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COASTAL ENVIRONMENTS AND TAINO OCCUPATION AT LOS BUCHILLONES, CUBA
MATTHEW CK4RLES PEROS
A thesis submitted to the Faculty of Graduate Studies in partial fulfillment of the requirements
for the degree of
Master of Science
Graduate Programme in Geography York University
North York, Ontario
September 2000
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Coastal Environments and Taino Occupation at Los Buchillones, Cuba
by MAlTl-iNV CHARLES PEROS
a thesis subrnitted to the Faculty of Graduate Studies of York University in partial fulfillrnent of the requirements for the degree of
MASER OF SCIENCE
@ 2000 Permission has been granted to the LIBRARY OF YORK UNI- VERSITY to tend or sel1 copies of this thesis, to the NATIONAL LIBRARY OF CANADA to microfilm this thesis and to lend or seil copies of the film. and to UNIVERSITY MiCROFILMS to publish an abstract of this thesis. The author reserves other publication rights, and neither the thesis nor extensive extracts from it rnay be printed or other- wise reproduced without the author's written permission.
Abstract
Los Buchiilones is a Taino site (occupied ca. AD 1220 - 1620) located on the north coast of central Cuba. The Iittoral zone consists of a lagoon separated £?am the sea by a chenier. The site, Iocated both offshore and in the lagoun, is submerged under approximately 50 cm of water, and aerial photographs reveal that the chenier has receded over 50 m since AD 1959. The coastal stratigraphy was investigated to reconstruct environmental conditions at Los Buchillones during Taino occupation-
Eleven sediment cores and two soil pits were sampled dong a transect perpendicular to the coast. The samples were andyzed for loss on ignition, particle size, rnolluscan ecology, total concentration of macro, micro, and rare earth elements, mineralogy of the <2pn fraction, and pollen. The extremely low Ievel of organic rnatter in the sediment and uncertainty in the provenance of the molIuscs prevented dating b y I4c.
The coastal stratigraphy records a recent marine transgression. The bottommost horizon is likely a buried soil, and therefore represents a former terrestrial environment. Overlying the buried soil are four lagoon and two marine deposits. A regional sea level curve and data on sedimentation rates in two coastal ponds from the Bahamas suggests the lagoon at Los Buchillones is 1000 to 2000 years old, and thus predates the Taino settlement-
The more than 40 Taino houses found preserved at the site were raised on pilings in the water. It is unclear what stratigraphie unit the archaeological material is associated with, but the site may have been located both offshore and in the lagoon. This location would have offered protection, transportation routes, and access to marine, lagoon, and terrestrial resources. There is no evidence that catastrophic environmental change, such as hwricane activity or excessive flooding, caused site abandonment.
Table of Contents
Abstract.. ...................................................................................................... Table of Contents ............................................................................................. List of Figures ................................................................................................. List of TabIes .................................................................................................. List of Plates ................................................................................................... List of Appendices ........................................................................................... Acknowledgments ............................................................................................
1 . 0 introduction and Research Question ................................................................... 1 . 1 Introduction ................................................................................... 1.2 Research Question ............................................................................
2.0 Study Area ............................................................................................... 2.1 Regional Background. ....................................................................... 2-2 Climate and Vegetation ...................................................................... 2.3 Geology ........................................................................................
.......................................... 2.3-1 Surficial GeoIogy and Hydrology
.......................................... 2.3.2 Structurai Geology and Tectonics ......................................... 2.3.3 Holocene Sea Level Change in the
Norihem Caribbean Region 2.4 Archaeology ..................................................................................
....................................... 2.4.1 Archaeolo,~ of the Greater Antilles ..................................... 2.46 Taino Occupation at Los BuchilIones
3.0 Literature Review ....................................................................................... 3.1 Introduction ..................................................................................
........................................... 3.2 Shoreline Migration and Coastal Stratigraphy -, -3 3.3 Barriers ........................................................................................
.......................................... 3.3.1 Barriet Formation and Migration ........................................... 3.3.2 Cheniers and Chenier Formation
3.4 Lagoons ........................................................................................ .......................................... 3.4.1 Lagoon Formation and Evolution
............................................ 3.4.2 Lagoon Sediments and Salini -, - 2.3 Mangrove Ecolo gy ........................................................................... 3 -6 Hurricanes, Storms, and Coastlines ........................................................
....................................................... 3.7 Clay Minerals in Marine Sediments
4.0 Methods .................................................................................................. 4.1 Introduction ................................................................................... 4.2 FieId Methods ................................................................................. 4.3 Laboratory Methods ..........................................................................
....................... 4.3.1 Documentation of Sedirnent Cores and Sampling ...................................................... 4.3.2 Sediment Composition
........................................................ 4-33 Particle Size Analysis ............................................................ 4.3.4 X-ray Diffraction
4.3.5 Geochemistry ................................................................. .............................. 4.3.6 Scanning Electron Microscopy (SEM) and
Energy-Dispersive Spectrometry (EDS) ........................................................... 4.3.7 Molluscan Ecology
............................................................... 4.3.8 Pollen Analysis
iv v vi i vii vii ... vi11
ix
................................................................................................... Results 5- 1 Site Stratigraphy ..............................................................................
............................................................................... 5 2 Loss on Ignition 5.3 MoIluscan EcoIogy ........................................................................... 5.4 Partide Site Analysis ........................................................................ 5.5 Mineralogy. ...................................................................................
................................................................................. 5.6 Geochemistry ............................................................................... 5.7 Pollen Analysis
5.8 Environments of Deposition ................................................................
.............................................................................................. Discussion., 6.1 Absolute Site Chronolo,oy ...................................................................
..................................................... 6.2 Where Were the Taino Houses Built? .............................................. 6.3 Environmental History o f the Littoral Zone
Conclusions ..............................................................................................
.............................................................................................. References Cited
Appendix A . Particle Size Results ........................................................................ Appendix B - Mn nodules ................................................................................... Appendix C - Standard deviations o f the REEs .................. ..,.. ......................... ... .......
List of Appendices
..................................................................... Appendix A Particle size results 106 ....................................................................... Appendix B Mn nodule results 107
................................................. Appendix C Standard deviations of the REE data 112
viii
Acknowledgements
1 wouid like to thank m y s u p e ~ s o r y cofllfnittee of Dr. Tony Davis (University of Toronto) and Dr. Elizabeth Graham (York University and University College London). I am also indebted to Dr. Bill Mahaney (Geomorphology and Pedology Laboratory, York Universiw) for help with laboratory analysis and advice. Mike Milner (York Universi@), Dr. Kandiah Sanmugadas (York University), Dr. Ron Hancock (Royal Military College of Canada), Dr. Dale Calder (Royal Ontario Museum), and Susan Russell (York University) assisted with laboratory analysis and discussion, Sarah Finkelstein (University of Toronto) provided valuable cornments on eariier drafts, and Dr. David Smith (University of Toronto) provided severai figures and advice.
1 am also gratem to Dr. David Pendergast (University College London) and Dr. Jorge Calvera (Cuban Ministry of Science) for financial support and permission to conduct research at Los Buchillones. José (Pepé) Herrera A., Adri5.n Garcia L., Nelson Toma, Pedro Guerra H., Jorge Calvera R-, and José Calvera participated in fieldwork and ensured that it was successful.
1 would h a l l y like to thank my family for their encouragement and support over the past two years.
1 .O Introduction and Research Question
1.1 Introduction
Los Buchillones is an archaeological site located on the north Coast of central Cuba, in
the province of Ciego de ~ v i l a (Graham et al., 2000). The site was occupied fiom ca.
AD 1220 to 1620 by the Taino, an aboriginal group indigenous to the Greater Antilles at
this tirne. Los Buchillones was discovered in the mid 1980's when two local fishermen
found Taino artifacts scattered dong the shoreline and in an adjacent lagoon (Pendergast,
1997). Archaeological and preliminary geological investigations have since been
undertaken by the Royal Ontario Museum and the Cuban Ministry of Science, and
researchers from York University, the University of Toronto, and the Institute of
Archaeology at the University College London.
The littoral zone at Los Buchillones consists of a chenier' separated from the
mainland by a lagoon. Aerial photographs from the 1950's indicate that the seaward side
of the chenier has receded hast 50 meters this century (Pendergast, 1998). The
beginning of this recession is roughly synchronous with the construction of a breakwater
in 1959, several kilometers east of Los Buchillones, which may have altered existing
coastal processes such as longshore drift (Pendergast, 1997). This erosion revealed the
Taino site, which is presently submerged under 0.5 - 1.0 m of water. The arcbaeological
material consists of various artifacts and the remains of at least 40 collapsed Taino houses
(Pendergast, personal communication, 1 999).
1 A chenier is a sand or shell beach-ridge that has formed above a mud substrate in micro-tidal conditions (Waters, 1992).
Because the site is submerged, archaeological investigations are carried out on the
following marner. A sandbag and polyethylene-sheet dyke is first constructed around the
area of investigation, and the entrapped water is then purnped fiom the dyke. The
sandbags provide a technologically simple and 1ow cost means for controlled excavation,
and have Iimited impact on the delicate archaeoiogical remains. The dyke surrounds an
area of 400 - 500 square meters, and seeping requires that the purnp run occasionally
throughout the day. The sediment is excavated by hand, and wet-screened through !4
inch steel mesh. Future excavation may forego the sandbags and use a semi-permanent
intrusive caisson to better control flooding, although this would create new logistical
problems for the project.
Limited surface excavations began in 1989, and yielded some Taino material,
although it was not until February 1997 when work focused on the richer submerged
areas at the site (Pendergast, 1997). This first year of wet-site archaeology concentrated
on the lagoon, but yielded only 14 artifacts. However, large arnounts of Taino house
debris (e-g. rafters) were recovered, and 17 groups of vertical house posts were identified
offshore. In May 1998, excavation of one of the ofYshore groups of house posts yielded
numerous artifacts associated with this house, and palm thatch was identified arnid its
rafters (Pendergast, 1998). DetaiIed survey and mapping of the Los Buchillones area
with a GPS unit also began that year. Fieldwork in February 1999 was back in the
lagoon, where additional artifacts and the remains of another house were revealed (Plate
1.1). As the good condition of the wooden artifacts and house remains attest, site
preservation is exceptional.
Plate 1.1. The 1999 excavation in the lagoon- The white arrow points to stmctural remains. View is to the southwest.
1.2 Research Question
The submerged nature of the site, coupled wiîh the recent shoreline recession, suggests
that the coastal environment at Los Buchillones may have changed since Taino
occupation. This prompts the question: what was the coastline like at the time of Taino
occupation, and how was Taino settlement adapted to it? in order to answer this,
preliminary paleoenvironmental investigations of the littoral zone were initiated in
Febmary 1999. This thesis reports the results of those investigations.
The specific objective of this thesis is to reconstruct the recent environmental
history of the Los Buchillones Coast, by documenting the stratigraphy of the littoral zone
and inferring the environments of deposition (e.g. terrestrial, lagoonal, or m a ~ e ) of the
stratigraphie units. By correlating the archaeological and geological stratigraphy, it may
be possible to determine environmental conditions (including the position of the
shoreline) at Los Buchillones during Taino occupation, and to reconsfruct the history of
the lagoon. It will then be possible to consider the reasons for settlement and eventual
site abandonment. This thesis will also lay the groundwork for M e r
paleoenvironrnental research in an area where recent environmental change is poorly
understood.
This thesis is divided into seven chapters, This chapter has introduced the site
and research objectives. Chapter 2 will descnbe the physicd and culturai setting of the
Los Buchillones area- Chapter 3 provides a review of literature and theoretical models
relevant to this research. Chapter 4 outlines the field and laboratory methods used in this
research, and chapter 5 presents the results of the laboratory analyses. A discussion of
the results follows in chapter 6, and chapter 7 provides a brief conclusion. Unless
otherwise stated, al1 dates reported in this thesis are caiibrated I4c years before present
(BPI-
2.0 Site Background
2.1 Regional Background
Los Buchillones (22Y2'2OyWY 78°48710"E) is located in the province of Ciego de ~ v i l a ,
on the north coast of central Cuba (Figure 2.1). "Ciego" means "dense forest," which is
in stark contrast to the sugar and banana plantations that presently dominate the northern
part of this province. Los Buchillones is situated between the towns of Punta Alegre and
Maximo Gomez on the Bahia de Buena Vista (Figure 2.2). A reef consisting largely of
the coral Acropora palmata parallels the north coast of Cuba for 15 km (Kühlrnann,
1974; Nuevo Atlas Nacional de Cuba, 1989)- Buchillones is the name of the family that
once owned the land (Pendergast, 1994).
2.2 Climate and Vegetation
North central Cuba has a sub-tropical climate, with a winter dry period fiom November
to March, a surnrner dry period in June and July, and two rainy seasons fiom April to
May and August to October (Borhidi, 1996). Mean annual temperature and precipitation
are 25.8"C and 1 1 50 mm respectively, and fhe seasonal temperature normally varies by
only 5°C (Nuevo Atlas Nacional de Cuba, 1989). Precipitation is often less than 50 mm
per month during the dry periods, and over 180 mm per month during the rainy seasons
(Nuevo Atlas Nacional de Cuba, 1989; Borhidi, 1996). Twenty hurricanes were reported
in central Cuba between AD 1800 - 2966 (Borhidi, 1996) and an average of 2 or 3 occur
Figure 2.1. Map of Cuba (modified fiom Canas Abri1 et aI., 1974).
Figure 2.2. Map of the Los Buchillones Area.
Cayes
Bahia de Buena Vista "3 Punta Alegre FauIt
Los Buchillones Maximo Gomez
I
Punta Alegre Diapir
in the Los Buchillones area per century. Hurricanes almost always occur in September or
October (Nuevo Atlas Nacional de Cuba, 1989).
The flora of the littoral zone is dominated by black mangrove (Avicennia
germinans), with smaIler amounts of red mangrove (Rhimphorn mangle), white
mangrove (Laguncularia racernosa), buttonwood mangrove (Conocarpzrs erectus) and
sea gras (Thalassia testudinurn). The mangrove understory is sparse, which might be
due to the dense canopies that characterize many mangrove cornmunities (Swiadek,
1997). There is no clear mangrove zonation, which is atypical (Kellman and Tackaberry,
1997) and may reflect recent shoreline recession. Many red mangroves at the site have
growth rings, although given the climate regime of the area it is unclear whether these
rings are annual. Several partially submerged r e k t tree sturnps (species unknown) are
present approximately 500 m east of the site, 10 rn offshore in 30 cm of water.
Late Quaternary paleoclimatic research in Cuba is sparse, and past climates must
therefore be iderred fkom studies done elsewhere in the northem Caribbean. At Lake
Miragoane, in Haiti, Hodell et al. (1991) analyzed the 6180 of fossil ostracod shells and
reported that a relatively dry period began 10,500 BP. Conditions then became graduaIly
wetter by 7000 BP, and persisted until 3200 BP, when another dry period began (Hodell
et al., 199 1). Charcoal and pollen fiorn Andros Island, Bahamas, indicate a similar dry
period fiorn 3200 to 1500 BP (Kjellrnark, 2 996). Pollen from southem Florida, however,
shows that oak scrub and prairie existed during the mid-Holocene, suggesting that drier
conditions prevailed in this afea (Watts, 1975). In perhaps the only Holocene
paleoclimatic study relating directly to Cuba, Cermak et ai. (1992a; b) argue that the
island has experienced a 2 - 3 O C warniing over the past 200 years. This is based on
temperature-depth curves f?om soils in a variety of sites around Cuba, although Cermak
et al. (1992a; b) acknowledge that agricultural activity during the past two centuries may
have affected the data, In short, there is no evidence that the climate at Los Buchillones
during Taino occupation was significantly different than at present.
2.3 Geology
2-3.1 Surficial Geology and Hydrology
As mentioned, the littoral zone at Los Buchillones consists of a chenier separated from
the mainland by a lagoon (Figure 2.3; Plate 2.1). The chenier varies between 2 m to 10 m
in width, and is no higher than 1 m above mean sea level (msl). It consists almost
exclusively of shells comrnon to shdlow marine environments in the northern Caribbean
(Tucker Abbott, 1974; Wannke and Tucker Abbott, 1961). Most of the shells are
bleached, and include Cerithium eburneztm and Chione cancellata, with smaller amounts
of Modulzls rnodulus, Polinices lacteus, and Anomalocardia auberiana. Roots and other
unidentified organic debris are comrnon near the surface of the chenier, and a thin Ah
horizon has forrned in some areas. An Ahb horizon (5 cm thick, 20 cm below the
surface) is also present in a portion of the chenier at the site. In addition, a 1 - 2 cm thick
hardpan has formed just above mean sea level on the seaward side of the chenier about 50
m west of the site (Plate 2.2). The buried soi1 and hardpan suggest that the chenier was
until recently, and for a brief period, stable and dry enough for their formation.
