
4.
97
0.21
9 ±
0.01
2
BH
5992
72
0°C
0.
0016
962
1.10
2 0.
0311
651
2.65
9 0.
0005
368
3.09
4 0.
0122
642
0.36
9 0.
5065
342
0.13
6 30
3.4
± 43
6.5
1.53
2.
55
0.16
9 ±
0.00
9
BH
5993
78
5°C
0.
0031
172
0.78
8 0.
1387
339
2.65
8 0.
0011
987
2.37
1 0.
0475
051
0.22
2 0.
9263
583
0.07
2 16
2.7
± 14
7.7
1.73
9.
88
0.14
7 ±
0.00
8
BH
5994
83
0°C
0.
0016
077
1.11
0 0.
0783
120
2.65
3 0.
0006
670
4.81
6 0.
0321
643
0.17
7 0.
4782
722
0.18
9 13
9.0
± 16
0.0
1.94
6.
69
0.17
6 ±
0.00
9
BH
5995
87
5°C
0.
0018
151
0.79
6 0.
1376
659
2.56
5 0.
0010
414
2.29
0 0.
0622
964
0.07
4 0.
5439
288
0.12
9 14
1.2
± 66
.9
3.36
12
.96
0.19
4 ±
0.01
0
BH
5996
92
5°C
0.
0019
168
0.79
4 0.
2035
477
2.57
6 0.
0014
591
2.07
1 0.
0942
405
0.09
5 0.
5763
821
0.11
8 13
1.9
± 46
.6
4.49
19
.60
0.19
9 ±
0.01
0
BH
5997
98
0°C
0.
0018
965
0.50
9 0.
2380
724
2.59
6 0.
0014
983
2.23
8 0.
0906
229
0.15
1 0.
5660
188
0.11
4 12
8.3
± 31
.5
4.27
18
.85
0.16
3 ±
0.00
8
BH
5998
10
50°C
0.
0023
519
0.77
1 0.
2256
117
2.58
9 0.
0012
030
3.24
8 0.
0565
749
0.11
8 0.
6907
812
0.07
9 11
4.1
± 92
.0
1.94
11
.75
0.10
8 ±
0.00
6
BH
5999
11
40°C
0.
0047
498
0.28
0 0.
1981
247
2.60
4 0.
0015
734
0.95
6 0.
0405
179
0.39
8 1.
3960
979
0.05
6 94
.9
± 95
.6
0.57
8.
41
0.08
8 ±
0.00
5
BH
6000
12
25°C
0.00
4087
3 0.
448
0.31
2391
4 2.
579
0.00
1228
7 1.
470
0.02
1048
4 0.
264
1.18
3366
5 0.
074
0.0
± 0.
0 0.
00
4.34
0.
029
± 0.
001
Σ 0.
0270
280
0.20
2 1.
6105
274
0.92
9 0.
0114
814
0.76
4 0.
4811
055
0.06
1 7.
9868
195
0.03
1
T
able
9.3
2: C
ontin
ued
Info
rmat
ion
on A
naly
sis
and
Con
stan
ts U
sed
in C
alcu
latio
ns
Sam
ple
= M
AD
004
Ext
ract
ion
Met
hod
= U
ndef
ined
M
ater
ial =
gro
undm
ass
Hea
ting
= 90
0 se
c L
ocat
ion
= U
W93
C44
Is
olat
ion
= 15
.00
min
A
naly
st =
Bria
n Ji
cha
Inst
rum
ent =
MA
P21
5 P
roje
ct =
UW
93C
L
ithol
ogy
= U
ndef
ined
M
ass
Dis
crim
inat
ion
Law
= L
IN
Lat
-Lon
= U
ndef
ined
- U
ndef
ined
Ir
radi
atio
n =
UW
93
Age
Equ
atio
ns =
Con
vent
iona
l J
= 0
.000
2623
0 ±
0.00
0000
13
Neg
ativ
e In
tens
ities
= F
orce
d Z
ero
FC
S =
28.
201
± 0.
023
Ma
Dec
ay C
onst
ant 4
0K =
5.4
63 ±
0.1
07 E
-10
1/a
IGS
N =
Und
efin
ed
Dec
ay C
onst
ant 3
9Ar =
2.9
40 ±
0.0
29 E
-07
1/h
Pre
ferr
ed A
ge =
Und
efin
ed
Dec
ay C
onst
ant 3
7Ar =
8.2
30 ±
0.0
82 E
-04
1/h
Cla
ssifi
catio
n =
Und
efin
ed
No
36C
l Cor
rect
ion
Exp
erim
ent T
ype
= U
ndef
ined
N
o 36
Cl C
orre
ctio
n
91
Tab
le 9
.32:
Con
tinue
d
Res
ults
40
(r)/3
9(k)
±
2σ
Age
±
2σ
MSWD
39A
r(k)
K
/Ca
± 2σ
(K
a)
(%,n
)
Age
Pla
teau
0.
2680
±
0.04
62
128.
7 ±
22.2
0.
25
95.6
6 0.
136
± 0.
031
± 17
.25%
±
17.2
5%
9
Min
imal
Ext
erna
l Err
or
± 22
.8
2.31
S
tatis
tical
T R
atio
Ana
lytic
al E
rror
±
22.2
1.
0000
E
rror
Mag
nific
atio
n
Tot
al F
usio
n A
ge
0.26
19
± 0.
0643
12
5.8
± 30
.9
10
0.
128
± 0.
002
± 24
.53%
±
24.5
3%
Min
imal
Ext
erna
l Err
or
± 31
.2
Ana
lytic
al E
rror
±
30.9
Nor
mal
Is
ochr
on
0.28
43
± 0.
0705
13
6.5
± 33
.8
0.23
95
.66
± 24
.79%
±
24.7
9%
9
Min
imal
Ext
erna
l Err
or
± 34
.3
2.01
S
tatis
tical
F ra
tio
Ana
lytic
al E
rror
±
33.8
1.
0000
E
rror
Mag
nific
atio
n
Inve
rse
Isoc
hron
0.
2842
±
0.03
48
136.
5 ±
16.7
0.
23
95.6
6
±
12.2
5%
± 12
.25%
9
Min
imal
Ext
erna
l Err
or
± 17
.5
2.01
S
tatis
tical
F ra
tio
Ana
lytic
al E
rror
±
16.7
1.
0000
E
rror
Mag
nific
atio
n
T
able
9.3
3: D
egas
sing
pat
tern
s for
MA
DE
RA
S-00
4
Deg
assi
ng P
atte
rns
36
Ar(
a)
%1σ
36
Ar(
c)
%1σ
36
Ar(
ca)
%1σ
36
Ar(
cl)
%1σ
37
Ar(
ca)
%1σ
38
Ar(
a)
%1σ
38
Ar(
c)
%1σ
38
Ar(
k)
%1σ
BH
5991
6
75 °
C
0.00
3777
0.
49
0.00
0000
0
.00
0.
0000
12
2.6
5
0.00
0000
0
.00
0.
0469
03
2.6
5 0.
0007
06
0.4
9 0.
0000
00
0.0
0 0.
0002
88
0.3
7
BH
5992
7
20 °
C
0.00
1688
1.
11
0.00
0000
0
.00
0.
0000
08
2.6
6
0.00
0000
0
.00
0.
0311
65
2.6
6 0.
0003
15
1.1
1 0.
0000
00
0.0
0 0.
0001
48
0.3
7
BH
5993
7
85 °
C
0.00
3081
0.
80
0.00
0000
0
.00
0.
0000
37
2.6
6
0.00
0000
0
.00
0.
1387
34
2.6
6 0.
0005
76
0.8
0 0.
0000
00
0.0
0 0.
0005
72
0.2
2
BH
5994
8
30 °
C
0.00
1587
1.
12
0.00
0000
0
.00
0.
0000
21
2.6
5
0.00
0000
0
.00
0.
0783
12
2.6
5 0.
0002
97
1.1
2 0.
0000
00
0.0
0 0.
0003
87
0.1
8
BH
5995
8
75 °
C
0.00
1779
0.
81
0.00
0000
0
.00
0.
0000
36
2.5
6
0.00
0000
0
.00
0.
1376
66
2.5
6 0.
0003
32
0.8
1 0.
0000
00
0.0
0 0.
0007
50
0.0
7
BH
5996
9
25 °
C
0.00
1863
0.
82
0.00
0000
0
.00
0.
0000
54
2.5
8
0.00
0000
0
.00
0.
2035
48
2.5
8 0.
0003
48
0.8
2 0.
0000
00
0.0
0 0.
0011
35
0.1
0
BH
5997
9
80 °
C
0.00
1834
0.
53
0.00
0000
0
.00
0.
0000
63
2.6
0
0.00
0000
0
.00
0.
2380
72
2.6
0 0.
0003
43
0.5
3 0.
0000
00
0.0
0 0.
0010
91
0.1
5
BH
5998
10
50 °
C
0.00
2292
0.
79
0.00
0000
0
.00
0.
0000
60
2.5
9
0.00
0000
0
.00
0.
2256
12
2.5
9 0.
0004
28
0.7
9 0.
0000
00
0.0
0 0.
0006
80
0.1
2
BH
5999
11
40 °
C
0.00
4698
0.
28
0.00
0000
0
.00
0.
0000
52
2.6
0
0.00
0000
0
.00
0.
1981
25
2.6
0 0.
0008
78
0.2
8 0.
0000
00
0.0
0 0.
0004
87
0.4
0
BH
6000
12
25 °
C
0.
0040
05
0.46
0.
0000
00
0.0
0
0.00
0082
2
.58
0.
0000
00
0.0
0
0.31
2391
2
.58
0.00
0748
0
.46
0.00
0000
0
.00
0.00
0251
0
.27
Σ 0.
0266
03
0.21
0.
0000
00
0.0
0
0.00
0425
0
.93
0.
0000
00
0.0
0
1.61
0527
0
.93
0.00
4972
0
.21
0.00
0000
0
.00
0.00
5789
0
.06
Σ
0.02
7028
0
.20
1.
6105
27
0.9
3
92
Tab
le 9
.33:
Con
tinue
d
38A
r(ca
) %
1σ
38A
r(cl
) %
1σ
39A
r(k)
%
1σ
39A
r(ca
) %
1σ
40A
r(r)
%
1σ
40A
r(a)
%
1σ
40A
r(c)
%
1σ
40A
r(k)
%
1σ
0.00
0000
0
.00
0.
0000
82
36.
83
0.
0238
39
0.3
7
0.00
0032
2
.65
0.
0029
37
190.
61
1.
1161
43
0.4
9
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
74
23.
06
0.
0122
43
0.3
7
0.00
0021
2
.66
0.
0077
36
71.
94
0.
4987
98
1.1
1
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
51
56.
28
0.
0474
12
0.2
2
0.00
0093
2
.66
0.
0160
62
45.
39
0.
9102
96
0.8
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.03
2112
0
.18
0.
0000
53
2.6
5
0.00
9296
5
7.57
0.46
8977
1
.12
0.
0000
00
0.0
0
0.00
0000
0
.00
0.00
0000
0
.00
0.
0000
00
0.0
0
0.06
2204
0
.07
0.
0000
93
2.5
6
0.01
8294
2
3.69
0.52
5634
0
.81
0.
0000
00
0.0
0
0.00
0000
0
.00
0.00
0000
0
.00
0.
0000
00
0.0
0
0.09
4103
0
.10
0.
0001
37
2.5
8
0.02
5853
1
7.66
0.55
0529
0
.82
0.
0000
00
0.0
0
0.00
0000
0
.00
0.00
0000
0
.00
0.
0000
65
52.
02
0.
0904
63
0.1
5
0.00
0160
2
.60
0.
0241
65
12.
27
0.
5418
54
0.5
3
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
94
41.
66
0.
0564
23
0.1
2
0.00
0152
2
.59
0.
0134
10
40.
29
0.
6773
72
0.7
9
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0002
08
7.3
7
0.04
0385
0
.40
0.
0001
33
2.6
0
0.00
7986
5
0.33
1.38
8112
0
.28
0.
0000
00
0.0
0
0.00
0000
0
.00
0.00
0000
0
.00
0.
0002
29
8.0
4
0.02
0838
0
.27
0.
0002
10
2.5
8
0.00
0000
0
.00
1.
1834
20
0.4
6
0.00
0000
0
.00
0.
0000
00
0.0
0
0.
0008
02
9.0
4
0.48
0022
0
.06
0.
0010
84
0.9
3
0.12
5738
1
2.27
7.86
1135
0
.21
0.
0000
00
0.0
0
0.00
0000
0
.00
0.00
0000
0
.00
0.
0115
64
0.6
3
0.48
1106
0
.06
7.
9868
73
0.2
8
T
able
9.3
4: A
dditi
onal
par
amet
ers f
or M
AD
ER
AS-
004
Add
ition
al
Par
amet
ers
40
(r)/
39(k
) 1σ
40
(r+a
) 1σ
40
Ar/
39A
r 1σ
37
Ar/
39A
r 1σ
36
Ar/
39A
r 1σ
T
ime
(day
s)
BH
5991
6
75 °
C
0.1
2318
2
0.23
480
1.1
1908
0
0.00
117
46.
8806
99
0.
1794
0 1
.964
859
0.
0525
0 0
.158
751
0.
0009
7 1
28.9
48
BH
5992
7
20 °
C
0.6
3185
3
0.45
458
0.5
0653
4
0.00
069
41.
3018
48
0.
1623
8 2
.541
141
0.
0682
1 0
.138
306
0.
0016
1 1
28.9
83
BH
5993
7
85 °
C
0.3
3878
6
0.15
378
0.9
2635
8
0.00
067
19.
5001
91
0.
0455
0 2
.920
401
0.
0779
0 0
.065
617
0.
0005
4 1
29.0
18
BH
5994
8
30 °
C
0.2
8947
9
0.16
667
0.4
7827
2
0.00
091
14.
8696
43
0.
0385
7 2
.434
747
0.
0647
3 0
.049
985
0.
0005
6 1
29.0
53
BH
5995
8
75 °
C
0.2
9410
4
0.06
968
0.5
4392
9
0.00
070
8.7
3130
0
0.01
297
2.2
0985
2
0.05
671
0.0
2913
7
0.00
023
129
.088
B
H59
96
925
°C
0
.274
733
0.
0485
2 0
.576
382
0.
0006
8 6
.116
078
0.
0092
9 2
.159
875
0.
0556
7 0
.020
339
0.
0001
6 1
29.1
23
BH
5997
9
80 °
C
0.2
6712
5
0.03
279
0.5
6601
9
0.00
065
6.2
4586
6
0.01
184
2.6
2706
5
0.06
832
0.0
2092
8
0.00
011
129
.158
B
H59
98
1050
°C
0
.237
661
0.
0957
6 0
.690
781
0.
0005
5 1
2.21
0023
0.01
734
3.9
8783
9
0.10
336
0.0
4157
1
0.00
032
129
.193
B
H59
99
1140
°C
0
.197
743
0.
0995
3 1
.396
098
0.
0007
8 3
4.45
6287
0.13
844
4.8
8980
0
0.12
880
0.1
1722
7
0.00
057
129
.228
B
H60
00
1225
°C
0.0
0000
0
0.00
000
1.1
8336
7
0.00
088
56.
2213
10
0.
1540
6 1
4.84
1599
0.38
470
0.1
9418
5
0.00
101
129
.263
93
Tab
le 9
.34:
Con
tinue
d
37A
r (d
ecay
) 39
Ar
(dec
ay)
40A
r (m
oles
)
12.7
7373
005
1.00
0910
42
6.60
5E-1
5 12
.782
6690
3 1.
0009
1067
2.
990E
-15
12.7
9143
882
1.00
0910
91
5.46
7E-1
5 12
.800
2146
3 1.
0009
1116
2.
823E
-15
12.8
0917
215
1.00
0911
41
3.21
0E-1
5 12
.817
9601
2 1.
0009
1165
3.
402E
-15
12.8
2675
412
1.00
0911
90
3.34
1E-1
5 12
.835
7302
1 1.
0009
1215
4.
077E
-15
12.8
4453
641
1.00
0912
39
8.24
0E-1
5 12
.853
3486
4 1.
0009
1264
6.
984E
-15
T
able
9.3
5: P
roce
dure
Bla
nks f
or M
AD
ER
AS-
004
Pro
cedu
re
Bla
nks
36A
r 1σ
37
Ar
1σ
38A
r 1σ
39
Ar
1σ
40A
r 1σ
BH
5991
6
75 °
C
0.0
0005
7 0
.000
008
0.0
0000
1 0
.000
009
0.0
0001
1 0
.000
013
0.0
0000
2 0
.000
011
0.0
1487
5 0
.000
529
BH
5992
7
20 °
C
0.0
0005
7 0
.000
008
0.0
0000
5 0
.000
010
0.0
0001
2 0
.000
013
0.0
0000
5 0
.000
012
0.0
1520
8 0
.000
576
BH
5993
7
85 °
C
0.0
0005
6 0
.000
008
0.0
0001
2 0
.000
010
0.0
0001
4 0
.000
013
0.0
0001
2 0
.000
012
0.0
1546
5 0
.000
576
BH
5994
8
30 °
C
0.0
0005
6 0
.000
008
0.0
0001
7 0
.000
010
0.0
0001
5 0
.000
013
0.0
0002
1 0
.000
012
0.0
1572
6 0
.000
576
BH
5995
8
75 °
C
0.0
0005
8 0
.000
008
0.0
0002
3 0
.000
010
0.0
0001
6 0
.000
013
0.0
0003
2 0
.000
012
0.0
1605
4 0
.000
576
BH
5996
9
25 °
C
0.0
0006
0 0
.000
008
0.0
0003
0 0
.000
010
0.0
0001
7 0
.000
013
0.0
0004
3 0
.000
012
0.0
1650
0 0
.000
576
BH
5997
9
80 °
C
0.0
0006
4 0
.000
008
0.0
0003
9 0
.000
010
0.0
0001
8 0
.000
013
0.0
0005
2 0
.000
012
0.0
1708
7 0
.000
576
BH
5998
10
50 °
C
0.0
0006
9 0
.000
007
0.0
0005
2 0
.000
010
0.0
0001
8 0
.000
012
0.0
0005
0 0
.000
008
0.0
1769
7 0
.000
527
BH
5999
11
40 °
C
0.0
0007
7 0
.000
007
0.0
0006
9 0
.000
010
0.0
0001
5 0
.000
012
0.0
0003
6 0
.000
008
0.0
1971
9 0
.000
527
BH
6000
12
25 °
C
0.0
0008
5 0
.000
007
0.0
0007
3 0
.000
010
0.0
0001
1 0
.000
012
0.0
0003
7 0
.000
008
0.0
2208
6 0
.000
527
94
Tab
le 9
.36:
Inte
rcep
t val
ues f
or M
AD
ER
AS-
004
Inte
rcep
t V
alue
s 36
Ar
1σ
r2
37
Ar
1σ
r2
38
Ar
1σ
r2
BH
5991
6
75 °
C
0.0
0392
4 0
.000
017
0.98
67
EX
P
8 of
8
0.0
0372
9 0
.000
025
0.96
29
EX
P
8 of
8
0.0
0109
7 0
.000
027
0.44
04
EX
P
8 of
8
BH
5992
7
20 °
C
0.0
0178
7 0
.000
017
0.92
09
LIN
8
of 8
0
.002
480
0.0
0001
5 0.
9646
E
XP
8
of 8
0
.000
555
0.0
0001
1 0.
8599
E
XP
7
of 8
B
H59
93
785
°C
0
.003
237
0.0
0002
4 0.
9589
E
XP
8
of 8
0
.011
023
0.0
0008
2 0.
9669
E
XP
8
of 8
0
.001
225
0.0
0002
6 0.
6078
E
XP
8
of 8
B
H59
94
830
°C
0
.001
697
0.0
0001
6 0.
9388
LI
N
6 of
8
0.0
0622
8 0
.000
044
0.95
96
EX
P
8 of
8
0.0
0068
9 0
.000
030
0.10
10
EX
P
8 of
8
BH
5995
8
75 °
C
0.0
0191
0 0
.000
012
0.96
69
EX
P
8 of
8
0.0
1093
4 0
.000
026
0.99
60
EX
P
8 of
8
0.0
0106
8 0
.000
020
0.29
58
LIN
8
of 8
B
H59
96
925
°C
0
.002
016
0.0
0001
3 0.
9784
LI
N
6 of
8
0.0
1615
2 0
.000
055
0.99
26
EX
P
8 of
8
0.0
0149
1 0
.000
028
0.72
44
EX
P
8 of
8
BH
5997
9
80 °
C
0.0
0199
9 0
.000
006
0.99
35
EX
P
8 of
8
0.0
1888
3 0
.000
088
0.98
57
EX
P
8 of
8
0.0
0153
2 0
.000
031
0.77
19
EX
P
8 of
8
BH
5998
10
50 °
C
0.0
0246
9 0
.000
017
0.97
20
LIN
7
of 8
0
.017
897
0.0
0007
5 0.
9860
E
XP
8
of 8
0
.001
234
0.0
0003
8 0.
3378
E
XP
8
of 8
B
H59
99
1140
°C
0
.004
923
0.0
0001
0 0.
9975
E
XP
7
of 8
0
.015
729
0.0
0007
8 0.
9838
E
XP
8
of 8
0
.001
605
0.0
0000
9 0.
8885
LI
N
7 of
8
BH
6000
12
25 °
C
0.0
0425
5 0
.000
017
0.98
87
LIN
8
of 8
0
.024
749
0.0
0008
5 0.
9908
E
XP
8
of 8
0
.001
252
0.0
0001
4 0.
5297
E
XP
8
of 8
T
able
9.3
6: C
ontin
ued
39A
r 1σ
r2
40A
r 1σ
r2
0.0
2397
2 0
.000
087
0.98
37
LIN
7
of 8
1
.133
954
0.0
0104
3 0.
9991
E
XP
8
of 8
0
.012
320
0.0
0004
4 0.
9763
LI
N
8 of
8
0.5
2174
3 0
.000
375
0.99
95
EX
P
8 of
8
0.0
4771
5 0
.000
104
0.96
05
EX
P
8 of
8
0.9
4182
3 0
.000
332
0.99
99
EX
P
8 of
8
0.0
3232
0 0
.000
055
0.98
61
EX
P
8 of
8
0.4
9399
8 0
.000
699
0.99
79
EX
P
8 of
8
0.0
6258
8 0
.000
040
0.99
95
EX
P
6 of
8
0.5
5998
3 0
.000
399
0.99
96
EX
P
7 of
8
0.0
9467
6 0
.000
085
0.99
91
EX
P
8 of
8
0.5
9288
2 0
.000
364
0.99
96
EX
P
8 of
8
0.0
9105
3 0
.000
135
0.99
74
EX
P
8 of
8
0.5
8310
6 0
.000
291
0.99
97
EX
P
4 of
8
0.0
5686
1 0
.000
064
0.99
62
EX
P
7 of
8
0.7
0847
8 0
.000
141
1.00
00
EX
P
6 of
8
0.0
4072
3 0
.000
161
0.81
06
EX
P
8 of
8
1.4
1581
7 0
.000
570
0.99
98
LIN
8
of 8
0
.021
173
0.0
0005
5 0.
9960
E
XP
7
of 8
1
.205
453
0.0
0070
2 0.
9997
E
XP
8
of 8
95
Tab
le 9
.37:
Sam
ple
para
met
ers f
or M
AD
ER
AS-
004
Sam
ple
Par
amet
ers
Sam
ple
Mat
eria
l Lo
catio
n A
naly
st
Temp
Sta
ndar
d %
1σ
J %
1σ
MD
F %
1σ
(in M
a)
BH
5991
6
75 °
C
MA
D00
4 gr
ound
mas
s U
W93
C44
B
rian
Jich
a 67
5 28
.201
0.
08
0.00
0262
3 0.
05
1.00
5096
0.
03
BH
5992
7
20 °
C
MA
D00
4 gr
ound
mas
s U
W93
C44
B
rian
Jich
a 72
0 28
.201
0.
08
0.00
0262
3 0.
05
1.00
5096
0.
03
BH
5993
7
85 °
C
MA
D00
4 gr
ound
mas
s U
W93
C44
B
rian
Jich
a 78
5 28
.201
0.
08
0.00
0262
3 0.
05
1.00
5096
0.
03
BH
5994
8
30 °
C
MA
D00
4 gr
ound
mas
s U
W93
C44
B
rian
Jich
a 83
0 28
.201
0.
08
0.00
0262
3 0.
05
1.00
5096
0.
03
BH
5995
8
75 °
C
MA
D00
4 gr
ound
mas
s U
W93
C44
B
rian
Jich
a 87
5 28
.201
0.
08
0.00
0262
3 0.
05
1.00
5096
0.
03
BH
5996
9
25 °
C
MA
D00
4 gr
ound
mas
s U
W93
C44
B
rian
Jich
a 92
5 28
.201
0.
08
0.00
0262
3 0.
05
1.00
5096
0.
03
BH
5997
9
80 °
C
MA
D00
4 gr
ound
mas
s U
W93
C44
B
rian
Jich
a 98
0 28
.201
0.
08
0.00
0262
3 0.
05
1.00
5096
0.
03
BH
5998
10
50 °
C
MA
D00
4 gr
ound
mas
s U
W93
C44
B
rian
Jich
a 10
50
28.2
01
0.08
0.
0002
623
0.05
1.
0050
96
0.03
B
H59
99
1140
°C
M
AD
004
grou
ndm
ass
UW
93C
44
Bria
n Ji
cha
1140
28
.201
0.