Figure 2.3. Map of the Los Buchillones a r e a UTM coordinates are along bottom and left borders.
Plate 2.1, The chenier and lagoon at Los Buchillones. View is to the north fiom 80 m above msl. The arrow points to the area of the 1999 excavations.
Plate 2.2. Hardpan in the seaward side of the chenier. A camera case provides scale, and the view is to the east,
The soils of northem Ciego de ~ v i l a consist mainly of Rendolls, Ultisols, and
Vertisols (Herrera, persona1 communication, 1999). Immediately south of the lagoon is
an unclassified soi1 of the Francisco series that is reddish brown, clayey, and consists of
montmorillonite and illite. These soils are characterized by thin Ah horizons (O - 10 cm)
and highly weathered B horizons (IO - 65 cm) (Suelos de la Provincia Ciego de ~ v i l a ,
1988; Herrera, persona1 communication, 1999). There are aIso numerous land-crab
(species unknown) burrows south of the lagoon that extend at least 50 cm below the
surface, indicating that some of the local soils have been severely bioturbated.
The lagoon (officially unnarned) has a maximum length and width of 1.6 km and
300 rn respectively, and covers an area of 26 hectares. Its maximum depth is 70 cm
below msl, and it gradually shallows landward. The sea and Iagoon have been
pennanently comected since at least 1975, when the sea breached the chenier in several
areas near the site. One opening in the chenier adjacent to the 1999 excavation area
resulted in the formation of second, smaller shell ridge roughly 10 rn inside the lagoon.
There are no rivers that presently empty into the lagoon,
The mean tidal range of the lagoon and sea is 20 cm (Nuevo Atlas Nacional de
Cuba, 1989), and while the maximum tide is unknown, casual observations made in
February 1999 indicate that it probably does not exceed 40 cm above msl. The longshore
current is fiom east to west, and Iocal fisherrnen have ïndicated that waves are norrnally
low to medium energy. The nearshore zone reaches a depth of only 1 m below rnsl 300
m offshore. There are two springs in the Los Buchillones area, one 0.5 km south and the
other 0.8 km east of the site, that are currently used by local famiers.
A 1975 aerial photograph confinns that the physiography and vegetation of the
lagoon have changed over the past 25 years (Calvera, personal communication, 2000).
This photo shows: 1) salt pans in the eastern end of the lagoon, 2) a wider beach ridge, 3)
less mangrove coverage on the beach ridge than at present, 4) a linear southeast corner of
the lagoon, suggesting human modification, 5) a possible second beach ridge in the West
end of the lagoon, enclosing two smaller lagoons, and 6) a breach in the beach ridge at its
western end, which has now closed, and no breach where the curent opening is. The
Cuban authorities did not allow this aenal photograph to be reproduced-
2.3 -2 Structural Geology and Tectonics
The structural geology of the coast at Los Buchillones is more closely reIated to that of
the Bahamas than elsewhere in Cuba- The north coast of central Cuba overlies the
southern portion of the tectonically stable Bahamas platform (Figure 2.4) (Carew and
Myiroie, 1995). The southern Bahamas platform is divided into three distinct
technostratigraphic zones, that include, corn north to south, the Great Bahama Bank, the
Old Bahama Channel, and the Cayo Coco-Remidios zone &ewis and Draper, 1990;
Carew and Mylroie, 1995). Los Buchillones is associated with the Cayo Coco-Remidios
zone, which is characterized by generalIy low relief (Pardo, 1975).
An exception to this low relief is a range of hilIs immediately south of Los
Buchillones (Figure 2.2). These hills are collectively known as the Punta Alegre diapir2,
and are comprised of upfaulted salt domes of the Upper Jurrasic Punta Alegre Formation
(Meyerhoff and Hatten, 1968; Sora et al., 1996). The diapir covers an area roughly
1 1.5km long and 3km wide, and has a maximum elevation of 138 m (Nuevo Atlas
Nacional de Cuba, 1989). The stratigraphy consists of Jurassic evaporites that overlie
Oligocene, Lower to Middle Eocene, and Upper Jurassic sedirnents (Pardo, 1975). It is
unclear when the upward rnovement of the evaporites began, but they were exposed
' A diapir is an intrusion that forms a hi11 or small mountain on the surface (Summerfield, 199 1).
Figure 2.4. Structural GeoIogy of Cuba (Lewis and Draper, 1990).
subaerially by the early Pleistocene (Iturralde-Vinent and Roque Marrero, 1982). The
Punta Alegre Formation fkequently outcrops on the diapir, and consists of approximately
75 percent gypsum, 15 percent dolomite, and IO percent limestone (Meyerhoff and
Hatten, 1968). The diapir has underground drainage. The one small Stream that drains its
northeastem part is presently used for the dumping of sugar cane mil1 wastes fiom the
plant at Maximo Gomez (Fagundo et al., 1993). F a p d o et al. (2993) indicate tiiat a
relict superficiai drainage network exists on the upper portion of the diapir, although they
do not provide an estimate of its age.
While the Bahamas Platform is tectonically stable, there is sorne evidence to
indicate that the Los Buchillones area may be locally active. The high elevation of the
Punta Alegre diapir, and the relatively unweathered limestone and dolomite outcrops that
exist at its summit, suggest post-Miocene movement (Meyerhoff and Hatten, 1968;
Pardo, 1979, although Iturralde-Vinent (personal communication, 1 999) argues that the
diapir has been inactive for most of the Quaternary. Meyerhoff and Hatten (1968) also
indicate that the Los Buchillones area is seisrnically active, and mention that several
earthquake epicenters have been identified in the vicinity. The nearly straight east-west
coast at Los Buchillones folIows a normal fault (the Punta Alegre Fault) downthrown to
the south (Meyerhoff and Hatten, 1968)pigure 2.5). Finally, al1 geologic maps of Cuba
identiQ the bedrock of the Los Buchillones area as "salt dome" (Nuevo Atlas Nacional
de Cuba, 1989).
Figure 2.5. Stratigraphy of the Los Buchillones area (Meyerhoff and Hatten, 1968). This section is perpendicular to the coast 10 km east of the archaeoIogica1 site.
2.3.3 Holocene Sea Level Change in the Northem Caribbean Region
Sea level is controlled by changes in the volume of the ocean (eustasy), and the vertical
movement of the coastline. Factors affecting the former include glacidinterglacial
cycles (glacio-eustasy) and sea-floor spreading (tectono-eustasy), while tectonism and
isostatic rebound mainly influence the latter (Summerfield, 1991). From deglaciation
until about 6000 BP, global sea level was controlled largely by eustasy. From 6000 BP
onwards, regional and local factors (e-g. tectonism and isostatic rebound) have had a
greater influence on relative sea level, making site-specific data critical for late Holocene
coastal research.
Sea level in the Caribbean region has risen at a decelerating rate since
deglaciation. A composite sea level curve for the eastem Caribbean, based on ''c and U-
Th dating of the marine coral Acropora palmata, indicates that sea level was roughly 90
m below its present level around 12,000 BP (Blanchon and Shaw, 1995). Sea levet then
rose to its present level, punctuated by two catastrophic rise events (each 10 - 15 m in
height) fkom Antarctic and Laurentide ice sheet coliapse at 11,500 and 7600 BP
respectively (Blanchon and Shaw, 1995). Local data also support this general model for
decelerating sea level rise. Scholl et al. (1969), for example, show that sea level has risen
2m off southwest Florida since 4000 BP, while a sea level rise of Sm has occurred around
Barbados since 3000 BP (Fairbanks, 1989).
Holocene sea level studies fiom Cuba are consistent with the general Caribbean
model (Dunayev, 1977). Dated buried peats from five areas around Cuba indicate that
sea level has risen since 6000 BP. Values range fi-om a low of 0.3 - 0.6 d y r at Bahia
Puerto Padre to 2.5 d y r at Bahia Cienfuegos (Figure 2.1). Because each estimate is an
average rate for the past 6000 years, and sea level rise in the Caribbean has generally
been decelerating, these figures overestimate the extent of recent (since 1000 BP) sea
level change. Furthermore, north central Cuba is not arnong the study areas. This
research is usefid to show that sea Ievel around Cuba has generaI1y risen since the mid-
Holocene, but site-specific data is still necessary for understanding whether sea leveI
change affècted the Taino at Los Buchillones. Unfortunately, there are no published sea
level curves for north central Cuba (Iturraide-Vinent, personal communication, 2 999).
Sea level research f?om the Bahamas provides the best analogue for the Los
Buchillones area, because of the proximity of the Bahamas to north central Cuba and the
tectonic stability of the underlying Bahamas platform (Carew and Mylroie, 1995).
Boardman et al. (1988) produced a composite sea level curve for the Bahamas by 14c
dating buried peat from San Salvador, Andros Island, and Bight of Abaco (Figure 2.6).
This cwve shows that sea level in the Bahamas was 0.5 - 1.0 m lower than present
between 800 - 400 BP (when Los Buchillones was occupied). However, studies from
Cat Island, Bahamas, show that between 600 - 300 BP sea level kvas 0.5 m higher than
present (Lind, 1969; Valdes, 1994), while Bourrouilh-Le and Evin (1992) argue that sea
level offshore Andros Island, Bahamas, was 1 m higher than present around 3500 BP,
before it dropped to its current level. The last 3000 years of the Boardman et al. (1988)
curve must also be used with caution since there is only one dated sample for that penod,
and errors are not reported for the individual I4c dates.
Figure 2.6. Bahamas' sea Ievel curve, from dated peat sarnples (Boardman et al., 1988).
7
- - Period of Taino O Occupation
q4C years BP
Sea level at Los Buchillones during Taino occupation is difficult to evaluate. In
addition to the inconsistencies with the Batiamas data, local tectonism at Los Buchillones
may have affected sea level differently than in the Bahamas. Furthermore, given that Los
Buchillones was occupied for at minimum 400 years, a significant change in sea level
could have occurred while the settlement was inhabited. Despite this, there is no obvious
evidence (such as a raised beach) for a recent higher than present sea Ievel at Los
Buchillones. It is also uniikely that sea Ievel could have risen several meters to its
present level in the 350 years since the site was abandoned, since rates of sea level
change exceeding this normally only occur imrnediately after deglaciation, or in areas of
recent glacial unloading or considerable seismic activity. That being said, sea level at
Guilford, Connecticut, has risen over 1 m since AD 1800, possibly from the rnelting of
ice and the thermal expansion of the oceans following the neoglacial varekemp and
Thomas, 2000). The available evidence therefore suggests that sea level at Los
Buchillones has probably risen only slightly during the late Holocene, although the
possibility that a 0.5 - 1.0 m rise in sea level has occurred following the neoglacial must
also be considered.
2.4 Archaeology
2.4.1 Archaeology of the Greater Antilles
Cuba was colonized around 7000 BP by hunter-gatherers from the Yucatan peninsda
(Rouse, 1992; Keegan, 1995). Several migrations into the Caribbean followed, each
beginning in the Orinoco River delta and moving north through the Lesser Antilles.
Cuba, however, remained isolated from these later migrations for some time, as Archaic
hunter-gatherers slowed the westward movement of agriculturists fiom Hispaniola
(Keegan, 1995). Around 1400 BP, a population explosion in Puerto Rico forced
migration into Cuba, and by 1200 BP people had spread fiom Cuba and Hispaniola to the
Bahamas and Turks and Caicos Islands (Keegan and MacLachlan, 1989). A hunter-
gatherer group known as the Guanahatebey may have persisted in western Cuba until
historic time, although archaeological evidence for their existence is limited (Rouse,
1992).
The Taino culture emerged around 800 BP. At their zenith, around 600 BP, the
Taino occupied central and eastem Cuba, the Bahamas, Hispaniola, Jamaica, and Puerto
Rico (Figure 2.7), and had a population of several million (Rouse, 1992). The Taino
cultivated cassava, squash, beans and peanut, although at Los Buchillones their diet was
supplemented with seafood. By Spanish contact, Taino settlements were usually
clustered together, implying that reasonably strong socio-politica. cohesion existed
(Keegan and MacLachlan, 1989). Taino houses were typically oval in shape mouse,
1992) and surrounded a central plaza (Keegan and MacLachlan, 1989). The Taino were
accomplished seafarers (Peck, 1998), and likely had contact with the Maya of the
Yucatan (Pendergast, personal communication, 2000).
On October 12, 1492, life for the Taino changed irrevocably. Christopher
Columbus landed on San SaIvador in the Bdiamas, and then sailed to the north coasts of
Cuba and Hispaniola. Columbus probably landed east of Los Buchillones, but there is no
evidence that he ever visited the site. Spanish colonizaiion of the Greater Antilles
quickly foIlowed, and by 1510 permanent settiements were cornmon. Warfare and a
smallpox epidemic soon decimated the Taino population, and those who swived were
seized for labour. By 1524, the Taino virtually disappeared as a distinct ethnic group,
although some aboriginal blood survived as Spanish men often took Taino wives (Rouse,
1992).
Figure 2.7. Spatial extent of Taino civilization ca. AD 1200 (Rouse, 1992).
3-42 Taino Occupation at Los BuchiIlones
Twenty AMS dates on wooden artifacts and wooden house remains suggest that Los
Buchillones was occupied fiom ca. AD 1220 to 1620 (Pendergast, 1996b). It is unlikely
that the oldest and youngest artifacts were recovered and dated, therefore site occupation
probably precedes and exceeds the aforementioned dates. The wooden artifacts include
stools, anthropomorphic figurines, and stone-tooI handles. Other material culture
includes pottery (used for cooking and storage), and a range of chert tools. The precise
area of the site is unknown, but Taino artifacts are scattered up to one kilometer dong the
beach. Many of these artifacts, however, may have been redeposited by Iongshore drift
as the chenier receded a . exposed the site. There is no evidence for pre-TaÏno people at
Los Buchillones,
The remains of at least 40 collapsed Taino houses are located at the eastern end of
the chenier. These houses cover an area approximately 200 meters east to West, and 100
meters north to south, Each house is identified by a circular or oval group of vertical
wood posts, made f?om lignum vitae (probably Guaiacum ofticinale) (Pendergast,
persond communication, 1999). Most of the houses are offshore in 50 cm of water, but a
house found in the lagoon in February 1999 indicates that the site extends underneath the
chenier. Al1 in situ archaeological material found to date is associated with a grey clay
known locally as fango (literally meaning mud). Due to seeping, the excavations have
yet to penetrate through the cultural layer, although casual probing indicates the
archaeological deposit is up to 50 cm thick (Pendergast, 1 998).
The archaeoIogical evidence permits the following reconstruction of Taino house
form. Houses were round, and one or two 20 - 30 cm diameter kingposts were placed
vertically at the centre for roof support. Smalfer vertical posts surrounded the penmeter
of the structure as wall supports, and each had a forked end to accornmodate a horizontal
beam, similar to a lintel. Roofs were conical, and consisted of a series of Iarge and srnall
(or prirnary and secondary) rafters. Palm thatch was placed over the rafters as roofing
(Pendergast, personal communication, 1999). The archaeological evidence from Los
Buciiillones is generally consistent with descriptions of Taino houses by early Spanish
chroniclers (Rouse, 1992) and post mould evidence from Puerto Rico (Antonio Curet,
1992). The condition and location of the house tirnbers excavated to date indicate that a
catastrophic event, such as a hurricane, kvas not responsible for their destruction
(Pendergasî, 1998).
Whether there was contact between the Spanish and Taino at Los Buchillones is
unclear. Two maps of Cuba, published in AD 1580 and 1598, show that European
settlements were established dong the north Coast by the end of the 1 6 ~ century (Nuevo
Atlas Nacional de Cuba, 1989). If habitztion at Los Buchillones persisted into the 1 7 ~
century, the likelihood of contact between the Spanish and Taino should have been hi&,
especially given the Spanish desire to acquire slaves (Rouse, 1992). Despite this, the
only evidence for European contact is a single fragment of late 15" century Spanish
rnajolica cerarnic (Pendergast, 1997). It may be that the natural barriers around the Los
Buchiliones area, such as the diapir and coral cayes, helped protect the site fiom Spanish
discovery until the 17" century. In addition, early maps are often inaccurate, and the
extent of Spanish settlements in northern Cuba may not have been as great as these maps
irnpl y.