08
0.00
0262
3 0.
05
1.00
5096
0.
03
BH
6000
12
25 °
C
MA
D00
4 gr
ound
mas
s U
W93
C44
B
rian
Jich
a 12
25
28.2
01
0.08
0.
0002
623
0.05
1.
0050
96
0.03
T
able
9.3
7: C
ontin
ued
Vol
ume
Rat
io
Sen
sitiv
ity
Day
Month
Year
Hour
Min
Resist
Irra
diat
ion
Pro
ject
E
xper
imen
t
Nmb
Sta
ndar
d N
ame
(mol
/vol
t)
1 5.
902E
-15
21
OC
T
2011
15
56
00
1 U
W93
U
W93
C
UW
93C
44
01
FC
S
1 5.
902E
-15
21
OC
T
2011
16
47
00
1 U
W93
U
W93
C
UW
93C
44
01
FC
S
1 5.
902E
-15
21
OC
T
2011
17
37
00
1 U
W93
U
W93
C
UW
93C
44
01
FC
S
1 5.
902E
-15
21
OC
T
2011
18
27
00
1 U
W93
U
W93
C
UW
93C
44
01
FC
S
1 5.
902E
-15
21
OC
T
2011
19
18
00
1 U
W93
U
W93
C
UW
93C
44
01
FC
S
1 5.
902E
-15
21
OC
T
2011
20
08
00
1 U
W93
U
W93
C
UW
93C
44
01
FC
S
1 5.
902E
-15
21
OC
T
2011
20
58
00
1 U
W93
U
W93
C
UW
93C
44
01
FC
S
1 5.
902E
-15
21
OC
T
2011
21
49
00
1 U
W93
U
W93
C
UW
93C
44
01
FC
S
1 5.
902E
-15
21
OC
T
2011
22
39
00
1 U
W93
U
W93
C
UW
93C
44
01
FC
S
1 5.
902E
-15
21
OC
T
2011
23
29
00
1 U
W93
U
W93
C
UW
93C
44
01
FC
S
96
Tab
le 9
.38:
Irra
diat
ion
Con
stan
ts fo
r M
AD
ER
AS-
004
Irra
diat
ion
C
onst
ants
40
/36(
a)
%1σ
40
/36(
c)
%1σ
38
/36(
a)
%1σ
38
/36(
c)
%1σ
39
/37(
ca)
%1σ
38
/37(
ca)
%1σ
36
/37
(ca)
%
1σ
40/3
9 (k
) %
1σ
BH
5991
6
75 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5992
7
20 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5993
7
85 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5994
8
30 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5995
8
75 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5996
9
25 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5997
9
80 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5998
10
50 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
5999
11
40 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
6000
12
25 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
T
able
9.3
8: C
ontin
ued
38/3
9(k)
%
1σ
36/3
8(cl
) %
1σ
K/C
a %
1σ
K/C
l %
1σ
Ca/
Cl
%1σ
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
97
128.7 ± 22.2 Ka
200
100
0
100
200
300
400
500
600
700
800
900
1000
0 10 20 30 40 50 60 70 80 90 100
Cumulative 39Ar Released [ % ]
UW93C44.AGE >>> MAD004 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU128.7 ± 22.2TOTAL FUSION 125.8 ± 30.9NORMAL ISOCHRON 136.5 ± 33.8INVERSE ISOCHRON136.5 ± 16.7
MSWD0.25
Sample Info
groundmassUW93C44Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000013
Figure 9.9: Age plateau for MADERAS-004
0.136 ± 0.031
0.00
0.03
0.07
0.10
0.13
0.17
0.20
0.23
0.27
0.30
0.33
0 10 20 30 40 50 60 70 80 90 100
Cumulative 39Ar Released [ % ]
UW93C44.AGE >>> MAD004 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU128.7 ± 22.2TOTAL FUSION 125.8 ± 30.9NORMAL ISOCHRON 136.5 ± 33.8INVERSE ISOCHRON136.5 ± 16.7
Sample Info
groundmassUW93C44Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000013
Figure 9.10: K-Ca plateau for MADERAS-004
98
0
30
60
90
120
150
180
210
240
270
300
330
360
390
0 5 10 15 20 25 30 35 40 45 50 55 60 65
39Ar / 36Ar
UW93C44.AGE >>> MAD004 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU128.7 ± 22.2TOTAL FUSION 125.8 ± 30.9NORMAL ISOCHRON 136.5 ± 33.8INVERSE ISOCHRON136.5 ± 16.7
MSWD0.23
40AR/36AR INTERCEPT295.0 ± 1.7
Sample Info
groundmassUW93C44Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000013
Figure 9.11: Normal isochron for MADERAS-004
0.0000
0.0005
0.0010
0.0015
0.0020
0.0025
0.0030
0.0035
0.0040
0.0045
0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20
39Ar / 40Ar
UW93C44.AGE >>> MAD004 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU128.7 ± 22.2TOTAL FUSION 125.8 ± 30.9NORMAL ISOCHRON 136.5 ± 33.8INVERSE ISOCHRON136.5 ± 16.7
MSWD0.23
40AR/36AR INTERCEPT295.0 ± 0.9
Sample Info
groundmassUW93C44Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000013
Figure 9.12: Inverse isochron for MADERAS-004
99 9.2.
4 Sa
mpl
e M
AD
ER
AS-
011
T
able
9.3
9: In
crem
enta
l hea
ting
sum
mar
y fo
r M
AD
ER
AS-
011
Incr
emen
tal
Hea
ting
36
Ar(
a)
37A
r(ca
) 38
Ar(
cl)
39A
r(k)
40
Ar(
r)
Age
±
2σ
40A
r(r)
39
Ar(
k)
K/C
a ±
2σ
(Ka)
(%
) (%
) B
H60
60
740
°C
0
.000
124
0.0
2301
9 0
.000
003
0.0
1568
8
0.00
3512
10
7.5
± 16
6.0
8.7
3 1
.51
0.29
3 ±
0.01
8 B
H60
61
800
°C
0
.000
228
0.0
7009
3 0
.000
000
0.0
5583
2
0.01
9952
17
1.6
± 44
.8
22.
87
5.3
9 0.
343
± 0.
018
BH
6062
8
50 °
C
0.0
0030
9 0
.121
757
0.0
0000
0 0
.125
356
0.
0454
82
174.
2 ±
21.9
3
3.23
1
2.09
0.
443
± 0.
024
BH
6063
9
00 °
C
0.0
0044
4 0
.166
247
0.0
0000
0 0
.200
783
0.
0730
28
174.
6 ±
12.5
3
5.77
1
9.37
0.
519
± 0.
028
BH
6064
9
50 °
C
0.0
0037
7 0
.157
022
0.0
0000
0 0
.212
810
0.
0788
61
177.
9 ±
9.4
41.
42
20.
53
0.58
3 ±
0.03
1 B
H60
65
1010
°C
0
.000
495
0.1
8714
3 0
.000
000
0.2
0170
7
0.07
3853
17
5.8
± 17
.5
33.
53
19.
46
0.46
3 ±
0.02
4 B
H60
66
1080
°C
0
.000
590
0.1
6152
0 0
.000
071
0.1
1465
6
0.04
3542
18
2.3
± 19
.5
19.
98
11.
06
0.30
5 ±
0.01
6 B
H60
67
1160
°C
0
.000
744
0.1
0641
8 0
.000
170
0.0
5235
7
0.02
0646
18
9.3
± 80
.2
8.5
8 5
.05
0.21
2 ±
0.01
1 B
H60
68
1225
°C
0
.001
367
0.2
1559
2 0
.000
269
0.0
5735
6
0.02
0090
16
8.2
± 64
.2
4.7
4 5
.53
0.11
4 ±
0.00
6
Σ 0
.004
679
1.2
0881
0 0
.000
514
1.0
3654
4
0.37
8966
T
able
9.3
9: C
ontin
ued
Info
rmat
ion
on A
naly
sis
R
esul
ts
40(r
)/39
(k)
± 2σ
A
ge
± 2σ
MSWD
39A
r(k)
K
/Ca
± 2σ
(Ka)
(%
,n)
Sam
ple
= M
AD
011
A
ge P
late
au
0.36
82
± 0.
0128
17
6.8
± 6.
1 0.
19
100.
00
0.21
2 ±
0.09
1 M
ater
ial =
gro
undm
ass
±
3.47
%
± 3.
47%
9
Loc
atio
n =
UW
93C
47
M
inim
al E
xter
nal E
rror
±
9.2
2.31
S
tatis
tical
T R
atio
A
naly
st =
Bria
n Ji
cha
A
naly
tical
Err
or
± 6.
1 1.
0000
E
rror
Mag
nific
atio
n P
roje
ct =
UW
93C
Mas
s D
iscr
imin
atio
n La
w =
LIN
Tot
al F
usio
n A
ge
0.36
56
± 0.
0179
17
5.5
± 8.
6
9 0.
369
± 0.
007
Irra
diat
ion
= U
W93
± 4.
90%
±
4.90
%
J =
0.0
0026
230
± 0.
0000
0013
Min
imal
Ext
erna
l Err
or
± 11
.0
FC
S =
28.
201
± 0.
023
Ma
A
naly
tical
Err
or
± 8.
6
100
Table 9.40: Normal Isochron Table for MADERAS-011
Normal Isochron
39(k)/36(a) ± 2σ 40(a+r)/36(a) ± 2σ
r.i.
BH6060 740 °C 126.2 ± 18.5 323.8 ± 47.8 0.9914 BH6061 800 °C 245.3 ± 18.7 383.1 ± 29.4 0.9895 BH6062 850 °C 405.3 ± 25.1 442.5 ± 27.5 0.9935 BH6063 900 °C 452.5 ± 17.9 460.1 ± 18.2 0.9890 BH6064 950 °C 563.8 ± 20.8 504.4 ± 18.6 0.9923 BH6065 1010 °C 407.2 ± 20.4 444.6 ± 22.3 0.9958 BH6066 1080 °C 194.3 ± 5.1 369.3 ± 9.8 0.9786 BH6067 1160 °C 70.3 ± 2.8 323.2 ± 12.8 0.9884 BH6068 1225 °C 42.0 ± 0.8 310.2 ± 5.9 0.9409
Table 9.40: Continued
Results 40(a)/36(a) ± 2σ 40(r)/39(k) ± 2σ Age ± 2σ
MS
WD
(Ka)
Normal Isochron
295.4061 ± 5.2321 0.3683 ± 0.0189 176.8 ± 9.1 0.23 ± 1.77% ± 5.14% ± 5.14%
Minimal External Error ± 11.4 Analytical Error ± 9.1
Statistics Statistical F ratio 2.01 Convergence 0.0000000023 Error Magnification 1.0000 Number of Iterations 17
Number of Data Points 9 Calculated Line Weighted York-2
Table 9.41: Inverse isochron table for MADERAS-011
Inverse Isochron
39(k)/40(a+r) ± 2σ 36(a)/40(a+r) ± 2σ
r.i.
BH6060 740 °C 0.389861 ± 0.007511 0.003089 ± 0.000456 0.1058 BH6061 800 °C 0.640108 ± 0.007115 0.002610 ± 0.000201 0.1346 BH6062 850 °C 0.915773 ± 0.006475 0.002260 ± 0.000140 0.0960 BH6063 900 °C 0.983482 ± 0.005769 0.002174 ± 0.000086 0.0831 BH6064 950 °C 1.117656 ± 0.005116 0.001983 ± 0.000073 0.0711 BH6065 1010 °C 0.915842 ± 0.004224 0.002249 ± 0.000113 0.0447 BH6066 1080 °C 0.526070 ± 0.002881 0.002708 ± 0.000072 0.1231 BH6067 1160 °C 0.217620 ± 0.001314 0.003094 ± 0.000123 0.0814 BH6068 1225 °C 0.135291 ± 0.000909 0.003224 ± 0.000061 0.0462
Table 9.41: Continued
Results 40(a)/36(a) ± 2σ 40(r)/39(k) ± 2σ Age ± 2σ
MS
WD
(Ka)
Inverse Isochron
295.4567 ± 2.6172 0.3683 ± 0.0095 176.8 ± 4.5 0.21 ± 0.89% ± 2.57% ± 2.57%
Minimal External Error ± 8.3 Analytical Error ± 4.5
Statistics Statistical F ratio 2.01 Convergence 0.0000013935 Error Magnification 1.0000 Number of Iterations 4
Number of Data Points 9 Calculated Line Weighted York-2
101
Tab
le 9
.42:
Rel
ativ
e ab
unda
nces
for
MA
DE
RA
S-01
1
Rel
ativ
e A
bund
ance
s
36A
r %
1σ
37A
r %
1σ
38A
r %
1σ
39A
r %
1σ
40A
r %
1σ
Age
±
2σ
40A
r(r)
39
Ar(
k)
K/C
a ±
2σ
(Ka)
(%
) (%
)
BH
6060
7
40 °
C
0.00
0130
4 6.