3 -O Literature Review
3-1 Introduction
This chapter reviews literature and theoretical rnodels relevant to this study. The first
section outlines the factors that drive shordine migration and introduces models of
transgressive and regressive coastal stratigraphic sequences. The following two sections
describe the formation, evolution, and general characteristics of barriers and lagoons, as
these are the dominant physiographic features at Los Buchillones. The next section
discusses the ecology of mangroves and their role in coastai environments. Following
this, given that Los Buchillones is in the northern Caribbean, a discussion of the effect
that hurricanes and tropical storms have on coastal environments and stratigraphy is
provided. This chapter ends by reviewing how the rnineralogy of clay in marine
sediments can be used to infer depositional environment.
3 -2 Shoreline Migration and Coastal S tratigraphy
As mentioned, there is evidence to suggest that the coastal environment at Los
Buchillones has changed over the p s t several hundred years. One change may have
been in the position of the shoreline, which makes an understanding of the processes that
affect shoreline position is important. These processes include sea level, wave regirne
and tides, and sediment supply (Kraft and Chrzastowski, 1978). Shorelines are stable
when these processes are balanced, and rnigrate when the eEect of one exceeds that of the
others. A landward migration of a shoreline is a transgression, while a seaward migration
is a regression. Transgression and regressions each produce distinctive stratigraphic
sequences that can be identified in the sedimentary record. As will be shown, the
positions of the younger facies relative to the older facies form the basis for interpreting
whether a stratigraphic sequence records transgressive or regressive conditions.
Shoreline migration is controlled mainly by two factors: the direction of relative
sea level change, and whether sediment is being deposited or eroded (Curray, 1964). The
relationship between sea level change. sediment supply, and shoreline position is
iUustrated in Figure 3.1. If the same amount of sediment is being deposited as is being
eroded, and sea level remains stable, the shoreline will not migrate. However, a rise in
sea level causes a transgression, while a drop in sea level produces a regression.
Conversely, if sea level remains stable, sediment deposition results in progradation (Le.
regression), while erosion results in transgression. Shoreline migration accelerates when
sediment erosion or deposition is respectively accompanied by a rise or drop in relative
sea level. Finally, it is possible that transgressions can occur with a falling sea level, and
regressions with a rising sea level. If the rate of progradation exceeds sea level rise, a
regression will occur. Likewise, a slowly dropping sea level accornpanied by rapid
erosion may cause transgression.
Kraft and Chrzastowitz (1 978) have deveIoped stratigraphic models for
transgressive and regressive Iagoon-barrier systems. Ln the transgressive mode1 (Figure
3.2), the lagoon and barrier rnigrate upward and landward in response to a rise in relative
sea level.
Figure 3.1. Relationship between relative sea level change, rate of net sediment deposition, and shorehe movement (Curray, 1964).
RELATIVE S E A L E V E L
I FALLING SEP, L E V E L , RISING SEA LEVEL OR EMERGENCE fi
I OR SU8SIDENCE
R A P l O SLOW S T A ~ L E SLOW RA Pl D
As long as the rate of sediment deposition within the lagoon, the rate of relative sea level
rise, and the dope o f the coastal plane remain constant, the configuration of the lagoon-
barrier system will stay the same. The resulting stratigraphy is characterized by
overlapping facies that lie roughly parallel to the coastal plane. In the regressive mode1
(Figure 3.3), the lagoon becornes impounded and the barrier progrades seaward,
Figure 3.2 (above) shows a model for a transgressive lagoon-bam'er stratigraphic sequence, which includes (1) Pleistocene upland surface, (2) fnnging marsh, (3) lagoonal muds, (4) and (5) back- barn-er sediments, (6) barrier sediments, and (7) nearshore sediments. Figure 3 -3 (below) shows a regressive model, which includes (1) - (4) barrier sediments, (5) lagoonal muds, and ( 6 ) pre- Woiocene sediments (Kraft and Chrzastowski, 1979).
TRANSGRESSION
L AGOON OCEAN
Regressive coastlines are characterized by a series of parallel beach r idge~ that represent
former beach faces, which overlie older near-shore marine deposits. stratigraphic
sequences may also record both transgressions and regressions; a profile fiom Nayarit,
Mexico, for exarnple, shows an earlier transgression followed by a more recent regression
(Figure 3 -4) (Cooper, 1994). By cornparhg the stratigraphy at Los Buchillones to these
models, it may be possibte to identi& the recent history of shoreline migration at the site.
The preservation of coastal facies depends largely on wave energy, since this
affects the depth of erosion across the shoreface (Fischer, 1961). High wave energy
causes deep shoreface erosion, which on a transgressive Coast may result in a loss of
earlier offshore sediment. Generally, regressive sequences are more complete than
transgressive sequences, because prograding coasts are rarely eroding on their seaward
side. However, sediment composition, shoreline orientation, tidal range, topography, and
the rate and direction of relative sea level change also influence facies preservation.
Belknap and Kraft (198 1) furthemore suggest that a slowly rising sea level will increase
the potential for erosion, because waves will be concentrated dong the shoreface for a
greater penod of time. Conversely, if sea level rise is rapid, wave action will be
temporary, limiting erosion and possibly allowing a greater portion of the offshore
stratigraphy to be preserved. This does not mean that al1 transgressive sequences are
incomplete, only that they must be interpreted with more caution han regressive
sequences. Given that recent sea level rise at Los Buchillones has been relatively slow,
the offshore coastal stratigraphic record may not be fully preserved.
Figure 3.4. Profile fiom Nayarit, Mexico, which records an earlier transgression followed by a later regression (Cooper, 1994).
Channel fiIl
Lagoon and ma6h
ShcW muds Litloral sand
3.3 Barriers
3 3.1 Barrier Formation and Migration
At Los Buchillones, the lagoon is separated fiom the ocean by a barrier. Barriers are
long, narrow accumulations of gravel, sand, shell, vegetation, or coral that generally
parallel the mainland (Kraft and Chrzastowski, 1978). Schwartz (1 973) suggests that
barriers develop by either: (1) the formation of a barrier spit that eventually links one
headland to another, (2) the emergence of offshore bars as sea level drops, or (3) a rise in
sea level that drowns shore-parallel features such as coastal dunes. Barriers are cornrnon
where a Iow-relief continental shelf is adjacent to a low-relief coastal plane, and are rare
on steep coasts, since waves are more likely to break and deposit sediment near the
maidand rather than offshore (Barnes, 1980).
Barriers migrate landward or seaward in response to changes in sea level,
sedirnent supply, and wave regime. On transgressive coasts, barriers may undergo one of
three responses: (1) overstepping, (2), erosion, or (3) rollover. In the fmt response, the
overstepping of a barrier Ieaves it drowned on the seabed as a relict feature. This
normally happens when sea level rïses rapidly, and enough sedirnent is available and
wave conditions are appropriate for a second barrier to form closer to shore. In the
second response, sediment is eroded fiom the shoreface and redeposited below wave base
in the nearshore zone. The same cross-sectional geometry is maintained, but the profile
has moved landward at a rate proportional to the rïse in sea level. Finally, during
rollover, the entire barrier migrates the coastal plain without any loss of sediment, again
rnaintaining the same cross-sectional geometry. This process is driven by washover,
which transports material fÎom the barrier's shoreface into the back-barrier. Rollover is
often episodic, and is driven mainly by storrns (Cooper, 1994).
3.3.2 Cheniers and Chenier Formation
The morphology and composition of the barriet at Los Buchillones identify it as a
chenier. A chenier is typically a long, narrow, low-Iying, shore-parallel ndge of sand and
shell which overlies a muddy substrate, and is usually separated from the mainland by a
mudflat or lagoon (Otvos and Price, 1979; Waters, 1992). Cheniers were f ~ s t described
in southwest Louisiana by Russell and Howe (1935), and nurnerous examples have since
been reported fiom northern Australia (Short, l989), Surinam and Guyana (Daniel,
1989), and southeast China (Cangzi and Waiker, 1989). Individual cheniers can be up to
500 meters wide and tens of kilometers long (Hoyt, 1969), and generally develop on low-
relief coastal plains near river deltas (Cangzi and Waiker, 1989). Numerous plants,
including mangroves, colonize the crests of cheniers (Penland and Suter, 1989).
Cheniers form in one of two ways. The fxst and most common way involves the
reworking and winnowing of a coastal mudflat, which produces sand and shell lags that,
if transported landward, concentrate in a chenier (Waters, 1992). The mudflat must
contain abundant coarse grained sediment or shell, and low to moderate wave energy and
a low tidal range is required for winnowing to occur. Shells are easily incorporated into
cheniers because their low specific gravity promotes landward transport into the
supratidal zone (Cangzi and Waker, 1989). Chenier formation begins at low tidal level,
and winnowing can be an episodic (e-g. during storms) or cor.tinuous process. The
second but less cornrnon way cheniers form is by the longshore transport and deposition
of sand from local rivers. In this case, shell will only be incorporated into the chenier if
reworked from existing cheniers. Some combination of processes can be expected on
coasts where cheniers are common (Augustinus, 1 9 89).
Cheniers generally have gently sloping laminations on their seaward side, and
steeper and thicker cross bedding on their landward side (Figure 3.5). However, if a
chenier has migrated landward, the seaward side will steepen from the erosion of
foreshore sediments, while the landward side will shallow and display fine laminations
interrupted by thicker cross bedding from the washover events (Figure 3.6) (Augustinus,
1989). Shells will often be fkagmented and abraded £?om transport and wave action, and
the species composition will reflect local marine and lagoon species (Cangzi and Walker,
1989)- The washover fans in the back-barrier at Los Buchillones indicate that rollover is
an active process, while the steep shoreface (Plate 2.2) confirms the erosion on the
seaward side of the chenier.
Individual cheniers are rare, and in most cases they exist as part of a chenier plain.
Chenier plains consist of two or more cheniers separated by a mudflat or lagoon, and
develop when chenier formation alternates with mudflat progradation (Otvos and Price,
1979). The shift fiom mudflat progradation to chenier building is usually driven by a
change in sediment supply or wave action and tidal regime (Augustinus, 1989). Chenier
plains are usually large; the Mississippi River chenier plain, for example, measures
roughly 200 km long, ranges fiom 20 to 30 km wide, and varies in eievation by 2 to 6
meters above mean sea Ievel (Penland and Suter, 1989). It is unclear whether the chenier
at Los Buchillones, pnor to its erosion, was a single wide chenier ndge or a narrow
chenier plain.
3.4 Lagoons
3 -4.1 Lagoon Formation and Evolution
Lagoons are geologically ephemeral, and most exist for only a few thousand years (Ward
and Ashley, 1989). They are found at almost all latitudes, and generally form in
microtidal environments, although examples aIso occur where mesotidal and macrotidal
conditions predorninate (Cooper, 1994). Lagoons are also usually shallow in relation to
Figure 3 -5. Schematic of the sedirnentary structure of a chenier (Augustinus, 1989).
- Seaward inland -
Figure 3.6. Schematic of the sedirnentary structure of a chenier after Iandward mi-qation - (Augustinus, 1989)-
MEAN LOW-WATER L M L
Cby
their area (Barnes, 1980). Lagoons forrn when the development of a barrier separates an
embayment or coastal depression fiom the sea (Cooper, 1994). Kjerfie and Magill
(1 989) identfi three main Iagoon types: (1) choked Iagoons, which form on coasts with
high wave energy and have one or more long and narrow entrance channels, (2) restricted
lagoons, which posses two or more entrance channels, and (3) leaky lagoons, which are
characterized by wide tidal passes and have unimpaireci exchange with the ocean. The
lagoon at Los Buchillones is a leaky lagoon, although it may have been a restricted
lagoon prior to its recent erosion,
Lagoon evolution is controlled by a nurnber of macro-scale and micro-scde
processes (Cooper, 1994). The macro-scale processes include sea-level change,
tectonism, and climate. The direction and rate of sea level change, which is in part
controlled by tectonism, is important for b d e r evolution because rapid sea level rise can
erode or breach a barrier, while a drop in sea level can impound a lagoon. Climate
influences lagoon evolution by controlling the rate of freshwater inflow and evaporation,
which affects sali&, and in tropical climates coral and mangrove growth influences
wave activity and shordine stability respectively. The micro-scak processes influencing
lagoon evolution hclude sedirnent supply, longshore drift, sdinity, local geology, coastd
morphology, wave energy, and tidal range. Where sediment supply is high, there is
increased likelihood of lagoon infilling. Wave energy is also important, as high wave
energy can erode a barrier, whereas sediment deposition is encouraged where wave
action is minunal. The antecedent topography also affects barrier location and lagoon
morphology. On transgressive coasts, barriers often become stabilized on a point of
inflection on the basement slope. Lagoons will also widen where the basement dope is
shallow, and narrow where the basernent slope steepens (Barnes, 1980).
Nichols (1989) has proposed an evolutionary mode1 for lagoons on trangressive
coasts. In this model, the accretionary status of a Zagoon is deteimined by the rate of
sediment accumulation and relative sea level rise. Lagoons fiom the eastern seaboard
and Gulf of Mexico coasts of the United States were organized in three groups: (1)
surplus lagoons, where sediment accumulation exceeds the rate of relative sea level rise,
(2) balance lagoons, where the rate of sediment accumulation equals relative sea level
nse, and (3) deficit lagoons, where the rate of relative sea level rise exceeds sedirnent
accumulation (Figure 3.7). This mode1 predicts, for example, that surplus lagoons will
eventually infill, forming a marsh or swamp-like feature. The lagoon at Los Buchillones
is likely a surplus lagoon, given that recent land clearance has probably increased its
sedimentation rate, and sea level rise is likely very slow (Boardman et al., 1988).
3.4.2 Lagoon Sedirnents and Salini5
Lagoon sediments derive from a varïety of sources. Marine sediments enter lagoons by
washing over the barrïer or being channeled through breaches, while terrestnal sediments
are generally introduced fluvially (Cooper, 1994). Eolian sedimentation is less comrnon,
although mineralogical and particle-size analysis fiom a lagoon in Tunisia shows that
large quantities of wind deposited sediment originated from nearby dunes (Pilkey et al.,
1989). In humid environments, lagoon sediments are often rich in organic matter from
local vegetation or plant debris washed in by rivers (Elliott, 1978).
Lagoon sediments are often stmctureless due to bioturbation (Elliott, 1978),
although fme larninations are cornmon in quiet water areas (Cooper, 1994).
Sedimentation rates in lagoons have generally increased over the past several hundred
years, in response to increasing colluviation fiorn land clearance (Cooper, 1994). Lagoon
sediments generally coarsen towards the barrier where the deposition of offshore sand is
cornmon (Pilkey et al., 1989).
Figure 3.7. Mode1 o f lagoon evolution based on the relative importance of sedimentation and relative sea level rise (Nichols, 1989).
ACCRETiONARY STATUS
\ SURPLUS
BALANCE
Increasing relalrve sea-ievei r isc
Low 4 VOLUMETFIIC CAPAClTY ) Hrgh
LOW 5 ENERGY + High
Progradhg = DEPOSITIONAL MODE - Retrograding
Transgressive
Washover fans and tidal inlet deltas form when sedirnent erodes fiom the seaward
side of the barrïer and is redeposited within the lagoon, especiaiiy during storms (Elliott,
1978). Washover involves sediment being transported over an intact barrier, while tidai
iniet deltas forrn when the barrier is breached and sediment channelizes through the
opening. Both deposits consist of lobe-shaped units of thinly bedded coarse-grained
sediment. Washover fans and tidal inlet deltas can also overlap and merge, formïng an
irregular sand apron called a V a t back-barrier" (Guillén et al., 1994). The extent of
washover is influenced by particle size; fine-grained barriers, for exarnple, often produce
washover fans that extend far into the lagoon, while coarser grained sedirnent will slump
in the back-barrier. Washover is generally unimportant if the barrier has accreted above
storm swge elevations (Cooper, 1994).
Since most lagoons are relatively shallow, horizontal stratification and
homogeneous water colurnns are common (Cooper, 1994). Lagoons can accordingly be
divided into four salinity-based zones, which include a zone of fl-eshwater discharge, a
zone dominated by water fiom the adjacent sea, an intermediate region of brackish water,
and a hyperhaline zone wi+h a salinity exceeding that of sea water (Figure 3.8) (Barnes,
1980). Not al1 Iagoons have four zones; a fieshwater zone, for exarnple, will not exist if
there is lirnited fluvial input. Because salinity is controlled in part by freshwater input
and evaporation, salinity, especially in the tropics, varies seasonally @ m e s , 1980).
Furtherrnore, hyperhaline or brackish conditions are common in microtidal settings
because there is Iess exchange of water between the Iagoon and sea, whereas in mesotidal
Figure 3.8. An hypothetical lagoon showing the four types of salinity zones that might occur. Not a11 l a p o n s contain al1 theseënvironrnenG (Barnes, 1980).
channel
S E A
conditions lagoon salinities approach that of seawater because of more frequent lagoon-
ocean communication (Elliott, 1978).
Salinity also influences the abundance and diversity of lagoon fauna. Saline
areas, such as the entrances of tidal inlets, are usually associated with higher diversity
assemblages, whereas lower diversity assemblages are generally associated with brackish
zones. Since sdinity gradients have implications for the distribution and composition of
lagoon fauna, an understanding of salinity is critical for paieoecological research.
3 -5 Mangrove Ecology
Mangroves are extremely important in low-latitude coastal environrnents, and since these
plants dominate the flora at Los Buchiliones, a discussion on their ecology is necessary.
Mangroves range fiom Bermuda to northem Australia (Tomlinson, 1986), and normally
grow where annual precipitation exceeds 1000 mm, and where temperature rarely fails
below 20°C and varies by no more than 1 O°C annualIy (Reading et al., 1995). Mangrove
cornmunities are typically Iow-diversity, and in the Caribbean consist of only four
species : red mangrove (Rhizophora mangle), b lack mangrove (Avicennia nitida), white
mangrove (Laguncularia racemosa), and buttonwood mangrove (Conocarpus erectus)
(Elorhidi, 1 9 8 7; Cintron-Molero and Schaeffer-Novelli, 1 992). The understories of
mangrove forests are generally sparse, possibly due to their dense canopies (Reading et
al., 1995).
Mangroves norrnally colonize the intertidal zone of low-relief sheltered coasts,
deltas or estuaries (Marius and Lucas, 199 1; Kellman and Tackaberry, 1997). In these
Io w-energy environments, seedlings and trees are protected from being uproo ted b y
waves and currents (Cintron-Molero and Schaeffer-Novelli, 1992), although some current
is necessary to dispersai mangrove propagules (Hutchings and Saenger, 1987).
Mangrove substrates usually consist of mud (Marius and Lucas, 1991), but also include
sand, shell, peat, and corai (Cintron-Molero and Schaeffer-Novelli, 1992). The spatial
range of mangrove forests is controiled by shoreline topography, the source and rate of
sediment supply, and sea level change (Marius and Lucas, 2991). Mangroves protect
coasts fiom erosion and prornote sediment accumulation (Reading et al., 1995), and
Cintron-Moiero and S chaeffer-Novelli (1 992) note that mangrove colonization O fien
follows coastal progradation.
Mangrove forests are zoned according to distance fiom source of tidal inundation.
Rhizophora forms a belt below low and mean tide, while Avicennia is dominant between
mean and high tide (Borhidi, 1987). The Rhizophora comuni ty is usually
monospecific, while the Avicennia zone can contain other species, in paaicular
Lagunmlaria. Conocarpus usually exists at the transition fkom mangrove to u p h d
vegetation, and may be mked with Avicennia and Lagrrncularia. Ln general, Rhizophora
usually dominates dong microtidal coasts, whereas Avicennia is more common in
mesotidal conditions (Marius and Lukas, 1991). The reasons for mangrove zonation are
unc lear, but likel y include succession following coastal pro gradation, and differing
salinity to lerances. In addition, topograp hy, substrate type, Local clirnate, and hydro logy
also likely contribute to zonaiion (Reading et al., 1995).
Mangroves have specialized root systems to accommodate soils that are
constantly waterlogged and without mechanical support (Hutchings and Saenger, 1987).
Above ground, these root systems include stilt roots, which branch and loop fiom the
lower trunk of Rhizuphora, and pneumatophores, which are erect, blunt tipped roots (20 -
30 cm long) usudly associated with Avicennia and Laguncularia (Tomlinson, 1 9 8 6) .
The most extensive root systems are almost always found in the most frequentiy
waterlogged areas, conf~rming their role as aeration mechanisms (Hutchings and Saenger,
1987). Stilt roots and pneumatophores ofien contain an algal flora or a fauna of oysters,
barnacles, or molluscs. Aerial roots also slow water velocity, which promotes the settling
of fine particles fiom suspension. This causes progradation, and Hutchings and Saenger
(1987) show that mud accumulation can exceed 1.5 cm.yfl. Mangrove roots below
ground are generally shailow, and consist of a laterally spreading cable root system with
smaller, vertically descending anchor roots.
Many mangrove communities also generate peat deposits. Mangrove peat is
fibrous and is composed largely of mangrove rernains and mineral matter. The peat
beneath monospecific zones varies in t ems of colour, organic matter content, and
plasticity, and deposits up to 6 rneters thick have been found on the Cayrnan Islands
(Woodroofe, 1981). Since mangrove peat forms at or near sea level, it can be a good
indicator of past sea levels when radiocarbon dated, and its recovery in the Los
Buchillones area shouid be a priority so the history of local sea level change can be
reliably reconstructed.
3.6 Hurricanes, Storrns, and Coastlines
Hurricanes and tropical storms are important geomorphic agents on low-Iatitude coasts
(Hubbard, 1992). The purpose of this section is to thus identiQ common characteristics
of hurricane deposits in order to evaluate the significance of severe storms dong the Los
Buchillones Coast. For storm activity to significantly affect coastal morphology, a large
storm surge is necessary to rework and transport sediment. Surges can reach k e e meters
in height, such as those produced by Hurricane Andrew in 1992 off Louisiana (Parsons,
1998). During hurricane approach, waves pile water on the windward shore, and after the
humcane passes, intense currents drain the shore. Storm activity is particularly important
for microtidal lagoon-barrier systems, because it may be the only tirne when
communication between the sea and lagoon occurs (Guillén et al., 1994).
Shoreline configuration and flora are sensitive to storm and hunicane activity.
Between July to December 1990, storms were responsible for the erosion of 80,000 m3 of
sedunent from the seaward side of a sand barrier in the Ebro Delta, southeast Spain
(Guillén, 1994), while on the Louisiana Coast, hurricanes are responsible for up to 90
percent of shoreline retreat (Stone et ai., 1997). Hurricane Andrew caused severe damage
to mangrove forests in southern Florida, aithough storm surge and wave action together
caused less than 15 meters of shoreline erosion. The damage to the mangroves was
mainly wind, rather than wave induced, possibly because offshore reefs dampened wave
energy (Swiadek, 1997).
Hurricanes and tropical storms often produce diagnostic stratigraphie horizons.
Storm facies fiom Sarasota Bay and Little Sarasota Bay, Florida, are dorninated by gravel
and sand. These units Vary between 25 cm to 145 cm in thickness and generally thin
landward, and were formed by the reworking of the offshore barrier and existing Iagoon
sediments. Some gravel, however, may have been deposited into the lagoon fluvially as
local river discharge increased as a result of the storm (Davis et al., 1989). Storm
generated deposits fiom lagoons in Grand Cayman, British West Indies, have a large
mean particle size, are poorly sorted, and unlike pre-hurricane deposits, contain corai
fkagments and foraminifera fkom the offshore reef and forereef zone (Kalbfleisch and
Jones, 1998). At Terrebonne Bay, Louisiana, a Hurricane Andrew deposit was identified
based on large mean grain size and poor sorting, while the diatom assemblage showed an
increase in species diversity reflecting multiple source areas (Parsons, 1998). In short,
storm facies generally consist of coarse and poorly sorted sediment whose lithologic and
biologic composition reflects a broad geographic range. Abrupt facies contacts would
aIso be expected, reflecting rapid change from low to high energy conditions.
3.7 ClayMineralsinMarùieSediments
Since most sediments at Los BuchiIlones are fine grained and are marine or lagoonal,
some background on the origin and composition of manne clays is necessary. Globally,
the vast majority of clay minerals in ocean sedirnents are detrital (Hillier, 1995). Most
denve fiom fluvial sources, dthough eolian transport, ice rafting, and volcanism are
regionally important (Weaver, 1989). Because of this, the mineral composition of ocean
sediments often reflects the clay mineral composition of nearby landmasses. Examples
include kaolinite, a mineral formed by intense weathering common in ocean sediments at
low latitudes, and chlorite, an easily weathered clay abundant in polar regions where
chernical weathering is limited (Weaver, 1989). The distribution of clay minerals in the
oceans aiso depends on such factors as currents, particle size, and water depth. Sorne
clay minerais, however, may also undergo chernical alteration once in the ocean. These
authigenic clays are dominated by the illite-smectite and illite groups, and generdly
comprise only a small proportion of al1 marine cIays. Nevertheless, because their
alteration is controiled by specific geochemical factors, authigenic clays can be good
paleoenvironrnental indicators (Hillier, 1 995).
Authigenic smectites form in three different ways: (1) through the alteration of
volcanic glass and associated material by hydration (palagonitisation), (2) by the
alteration of sediment associated with the &g of ocean waters and hydrothermal
plumes, and (3) by the submarine weathering (halmyrolysis) of voIcanic glass, biogenic
silica, and Fe-oxy-hydroxides. The temperatures required for these processes Vary fiom
normal ocean conditions to 500°C, and they generally form at depths of 500 to several
thousand meters (Weaver, 1989). The potential for mixing with similar detrital material,
however, makes the identification of authigenic smectites difficult (Hillier, 1995). In
addition, the occurrence of authigenic smectite does not necessarïiy indicate that the
specinc conditions for its formation are local, since it may have been transported long
distances by ocean currents (Hillier, 1995).
GIauconite and glauconite/smectite are authigenic clays that form in shallow
marine environrnents (glauconite is an Fe-rich dioctahedral illite), and are the main
constituents of silt to sand size blue-green pellets referred to as glaucony (Weaver, 1989).
Glaucony forms at the seawater-sediment interface at depths between 100 m to 300 m,
and is common in (but not restricted to) tropical latitudes (Hillier, 1995). The formation
of glaucony begins with a source of Fe-rich (20% Fer03) detrital smectite. With time, K"
is fixed fiom seawater and the mineralogy evolves from mixed-layer glauconite/smectite
to glauconite. Highly evolved glaucony requires ca. 106 years to form, and c m comprise
between 10 to 80% of the sand fraction in recent sediments (Weaver, 1989). Glauconite
and gIauconite/smectite are identified by the same 10 A and 12 A peaks as illite and
illite/smectite on x-ray diEactograms (Weaver, 1989).
4.0 Methods
4- 1 Introduction
This chapter reviews the fieldwork and laboratory procedures. The fieldwork involved
the recovery of 11 sediment cores fiom offshore and in the lagoon, the excavation and
sampling of two soil pits, and the description of the site and its vicinity. The laboratory
methods consisted of a detailed documentation of the cores and soil sarnpies, loss on
ignition (LOI), particle size analysis, X-ray difiaction, Instrumental Neutron Activation
Analysis (INAA), scanning electron microscopy and energy-dispersive spectrometry
(SEM and EDS), mollusc identification, and preliminary pollen andysis. Unless
othenvise stated, ail laboratory andysis was done in the Geomorphology and Pedology
Laboratory, Atkinson College, York University.
4.2 Field Methods
In Febmary 1999, 11 sediment cores and two soi1 pits were sampled dong a 500 m
northwest-southeast trending transect (Figure 4.1). This transect intersected the 2999
excavation so the archaeological and geological stratigraphies could be integrated. The
positions of the cores and soi1 pits were recorded with a Garmin GPS 12. Whether the
stratigraphy along this transect is representative of the entire littoral zone is unclear.
Sediments in the north side of the lagoon associated with the break in the chenier may not
reflect the stratigraphy elsewhere along the back-barrier. However, since washover fans
are common elsewhere in the lagoon, a singIe representative location probably does not
Figure 4.1. The Los BuchiIIones area showing the location of the transect (A' - A).
exist. Multiple transects are clearly necessary to fülly reconstruct the coastal stratigraphy
at Los Buchillones.
The 1 I sediment cores were lifted with a Livingston corer (Wright, 1967), and the
top of each core was measured below msl. The coring platform was a stationary punt,
and the sediment, once extracted fiom the corer, was sealed first with saran wrap and
then aluminurn foil. The maximum depth of each core was determined by an
impenetrable brown mud. One core was sampled fiom the base of the 1999 excavation
area in an effort to provide as deep a recovery as possible. The cores are nurnbered 1 to
11 in a landward direction. Several dozen sediment samples were also taken with a soi1
probe at various depths between 20 m and 50 m offshore. This sediment was described
in the field, although none was kept for analysis.
The soil pits were located south of the lagoon and were excavated to a depth of 50
cm. Soi1 samples were taken in plastic bags fiom the B horizons, but the C horizons were
not reached in either pit, and time constraints prevented the pits from being described-
The northern pit is identified as Pit 1 and the southem pit as Pit 2. The physiography and
vegetation of the littoral zone were also described. A prelirninary description of the cores
and soil samples was made two days afier sampling while still in Cuba. The cores and
soil samples were then resealed for transportation to Canada, and were stored in a
refigerator at 4OC at York University.
In May 2000, two new transects were established: one 50 m east and the other 100
m West of the 1999 transect (al1 three transects are parallel). AIong each new transect,
sediment cores were lifted with the Livingston corer at 40, 80, and 120 m offshore, while
a soi1 probe was used to identiQ the depth of each stratigraphic unit at five equally
spaced intervals across the lagoon. The horizontal and vertical positions of al1 samples
were recorded using the same methods as those taken the previous year, and a
preliminary description of the cores was made three days after sarnpling. Unfortunately,
on our retwn trip, the airport authonties in Ciego de Avila confiscated the sediment, and
by July 2000 the samples had not reached Canada.
4.3 Laboratory Methods
4.3.1 Documentation of Sediment Cores and Sampling
In the laboratory, each core was tightIy wrapped in 3 layers of saran wrap, split
lengthwise, scraped clean, and photographed- Wet colours were recorded with a soil
colour chart (Oyama and Takehara, 1970) under fluorescent light, and the texture and
composition of each core was described. The colour, texture, and composition were used
to identie the stratigraphie units in each core, and a prelirninary mode1 of the coastal
stratigraphy was devised by correlating the core stratigraphies based on these
characteristics,
From one-haif of each split core, 60 g samples were taken from the centre of each
stlatigraphic unit. niese samples were air-dried for 24 hours, disaggregated in a
porcelain mortar and pestle, and passed through a 2 mm sieve (soi1 samples were treated
in the same mariner). The >2 mm (pebbles) and Q mm (sand, silt, and clay) fkactions
were air-dried, weighed, and stored separately in brown paper bags. The air-dried <2 mm
sarnples were used for the particle s i x , X-ray difYkaction, INAA, and the SEM-EDS
andysis. In core 10, a concentration of black nodules was identified. These nodules
were photographed in the core, and several were removed with forceps, air-dried, and
described under a Iight microscope. A srna11 sample of nodules was also collected for
NAA.
From the other half of each core, approximately 2 cm3 of sediment was
subsarnpled at lOcm intervals, or as close to each stratigraphic boundary as possible, for
LOI and pollen analysis. For mollusc sampling, every second half-core was divided into
5 cm increments down its length. The remaining half-cores were left intact, and would
be used if important differences in the mollusc assemblage were identified. Al1 sarnples
for LOI, pollen, and molluscs were stored in airtight plastic bags, and were refrigerated
with the remaining sediment until andysis.