981
0.0
2301
92
3.00
0 0
.000
2159
5.
827
0.0
1570
33
0.42
0 0
.040
2394
0.
867
107.
5 ±
166.
0 8
.73
1.5
1 0.
293
± 0.
018
BH
6061
8
00 °
C
0.00
0246
2 3.
514
0.0
7009
31
2.66
8 0
.000
6623
4.
774
0.0
5587
93
0.14
6 0
.087
2230
0.
536
171.
6 ±
44.8
2
2.87
5
.39
0.34
3 ±
0.01
8
BH
6062
8
50 °
C
0.00
0341
5 2.
785
0.1
2175
69
2.66
0 0
.001
4062
1.
053
0.1
2543
75
0.14
0 0
.136
8849
0.
325
174.
2 ±
21.9
3
3.23
1
2.09
0.
443
± 0.
024
BH
6063
9
00 °
C
0.00
0487
6 1.
775
0.1
6624
65
2.65
3 0
.002
3439
1.
198
0.2
0089
52
0.19
4 0
.204
1555
0.
220
174.
6 ±
12.5
3
5.77
1
9.37
0.
519
± 0.
028
BH
6064
9
50 °
C
0.00
0418
9 1.
636
0.1
5702
17
2.65
5 0
.002
5520
1.
550
0.2
1291
56
0.14
9 0
.190
4073
0.
173
177.
9 ±
9.4
41.
42
20.
53
0.58
3 ±
0.03
1
BH
6065
10
10 °
C
0.00
0544
8 2.
260
0.1
8714
33
2.63
1 0
.002
5164
0.
458
0.2
0183
34
0.16
5 0
.220
2427
0.
161
175.
8 ±
17.5
3
3.53
1
9.46
0.
463
± 0.
024
BH
6066
10
80 °
C
0.00
0632
8 1.
207
0.1
6151
97
2.66
8 0
.001
5643
2.
054
0.1
1476
44
0.17
4 0
.217
9478
0.
211
182.
3 ±
19.5
1
9.98
1
1.06
0.
305
± 0.
016
BH
6067
11
60 °
C
0.00
0772
4 1.
898
0.1
0641
80
2.67
1 0
.000
9406
2.
162
0.0
5242
85
0.20
6 0
.240
5887
0.
221
189.
3 ±
80.2
8
.58
5.0
5 0.
212
± 0.
011
BH
6068
12
25 °
C
0.00
1423
6 0.
896
0.2
1559
21
2.65
3 0
.001
2159
2.
367
0.0
5750
08
0.31
3 0
.423
9441
0.
121
168.
2 ±
64.2
4
.74
5.5
3 0.
114
± 0.
006
Σ 0.
0049
982
0.61
9 1
.208
8104
0.
961
0.0
1341
75
0.58
4 1
.037
3580
0.
067
1.7
6163
34
0.07
5
T
able
9.4
2: C
ontin
ued
Info
rmat
ion
on A
naly
sis
and
Con
stan
ts U
sed
in C
alcu
latio
ns
Sam
ple
= M
AD
011
Ext
ract
ion
Met
hod
= U
ndef
ined
M
ater
ial =
gro
undm
ass
Hea
ting
= 90
0 se
c L
ocat
ion
= U
W93
C47
Is
olat
ion
= 15
.00
min
A
naly
st =
Bria
n Ji
cha
Inst
rum
ent =
MA
P21
5 P
roje
ct =
UW
93C
L
ithol
ogy
= U
ndef
ined
M
ass
Dis
crim
inat
ion
Law
= L
IN
Lat
-Lon
= U
ndef
ined
- U
ndef
ined
Ir
radi
atio
n =
UW
93
Age
Equ
atio
ns =
Con
vent
iona
l J
= 0
.000
2623
0 ±
0.00
0000
13
Neg
ativ
e In
tens
ities
= F
orce
d Z
ero
FC
S =
28.
201
± 0.
023
Ma
Dec
ay C
onst
ant 4
0K =
5.4
63 ±
0.1
07 E
-10
1/a
IGS
N =
Und
efin
ed
Dec
ay C
onst
ant 3
9Ar =
2.9
40 ±
0.0
29 E
-07
1/h
Pre
ferr
ed A
ge =
Und
efin
ed
Dec
ay C
onst
ant 3
7Ar =
8.2
30 ±
0.0
82 E
-04
1/h
Cla
ssifi
catio
n =
Und
efin
ed
No
36C
l Cor
rect
ion
Exp
erim
ent T
ype
= U
ndef
ined
N
o 36
Cl C
orre
ctio
n
102
Tab
le 9
.42:
Con
tinue
d
Res
ults
40
(r)/
39(k
) ±
2σ
Age
±
2σ
MSWD
39A
r(k)
K
/Ca
± 2σ
(K
a)
(%,n
)
Age
Pla
teau
0.
3682
±
0.01
28
176.
8 ±
6.1
0.19
10
0.00
0.
212
± 0.
091
± 3.
47%
±
3.47
%
9
Min
imal
Ext
erna
l Err
or
± 9.
2 2.
31
Sta
tistic
al T
Rat
io
Ana
lytic
al E
rror
±
6.1
1.00
00
Err
or M
agni
ficat
ion
Tot
al F
usio
n A
ge
0.36
56
± 0.
0179
17
5.5
± 8.
6
9 0.
369
± 0.
007
± 4.
90%
±
4.90
%
Min
imal
Ext
erna
l Err
or
± 11
.0
Ana
lytic
al E
rror
±
8.6
Nor
mal
Is
ochr
on
0.36
83
± 0.
0189
17
6.8
± 9.
1 0.
23
100.
00
± 5.
14%
±
5.14
%
9
Min
imal
Ext
erna
l Err
or
± 11
.4
2.01
S
tatis
tical
F ra
tio
Ana
lytic
al E
rror
±
9.1
1.00
00
Err
or M
agni
ficat
ion
Inve
rse
Isoc
hron
0.
3683
±
0.00
95
176.
8 ±
4.5
0.21
10
0.00
±
2.57
%
± 2.
57%
9
Min
imal
Ext
erna
l Err
or
± 8.
3 2.
01
Sta
tistic
al F
ratio
A
naly
tical
Err
or
± 4.
5 1.
0000
E
rror
Mag
nific
atio
n
T
able
9.4
3: D
egas
sing
pat
tern
s for
MA
DE
RA
S-01
1
Deg
assi
ng
Pat
tern
s
36A
r(a)
%
1σ
36A
r(c)
%
1σ
36A
r(ca
) %
1σ
36A
r(cl
) %
1σ
37A
r(ca
) %
1σ
38A
r(a)
%
1σ
38A
r(c)
%
1σ
38A
r(k)
%
1σ
BH
6060
7
40 °
C
0.00
0124
7
.32
0.00
0000
0
.00
0.00
0006
3
.00
0.00
0000
0
.00
0.02
3019
3
.00
0.
0000
23
7.3
2
0.00
0000
0
.00
0.
0001
89
0.4
2
BH
6061
8
00 °
C
0.00
0228
3
.81
0.00
0000
0
.00
0.00
0019
2
.67
0.00
0000
0
.00
0.07
0093
2
.67
0.
0000
43
3.8
1
0.00
0000
0
.00
0.
0006
73
0.1
5
BH
6062
8
50 °
C
0.00
0309
3
.09
0.00
0000
0
.00
0.00
0032
2
.66
0.00
0000
0
.00
0.12
1757
2
.66
0.
0000
58
3.0
9
0.00
0000
0
.00
0.
0015
12
0.1
4
BH
6063
9
00 °
C
0.00
0444
1
.97
0.00
0000
0
.00
0.00
0044
2
.65
0.00
0000
0
.00
0.16
6247
2
.65
0.
0000
83
1.9
7
0.00
0000
0
.00
0.
0024
21
0.1
9
BH
6064
9
50 °
C
0.00
0377
1
.84
0.00
0000
0
.00
0.00
0041
2
.66
0.00
0000
0
.00
0.15
7022
2
.66
0.
0000
71
1.8
4
0.00
0000
0
.00
0.
0025
66
0.1
5
BH
6065
10
10 °
C
0.00
0495
2
.50
0.00
0000
0
.00
0.00
0049
2
.63
0.00
0000
0
.00
0.18
7143
2
.63
0.
0000
93
2.5
0
0.00
0000
0
.00
0.
0024
33
0.1
7
BH
6066
10
80 °
C
0.00
0590
1
.31
0.00
0000
0
.00
0.00
0043
2
.67
0.00
0000
0
.00
0.16
1520
2
.67
0.
0001
10
1.3
1
0.00
0000
0
.00
0.
0013
83
0.1
7
BH
6067
11
60 °
C
0.00
0744
1
.97
0.00
0000
0
.00
0.00
0028
2
.67
0.00
0000
0
.00
0.10
6418
2
.67
0.
0001
39
1.9
7
0.00
0000
0
.00
0.
0006
31
0.2
1
BH
6068
12
25 °
C
0.00
1367
0
.94
0.00
0000
0
.00
0.00
0057
2
.65
0.00
0000
0
.00
0.21
5592
2
.65
0.
0002
55
0.9
4
0.00
0000
0
.00
0.
0006
92
0.3
1
Σ 0.
0046
79
0.6
6 0.
0000
00
0.0
0 0.
0003
19
0.9
6 0.
0000
00
0.0
0 1.
2088
10
0.9
6
0.00
0875
0
.66
0.
0000
00
0.0
0
0.01
2501
0
.07
Σ
0.
0049
98
0.6
3 1.
2088
10
0.9
6
103
Tab
le 9
.43:
Con
tinue
d
38A
r(ca
) %
1σ
38A
r(cl
) %
1σ
39A
r(k)
%
1σ
39A
r(ca
) %
1σ
40A
r(r)
%
1σ
40A
r(a)
%
1σ
40A
r(c)
%
1σ
40A
r(k)
%
1σ
0.
0000
00
0.0
0
0.00
0003
37
0.21
0.01
5688
0
.42
0.
0000
15
3.0
0
0.00
3512
7
7.22
0.03
6727
7
.32
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0558
32
0.1
5
0.00
0047
2
.67
0.
0199
52
13.
04
0.
0672
71
3.8
1
0.00
0000
0
.00
0.
0000
00
0.0
0
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
1253
56
0.1
4
0.00
0082
2
.66
0.
0454
82
6.2
8
0.09
1402
3
.09
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
2007
83
0.1
9
0.00
0112
2
.65
0.
0730
28
3.5
9
0.13
1127
1
.97
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
2128
10
0.1
5
0.00
0106
2
.66
0.
0788
61
2.6
4
0.11
1547
1
.84
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
2017
07
0.1
7
0.00
0126
2
.63
0.
0738
53
4.9
8
0.14
6390
2
.50
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0071
4
5.26
0.11
4656
0
.17
0.
0001
09
2.6
7
0.04
3542
5
.35
0.
1744
06
1.3
1
0.00
0000
0
.00
0.
0000
00
0.0
0
0.
0000
00
0.0
0
0.00
0170
1
2.09
0.05
2357
0
.21
0.
0000
72
2.6
7
0.02
0646
2
1.17
0.21
9943
1
.97
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0269
1
0.78
0.05
7356
0
.31
0.
0001
45
2.6
5
0.02
0090
1
9.07
0.40
3854
0
.94
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0514
9
.67
1.
0365
44
0.0
7
0.00
0814
0
.96
0.
3789
66
2.4
5
1.38
2668
0
.66
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0138
89
0.3
6
1.03
7358
0
.07
1.
7616
33
0.7
4
T
able
9.4
4: A
dditi
onal
par
amet
ers f
or M
AD
ER
AS-
011
Add
ition
al
Par
amet
ers
40
(r)/3
9(k)
1σ
40
(r+a
) 1σ
40
Ar/
39A
r 1σ
37
Ar/
39A
r 1σ
36
Ar/
39A
r 1σ
T
ime
(day
s)
37A
r (d
ecay
) 39
Ar
(dec
ay)
40A
r (m
oles
)
BH
6060
7
40 °
C
0.2
2387
8
0.17
289
0.0
4023
9
0.00
035
2.5
6248
6
0.02
468
1.4
6588
6
0.04
440
0.0
0830
2
0.00
058
132
.021
13
.573
0603
5 1.
0009
3212
2.
375E
-16
BH
6061
8
00 °
C
0.3
5735
3
0.04
661
0.0
8722
3
0.00
047
1.5
6091
7
0.00
867
1.2
5436
5
0.03
352
0.0
0440
5
0.00
015
132
.056
13
.582
3724
0 1.
0009
3237
5.
148E
-16
BH
6062
8
50 °
C
0.3
6282
8
0.02
279
0.1
3688
5
0.00
044
1.0
9126
0
0.00
386
0.9
7065
8
0.02
585
0.0
0272
2
0.00
008
132
.091
13
.591
8772
7 1.