The following analyticd techniques were selected based on: (1) their potential for
characterizhg the properties and inferring the depositional environments of marine,
Iagoon, and terrestrial deposits, and (2) the availability of laboratory equipment-
4.3 -2 Sediment Composition
Sediment composition (organic matter, carbonates, and silicates) was estimated by LOI at
the Department of Geography, Universisr of Toronto. Each subsample was placed in a
preweighed ceramic crucible and oven-dried at 110°C for 24 hours to yield moisture
content. Organic matter was estimated after ignition at 500°C for 1 hou, and carbonates
afier ignition at 900°C for 1 hour. The remaining residue consisted maïnly of silicates
(Dean, 1974). Ail subsarnples were placed in a desiccator for 30 minutes before
weighing.
4.3.3 Particle Size Analysis
The proportion of sand (2 mm-63 p), silt (63 p - 2 p), and cIay (<2 p) in each
sample was determined fiom the <2 mm air-dried fraction. The size &actions follow the
Wentworth scale (Folk, 1968), with the exception of the clay/silt boundary, which is set
at 2 pm (Soil Survey Staff, 1975). Sarnples of approximately 25 g of sediment were air-
dried and as much shell as possible was removed with forceps. These sarnples were then
weighed into beakers with 50 ml sodium pyrophosphate to disperse the sand, silt, and
clay, and 5 - 10 ml of 30% hydrogen peroxide to digest any organic matter. The sarnples
were agitated with a mechanical mixer and a ce11 disrupter to ensure full separation of the
particles. The sand was separated fiom the silt and clay by wet washing through a 63 p u
stainless steel sieve- Dry sieving (with mesh intervals of 1000, 500, 250, 125, and 63
p) was used to determine the particle size for the sand fraction, and the standard
hydrorneter method was used for the silt and clay @ay, 1965).
4.3 -4 X-ray Difiaction
The relative abundance of the major prirnary and secondary (clay) minerals was
detennined by X-ray diffraction. M e r 24 hours, the sediment suspended in the
hydrorneter jars fiom the particle size analysis consists of the clay fkaction. This
suspension was siphoned into glass jars, centrifuged onto ceramic tiles, and air-dried
overnight. Each tile was X-rayed using a Toshiba ADG-301H X-ray diffiactometer with
Ni-filtered CuKc radiation for 60 minutes following procedures established by Whittig
(1965). The tiles were then saturated in ethylene glycol vapour at 60°C for 24 hours and
X-rayed for 15 minutes each. Following this, each tile was heated for 2 hours at 300°C
and X-rayed for 15 minutes. This procedure was repeated at 500°C and 550°C
respectively. Interpretation of the difiactograms was made by reference to several
manuals (Moore and Reynolds, 1989; Carroll, 1970) and personal instruction (Mahaney,
personal communication, 2000).
4.3 -5 Geochemistry
Geochemical analysis was done by Instrumentai Neutron Activation Analysis (WAA) at
the SLOWPOKE-2 Reactor Facility, Royal Military ColIege of Canada, Kingston,
Ontario. This analysis determines the total concentrations of selected macro, minor, and
rare earth elements. Samples between 600 mg and 850 mg of air-dried sediment from the
-G mm fraction and severai clurnps of the black nodules were placed in fiip-top polyvials
and mailed to Kingston for analysis.
To determine the concentration of elements that produce short-lived
radioisotopes, such as Al, Br, Ca, Cl, Dy, 1, Mg, Mn, Na, Ti, U, and V, irradiation of the
samples occurred for 30 seconds at a neutron flux of 5.0 x 10' ' n.~rn-~s". M e r waiting
19 minutes to allow short-lived to decay to acceptable levels, each sample was
assayed with 5 minute counts using on site gamma-ray spectrometers. The next day, the
samples were al1 recounted for 5 minutes for Eu, Ga, Na, and K, and the chernical
concentrations were then calculated by a cornparison with previously run standards.
Following this, each sample was then packaged in individual polyethylene bags and batch
irradiated for 3 hours at a neutron flwr of 5.0 x 10 ' ' n.~rn-~s". After waiting four to six
days to allow 2%a to decay to acceptable levels, the samples were senally couoted for 10
minutes each for As, Br, Cr, Fe, La, Na, Sb, Sc, Sm, U, and Yb, and d e r 14 days the
samples were recounted for 3 hours each to determine the concentrations of Ba, Ce, Co,
Cr, Cs, Eu, Fe, Hf, Lu, Nd, Ni, Rb, Sc, Sr, Ta, Tb, Th, and Yb. Fe, Sc, and Yb were used
to cross check the long-lived radioisotope measurements. The Mg data were corrected
for an interference fiom Al by the equation: Mgre.1 = Mgmeaured - (0.21 x Al), and high Cl
required that Na be corrected using the equation: Na,,l= Namzured - (CV1.54) (Hancock,
personal communication, 2000).
4.3 -6 Scanning Electron Microscopy (SEM) and Energy-Dispersive Spectrometry
( E W
Approximately 30 black nodules and clumps of nodules were mounted on two SEM
stubs, described and illustrated with a light microscope, and later coated with carbon for
SEM analysis. Several of the nodules were also cleaved to reveal interna1 structure.
Observations, photographs, and anaiysis with the EDS probe were made at
rnagnifications of 40 - 10000~. SEM and EDS was done at the Department of Geology,
University of Toronto.
4.3.7 Molluscan Ecology
Each 5 cm sample was wet-sieved through a 63 p stainless steel sieve, and al1
identifiable molluscs were collected and air-dried. The molluscs were divided by taxa
and identified to genus or species. Identification was made macroscopically by
cornparison to severai mollusc reference volumes (Tucker Abbott, 1974; Warmke and
Tucker Abbott, 1961) and personal instruction at the Department of hvertebrate
Zoology, Royal Ontario Museum (Calder, personai communication, 1999).
4.3 -8 Pollen Analysis
Pollen anaiysis was initiated in an attempt to reconstruct the vegetation history of the
area. Six subsarnples were randomly selected to determine the potential for detailed
pollen analysis. Each subsample was first spiked with approximately 24000 Eucalyptus
spores to estimate pollen concentration. The sedirnent was then treated with HC1 (to
dissolve the Eucalyptus tablets and carbonates), KOH (to disaggregate the sediment), HF
(to digest the silicates), and acetolysis (to digest the organic matter)(Faegri and Iverson,
1989). The KOH, HF, and acetolysis were heated in a water bath for 2 minutes to
accelerate the reactions, The subsamples were stirred to avoid dumping, and were sieved
with 150 pm and 10 p nylon mesh to remove particles outside the size range of most
pollen (Cwynar et aI., 1979). TBA was used to transfer the sediment I?om the test tubes
to the vids, and safranin stain was added to aid pollen identification. The sedirnent was
then mixed with silicone oïl, rnounted on glas slides, and viewed at 250x and 400x
magnifications with a bînocular microscope. Ai1 processing and microscopy was done at
the Department of Geography, University of Toronto.
5.0 Resuits
5.1 Site Stratigraphy
Based on similarities in colour, texnire, and composition, six distinct stratigraphic units
were identified among the 11 cores and 2 soi1 pits. Unit 1 is clayey, red brown (7.5Y
4/4), compact and dry. Shell and roots are rare, and have probably been incorporated
through bioturbation. Unit II is a grey brown (7.5 Y 4/2) clay, moist and slightly plastic,
and without shell or roots. Unit III has numerous prominent dark yellow (5Y 4/3) mottles
superimposed on a light grey matrix. The sediment is clayey and does not have shells or
roots. Unit N is light grey (5Y 6/1), contains abundant shells and roots (especidly near
the chenier), and has a texture that varies between silty clay and clay. Unit V is olive
grey (5Y 5/11 and has a clayey and very sticky texture. There is no shell, but poorly
preserved roots (30 - 70 mm long and 3 - 5 mm wide) are comrnon. Finally, unit VI is
olive grey (5Y 5/1) and has alternating 2 - 3 cm thick lenses of sand and shell. This
sediment is unconsolidatec! and moist, and roots are rare,
Individual stratigraphic units fiom adjacent cores were correlated based on these
characteristics, and the resulting stratigraphy is illustrated in Figure 5.1. This profile
shows the coastal stratigraphy in association with the approximate extent of identified
archaeological material and the 1999 excavation area. At the bottom is unit 1, which
extends at least 300 m offshore and continues onshore south of the lagoon. Observations
made in ~May 2000 confïrrn this brown unit also extends east and West of the 1999
transect, at roughly the same slope and depth below mean sea level. Above this, units II
and III rinderlie the back-barrier, and may extend partially offshore. Unit N is the
dominant lagoon sediment, and rnay also extend offshore (the most recent lagoon deposit
is a 10 - 15 cm thick grey-black mud that was not sampled, and probably consists of
waste from the sugar mil1 at Maxirno Gomez). A lens of light grey sediment was also
identified in core 4, and at this time has not been assigned to a specific unit. Unit V is
offshore and may overlie unit IV, and unit VI represents the most recent marine deposit.
While no sediment associated with the offshore archaeological material was analyzed, the
samples collected with a soi1 probe in this area appear similar in composition and texture
to units IV and V. Based on the overlapping positions of these units, their order fiom
oldest to youngest is probably: unit 1, unit II, unit III, unit IV, unit V, and unit VI.
The laboratory analysis has three objectives: (1) to evaluate the accuracy of the
visual description of the sediment, (2) to assess the uniformity of the physical, chernical,
and minerdogic properties of the sarnples from each unit, and (3) to infer the depositional
environments of the various deposits. A description of the stratigraphy of each core is
provided in Figure 5-2. Nurnbers 1 to 32 correspond to the sample numbers listed in the
result tables. No samples were taken fkom core 1, which was described and discarded in
Cuba, and samples 10 and 1 1 are fiom soi1 pits 1 and 2 respectively.
5.2 Loss on Ignition (LOI)
The LOI results (Figure 5.2) show that unit II has the highest organic matter content
(roughiy 12%), while unit I has the lowest (5 - 7%). Carbonates make up between 20%
to 40% of each core and generdly decrease with depth. Silicates constitute the bulk of
Each core is Iisted as Figure 5.2(a-k). The location (in UTM coordinates) and depth below mean sea level (in meters) of the top of each core is provided. This is accompanied by the loss on ignition results in the centre charts, where the dashed lines represent organic matter, the dotted lines carbonates, and the solid lines silicates. A description of each unit is also provided
Figure 5.2a. Core 1 (7260 10E 2477375N) - Offshore, 1 .O m below msl.
-sheIly sand -unconsolidated
UNIT V (80 - 160 cm) -abrupt contact with unit VI -some shells -compact and rnoist
UNIT I (1 6O+ cm) -abrupt contact with unit
Figure 5.2b. Core 2 (726050E 24773 15N) - Offshore, 0.9 m below msI.
uNlTV(80-150 cm) -abrupt contact Mth unit
-
-shells decreasc with
-compact and moist -roots cornmon
UNITVI(0-80 cm) -sheiiy sand -sheUs dominate between O - 14 cm and decrease in abundance with depth -roots appear at 23 cm and continue down-core
UNIT 1 (150 + cm) -abrupt contact with unit
Figure 5.3~. Core 3 (726085E 2477260N) -Offshore, 0.8 m below msI.
UNIT VI (O - 70 cm) -sediment dominateci by shell and 2 - 3 cm thick sand lenses -shells concentrated in 1 - 2 cm layes - h e roots appear at 13 CIIL
-sheiis decrease in size between 42 - 70 cm
LNT v(70 - 114cm) -abrupt contact tvith unit VI -compact and sticky texture -large roots are common. but are pooriy preserved
UNITV(114- 1 2 6 ~ ~ 1 ) -sediment has the sarne composition as unit V (above), but grades into a slightly lighter grey
UMT 1 (126 + cm) -abrupt contact with unit v
Figure 5.3d. Core 4 (726 l4OE 24771 8 0 - Lagoon, 0-6 m below rnsl.
UNITIV(0-49 cm> - -abundant sheiïs and roots
UNIT IV (49 - 53 a) marine sheli layer -no sample taken
composition to unit IV -abrupt contact with unit
1 1 IV, ni she~i or roots
UNIT II (59 - 70 cm) -no shell or roots
UNIT IV (70 - 76 cm) -similx to unit N in composition and colour -no sheil or roots
i UNITIi(76-110cm) -no die11 or roots
I
UNiT I(l10 +cm) -transition nom unit II grades over 15 - 20 cm. -drier and more compact tllian unit Ii
Figure 5.3e. Core 5 (726152E 2477 l55N) - Lagoon, 0.6 m below msl.
UNIT IV (O - 53 cm) -sheily behveen 13 - 16 cm, few shells otherwise -some roots
UNIT ïïI (53 - 59 cm) -sediment similar in composition and texhire to unit IV, but no shelt -abru$ contact with unit IN -contact with unit III abrupt
Figure 5.3f. Core 6 (7261 75E 2477 l3ON) - Lagoon, 0.6 m below msl.
UNIT N(0-46 cm) -aImost no shell, except at top 5 c m of core -some roots
UNIT m (46 -50 cm) -sediment similar in composition to unit IV -no sheU or roots -transition between unis N and ïII grades over 3 cm
UNIT II (50 - 68 cm) -abrupt contact ~ l t h unit
-no roots or sheil
UNIT 1 (68 t cm) -transition fkom unit 11 gradual over 15-20 cm -dner and more compact than unit II
Figure 5.39. Core 7 (726200E 2477070N) - Lagoon, 0.5 m below msl.
-shelIs common between O - 15cm
71 -some roots
UNIT11 (20-26m) -abmpt contact with tmît rv -no roots or sheii
4 UMT I (26+ cm) -transition fkom unit II gradual over 5 cm
Figure 5.3h. Core 8 (726230E 2477035N) - Lagoon, 0.25 m below msl.
Figure 5.3 i . Core 9 (726245E 24770 1 ON) - Lagoon, 0.1 5 m below mean sea Ievel.
r I 1
1 : -no sheiis, except for thin
R Iayer at 7 - 8 cm t -no roots
UNIT FI (18 -28 cm) -abrupt contact with unit
-no roots
-abrupt contact with unit
- rn -no sheii or roots
UNIT I(Z8 +cm) -abrupt contact with unit II
Figure 5.3j. Core 10 (726255E 2476990N) - Lagoon, 0.1 m below msl.
-no shelï, some mots -corne t e l m e -Mn nodules
\ Mn Nodule band
Figure 5.3k. Core 1 1 (726260E 2476975N) - Onshore, 0.1 5 rn above msl.
Y0
O 25 50 75 100
Ah horizon (O - 7 cm) -O rganic horizon, dark brown/black -no sample taken
UNIT T (7 +cm) -abrupt contact with Ah horizon -roots are c o m o n and are thicker than those in uni6 WandV a a r s e te.uture
each core (>60%), and generally increase with depth. These results are consistent with
the visual descriptions of each core: the units dominated by shell (IV and VI) contain the
highest carbonate values, while unit 1, with almost no shell, yields the highest silicate
results. There are no spatial trends among the LOI results,
LOI is a cmde analytical technique, and is extremely cornmon in earth sciences
literature largely because of analytical speed. Fume research, however, should use
techniques such as the Walkiey-Black (1934) method for the determination of organic
matter/carbon to produce more reliable results.
5.3 Molluscan Ecology
The results fiom the mollusc analysis are reported in Table 5.1. The total nurnber of each
identified taxa fiom cores 3, 5, 7, and 9 are listed in 5 cm increments, providing a rough
idea of mollusc abundance spatially and ternporally. The bivalves (Anornalocardia,
Chione, and most of the unknown examples) almost always exist in halves, and to
maintain whole nurnbers, each h d f was counted individually with the result that the
bivalves are over-represented- Core 3 has the longest rnollusc record, followed in a
landward direction by cores 5, 7, and 9. Molluscs are almost always associated with units
VI and IV, with the exception of unit V which contains four Anornalocardia shells and
three unidentified bivalves. The total abundance in core 4 varies with depth (although
there is a decrease towards the bottom of unit VI), while the abundance of molluscs in
cores 5 and 7 increase and decrease respectively down-core.
The mollusc species, in order of abundance, are Cerithium eburneum,
Anomalocardia auberiana, Modultcs rnodulus, Chione cancellata, Marginella apicina,
and Urosalpix spp. All are common in shallow marine conditions across the northern
Caribbean (Tucker Abbott, 1974; Warmke and Tucker Abbott, 196 1). The proportions of
each taxa Vary little down each core. The molluscs oear the top of core 3 are brownish
(probably their original colour) and becorne increasingly bleached with depth. Because
there are no obvious temporal or spatial trends in cores 3, 5, 7, and 9, an analysis of the
molluscs from the remaïning cores was not attempted. The results of the mollusc
analysis indicate that units IV and VI are associated with marine conditions. However,
since al1 the molluscs are bleached, abraded, and have no comrnon orientation, they have
probably been transported long distances and reworked fiom farther offshore, meaning
their exact provenance cannot be detennined.