0009
3262
8.
079E
-16
BH
6063
9
00 °
C
0.3
6371
8
0.01
307
0.2
0415
6
0.00
045
1.0
1622
9
0.00
298
0.8
2752
9
0.02
201
0.0
0242
7
0.00
004
132
.126
13
.601
2022
3 1.
0009
3286
1.
205E
-15
BH
6064
9
50 °
C
0.3
7056
8
0.00
978
0.1
9040
7
0.00
033
0.8
9428
5
0.00
205
0.7
3748
3
0.01
961
0.0
0196
8
0.00
003
132
.160
13
.610
5335
9 1.
0009
3311
1.
124E
-15
BH
6065
10
10 °
C
0.3
6613
7
0.01
823
0.2
2024
3
0.00
035
1.0
9121
0
0.00
252
0.9
2721
7
0.02
444
0.0
0269
9
0.00
006
132
.196
13
.620
0581
7 1.
0009
3336
1.
300E
-15
BH
6066
10
80 °
C
0.3
7976
0
0.02
031
0.2
1794
8
0.00
046
1.8
9908
9
0.00
520
1.4
0740
3
0.03
764
0.0
0551
4
0.00
007
132
.231
13
.629
4024
7 1.
0009
3360
1.
286E
-15
BH
6067
11
60 °
C
0.3
9433
6
0.08
348
0.2
4058
9
0.00
053
4.5
8889
5
0.01
384
2.0
2977
5
0.05
438
0.0
1473
2
0.00
028
132
.265
13
.638
7531
7 1.
0009
3385
1.
420E
-15
BH
6068
12
25 °
C
0.3
5026
6
0.06
682
0.4
2394
4
0.00
051
7.3
7283
8
0.02
472
3.7
4937
4
0.10
016
0.0
2475
8
0.00
024
132
.301
13
.648
2975
0 1.
0009
3410
2.
502E
-15
104
Tab
le 9
.45:
Pro
cedu
re B
lank
s for
MA
DE
RA
S-01
1
Pro
cedu
re
Bla
nks
36A
r 1σ
37
Ar
1σ
38A
r 1σ
39
Ar
1σ
40A
r 1σ
BH
6060
7
40 °
C
0.0
0004
3 0
.000
006
0.0
0000
6 0
.000
010
0.0
0002
7 0
.000
009
0.0
0001
7 0
.000
014
0.0
1324
2 0
.000
329
BH
6061
8
00 °
C
0.0
0004
4 0
.000
006
0.0
0000
8 0
.000
010
0.0
0002
2 0
.000
009
0.0
0001
7 0
.000
014
0.0
1365
0 0
.000
329
BH
6062
8
50 °
C
0.0
0004
5 0
.000
006
0.0
0000
9 0
.000
010
0.0
0001
9 0
.000
009
0.0
0001
7 0
.000
014
0.0
1399
0 0
.000
329
BH
6063
9
00 °
C
0.0
0004
6 0
.000
006
0.0
0001
1 0
.000
010
0.0
0001
7 0
.000
009
0.0
0001
8 0
.000
014
0.0
1433
0 0
.000
329
BH
6064
9
50 °
C
0.0
0004
7 0
.000
006
0.0
0001
4 0
.000
010
0.0
0001
5 0
.000
009
0.0
0001
9 0
.000
014
0.0
1467
0 0
.000
329
BH
6065
10
10 °
C
0.0
0004
8 0
.000
006
0.0
0001
7 0
.000
010
0.0
0001
3 0
.000
009
0.0
0002
1 0
.000
014
0.0
1507
8 0
.000
329
BH
6066
10
80 °
C
0.0
0005
0 0
.000
006
0.0
0002
1 0
.000
010
0.0
0001
3 0
.000
009
0.0
0002
3 0
.000
014
0.0
1555
4 0
.000
329
BH
6067
11
60 °
C
0.0
0005
1 0
.000
006
0.0
0002
6 0
.000
010
0.0
0001
4 0
.000
009
0.0
0002
7 0
.000
014
0.0
1609
8 0
.000
329
BH
6068
12
25 °
C
0.0
0005
2 0
.000
006
0.0
0003
1 0
.000
010
0.0
0001
6 0
.000
009
0.0
0003
1 0
.000
014
0.0
1654
0 0
.000
329
T
able
9.4
6: In
terc
ept v
alue
s for
MA
DE
RA
S-01
1
Inte
rcep
t V
alue
s 36
Ar
1σ
r2
37
Ar
1σ
r2
38
Ar
1σ
r2
BH
6060
7
40 °
C
0.00
0176
0.
0000
07
0.41
93
EX
P
8 of
8
0.00
1728
0
.000
023
0.89
01
EX
P
8 of
8
0.00
0245
0.
0000
09
0.70
94
EX
P
8 of
8
BH
6061
8
00 °
C
0.00
0295
0.
0000
07
0.80
20
EX
P
8 of
8
0.00
5248
0
.000
027
0.98
39
EX
P
8 of
8
0.00
0692
0.
0000
31
0.30
05
EX
P
8 of
8
BH
6062
8
50 °
C
0.00
0394
0.
0000
08
0.81
00
EX
P
8 of
8
0.00
9106
0
.000
045
0.98
49
EX
P
8 of
8
0.00
1440
0.
0000
12
0.94
50
EX
P
8 of
8
BH
6063
9
00 °
C
0.00
0544
0.
0000
07
0.88
28
EX
P
8 of
8
0.01
2423
0
.000
057
0.98
87
EX
P
8 of
8
0.00
2385
0.
0000
27
0.89
81
EX
P
8 of
8
BH
6064
9
50 °
C
0.00
0475
0.
0000
04
0.93
31
EX
P
6 of
8
0.01
1728
0
.000
055
0.98
50
EX
P
8 of
8
0.00
2593
0.
0000
39
0.82
74
EX
P
8 of
8
BH
6065
10
10 °
C
0.00
0604
0.
0000
11
0.53
02
EX
P
8 of
8
0.01
3969
0
.000
041
0.99
45
EX
P
8 of
8
0.00
2556
0.
0000
07
0.99
60
EX
P
8 of
8
BH
6066
10
80 °
C
0.00
0695
0.
0000
05
0.94
54
LIN
8
of 8
0.
0120
55
0.0
0006
4 0.
9844
E
XP
8
of 8
0.
0015
93
0.00
0031
0.
6417
E
XP
8
of 8
B
H60
67
1160
°C
0.
0008
39
0.00
0014
0.
8368
LI
N
8 of
8
0.00
7949
0
.000
042
0.98
47
EX
P
8 of
8
0.00
0964
0.
0000
18
0.84
96
EX
P
8 of
8
BH
6068
12
25 °
C
0.00
1505
0.
0000
11
0.98
26
PA
R
6 of
8
0.01
6071
0
.000
071
0.98
91
EX
P
8 of
8
0.00
1244
0.
0000
28
0.70
76
EX
P
8 of
8
105
Table 9.46: Continued
39Ar 1σ r2 40Ar 1σ r2
0.015786 0.000065 0.9760 EXP 6 of 8 0.053481 0.000116 0.9823 EXP 8 of 8 0.056131 0.000079 0.9988 EXP 7 of 8 0.100873 0.000333 0.9876 PAR 8 of 8 0.125982 0.000172 0.9987 EXP 8 of 8 0.150875 0.000299 0.9943 EXP 8 of 8 0.201758 0.000387 0.9975 EXP 8 of 8 0.218485 0.000305 0.9973 EXP 8 of 8 0.213829 0.000313 0.9985 EXP 8 of 8 0.205077 0.000029 1.0000 EXP 4 of 8 0.202702 0.000329 0.9981 EXP 8 of 8 0.235321 0.000131 0.9997 EXP 7 of 8 0.115270 0.000197 0.9979 EXP 8 of 8 0.233502 0.000323 0.9978 EXP 8 of 8 0.052676 0.000106 0.9967 EXP 8 of 8 0.256687 0.000417 0.9977 EXP 7 of 8 0.057773 0.000179 0.9872 LIN 8 of 8 0.440484 0.000395 0.9993 EXP 4 of 8
Table 9.47: Sample parameters for MADERAS-011
Sample Parameters Sample Material Location Analyst
Tem
p Standard %1σ J %1σ (in Ma)
BH6060 740 °C MAD011 groundmass UW93C47 Brian Jicha 740 28.201 0.08 0.0002623 0.05
BH6061 800 °C MAD011 groundmass UW93C47 Brian Jicha 800 28.201 0.08 0.0002623 0.05
BH6062 850 °C MAD011 groundmass UW93C47 Brian Jicha 850 28.201 0.08 0.0002623 0.05
BH6063 900 °C MAD011 groundmass UW93C47 Brian Jicha 900 28.201 0.08 0.0002623 0.05
BH6064 950 °C MAD011 groundmass UW93C47 Brian Jicha 950 28.201 0.08 0.0002623 0.05
BH6065 1010 °C MAD011 groundmass UW93C47 Brian Jicha 1010 28.201 0.08 0.0002623 0.05
BH6066 1080 °C MAD011 groundmass UW93C47 Brian Jicha 1080 28.201 0.08 0.0002623 0.05
BH6067 1160 °C MAD011 groundmass UW93C47 Brian Jicha 1160 28.201 0.08 0.0002623 0.05
BH6068 1225 °C MAD011 groundmass UW93C47 Brian Jicha 1225 28.201 0.08 0.0002623 0.05
Table 9.47: Continued
MDF %1σ Volume
Ratio Sensitivity
Day
Mon
th
Yea
r
Hou
r
Min
Res
ist
Irradiation Project Experimen
t Nm
b Standard
Name (mol/volt)
1.00515 0.03 1 5.902E-15 24 OCT 2011 17 41 001 UW93 UW93C UW93C47 01 FCS
1.00515 0.03 1 5.902E-15 24 OCT 2011 18 31 001 UW93 UW93C UW93C47 01 FCS
1.00515 0.03 1 5.902E-15 24 OCT 2011 19 22 001 UW93 UW93C UW93C47 01 FCS
1.00515 0.03 1 5.902E-15 24 OCT 2011 20 12 001 UW93 UW93C UW93C47 01 FCS
1.00515 0.03 1 5.902E-15 24 OCT 2011 21 02 001 UW93 UW93C UW93C47 01 FCS
1.00515 0.03 1 5.902E-15 24 OCT 2011 21 53 001 UW93 UW93C UW93C47 01 FCS
1.00515 0.03 1 5.902E-15 24 OCT 2011 22 43 001 UW93 UW93C UW93C47 01 FCS
1.00515 0.03 1 5.902E-15 24 OCT 2011 23 33 001 UW93 UW93C UW93C47 01 FCS
1.00515 0.03 1 5.902E-15 25 OCT 2011 00 24 001 UW93 UW93C UW93C47 01 FCS
106
Tab
le 9
.48:
Irra
diat
ion
cons
tant
s for
MA
DE
RA
S-01
1
Irra
diat
ion
Con
stan
ts
40/3
6(a)
%
1σ
40/3
6(c)
%
1σ
38/3
6(a)
%
1σ
38/3
6(c)
%
1σ
39/3
7(ca
) %
1σ
38/3
7(ca
) %
1σ
36/3
7(ca
) %
1σ
BH
6060
7
40 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
BH
6061
8
00 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
BH
6062
8
50 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
BH
6063
9
00 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
BH
6064
9
50 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
BH
6065
10
10 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
BH
6066
10
80 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
BH
6067
11
60 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
BH
6068
12
25 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
T
able
9.4
8: C
ontin
ued
40/3
9(k)
%
1σ
38/3
9(k)
%
1σ
36/3
8(cl
) %
1σ
K/C
a %
1σ
K/C
l %
1σ
Ca/
Cl
%1σ
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0
107
176.8 ± 6.1 Ka
50
0
50
100
150
200
250
300
350
400
0 10 20 30 40 50 60 70 80 90 100
Cumulative 39Ar Released [ % ]
UW93C47.AGE >>> MAD011 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU176.8 ± 6.1TOTAL FUSION 175.5 ± 8.6NORMAL ISOCHRON 176.8 ± 9.1INVERSE ISOCHRON176.8 ± 4.5
MSWD0.19
Sample Info
groundmassUW93C47Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000013
Figure 9.13: Age plateau for MADERAS-011
0.212 ± 0.091
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0 10 20 30 40 50 60 70 80 90 100
Cumulative 39Ar Released [ % ]
UW93C47.AGE >>> MAD011 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU176.8 ± 6.1TOTAL FUSION 175.5 ± 8.6NORMAL ISOCHRON 176.8 ± 9.1INVERSE ISOCHRON176.8 ± 4.5
Sample Info
groundmassUW93C47Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000013
Figure 9.14: K-Ca plateau for MADERAS-011
108
0
50
100
150
200
250
300
350
400
450
500
550
600
650
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700
39Ar / 36Ar
UW93C47.AGE >>> MAD011 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU176.8 ± 6.1TOTAL FUSION 175.5 ± 8.6NORMAL ISOCHRON 176.8 ± 9.1INVERSE ISOCHRON176.8 ± 4.5
MSWD0.23
40AR/36AR INTERCEPT295.4 ± 5.2
Sample Info
groundmassUW93C47Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000013
Figure 9.15: Normal isochron for MADERAS-011
0.0000
0.0005
0.0010
0.0015
0.0020
0.0025
0.0030
0.0035
0.0040
0.0045
0.0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3
39Ar / 40Ar
UW93C47.AGE >>> MAD011 >>> UW93C PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU176.8 ± 6.1TOTAL FUSION 175.5 ± 8.6NORMAL ISOCHRON 176.8 ± 9.1INVERSE ISOCHRON176.8 ± 4.5
MSWD0.21
40AR/36AR INTERCEPT295.5 ± 2.6
Sample Info
groundmassUW93C47Brian Jicha
IRR = UW93J = 0.00026230 ± 0.00000013
Figure 9.16: Inverse isochron for MADERAS-011
109 9.2.