5.4 Particle Size Analysis
The proportions of sand, silt, and clay for each sample analyzed are plotted on a temary
diagram in Figure 5.3. Temary diagrarns ailow sarnples with similar particle size
distributions to be easily grouped, with the degree of homogeneity in each group reflected
by the spread of the data. Particle size was also analyzed every four centimeters for units
I and II in core 4 (time constraints prevented the analysis of the other units) to determine
whether there is textural change with depth (Figure 5.4). The particle size results are
presented in tabular fonn in Appendix A.
Figure 5.3. Ternary diagram o f the proportion of sand, silt, and clay in each sample. Sample nurnbers are colour coded by unit.
% Sand
Key: UNIT 1 UNIT II UNIT III UNIT IV UNIT V UNIT V1
Figure 5,4. Particle size distribution with depth in core 4. The chart on the left in for unit II (including wample 21 at 70 - 76 cm), and the chart on the rightis for unit 1. Values on the y-axes are in cm below top of the core. Bl ack i s sand, medium grey i s silt, and light grey i s clay.
The ternary diagram shows that units 1, III, and V consist of silty clay, unit IV
varies between silty clay and silty sand, unit II is predorninantly clay, and unit VI is silty
sand. The clustering of samples Tom units 1, II, III, V, and VI suggests that particle size
is fairly homogenous across each of these units (although this may also reflect their srnall
sample sizes), whereas the broad spread of the unit IV sarnples indicates the texture of
this unit varies, possibly due to the shell. The particle size resdts nevertheless show that
units II and VI can be can be distinguished from the other units (and fiom each other) on
the basis of texture, whiie the other units have similar particle size distributions. Figure
5.4 shows that unit 1 h e s slightly with depth, while unit II has a relatively uniform
down-core texture. The Iack of data fiom other cores makes it ünclear whether these
conditions are local or extend across each unit,
The particie size results arc concordant with the visual description of the
sediment. Future research should consider the use of a sedigraph (or similar device) to
allow a larger number of smailer sarnples to be analyzed, which would be particularly
useM for down-core textural trends. In addition, the possibility that the coûïse nature of
units IV and VI is in part due to flocculation must be considered, since salt and organic
flocculation are prevalent processes in nearshore lagoonal and estuarine settings millier,
1995). Finally, while as much shell as possible was removed from units IV and VI prier
to analysis, residual shell fragments may have contributed to the coarse fraction of these
units.
5.5 Mineralogy
The resuits of the mineralogy of the clay sized fraction are reported in Table 5.2. The
clay mineral results show that units 1, II, III, and N are fairly homogeneous and can for
the most part be characterized by minor to moderate to quantities of illite, chiorite, illite-
smectite, and kaolinite. The only exception is unit 1, which shows an increase in the
abundance of illite, chlorite, and kaolinite on the seaward side of the lagoon. Unit V, on
the other hand, has abundant illite, chlorite, illite-smectite, and kaolinite, while unit VI is
charactenzed by moderately abundant smectite and, compared to unit V, less abundant
kaolinite and illite. Unit VI can hence be differentiated fiom units 1 through V by the
presence of smectite, while unit V differs fiom units 1 through IV on the basis of high
quantities of illite, illite-smectite, and kaolinite. Spatial patterns in the mineralogy of
units II, III, V, and VI cannot be identified because of their small sample sizes.
Of the primary minerals, gypsum, calcite, and quartz are present in either minor or
moderate quantities in almost d l sarnples, and in unit IV gypsurn increases in abundance
towards the center of the lagoon. Units 1, IV, V, and VI also contain some orthoclase.
Fagundo et al- (1993) show that the groundwater around the Punta Alegre diapir is
supersaturated with calcite and is at near saturation with gypsum, and that drainage from
the diapir is largely seaward through springs below sea level. The calcite and gypsurn
could have entered the lagoon fkorn these offshore springs, although it is possible some
entered the lagoon through the w e a t h e ~ g of unit I. Surface runoff originating fiom the
spnngs south of the lagoon couId be an altemate source of dissolved calcite and gypsurn,
especially during penods of high rainfàll-
Table 5.2. Mineral abundance is estimated fiorn peak height on the diffractograrns: ni1 (-), minor arnount (tr), moderate amount (x), and abundant (xx), Minerats are smectite (S), illite (1), chionte (ChI), illite-smectite (1-S), kaohnite (K), calcite (Cal), gypsum (Gyp), quartz (Q), and orthoclase (O). These results are organized by stratigraphic unit and are ordered in a landward direction within each unit-
Clay Minerals S 1 1 1 Ch1 1 1-S 1 K
Pnrnary Minerals Cal 1 GYP 1 Q 1 O
UNIT II
UNIT IV
UNIT 1
12 13 14
UNIT III 18 19
- - -
UNIT V
- -
20 1 -
28 29 30
tr x tr
tr tr tr
tr x x
- - -
tr x tr
tr x
tr -
tr -
tr tr tr
x x x
tr tr tr
tr - tr
x tr
tr tr
x x
xx
x tr x
xx x
xx
tr -
tr tr
x tr x
- - -
tr tr -
tr
tr tr
x x xx
tr x tr
- -
tr
x x x
-
Because only the clay sized fiactions were studied, the results from the units
dominated by clay (units 1, 11, III, and V) are surely much more representative of the
entire mineral suite than the results fiom the coarser units (N and VI). Future studies
should thus analyze the silt and sand fiactions to develop a more comprehensive
mineralogy .
5 -6 Geochemistry
The concentrations of macro- and microelements for each sarnple are presented in Table
5.3, and the median values f?om each unit are in Table 5.4. The median concentration
allows the various units to be characterized by a single value for each element, and was
used instead of the mean to elùninate the effect of outliers. Advanced statistical analysis
was avoided due to the small sample sizes of some units.
The results in Table 5.3 show that unit 1 is characterized by high Ba, Hf, Ta, Ti,
and V, moderately high IeveIs of AI and Fe, and low levels of Ca, Cl, Br, Cr, Sr and U
when compared to the other units. Unit II is characterized by high Al, K, Mg, Co, Rb, Sc
and Th, moderately high Cs, Ta, U, and V, and low Ca and Na. Unit III is characterized
by high concentrations of Cl, As, and B. and moderately high K, Na, and Cr, and is not
depleted in any element in relation to the other wiits. Unit IV has moderately high Ca,
Mg, As, Mn and Sr, and low values of Al, Na, Fe, K, Ba, Co, Cs, Hf, Rb, Sc, Ta, Ti, Th,
and V. Unit V has very high Fe, Na, Mn, and Sc, rnoderately high Ba, Hf, Ti, and Th,
and low Cl, Mg, Br, Cr, and Sr. Finally, unit VI has the most distinctive chernical
composition, which is characterized by very high Ca, Cr, Sr, and U, and very low
Table 5.3. Concentrations of macro- and microelements are in ppm unless othenvise noted. These are organized in a landward direction within individual stratigraphic units for each element. "e7 indicates values below detection lirnits. Only concentrations above detection lirnits are considered reIiab1e for analysis,
UNIT I 1 2 3 4 5 6 7 8 9 1 O I I
UNIT II 12 13 14 15 16 17
UNIT III 18 19 20
UNIT IV 2 1 22 23 24 25 26 27
UNIT V 2 8 30 29
UNIT VI 3 1 32
UNIT I 1 2 3 4 5 6 7 8 9 10 11
UNIT II 12 13 14 15 16 17
UNIT III 18 19 20
UNTT IV 2 1 22 23 24 25 26 27
UNIT V 28 29 30
UNIT VI 3 1 32
UNIT 1 1 2 3 4 5 6 7 8 9 10 11
UNIT iI 12 13 14 1s 16 17
UNIT III 18 19 20
UNIT IV 2 1 22 23 24 25 26 27
iJNIT V 2 8 29 30
UNIT VI 3 1 3 2
Table 5.4. Median values of macro- and microelements for each unit. Elements dominated by sarnples below detection limits have been omitted. A11 values in ppm unless otherwise noted.
UNIT 1 UNIT U UNIT III UNIT IV UNIT V UNIT VI
UNIT I UNIT II UNIT III UNIT IV UNIT V UNIT VI
UNIT I UNIT II UMT III UNIT IV UNIT V UNIT VI
concentrations of Al, Fe, K, Mg, As, Ba, Co, Cs, Hf, Mn, Rb, Sc, Ta, Ti, Th, V. These
results indicate that no two units have the sarne chernical compositions.
Much of the rnacro- and microelementai data are consistent with the visual
description of the sediment. The extremely high Mn in. sample 8 prompted a closer
inspection of core 10, which reveaied an accumulation of Mn nodules. However, the
relatively low Mn values for the other unit 1 samples suggests this is a local phenornenon.
A description of these nodules and a scenho for their formation is provided in Appendk
B. There is no evidence to indicate that the Mn nodules have an anthropogenic ongin.
The high Ca in sarnples 7 and 11 is probably corn shell incorporated into unit 1 through
bioturbation. Likewise, the high Ca in units N and VI are also probably due to their high
shell content.
The REE results are listed in Table 5.5. The resuits fiom each unit were first
averaged, and the mean concentrations were then chondrite normalized following
Boynton (1984). These concentrations are plotted in Figure 5.5, and the respective
standard deviations are in Appendix C . Figure 5.5 shows that each unit is depleted in the
heavy REEs (Tb, Dy, Yb, and Lu) compared to the light REEs (La, Ce, Nd, and Sm).
The proportions of REEs in each unit are extremely uniform, aithough unit VI is slightly
enriched in Nd and Lu and depleted in Dy. Unit V I also has the lowest concentration of
REEs, foflowed by units IV and III, while the concentrations of units 1, II, and V are
highest and alrnost identical. Each unit also has a strong negative Eu anornaly and a
weak negative Ce anomaiy.
The REEs in nearshore sediments generally have a detrital onD& and usually
display a negative slope (Fleet, 1984). This indicates that units 1, II, III, IV, and V
probably derive fiom a similar terrestrial source. The similarity of the unit VI c u v e also
suggests that much of this sediment is detrital. The positive Nd and Yb anomalies could
be fkom small quantities of authigenic marine material, but more likely reflect a different
source area than units 1 to V. Many marine authigenic sediments are also chstracterized
by extremely strong Ce depletions (Piper, 1974), and the absence of this trend supports a
Table 5.5. Concentration of REEs in ppm.
UNIT 1 1 2 3 4 5 6 7 8 9 1 O II
UNIT II 12 13 14 15 16 17
üNIT III 18 19 20
UNIT IV 2 1 22 23 24 25 26 27
UNIT V 2 8 29 30
UNIT VI 3 1 3 2
Figure 5.5. Chondrite normalized concentrations of REEs by stratigraphie unit.
+ UNiT I
UNiT II
A UNIT III
x UNiT lV
x U N i T V
e U N T T V I
Eiernent
largely detrital origin for unit VI. The high concentrations in units 1 and V can in part be
explained by the f5ne texture of these sedients, which likely contain abundant clay
minerais to which the REEs are adsorbed (Xianjue et al., 1983). However, the
mineralogy results (Table 5.2) show that unit VI is also abundant in certain clays,
implying there is another reason for the Iow concentration of REEs in unit VI. Finally,
the Eu depletions are likely ioconsequential as vimially ail post-Archean sedimentary
rocks display this trend (Taylor and McLennan, 1985).
5.7 Pollen Analysis
Two samples fiom unit IV in core 6 were exarnined for pollen, but only two grains were
discovered. Both were vesiculate grains, probably Pinus cnribaea, and in good
condition. However, the extremely low pollen concentration suggests that palynology
may be of limited use for paleoecologicd reconstruction or biostratigraphic correlation in
the lagoon at Los Buchillones. Because of this, pollen analysis was discontinued.
although fùture analysis using other polIen concentration techniques, such as heavy-
liquid separation, rnight isolate enough pollen for Iarger counts to be made.
5.8 Environrnents of Deposition
Unit 1
Unit I was formed in a terrestrial environment. Since the onshore portion is a soil
(because it supports mangrove and other plants), the portion underlying the lagoon,
chenier, and offshore sediment must be a buried soil. It is unclear, however, what soil
horizon(s) the buried portion represents. The low organic matter content and scarcity of
roots in cores 1 - 10 implies the A horizon rnay have been partiaily truncated, possibly by
rishg sea level. The physicai properties of unit I are also consistent with the B horizon of
the Francisco series soil, which is characterized by a brownish red colour, h e texture,
dry consistence, and "abundant black pellets" (Suelos de la Provincia Ciego de ~ v i l a ,
1983:127). While the description of the pellets is vague, it leaves open the possibility
that Mn nodules are more common in this area than the geochemistry results imply.
Finally, the slight £k ing with depth of unit 1 may reflect clay translocation, which is a
cornmon feature of many B horizons (Birkeland, 1999), but this cannot be confirmed on
the basis of one short core.
Assuming the underlying parent material is uniform, unit 1 represents the
footslope of a toposequence. Appendix A shows that the particle size of unit 1 fines
seaward, suggesting a downslope movement of clay has occurred. This accumulation of
clay could partially explain the high illite and kaolinite values in the soil underlying the
lagoon. However, the shallow dope of unit 1 implies that downslope rnovement is not a
dominant process, and that these elevated values may also reflect in situ weathering.
Additional sampling south of the lagoon is needed to better characterize the
properties of the local soils, and determine whether a local analogue exists for unit 1. If
deeper cores c m be recovered, an assessment of down-profile variation in Fe and Al
would be useful to demonstrate whether translocation is active, and identie what portion
of the profile is preserved. This might require the use of a vibracorer (or similar device)
for deeper penetration into the sediment. Down-profile analysis would also be
complicated by land-crab bioturbation, especially at the south end of the lagoon. Future
research should analyze the pH, base cations (~a*, ~ g * , ~ a + , KY, and CEC to facilitate
cornparison between unit 1 and the soils in the Los Buchillones area.
Unit II
Unit 11 was probably deposited in a lagoon. This is suggested by its Location relative to
the present lagoon, its fine texture which indicates deposition in low energy conditions,
and its grey colour indicating a reduced environment existed. Unit 11 has higher total Fe
than units III and IV, and much is probably in the soluble ~ e * form because of the
reducing conditions (Birkeland, 1999). This indirectly supports the idea of deposition in
a lagoon, as the ~ e * might have draùied unless it was impounded. The similarity of the
mineralogy and REE concentrations of units 1 and II implies most of this sediment is
detritd and originated upslope, although some may have also been reworked from unit 1
as the lagoon transgressed the coast. The gradual transition between units I and II is an
indication that the deposition of unit II began slowly, which implies lagoon formation
was a h gradual, and likely not f?om hurricane activity. Finally, particle size,
mineralogy, and geochemistry results indicate that sample 21 cannot be assigned to any
stratigraphic unit at this time.
Ohir 111
Unit III is also probably lagoonal. This is supported by its fine texture, which again
suggests deposition in a low energy system. The yellow mottles (Plate 5.1) likely
Plate 5.1, Photograph of a section of core 6. Unit III is between 46 - 50 cm. Unit IV ends at 46 cm, and unit II begins abniptly at 50 cm.
represent the accumulation of Fe. Yellowish Fe compounds cm form if the moisture
content of a sedirnent varies sufficiently between seasonally saturated (reducing
conditions) followed by a season of low water (oxidizing conditions) (Birkeland, 1999).
This might indicate that the hydrology of the lagoon was characterized by low or
fluctuating water levels, possibly driven by tides, storms, or a change in precipitation.
Unit w
Unit IV was deposited in a lagoon. The mineralogy and REE concentration of unit N
closely resembles units 1, II, and III, sugpsting an upslope source. The relatively low
quantities of kaolinite, smectite, and illite, which characterize units V and VI, indicate
that marine sediments have not been incorporated into the lagoon to any great degree.
Nevertheless, some communication between the lagoon and sea has been ongoing, since
marine shells are present throughout unit N in cores 5, 7, and 9. While the fairly coarse
particle size suggests deposition in higher-energy conditions than unit II, there is no
evidence for severe storm activity, such as lenses of sand or gravel.
Unir V
Unit V was likely deposited in a shdIow nearshore environment. Its location outside the
chenier implies a marine origin, and the strong 10 A and 12 A peaks on the unit V
difiactograms couId represent glauconite and glauconite/smectite. The presence of
these niinerals is also supported by the olive colour of the sediment. If glaucony is
present, the high proportion of glauconite and glauconite/smectite, coupled with an
absence of smectite implies that highly evolved pellets have formed. Large quantites of
chlorite and kaolinite in this unit may be detrital, and a possible source for the gypsurn,
quartz, and calcite is groundwater fiom the Punta Alegre diapir via the offshore springs.
unit vr
Unit VI is clearly marine in origin. The lack of smectite in other units suggests that this
minera1 may have an authigenic rather than detrital origin. This is, however, inconsistent
with the REE results, and Pavlidis et al. (1995) argue that the clay minerd suite in recent
sediments offshore southem Cuba aiso derives largely from terrestrial sources.
Nevertheless, since authigenic smectites ofien form fiom volcanic material (Hillier, 1995;
Weaver, 1989), a possible source would be the voicanic islands of the eastem Caribbean.
Geochemically altered smectite is common offshore in Puerto Rico (Breyer and Ehlrnann,
1981), and the westward curent north of Puerto Rico and Hispaniola could be a vector
for its transport to northern Cuba Moderately hi& diffiraction peaks at 10 A and 12 A
couid be fiom glauconite and glauconite/smectite. While the coarse texture and olive
colour of unit VI implies that highly evolved glaucony pellets may be present, the
moderately abundant glauconite and glauconite/srnectite suggests an earlier stage of
development than the glaucony in unit V.
6.0 Discussion
6.1 Absolute Site Chronology
The lack of datable material, such as mangrove peat and seeds, has made it difficult to
establish an absolute site chronology. Dating the roots and molluscs was avoided
because of theü uncertain provenance. The archaeological material can nevertheless be
used to estimate maximum and minimum dates for certain units. If the Taino remains
date between AD 1220 and 1620 and are associated with unit IV, units 1, II, and III would
predate AD 1220, and the latest the deposition of unit IV could have begun is AD 1220.
If the site is associated with unit V, then the begùining of deposition of unit IV would
also predate AD 1220-
Maximum dates can also be estimated fiom the Bahamas' sea level cuve (Figure
2.6). This indicates that the lagoon is unlikely to be more than 3300 years old, unit III
has a maximum age of 2800 BP, and unit IV probably dates no earlier than 2500 BP.
M i l e this in concordance with dates estimated fiom the archaeological evidence, it does
not necessarily mean the Iagoon is 3000 years old. Basal sediments in two small,
shallow, coastal ponds fÎom Lee Stocking Island, Bahamas, date to 1500 * 70 BP (Dix et
al., 1999), suggesting 1000 to 2000 years is more realistic for the age of the lagoon at Los
Buchiliones. It is thus probable the lagoon predates the Taino settlement.
Given the need for a firm site chronology, future research rnight consider
optically-stimuiated luminescence (OSL) and mass-spectrometric uranium series dating
(MSIU-series). These techniques cm be used on waterlaid sediments and calcite rich
soils respectively, although since they are only useful for periods >1 ka, they are probably
only relevant to the pre-Taino stratigraphy (Rapp and Hill, 1998). Ln the meantirne, the
possibility of conventionally radiocarbon dating a large sample of unit 1 should be
considered, but only after the organic carbon content is more precisely determined.
6-2 Where Were the Taino Houses Built?
The geologicai and archaeological evidence together support the hypothesis that the
Taino houses were built over water. If the houses were built on land, a marine
transgression siilce site abandonment would have had to occur. As Figure 3.1 illustrates,
a transgression occurs when sea level rises or a shoreline erodes (Curray, 1964). Since
the base of the archaeo1ogical deposit is at least 1 m below present mean sea leveI, sea
level between AD 1220 and 1620 wodd have had to be signXcantly Lower than that,
which is inconsistent with regional sea level data (Boardman et al., 1988). An alternative
scenario is that the Taino houses collapsed on a beach that has since eroded. This is not
in agreement with the archaeological evidence, however, which has yieIded well
preserved roofs. Since a roof will logically be at the top of a collapsed (and undisturbed)
house deposit, most of the sediment eroded fiom the chenier since the 1950's was likely
deposited after AD 1620.
While it is likely the houses were built in the water, it is unclear whether they
were in the lagoon or offshore. As mentioned, before the 1950's the chenier extended at
least 50 m seaward of its present position, and a portion of the site is presently in the
Iagoon. From this, three models for the evolution of the lagoon-barrier system since AD
1620 c m be devised (Figure 6.1). The f i s t mode1 has the village completely offshore. In
this case, the chenier would have had to first prograde at least 60 m seaward, and the
back-barrïer would have had to erode to reveal the southem portion of the site. The
second model has the village entirely in the lagoon. One possible scenario is that the
seaward side of the chenier remained stable, and the back-banier migrated landward over
50 m to its position in the 1950's. A second possible scenario is that the chenier
transgressed the site to its present position, and then prograded seaward until the 1950's.
Finally, the third model has the village in both the lagoon and sea. In this case, the
seaward side of the chenier progrades to its position in the 195OYs, and îhen erodes while
the back-barrier migrates several meters into the lagoon.
The available evidence supports the notion that at least part of the village was in
the lagoon. Mode1 1 is unlikely, since an eroding back-barrier is inconsistent with the
washover fans, which clearly reflect a recent landward movement of the chenier. Models
2 and 3 are both possible, as they can explain why some of the site is presentIy in the
lagoon. The hardpan in the chenier provides additional support for model 3, since it has
presurnably required the chenier to have remained stable for its formation. Despite this,
these models assume that al1 the Taino houses are contemporary; it may be that the Taino
originally settled offshore, and later rnoved into the lagoon. In addition, significant
environmental change could have also occured during the 400 years the site appears to
have been occupied for. Another possibility is that the Taino settlement was on a beach
that eroded, and was later raised on pilings in the same area, which is an adaptation
common today in coastal villages in peninsular Malaysia (Chan and Parker, 1996)-
AD 1955 Present
Figure 6.1. rl'lie circles represent (in plan view) the Taiiio site, and the vertical bars represeni the clienier. The lagoon is always to the riglit. 1ii inodel 1, the site is completely offsliore. In iiiodel 2, the site is completely in tlie lagoon. In mode1 3, the site is in tlie lagoon and offsliore. Tliis schematic is not to scaie.
6.3 Environmental History of the Littoral Zorze
The presence of marine and lagoon sediments over a terrestrial surface indicates a recent
marine transgression has occurred. This is consistent with the transgressive mode1 of
Kraft and Chrzastowski (1978)(Figure 3.2) and the Bahamas' sea level curve (Boardman
et al., 1988). Nonetheless, based on this sea levei curve, and using an estimated
chronology, it is possible to partially reconstruct the Late Holocene environmentai history
of the Los Buchiliones coast.
3000 BP [O 1500 BP
Sea level had been rising at a decelerating rate since at least 8000 BP, and the climate
waç probably much like the present. There was no bamer or lagoon, and the nearshore
sediment was unit V. Whether a sand or sheII beach was present is uncertain, but the
roots in unit V suggest the flora of the littoral zone may have consisted of seagrass and
mangrove.
1500 BP to 1000 BP
Around 1500 BP, a barrier formed and enclosed a lagoon. The composition of this
barrier is unknown, but the lack of shell in unit V suggests it may have consisted largely
of sand. Whether this barrier was specifically a chenier cannot be determined with the
available evidence. The deposition of unit II followed as the Lagoon fonned. The lagoon
may have been farther north than at present, but this cannot be confïrrned until the
stratigraphy ùnmediately offshore is refined.
1000 BP tu 730 BP (AD 1220)
Oxidizing conditions characterized the lagoon around 1000 BP, possibly reflecting a
period of low (or no) water. A low lagoon level can occur when the rate of sedimentation
exceeds the rate of sea level rise, or sea level experiences a stillstand or drops (Figure
3.7). However, whether either of these conditions was responsible is impossible to
determine fiom the lack of radiocarbon dates and the crude sea level curve. The possible
drop in lagoon level would have been followed by a rise in the level of the lagoon and the
deposition on unit N, sometime prior to AD 1220.
AD 1220 tu AD 1955
Around AD 1220, the Taino likely settled at the interface between the lagoon and sea.
This area would have offered access to marine, lagoon, and terrestrial resources, while
the diapir and offshore cayes appear to have offered protection against severe stoms.
The lagoon would have provided a defensive barrier, while the proximity to the ocean
would have facditated transport dong the Coast. Pilings would have been necessary to
support structures in the fine textured substrate (Sowers and Sowers, 1970). Houses on
piIings are common today in northern South Arnerica and Southeast Asia, and are usually
occupied by people whose economy is based Iargely on seafood (Oliver, 1987), perhaps
like the Taino at Los Buchiilones.
Los Buchillones was probably abandoned around AD 1620. The nwnber of
portable and ceremonid artifacts recovered suggests that abandonment was sudden.
Given that Spanish colonies were common in the Greater Antilles by AD 1600 (Nuevo
Atlas Nacional de Cuba, 1989), a possible explanation is that the Taino at Los
Buchillones were pressed into slavery or simply killed. If these dates are correct, it
appears that Los Buchillones was occupied for an uncharacteristically long penod of tirne
d e r Spanish arrival in the New World. The archaeologicai and sedimentological
evidence show that severe storm activity or some other local environmental catastrophe
are unlikely causes of abandonment.
The excellent preservation of the wooden artifacts can in part be explained by the
flooded nature of the site. The artifacts and structures probably immediately entered a
reduced environment, and the low-energy conditions of the coast and lagoon would have
prevented physical damage- Nonetheless, early Spanish shipwrecks in the Gulf of
Mexico and Caribbean are rarely as well preserved (Bowden, 1996), which implies some
microenvironmental factor at Los Buchillones also contributed to the preservation.
Finally, since archaeological wood often undergoes mineralogical, chernical, and physical
change once deposited in a marine environment (Florian, 1990), the possibility of usulg
the composition of the Taino artifacts as a paleoenvironmental indicator should be
explored, especidly since the wood c m be reliably dated by "c.
AD 1955 to the Present
The construction of a breakwater in 1950's was roughly synchronous with the beginning
of erosion to the seaward side of the chenier (Pendergast, 1997). The chenier was
breached at least as early as 1959, and the hydrology of the lagoon appears to have since
been aimost completely controlled by the offshore tide. WhiIe local residents indicate the
erosion of the chenier is continuing, mangrove progradation on the washover fans will
help maintain the chenier, although at its present rate of recession, it is unlikely to survive
more than a few decades.
7.0 Conclusions
The coastd stratigraphy records a recent marine transgression, which is concordant with
data fiom the Bahamas showing that relative sea level has risen at a decelerathg rate
since 8000 BP. The bottommost stratigraphie unit identined likely represents a former
terrestrial surface. Overlying the buried soi1 are four lagoonal and two marine units. An
accumulation of dark yellow rnottles in one unit indicates that oxidizing conditions,
possibly fiom a period of low water, characterized the early history of the lagoon- The
absence of material suitable for 14c dating (e.g. mangrove peat, seeds) has prevented the
establishment of a firm chronology. Nevertheless, regional sea level data and
sedimentation rates iTom shallow coastal ponds in the Bahamas suggest the lagoon at Los
Buchillones is ZOO0 to 2000 years old, and likely predates the Taino settlement. Finally,
although pollen analysis of the Los Buchillones lagoonal sediments was unsuccessfd,
friture research rnight consider diatoms or benthic foraminifera for paleoecological
reconstruction and biostratigraphic correlation.
This thesis has also shown that the Taino houses were likely located both offshore
and in the lagoon. This is impossible to confirm fiom the limited fieldwork done to date,
and additional transects are needed to more accurately reconstnict the history of chenier
migration. This coast would have been attractive for settlement because its proximity to
the sea offered routes for transportation, it is protected (from hurricanes and people) by
the offshore cayes, diapir, and lagoon, and it offers accessibility to marine, lagoon, and
terrestrial resources. Similar reasons prompt many people to Iive in houses raised on
pitings today, especially in northem South Arnerica and Southeast Asia (Oliver, 1987).
An analysis of the sediment in direct association with the archaeological material
would Iikely confirm what environment(s) the Taino houses were built An examination
of the internal structure of the chenier would also be usefid, although this would require
the use of an intrusive caisson to control flooding. The development of a high resolution
late Holocene sea level cuve should be a priority, and may involve sampling in lagoons
elsewhere dong the Coast to recover material suitable for dating, such as mangrove peat.
References Cited
Antonio Curef L. (1992). "House Structure and Cultural Change in the Caribbean: Three Case Stuclies fiom Puerto Rico." Latin Amencan Antiquiv. 3(2): 160-1 74.
Arshad, M.A. and St. Arnaud, R.J. (1980). ccOccurrence and Characteristics of Ferromanganiferous Concretions in some Saskatchewan Soils." Canadian Journal of Soi1 Science. 60:685-695.
Augustinus, P.G.E.F. (1989). "Cheniers and Chenier Plains: A General Introduction." Marine Geolow. 90:2 19-229.
Barnes, R.S.K. (1980). Coastal Lagoons: The Natural Histow of A Neglected Habitat. New York: Cambridge University Press. 106p.
Beiknap, D.F. and Kraft, J-C. (1 98 1). "Preservation potential of transgressive coastal lithosornes on the US. Atlantic shelf" Marine Geology. 42:429-442.
Birkeland, P. W. (1999). Soils and Geomorpholow. New York, Oxford University Press. 430p.
Blanchon, P. and Shaw, J. (1 995). "Reef drowning during the last deglaciation: Evidence for catastrophic sea-level rïse and ice sheet collapse." Geoloev. 23(1):4- 8.
Boardman, M.R., Neumann, AC. and Rasmussen, K.A. (1 988). ccHolocene Sea Level in the Bahamas." In: Mylroie, J. (ed.). Proceedings of the 4" Symposium on the Geolow of the Bahamas. Bahamian Field Station, Bahamas. p. 45-52.
Borhidi, A. (1 987). "The Main Vegetation Units of Cuba." Acta Botanica Hunearica. 33(3-4):151-185.
Borhidi, A. (1996). Phflogeoma~hv and Vegetation Ecolo~y of Cuba. Budapest, Akademiai Kiado. 923p.
Bourrouilh-Le, J. F. G. and Evin, J. (1992). "Mid Holocene hi& sea level stand in the Bahamas and the hurricane sedimentological and diagenetical control on carbonates deposition. (super 14) C results on the tidal flats of Andros Island." 2gLh International Geoloeical Coneress: Abstracts. Kyoto, Japan. p. 390.
Bowden, T. (1996). "Gleaning Treasures fiom the Silver Bank." National Geo.~aphic. 190(1):90-105.
Boynton, W.V. (1 984). c'Cosmochemistry of the Rare Earth Elements." In: Henderson (ed.). Rare Earth Element Geochernistry. Amsterdam, Elsevier Science Publishers B.V. 50 2 p.
Breyer, J.A. and Ehlrnann, A. J. (1 98 1). "Mineralogy of arc-derived sediment: diciclastic sediment on the in&lar shelf ofPuerto Rico." Sedimentolow. 28:61- 74.
Canas ibril, P., Quintero, M., Elisa Olivera, H., and Materno, F. (1 974). Geographia de Cuba. La Habana, Editorial Pueblo y Educacion. 1 5 2 ~ .
Cangzi, L. and Walker, H.J. (1 989). "Sedirnentary Characteristics of Cheniers and the Formation of the Chenier Plains of East China-" Journal of Coastal Research. 5(2):353-368.
Carew, J.L. and Mylroie, J.E. (1995). "Quaternary Tectonic Stability of the Bahamian Archipelago: Evidence fiom Fossil Coral Reefs and Flank Margin Caves." Ouaternary Science Reviews. 14: 145- 153.
Carroll, D, (1970). Clay Minerals: A Guide to Their X-ray Identification. The Geological Society of America Special Paper 126. Boulder, Geological Society of America. 80p.