5 Sa
mpl
e M
AD
ER
AS-
013
Tab
le 9
.49:
Incr
emen
tal h
eatin
g su
mm
ary
for
MA
DE
RA
S-01
3
Incr
emen
tal
Hea
ting
36
Ar(
a)
37A
r(ca
) 38
Ar(
cl)
39A
r(k)
40
Ar(
r)
Age
±
2σ
40A
r(r)
39
Ar(
k)
K/C
a ±
2σ
(Ka)
(%
) (%
) B
H60
76
675
°C
0
.000
044
0.0
0562
7 0
.000
000
0.0
3038
5
0.00
6506
10
0.1
± 68
.1
33.
16
1.6
2 2.
32
± 0.
25
BH
6077
7
40 °
C
0.0
0010
9 0
.015
823
0.0
0000
0 0
.091
692
0.
0180
62
92.1
±
27.4
3
5.99
4
.87
2.49
±
0.16
B
H60
78
800
°C
0
.000
280
0.0
5780
5 0
.000
000
0.3
4537
8
0.06
2318
84
.4
± 8.
0 4
3.00
1
8.36
2.
57
± 0.
14
BH
6079
8
50 °
C
0.0
0034
1 0
.081
124
0.0
0000
0 0
.455
868
0.
0847
35
86.9
±
5.8
45.
71
24.
24
2.42
±
0.13
B
H60
80
900
°C
0
.000
453
0.0
8634
2 0
.000
000
0.4
2979
6
0.07
6329
83
.0
± 5.
5 3
6.31
2
2.85
2.
14
± 0.
11
BH
6081
9
50 °
C
0.0
0064
1 0
.063
424
0.0
0000
0 0
.229
797
0.
0420
19
85.5
±
9.7
18.
16
12.
22
1.56
±
0.09
B
H60
82
1010
°C
0
.001
543
0.0
5218
0 0
.000
388
0.1
8417
9
0.03
4426
87
.4
± 10
.0
7.0
2 9
.79
1.52
±
0.08
B
H60
83
1080
°C
0
.001
969
0.0
3544
8 0
.000
176
0.0
9619
7
0.01
3979
67
.9
± 48
.6
2.3
5 5
.11
1.17
±
0.07
B
H60
84
1160
°C
0
.001
355
0.0
2460
1 0
.000
027
0.0
1589
4
0.00
2811
82
.7
± 21
3.4
0.7
0 0
.85
0.28
±
0.02
B
H60
85
1225
°C
0
.000
192
0.0
0802
2 0
.000
004
0.0
0177
6
0.00
1211
31
8.9
± 14
51.1
2
.09
0.0
9 0.
10
± 0.
01
Σ 0
.006
925
0.4
3039
6 0
.000
595
1.8
8096
1
0.34
2396
T
able
9.4
9: C
ontin
ued
Info
rmat
ion
on A
naly
sis
R
esul
ts
40(r
)/39
(k)
± 2σ
A
ge
± 2σ
MSWD
39A
r(k)
K
/Ca
± 2σ
(Ka)
(%
,n)
Sam
ple
= M
AD
013
A
ge P
late
au
0.18
22
± 0.
0067
85
.2
± 3.
1 0.
25
100.
00
0.19
±
0.22
M
ater
ial =
gro
undm
ass
±
3.69
%
± 3.
70%
10
Loc
atio
n =
UW
93D
48
M
inim
al E
xter
nal E
rror
±
4.6
2.26
S
tatis
tical
T R
atio
A
naly
st =
Bria
n Ji
cha
A
naly
tical
Err
or
± 3.
1 1.
0000
E
rror
Mag
nific
atio
n P
roje
ct =
UW
93D
Mas
s D
iscr
imin
atio
n La
w =
LIN
Tot
al F
usio
n A
ge
0.18
20
± 0.
0101
85
.1
± 4.
7
10
1.88
±
0.04
Ir
radi
atio
n =
UW
93
±
5.56
%
± 5.
56%
J =
0.0
0025
540
± 0.
0000
0020
Min
imal
Ext
erna
l Err
or
± 5.
8
F
CS
= 2
8.20
1 ±
0.02
3 M
a
Ana
lytic
al E
rror
±
4.7
110
Table 9.50: Normal isochron table for MADERAS-013
Normal Isochron
39(k)/36(a) ± 2σ 40(a+r)/36(a) ± 2σ
r.i.
BH6076 675 °C 684.8 ± 231.0 442.1 ± 149.2 0.9997 BH6077 740 °C 843.3 ± 141.0 461.6 ± 77.2 0.9995 BH6078 800 °C 1235.4 ± 87.9 518.4 ± 36.9 0.9995 BH6079 850 °C 1338.7 ± 74.9 544.3 ± 30.5 0.9990 BH6080 900 °C 948.5 ± 36.0 463.9 ± 17.6 0.9983 BH6081 950 °C 358.6 ± 9.0 361.1 ± 9.0 0.9926 BH6082 1010 °C 119.4 ± 1.1 317.8 ± 2.7 0.9413 BH6083 1080 °C 48.9 ± 0.8 302.6 ± 5.2 0.9921 BH6084 1160 °C 11.7 ± 0.2 297.6 ± 5.4 0.9250 BH6085 1225 °C 9.2 ± 0.9 301.8 ± 29.3 0.9731
Table 9.50: Continued
Results
40(a)/36(a) ± 2σ 40(r)/39(k) ± 2σ Age ± 2σ
MS
WD
(Ka)
Normal Isochron
295.5822 ± 2.3714 0.1818 ± 0.0082 85.0 ± 3.8 0.28 ± 0.80% ± 4.49% ± 4.49%
Minimal External Error ± 5.1 Analytical Error ± 3.8
Statistics Statistical F ratio 1.94 Convergence 0.0000000018 Error Magnification 1.0000 Number of Iterations 21
Number of Data Points 10 Calculated Line Weighted York-2
Table 9.51: Inverse isochron table for MADERAS-013
Inverse Isochron
39(k)/40(a+r) ± 2σ 36(a)/40(a+r) ± 2σ
r.i.
BH6076 675 °C 1.548944 ± 0.013157 0.002262 ± 0.000763 0.0183 BH6077 740 °C 1.826888 ± 0.009483 0.002166 ± 0.000362 0.0183 BH6078 800 °C 2.383012 ± 0.005496 0.001929 ± 0.000137 0.0207 BH6079 850 °C 2.459332 ± 0.006094 0.001837 ± 0.000103 0.0297 BH6080 900 °C 2.044369 ± 0.004511 0.002155 ± 0.000082 0.0290 BH6081 950 °C 0.993136 ± 0.003036 0.002770 ± 0.000069 0.0412 BH6082 1010 °C 0.375695 ± 0.001136 0.003146 ± 0.000027 0.0680 BH6083 1080 °C 0.161492 ± 0.000351 0.003305 ± 0.000057 0.0131 BH6084 1160 °C 0.039432 ± 0.000291 0.003360 ± 0.000061 0.0218 BH6085 1225 °C 0.030619 ± 0.000702 0.003313 ± 0.000322 0.0088
Table 9.51: Continued
Results 40(a)/36(a) ± 2σ 40(r)/39(k) ± 2σ Age ± 2σ
MS
WD
(Ka)
Inverse Isochron
295.5736 ± 1.1856 0.1820 ± 0.0041 85.1 ± 1.9 0.28 ± 0.40% ± 2.24% ± 2.24%
Minimal External Error ± 3.8 Analytical Error ± 1.9
Statistics Statistical F ratio 1.94 Convergence 0.0000000220 Error Magnification 1.0000 Number of Iterations 4
Number of Data Points 10 Calculated Line Weighted York-2
111
Tab
le 9
.52:
Rel
ativ
e ab
unda
nces
for
MA
DE
RA
S-01
3
Rel
ativ
e A
bund
ance
s
36A
r %
1σ
37A
r %
1σ
38A
r %
1σ
39A
r %
1σ
40A
r %
1σ
Age
±
2σ
40A
r(r)
39
Ar(
k)
K/C
a ±
2σ
(Ka)
(%
) (%
)
BH
6076
6
75 °
C
0.0
0004
59
16.
316
0.0
0562
74
5.32
3 0
.000
3713
5.97
5 0
.030
3883
0.
222
0.0
1961
63
0.36
2 10
0.1
± 68
.1
33.
16
1.6
2 2.
32
± 0.
25
BH
6077
7
40 °
C
0.0
0011
29
8.
047
0.0
1582
26
3.22
6 0
.001
0900
1.63
0 0
.091
7022
0.
166
0.0
5019
00
0.19
9 92
.1
± 27
.4
35.
99
4.8
7 2.
49
± 0.
16
BH
6078
8
00 °
C
0.0
0029
48
3.
372
0.0
5780
49
2.69
2 0
.003
8727
0.68
3 0
.345
4171
0.
069
0.1
4493
34
0.09
2 84
.4
± 8.
0 4
3.00
1
8.36
2.
57
± 0.
14
BH
6079
8
50 °
C
0.0
0036
20
2.
626
0.0
8112
42
2.69
1 0
.005
3339
1.03
6 0
.455
9231
0.
071
0.1
8536
28
0.10
1 86
.9
± 5.
8 4
5.71
2
4.24
2.
42
± 0.
13
BH
6080
9
00 °
C
0.0
0047
59
1.
800
0.0
8634
17
2.66
2 0
.005
2352
1.15
7 0
.429
8543
0.
078
0.2
1023
41
0.07
8 83
.0
± 5.
5 3
6.31
2
2.85
2.
14
± 0.
11
BH
6081
9
50 °
C
0.0
0065
76
1.
214
0.0
6342
41
2.75
3 0
.002
8498
1.28
5 0
.229
8392
0.
124
0.2
3138
49
0.08
9 85
.5
± 9.
7 1
8.16
1
2.22
1.
56
± 0.
09
BH
6082
10
10 °
C
0.0
0155
63
0.
421
0.0
5217
97
2.78
2 0
.002
8978
1.11
5 0
.184
2142
0.
136
0.4
9023
63
0.06
7 87
.4
± 10
.0
7.0
2 9
.79
1.52
±
0.08
BH
6083
10
80 °
C
0.0
0197
79
0.
855
0.0
3544
80
2.88
7 0
.001
7038
2.83
9 0
.096
2205
0.
103
0.5
9567
34
0.03
5 67
.9
± 48
.6
2.3
5 5
.11
1.17
±
0.07
BH
6084
11
60 °
C
0.0
0136
10
0.
898
0.0
2460
08
3.03
5 0
.000
4714
6.70
7 0
.015
9109
0.
359
0.4
0307
97
0.08
5 82
.7
± 21
3.4
0.7
0 0
.85
0.28
±
0.02
BH
6085
12
25 °
C
0.0
0019
43
4.
796
0.0
0802
24
4.17
9 0
.000
0618
2
8.56
6 0
.001
7810
1.
122
0.0
5799
16
0.22
2 31
8.9
± 14
51.1
2
.09
0.0
9 0.
10
± 0.
01
Σ 0
.007
0385
0.45
6 0
.430
3958
1.
031
0.0
2388
77
0.
500
1.8
8125
09
0.03
6 2
.388
7025
0.
027
T
able
9.5
2: C
ontin
ued
Info
rmat
ion
on A
naly
sis
and
Con
stan
ts U
sed
in C
alcu
latio
ns
Sam
ple
= M
AD
013
Ext
ract
ion
Met
hod
= U
ndef
ined
M
ater
ial =
gro
undm
ass
Hea
ting
= 90
0 se
c L
ocat
ion
= U
W93
D48
Is
olat
ion
= 15
.00
min
A
naly
st =
Bria
n Ji
cha
Inst
rum
ent =
MA
P21
5 P
roje
ct =
UW
93D
L
ithol
ogy
= U
ndef
ined
M
ass
Dis
crim
inat
ion
Law
= L
IN
Lat
-Lon
= U
ndef
ined
- U
ndef
ined
Ir
radi
atio
n =
UW
93
Age
Equ
atio
ns =
Con
vent
iona
l J
= 0
.000
2554
0 ±
0.00
0000
20
Neg
ativ
e In
tens
ities
= F
orce
d Z
ero
FC
S =
28.
201
± 0.
023
Ma
Dec
ay C
onst
ant 4
0K =
5.4
63 ±
0.1
07 E
-10
1/a
IGS
N =
Und
efin
ed
Dec
ay C
onst
ant 3
9Ar =
2.9
40 ±
0.0
29 E
-07
1/h
Pre
ferr
ed A
ge =
Und
efin
ed
Dec
ay C
onst
ant 3
7Ar =
8.2
30 ±
0.0
82 E
-04
1/h
Cla
ssifi
catio
n =
Und
efin
ed
No
36C
l Cor
rect
ion
Exp
erim
ent T
ype
= U
ndef
ined
N
o 36
Cl C
orre
ctio
n
112
Tab
le 9
.52:
Con
tinue
d
Res
ults
40
(r)/
39(k
) ±
2σ
Age
±
2σ
MSWD
39A
r(k)
K
/Ca
± 2σ
(K
a)
(%,n
)
Age
Pla
teau
0.
1822
±
0.00
67
85.2
±
3.1
0.25
10
0.00
0.
19
± 0.
22
± 3.
69%
±
3.70
%
10
Min
imal
Ext
erna
l Err
or
± 4.
6 2.
26
Sta
tistic
al T
Rat
io
Ana
lytic
al E
rror
±
3.1
1.00
00
Err
or M
agni
ficat
ion
Tot
al F
usio
n A
ge
0.18
20
± 0.
0101
85
.1
± 4.
7
10
1.88
±
0.04
±
5.56
%
± 5.
56%
M
inim
al E
xter
nal E
rror
±
5.8
Ana
lytic
al E
rror
±
4.7
Nor
mal
Is
ochr
on
0.18
18
± 0.
0082
85
.0
± 3.
8 0.
28
100.
00
± 4.
49%
±
4.49
%
10
Min
imal
Ext
erna
l Err
or
± 5.
1 1.
94
Sta
tistic
al F
ratio
A
naly
tical
Err
or
± 3.
8 1.
0000
E
rror
Mag
nific
atio
n In
vers
e Is
ochr
on
0.18
20
± 0.
0041
85
.1
± 1.
9 0.
28
100.
00
± 2.
24%
±
2.24
%
10
Min
imal
Ext
erna
l Err
or
± 3.
8 1.
94
Sta
tistic
al F
ratio
A
naly
tical
Err
or
± 1.
9 1.
0000
E
rror
Mag
nific
atio
n
T
able
9.5
3: D
egas
sing
pat
tern
s for
MA
DE
RA
S-01
3
Deg
assi
ng
Pat
tern
s
36A
r(a)
%
1σ
36A
r(c)
%
1σ
36A
r(ca
) %
1σ
36A
r(cl
) %
1σ
37A
r(ca
) %
1σ
38A
r(a)
%
1σ
38A
r(c)
%
1σ
38A
r(k)
%
1σ
BH
6076
6
75 °
C
0.00
0044
1
6.86
0.00
0000
0
.00
0.
0000
01
5.3
2
0.00
0000
0
.00
0.
0056
27
5.3
2
0.00
0008
1
6.86
0.00
0000
0
.00
0.
0003
66
0.2
2
BH
6077
7
40 °
C
0.00
0109
8
.36
0.
0000
00
0.0
0
0.00
0004
3
.23
0.
0000
00
0.0
0
0.01
5823
3
.23
0.
0000
20
8.3
6
0.00
0000
0
.00
0.
0011
06
0.1
7
BH
6078
8
00 °
C
0.00
0280
3
.56
0.
0000
00
0.0
0
0.00
0015
2
.69
0.
0000
00
0.0
0
0.05
7805
2
.69
0.
0000
52
3.5
6
0.00
0000
0
.00
0.
0041
65
0.0
7
BH
6079
8
50 °
C
0.00
0341
2
.80
0.
0000
00
0.0
0
0.00
0021
2
.69
0.
0000
00
0.0
0
0.08
1124
2
.69
0.
0000
64
2.8
0
0.00
0000
0
.00
0.
0054
98
0.0
7
BH
6080
9
00 °
C
0.00
0453
1
.90
0.
0000
00
0.0
0
0.00
0023
2
.66
0.
0000
00
0.0
0
0.08
6342
2
.66
0.
0000
85
1.9
0
0.00
0000
0
.00
0.
0051
83
0.0
8
BH
6081
9
50 °
C
0.00
0641
1
.25
0.
0000
00
0.0
0
0.00
0017
2
.75
0.
0000
00
0.0
0
0.06
3424
2
.75
0.
0001
20
1.2
5
0.00
0000
0
.00
0.
0027
71
0.1
2
BH
6082
10
10 °
C
0.00
1543
0
.43
0.
0000
00
0.0
0
0.00
0014
2
.78
0.
0000
00
0.0
0
0.05
2180
2
.78
0.
0002
88
0.4
3
0.00
0000
0
.00
0.
0022
21
0.1
4
BH
6083
10
80 °
C
0.00
1969
0
.86
0.
0000
00
0.0
0
0.00
0009
2
.89
0.
0000
00
0.0
0
0.03
5448
2
.89
0.
0003
68
0.8
6
0.00
0000
0
.00
0.
0011
60
0.1
0
BH
6084
11
60 °
C
0.00
1355
0
.90
0.
0000
00
0.0
0
0.00
0006
3
.03
0.
0000
00
0.0
0
0.02
4601
3
.03
0.
0002
53
0.9
0
0.00
0000
0
.00
0.
0001
92
0.3
6
BH
6085
12
25 °
C
0.00
0192
4
.85
0.
0000
00
0.0
0
0.00
0002
4
.18
0.
0000
00
0.0
0
0.00
8022
4
.18
0.
0000
36
4.8
5
0.00
0000
0
.00
0.
0000
21
1.1
3
Σ 0.
0069
25
0.4
6
0.00
0000
0
.00
0.
0001
14
1.0
3
0.00
0000
0
.00
0.
4303
96
1.0
3
0.00
1294
0
.46
0.
0000
00
0.0
0
0.02
2684
0
.04
Σ
0.00
7039
0
.46
0.
4303
96
1.0
3
113
Tab
le 9
.53:
Con
tinue
d
38A
r(ca
) %
1σ
38A
r(cl
) %
1σ
39A
r(k)
%
1σ
39A
r(ca
) %
1σ
40A
r(r)
%
1σ
40A
r(a)
%
1σ
40A
r(c)
%
1σ
40A
r(k)
%
1σ
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0303
85
0.2
2
0.00
0004
5
.32
0.
0065
06
34.
00
0.
0131
11
16.
86
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0916
92
0.1
7
0.00
0011
3
.23
0.
0180
62
14.
88
0.
0321
28
8.3
6
0.00
0000
0
.00
0.
0000
00
0.0
0
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
3453
78
0.0
7
0.00
0039
2
.69
0.
0623
18
4.7
2
0.08
2615
3
.56
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
4558
68
0.0
7
0.00
0055
2
.69
0.
0847
35
3.3
3
0.10
0628
2
.80
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
4297
96
0.0
8
0.00
0058
2
.66
0.
0763
29
3.3
3
0.13
3906
1
.90
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
2297
97
0.1
2
0.00
0043
2
.75
0.
0420
19
5.6
5
0.18
9366
1
.25
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0388
8
.36
0.
1841
79
0.1
4
0.00
0035
2
.78
0.
0344
26
5.7
2
0.45
5811
0
.43
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0176
2
7.58
0.09
6197
0
.10
0.
0000
24
2.8
9
0.01
3979
3
5.77
0.58
1694
0
.86
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0027
11
9.36
0.01
5894
0
.36
0.
0000
17
3.0
3
0.00
2811
12
9.05
0.40
0269
0
.90
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0004
39
5.75
0.00
1776
1
.13
0.
0000
05
4.1
8
0.00
1211
22
7.53
0.05
6780
4
.85
0.
0000
00
0.0
0
0.00
0000
0
.00
0.
0000
00
0.0
0
0.00
0595
1
1.55
1.88
0961
0
.04
0.
0002
90
1.0
3
0.34
2396
2
.78
2.
0463
07
0.4
6
0.00
0000
0
.00
0.
0000
00
0.0
0
0.
0245
74
0.2
8
1.88
1251
0
.04
2.
3887
02
0.5
6
T
able
9.5
4: A
dditi
onal
par
amet
ers f
or M
AD
ER
AS-
013
Add
ition
al
Par
amet
ers
40
(r)/3
9(k)
1σ
40
(r+a
) 1σ
40
Ar/
39A
r 1σ
37
Ar/
39A
r 1σ
36
Ar/
39A
r 1σ
T
ime
(day
s)
37A
r (d
ecay
) 39
Ar
(dec
ay)
40A
r (m
oles
)
BH
6076
6
75 °
C
0.2
1410
7 0.
0728
0 0
.019
616
0.00
007
0.6
4552
1 0.
0027
4 0
.185
184
0.00
987
0.0
0150
9 0.
0002
5 1
32.9
81
13.8
3281
136
1.00
0938
90
1.15
8E-1
6
BH
6077
7
40 °
C
0.1
9698
5 0.
0293
0 0
.050
190
0.00
010
0.5
4731
5 0.
0014
2 0
.172
543
0.00
557
0.0
0123
1 0.
0001
0 1
33.0
16
13.8
4249
149
1.00
0939
15
2.96
2E-1
6
BH
6078
8
00 °
C
0.1
8043
4 0.
0085
2 0
.144
933
0.00
013
0.4
1959
0 0.
0004
8 0
.167
348
0.00
451
0.0
0085
4 0.
0000
3 1
33.0
51
13.8
5198
839
1.00
0939
39
8.55
4E-1
6
BH
6079
8
50 °
C
0.1
8587
6 0.
0061
9 0
.185
363
0.00
019
0.4
0656
6 0.
0005
0 0
.177
934
0.00
479
0.0
0079
4 0.
0000
2 1
33.0
85
13.8
6149
180
1.00
0939
64
1.09
4E-1
5
BH
6080
9
00 °
C
0.1
7759
3 0.
0059
2 0
.210
234
0.00
016
0.4
8908
2 0.
0005
4 0
.200
863
0.00
535
0.0
0110
7 0.
0000
2 1
33.1
21
13.8
7119
200
1.00
0939
89
1.24
1E-1
5
BH
6081
9
50 °
C
0.1
8285
5 0.
0103
3 0
.231
385
0.00
021
1.0
0672
5 0.
0015
4 0
.275
950
0.00
760
0.0
0286
1 0.
0000
3 1
33.1
56
13.8
8070
859
1.00
0940
13
1.36
6E-1
5
BH
6082
10
10 °
C
0.1
8691
4 0.
0106
9 0
.490
236
0.00
033
2.6
6122
9 0.
0040
2 0
.283
255
0.00
789
0.0
0844
8 0.
0000
4 1
33.1
90
13.8
9023
171
1.00
0940
38
2.89
3E-1
5
BH
6083
10
80 °
C
0.1
4532
1 0.
0519
8 0
.595
673
0.00
021
6.1
9071
3 0.
0067
3 0
.368
404
0.01
064
0.0
2055
6 0.
0001
8 1
33.2
26
13.8
9995
202
1.00
0940
63
3.51
6E-1
5
BH
6084
11
60 °
C
0.1
7685
3 0.
2282
4 0
.403
080
0.00
034
25.
3335
51
0.09
340
1.5
4615
8 0.
0472
5 0
.085
541
0.00
083
133
.260
13
.909
4883
4 1.
0009
4087
2.
379E
-15
BH
6085
12
25 °
C
0.6
8216
6 1.
5521
7 0
.057
992
0.00
013
32.
5607
25
0.37
239
4.5
0435
4 0.
1948
8 0
.109
076
0.00
537
133
.295
13
.919
0312
0 1.
0009
4112
3.
423E
-16
114
Tab
le 9
.55:
Pro
cedu
re b
lank
s for
MA
DE
RA
S-01
3
Pro
cedu
re
Bla
nks
36A
r 1σ
37
Ar
1σ
38A
r 1σ
39
Ar
1σ
40A
r 1σ
BH
6076
6
75 °
C
0.0
0003
1 0
.000
006
0.0
0000
1 0
.000
015
0.0
0000
2 0
.000
012
0.0
0000
5 0
.000
010
0.0
0843
9 0
.000
053
BH
6077
7
40 °
C
0.0
0003
1 0
.000
006
0.0
0001
3 0
.000
015
0.0
0001
4 0
.000
012
0.0
0000
5 0
.000
010
0.0
0843
9 0
.000
053
BH
6078
8
00 °
C
0.0
0003
0 0
.000
006
0.0
0002
5 0
.000
015
0.0
0001
8 0
.000
012
0.0
0000
6 0
.000
010
0.0
0888
7 0
.000
053
BH
6079
8
50 °
C
0.0
0003
3 0
.000
006
0.0
0002
9 0
.000
015
0.0
0001
5 0
.000
012
0.0
0000
8 0
.000
010
0.0
0945
9 0
.000
053
BH
6080
9
00 °
C
0.0
0003
8 0
.000
006
0.0
0002
9 0
.000
015
0.0
0000
9 0
.000
012
0.0
0001
1 0
.000
010
0.0
0998
3 0
.000
053
BH
6081
9
50 °
C
0.0
0004
2 0
.000
006
0.0
0002
4 0
.000
015
0.0
0000
5 0
.000
012
0.0
0001
0 0
.000
010
0.0
1037
0 0
.000
053
BH
6082
10
10 °
C
0.0
0004
4 0
.000
006
0.0
0001
6 0
.000
015
0.0
0000
2 0
.000
012
0.0
0000
7 0
.000
010
0.0
1071
7 0
.000
053
BH
6083
10
80 °
C
0.0
0004
6 0
.000
006
0.0
0000
7 0
.000
015
0.0
0000
3 0
.000
012
0.0
0000
2 0
.000
010
0.0
1136
4 0
.000
053
BH
6084
11
60 °
C
0.0
0005
0 0
.000
006
0.0
0000
8 0
.000
015
0.0
0000
7 0
.000
012
0.0
0000
7 0
.000
010
0.0
1359
2 0
.000
053
BH
6085
12
25 °
C
0.0
0006
3 0
.000
006
0.0
0002
9 0
.000
015
0.0
0000
5 0
.000
012
0.0
0003
3 0
.000
010
0.0
1796
7 0
.000
053
T
able
9.5
6: In
terc
ept v
alue
s for
MA
DE
RA
S-01
3
Inte
rcep
t V
alue
s 36
Ar
1σ
r2
37
Ar
1σ
r2
38
Ar
1σ
r2
BH
6076
6
75 °
C
0.00
0077
0.
0000
05
A
VE
7
of 8
0.
0004
14
0.00
0012
0.
6578
E
XP
8
of 8
0.
0003
77
0.00
0019
0.
5255
E
XP
8
of 8
B
H60
77
740
°C
0.
0001
46
0.00
0007
0.
1077
E
XP
8
of 8
0.
0011
73
0.00
0016
0.
8711
E
XP
8
of 8
0.
0011
15
0.00
0013
0.
9221
E
XP
8
of 8
B
H60
78
800
°C
0.
0003
31
0.00
0008
0.
3834
E
XP
8
of 8
0.
0042
62
0.00
0020
0.
9845
E
XP
8
of 8
0.
0039
30
0.00
0024
0.
9772
E
XP
8
of 8
B
H60
79
850
°C
0.
0004
03
0.00
0008
0.
2945
E
XP
8
of 8
0.
0059
72
0.00
0030
0.
9808
E
XP
8
of 8
0.
0054
03
0.00
0054
0.
9229
E
XP
8
of 8
B
H60
80
900
°C
0.
0005
24
0.00
0006
0.
6735
E
XP
8
of 8
0.
0063
49
0.00
0021
0.
9865
E
XP
7
of 8
0.
0052
99
0.00
0060
0.
9004
E
XP
8
of 8
B
H60
81
950
°C
0.
0007
13
0.00
0006
0.
9127
LI
N
7 of
8
0.00
4664
0.
0000
35
0.96
14
EX
P
8 of
8
0.00
2884
0.
0000
35
0.92
04
PA
R
8 of
8
BH
6082
10
10 °
C
0.00
1633
0.
0000
03
0.99
91
PA
R
5 of
8
0.00
3830
0.
0000
31
0.95
65
EX
P
8 of
8
0.00
2930
0.
0000
30
0.91
55
EX
P
8 of
8
BH
6083
10
80 °
C
0.00
2064
0.
0000
16
0.97
03
LIN
6
of 8
0.
0025
96
0.00
0027
0.
9359
E
XP
8
of 8
0.
0017
24
0.00
0047
0.
6132
E
XP
8
of 8
B
H60
84
1160
°C
0.
0014
39
0.00
0011
0.
9717
P
AR
7
of 8
0.
0018
04
0.00
0023
0.
9007
E
XP
8
of 8
0.
0004
83
0.00
0029
0.
0719
E
XP
8
of 8
B
H60
85
1225
°C
0.
0002
61
0.00
0007
0.
3512
E
XP
8
of 8
0.
0006
15
0.00
0012
0.
5923
E
XP
8
of 8
0.
0000
67
0.00
0013
0.
0930
E
XP
8
of 8
115
Table 9.56: Continued
39Ar 1σ r2 40Ar 1σ r2
0.030521 0.000066 0.9943 EXP 8 of 8 0.028056 0.000048 0.7891 LIN 7 of 8 0.092092 0.000150 0.9980 EXP 8 of 8 0.058629 0.000085 0.9913 PAR 8 of 8 0.346872 0.000216 0.9997 EXP 8 of 8 0.153820 0.000123 0.9975 EXP 7 of 8 0.457845 0.000295 0.9997 EXP 8 of 8 0.194822 0.000181 0.9969 EXP 8 of 8 0.431669 0.000311 0.9996 EXP 7 of 8 0.220217 0.000155 0.9986 EXP 8 of 8 0.230814 0.000279 0.9989 EXP 7 of 8 0.241755 0.000199 0.9990 EXP 7 of 8 0.184994 0.000245 0.9984 EXP 8 of 8 0.500953 0.000322 0.9995 EXP 8 of 8 0.096627 0.000095 0.9990 EXP 8 of 8 0.607038 0.000201 0.9999 EXP 8 of 8 0.015985 0.000056 0.0843 EXP 8 of 8 0.416671 0.000340 0.9994 EXP 8 of 8 0.001821 0.000017 0.9870 EXP 8 of 8 0.075959 0.000117 0.9948 EXP 7 of 8
Table 9.57: Sample parameters for MADERAS-013
Sample Parameters Sample Material Location Analyst
Tem
p
Standard %1σ J %1σ MDF (in Ma)
BH6076 675 °C MAD013 groundmass UW93D48 Brian Jicha 675 28.201 0.08 0.0002554 0.08 1.00515
BH6077 740 °C MAD013 groundmass UW93D48 Brian Jicha 740 28.201 0.08 0.0002554 0.08 1.00515
BH6078 800 °C MAD013 groundmass UW93D48 Brian Jicha 800 28.201 0.08 0.0002554 0.08 1.00515
BH6079 850 °C MAD013 groundmass UW93D48 Brian Jicha 850 28.201 0.08 0.0002554 0.08 1.00515
BH6080 900 °C MAD013 groundmass UW93D48 Brian Jicha 900 28.201 0.08 0.0002554 0.08 1.00515
BH6081 950 °C MAD013 groundmass UW93D48 Brian Jicha 950 28.201 0.08 0.0002554 0.08 1.00515
BH6082 1010 °C MAD013 groundmass UW93D48 Brian Jicha 1010 28.201 0.08 0.0002554 0.08 1.00515
BH6083 1080 °C MAD013 groundmass UW93D48 Brian Jicha 1080 28.201 0.08 0.0002554 0.08 1.00515
BH6084 1160 °C MAD013 groundmass UW93D48 Brian Jicha 1160 28.201 0.08 0.0002554 0.08 1.00515
BH6085 1225 °C MAD013 groundmass UW93D48 Brian Jicha 1225 28.201 0.08 0.0002554 0.08 1.00515
Table 9.57: Continued
%1σ Volume Ratio
Sensitivity
Day
Mon
th
Yea
r
Hou
r
Min
Res
ist
Irradiation Project Experiment
Nm
b Standard Name (mol/volt)
0.03 1 5.902E-15 25 OCT 2011 16 43 001 UW93 UW93D UW93D48 01 FCS
0.03 1 5.902E-15 25 OCT 2011 17 34 001 UW93 UW93D UW93D48 01 FCS
0.03 1 5.902E-15 25 OCT 2011 18 24 001 UW93 UW93D UW93D48 01 FCS
0.03 1 5.902E-15 25 OCT 2011 19 14 001 UW93 UW93D UW93D48 01 FCS
0.03 1 5.902E-15 25 OCT 2011 20 05 001 UW93 UW93D UW93D48 01 FCS
0.03 1 5.902E-15 25 OCT 2011 20 55 001 UW93 UW93D UW93D48 01 FCS
0.03 1 5.902E-15 25 OCT 2011 21 45 001 UW93 UW93D UW93D48 01 FCS
0.03 1 5.902E-15 25 OCT 2011 22 36 001 UW93 UW93D UW93D48 01 FCS
0.03 1 5.902E-15 25 OCT 2011 23 26 001 UW93 UW93D UW93D48 01 FCS
0.03 1 5.902E-15 26 OCT 2011 00 16 001 UW93 UW93D UW93D48 01 FCS
116
Tab
le 9
.58:
Irra
diat
ion
cons
tant
s for
MA
DE
RA
S-01
3
Irra
diat
ion
Con
stan
ts
40/3
6(a)
%
1σ
40/3
6(c)
%
1σ
38/3
6(a)
%
1σ
38/3
6(c)
%
1σ
39/3
7(ca
) %
1σ
38/3
7(ca
) %
1σ
36/3
7(ca
) %
1σ
40/3
9(k)
%
1σ
BH
6076
6
75 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
6077
7
40 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
6078
8
00 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
6079
8
50 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
6080
9
00 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
6081
9
50 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
6082
10
10 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
6083
10
80 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
6084
11
60 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
BH
6085
12
25 °
C
295.
5 0
0.01
8 35
0.
1869
0
1.49
3 3
0.00
0673
0
0 0
0.00
0264
0
0 0
T
able
9.5
8: C
ontin
ued
38/3
9(k)
%
1σ
36/3
8(cl
) %
1σ
K/C
a %
1σ
K/C
l %
1σ
Ca/
Cl
%1σ
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
0.01
206
0 0
0 0.
43
0 0
0 0
0 0.
0120
6 0
0 0
0.43
0
0 0
0 0
117
85.2 ± 3.1 Ka
100
50
0
50
100
150
200
250
300
350
400
450
500
0 10 20 30 40 50 60 70 80 90 100
Cumulative 39Ar Released [ % ]
UW93D48.AGE >>> MAD013 >>> UW93D PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU85.2 ± 3.1TOTAL FUSION 85.1 ± 4.7NORMAL ISOCHRON 85.0 ± 3.8INVERSE ISOCHRON85.1 ± 1.9
MSWD0.25
Sample Info
groundmassUW93D48Brian Jicha
IRR = UW93J = 0.00025540 ± 0.00000020
Figure 9.17: Age plateau for MADERAS-013
0.19 ± 0.22
0.0
0.3
0.6
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
3.3
3.6
3.9
0 10 20 30 40 50 60 70 80 90 100Cumulative 39Ar Released [ % ]
UW93D48.AGE >>> MAD013 >>> UW93D PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU85.2 ± 3.1TOTAL FUSION 85.1 ± 4.7NORMAL ISOCHRON 85.0 ± 3.8INVERSE ISOCHRON85.1 ± 1.9
Sample Info
groundmassUW93D48Brian Jicha
IRR = UW93J = 0.00025540 ± 0.00000020
Figure 9.18: K-Ca plateau for MADERAS-013
118
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700
39Ar / 36Ar
UW93D48.AGE >>> MAD013 >>> UW93D PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU85.2 ± 3.1TOTAL FUSION 85.1 ± 4.7NORMAL ISOCHRON 85.0 ± 3.8INVERSE ISOCHRON85.1 ± 1.9
MSWD0.28
40AR/36AR INTERCEPT295.6 ± 2.4
Sample Info
groundmassUW93D48Brian Jicha
IRR = UW93J = 0.00025540 ± 0.00000020
Figure 9.19: Normal isochron for MADERAS-013
0.0000
0.0005
0.0010
0.0015
0.0020
0.0025
0.0030
0.0035
0.0040
0.0045
0 1 1 2 2 3 3 4 4 5 5 6 6 7 7
39Ar / 40Ar
UW93D48.AGE >>> MAD013 >>> UW93D PROJECT
Ar-Ages in Ka
WEIGHTED PLATEAU85.2 ± 3.1TOTAL FUSION 85.1 ± 4.7NORMAL ISOCHRON 85.0 ± 3.8INVERSE ISOCHRON85.1 ± 1.9
MSWD0.28
40AR/36AR INTERCEPT295.6 ± 1.2
Sample Info
groundmassUW93D48Brian Jicha
IRR = UW93J = 0.00025540 ± 0.00000020
Figure 9.20: Inverse isochron for MADERAS-013