Cermak, V., Bodri, L., and Safanda, 1. (1992a). "Underground temperature fields and changing climate: evidence fiom Cuba," Palaeo~eopra~hv. Palaeoclimatolow. Pdaeoecologv (Global and Planetary Change Section). 97:325-337.
Cern&, V., Bodri, L., and Safanda, .J. (1992b). "Recent clirnate change recorded in the underground: evidence from Cuba," Palaeoneographv. PalaeocIimatolo W. Palaeoeco1o.q (Global and Planetary Change Section). 98:2 1 9-223.
Cescas, M.P., Tyner, E.H., and Harmer, R.S. (1970). "Ferromanganiferous Soil Concretions: A Scanning Electron Microscope Study of Their Micropore Structures." Soil. Sci. Soc. Amer. Proc. 34:641-644.
Chan, N.W. and Parker, D.J. (1996). "Response to dynamic flood hazard factors in peninsular Malaysia." The Geographical Journal. 1 62(3) :3 13-325.
Cintron-Molero, G. and Schaeffer-Novelli, Y. (1 992). "Ecology and Management of New World Mangroves." In: Seeliger, U. (ed.). Coastal Plant Cornrnunities of Latin America. San diego, Academic Press Inc. p. 234-258.
Coffin, D.E. (1963). "A method for the determination of fiee iron in soils and clays." Canadian Journal of Soil Science. 43 :7-17.
Cooper, J.A.G. (1994). "Lagoons and microtidal coasts." In:Carter, R.W.G. and Woodroffe, C.D. (eds.). Coastal Evolution: Late Q u a t e m q Shoreline Morr>hodvnamics. New York, Cambridge University Press. p. 2 1 9-266.
Curray, J.R. (1964). "Transgressions and Regressions." In: Miller, R.L. (ed.). Papers in Marine Geolom. New York, Macmillan Publishing Co. p. 175-203.
Cwynar, L.C., Burden, E. and McAndrews, J.H. (1 979). "An inexpensive sieving method for concentrating pollen and spores fkom fine grained sediments," Canadian Journal of Earth Sciences. 19: 1 1 15-1 120.
Daniel, J .RK (1989). "The chenier plain coasta! system of Guyana." Marine Geolow. 90:283-297.
Davis, R.A., Knowles, S C . , and Bland, M.J. (1989). "Role of Hurricanes in the Holocene Stratigraphy of Estuaries: Examples fkom the Gulf Coast of Florida." Journal of Sedirnentarv Petrologv. 59(6): 1052-1061.
Day, P.R. (1 965). ParticIe fiactionation and particle-size analysis. In: Black, C.A. (ed.). Methods of Soi1 Anaivsis. Madison, Amencan Society for Agronomy. p. 545-567.
Dean, W.E. (1 974). "Determination of carbonate and organic matter in calcareous sediment and sedimentary rocks by loss on ignition: a cornparison with other methods." Journal of Sedimentaw Petrolom. 44:242-248.
Dix, G.R., Patterson, R.T., and Park, L.E. (1999). "Marine saline ponds as sedimentary archives of late Holocene climate and sea-level variation dong a carbonate platfom margin: Lee Stocking Island, Bahamas." Palaeogeoaaphy. Palaeoclimatology, Palaeoecolow. 150:223-246.
Dunayev, N-A- (1977). "A Quantitative Analysis of Vertical Tectonic Movements on the Cuban Shelf." Oceanology. 17(6):695-697.
Elliott, T. (1978). "Clastic Shorelines." In: Reading, H.G. (ed.). Sedimentarv Environments and Facies. New York, Elsevier. p. 143- 177.
Faegri, K. and Iverson, J. 1989. Textbook of Pollen Analysis. New York, J. Wiley & Sons. 237p.
Fagundo, J-R-, Rodriguez, I.E., de la Torre, J., Arencibia, J.A., and Forti, P. (1993). "Hydrologie and Hydrochemical Characterization of the Punta Alegre Gypsurn Kasa (CUBA)," In: Masiabian, A. (ed.). International Symposium on Water Resources in Karst with Saecial Emphasis on Arid and Semi Arid Zones. Proceedings of Articles of International Karst Symposium, S hiraz, Iran, Octo ber 1993. p. 485-498.
Fairbanks, R.G. (1 989). "A 17,000-year glacio-eustatic sea Ievel record: influence of glacial melting rates on the Younger Dryas event and deep-ocean circulation." Nature. 342(7) :63 7-642.
Fischer, A.G. (1961). "Stratigraphie Record of Transgressing Seas in Light of Sedimentation on Atlantic Coast of New Jersey." The American Association of Petroleurn Geologists Bulletin. 4S(lO): 1 656- 1666.
Fitzpatrick, E.A. (1986). An Introduction to Soil Science. Addison Wesley Longman Limited, Edinburgh Gate. 25513.
Fleet, A.J. (1 984). "Aqueous Sedimentary Geochemistry of the Rare Earth Elements." In: Henderson (ed.). Rare Earth Element Geochernistry. Amsterdam, Elsevier Science Publishers B.V. 50 1p.
Florian, M.E. (1 990). "Scope and History of Archaeological Wood." In: Rowell, R.M. and Barbour, R.J. (eds.). Archaeological Wood: Properties. Chemistry. and Preservation. Washington, D.C., American Chernical Association. p. 3 -32.
Folk, R.L. (1968). Petroloe, of Sedimentary Rocks. Hemphill, University Station, Austin, Texas. 170p.
Graham, E., Pendergast, D.M., Calvera, J., and Jardines, J. (2000). "Excavations at Los Buchillones, Cuba." Antiquity. 74(284):263-264.
Guillén, J., Camp, J., and Palanques, A. (1 994). "Short-time evolution of a microtidal barrier-lagoon system affected by storm and overwashing: the Trabucador Bar (Ebro Delta, NW Mediterranean)." Zeitschrifi für ~eorn&pholoeie N.F. 38(3):267-28 2 .
Hillier, S. (1995). "Erosion, Sedimentation, and Sedimentary Origin of Clays." In: Velde, B. (ed.). Oriein and Mineraloav of Clavs: Clavs and the Environment. Springer, Berlin. p. 162-219.
Hodell, D.A., Curtis, J. H., Jones, G.A., Higuera-Gundy, A. Brenner, M. Binford, M.W. and Dorsey, KT. (1 99 1). ccReconstruction of Caribbean clirnate change over the past 10,500 years." Nature. 3 52(29):790-793.
Hoyt, J.H. (1969). "Chenier Versus Barrier, Genetic and Stratigraphic Distinction." The American Association of Petroleum Geologists Bulletin. 53(2):299-306.
Hubbard, D.K. (2992). "Hurricane induced sediment transport in open-shelftropical systems - An example fiom St. Croix, .U.S. Virgin Islands." Journal of Sedimentary Petrology. 62:946-960.
Hutchings, P. and Saenger, P. (1987). Eco1o.q of Manmoves. University of Queensland Press, Queensland, Australia. 3 88p-
Iturralde-Vinent, M.A. and Roque Marrero, F.D. (1 982). c'Nuevos datos sobre las estructuras diapiricas de Punta Alegre y Turiguano, en la Provhcia Ciego de Avila." Ciencias de la Tierra y del Espacio. 4:47-55-
Kalbfleisch, W.B.C. and Jones, B. (1998). ccSedimentology of Shaliow, Hurricane- AfEected Lagoons: Grand C a p a n , British West Indies." Journal of Coastal Research. 14(3): 140-1 60.
Keegan, W.F. (1995). "Modeling dispersal in the prehistoric West Indies." World Archaeolog7/. 26(3):4O 1-41 9.
Keegan, W.F. and MacLachlan, M.D. (1 989). "The Evolution of Avunculocal Chiefdorns: A Reconstruction of Taino Kinship and Politics." Arnerican Anthro~ologist. 9 1 (3):6 13-630.
Kellrnan, M. and Tackaberry, R. (1 997). Tropical Environments: The Functioning and Management of Tropical Ecosvstems. London, Routlage. 380p.
Kjellmark, E. (1996). "Late Holocene climate change and hurnan disturbance on Andros Island, Bahamas." Jounial of Paleolimnolo~y. 15 : 2 33-145.
Kjerfve, B. and Magill, K.E. (1 989). "Geographic and Hydrodynamic Characteristics of Shallow Coastal Lagoons." Marine Geolow. 88: 187-1 99.
Kraft, J-C. and Chrzastowski, M.J. (1978). ''Coastal Stratigraphic Sequences." In: Davis, R.A. (ed.) Coastal Sedimentarv Environrnents. New York, Springer-Verlag. p. 625-663.
Kraft, JC., Kayan, I., and Aschenbrenner, SE- (1983). ccGeological Studies of Coastal Change Applied to Archaeological Settings." In: Masters, P.M. and Flemming, N.C. (eds.). p.57-84.
Kuhlmann, D.H.H. (1974). "The Coral Reefs of Cuba." In Proceedinas of the Second International Coral Reef Symposium 2. Great Barrier Reef Committee, Brisbande, December 1974, p.69-83.
Lewis, J.F. and Draper, G. (1 990). "Geology and tectonic evolution of the northern C Caribbean margin." In: Dengo, G. and Case, J.E. (eds.). The Caribbean reion. Boulder, Colorado, Geological Society of America, the Geology of North America, v. H.
Lind, A.O. (1969). Coastal Landforms of Cat Island. Bahamas: A Studv of Holocene Accretionarv Topography and Sea-Level Change. Department of Geography Research Paper No. 122, University of Chicago. 156p.
Mahaney, W.C., Hancock, R.G.V., and Sanmugadas, K. (1 99 1). "Extractable Fe-AI and geochemistry of Late Pleistocene paieosols in the Dalijia Shan, western China." Journal of Southeast Asian Earth Science. 6(2):75-82.
Mahaney, W.C., Milner, M.W, Bezada, M., and Hancock, R.G.V. (1 999) "Paleosols and Andean Uplift in Venezuela: Assessing Competing Hypotheses of Relict Tropical Soils Versus Paieohydrogeochemica1 Variations," Unpublished Manuscript.
Marius, C. and Lucas, J. (1 99 1). "Holocene Mangrove S wamps of West Afica." Journal of Afiican Earth Sciences. 12(1-2):4 1-54.
Meyerhoff, A.A. and Hatten, C. W. (1 968). "Diapiric Structures in Central Cuba." Arnerican Association of Petroleum Geologists Memoir 8. p.3 15-357.
Moore, D.M. and Reynolds, R.C. (1 989). X-Ray Diffraction and the Identification and Analysis of Clay Minerais. Oxford, Oxford University Press. 332p.
Nichols, M.M. (1 989). "Sediment Accumulation Rates and Relative Sea-Level Rise in Lagoons." Marine Geolom. 88:20 1-2 19.
Nuevo Atlas Nacional de Cuba. (1989). La Habana, Institut0 de Geografia de la Acadernia de Ciencias de Cuba-
Oliver, P. (1 987). DweIIinas: The House Across the World. Phaidon, Oxford. 256p.
Otvos, E.G. and Price, A. (1979). "Problems of Chenier Genesis and Terminology -An Overview." Marine Geoloa. 3 1 :25 1-263.
Oyama, M. and Takehara, H. (1970). Revised standard soi1 colour charts. Japan Research Council for Agriculture, Forestry and Fisheries,
Pardo, G. (1975). "Geology of Cuba." In: Nairn, A.1.M and Stehli, F.G. (eds.). ocean basins and mirgins: The Gulf of Mexico and the Caribbean, New York, Plenum Press, p. 553-615.
Parfitt, R.L. and Childs, C.W. (1988) "Estimation of forms of Fe and Al: A review and analysis of contrasting soils by dissolution and Moessbauer methods-" Australian Journal of Soi1 Research. 26: 121-144.
Parsons, M.L. (1998). "Salt Marsh Sedimentary Record of the Landfail of Hurricane Andrew on the Louisiana Coast: Diatoms and Other Pdeoindicators." Journal of Coastal Research. l4(3):939-950.
Pattan, J.N., Rao, Ch.M., Higgs, N-C., Colley, S. and Parthiban, G. (1 995). "Distribution of major, trace, and rare-earth elements in surface sediments of the Wharton Basin, Indian Ocean." Chernical Geolom. - - 2 2 1 :20 1 -2 1 5.
Pavlidis, Y.A., Scherbakov, F.A., and Shevchenko, A. Y. (1995). "Clay minerals in bottom sediments of Cuba and White Sea shelves: A cornparison of geologic and climatic controls." Oceanolo~y. 3S(l): 1 12- 2 18.
Peck, D.T. (1998). "The Case for Prehistorïc Cultural Contact between the Maya on the Yucatan and the Indians of Florida." The Flonda Anthropologist. 5 1 (l):3-14.
Pendergast, D.M. (1994). "Up to Your Knees (Not Headfirst, Luckily) in the Fango: El Sitio Arqueologica Los Buchillones, Prov. de Ciego de Avila, Cuba." Archaeologicd Newsletter, Series Il No.55.
Pendergast, D.M. (1996a). "The Los Buchillones Site, North Coastal Cuba." NewsWARP. 19~3-6-
Pendergast, D.M. (1996b). "AMS Dates from Los Buchillones, Cuba." NewsWARP. 20:33.
Pendergast, DM. (1 997). "Up fiom the Shallows: A look at the ROM'S first archaeological excavation in Cuba." Rotunda. 30(2):28-35.
Pendergast, D.M. (1 998). "The House in the Water." Rotunda. 3 1(2):26-3 1.
Penland, S. and Suter, J.R (1989). "The Geomorphology of the Mississippi River Chenier Plain." Marine Geolow. 90:23 1-258-
Pilkey, O., Heron, D., Harbridge, W., Kamens, J., Keer, F., and Thoaon, S. (1989). "The Sedimentology of Three Tunisian Lagoons." Marine Geolom. 88:285-30 1.
Piper, D.Z. (1974). "Rare Earth Elements in the Sedimentary Cycle: A Summary." Chemical Geology. 1 7:287-297.
Rapp, G. and Hill, CL. (1998). Geoarchaeolow: The Earth-Science Ap~roach to Archaeological Intemretation. New Haven, Yale University Press. 274p.
Reading, A.J., Thompson, R.D., and Millington, A.D. (1 995). Humid Tro~icd EnWonments. Oxford, Blackwell Publishers Limited. 429p.
Rouse, 1. (1992). The Tainos: Rise and Decline of the People Who Greeted Columbus. New Haven, Yale University Press. 2 1 1p.
Russell, R.J. and Howe, H.V. (1935). "Cheniers of southwestern Louisiana." Geographical Review. 25:449-46 1.
Scholl, D.W., Craighead, F.C., and Stuiver, M. (1969). "Flonda Submergence Cuve Revised: Its Relation to Coastal Sedimentation Rates." Science. 163 :562-564.
Schwarz, ML. (1973). Barrier Islands. Stroudsburg, Dowden, Hutchinson and Ross. 45lp.
Short, A.D. (1989). "Chenier research on the Australian coast." Marine Geology. 90:289- 296.
Soil Survey Staff. (1 975). Soil Taxonomv. Agriculture Handbook 4jl . Washington, U.S.D.A. 754p.
Sora, A., Martinez, E., and Alvarez, J. (1996). "Caracterization sisrnica de las sales en Cuba central." Amencan Association of Petroleum Geolonists Bulletin. 80(8):1338.
Sowers, G.B. and Sowers, G.F. (1970). htroductory Soil Mechanics and Foundations. New York, MacMillan Publishing Co., Inc. 556p.
Stone, G.W., Grymes III, J.M., Dingler, J.R., and Pepper, D.A. (1 997). "Overview and Significance of Hurricanes on the Louisiana Coast, U.S.A." Journal of Costal Research. 13 (3):656-669.
Suelos de la Provincia Ciego de ~ v i l a (1 983). La Habana, Ministerio de la Agricultura.
Swiadek, J.W. (1997). "The Impacts of HtuTicane Andrew on Mangrove Coasts in Southem Florida: A Review." Journal of Coastal Research. 13(3):656-669.
Summerfield, M.A. (1 99 1). Global Geomomhologv: An Introduction to the Studv of Landfoms. Longman Scientific & Technical, New York. 53713.
Taylor, S.R. and McLennan, S.M. (1985). The Continental Crust: its Com~osition and Evolution. Oxford, Blackwell Scientific Publications. 3 12p.
TomLinson, P.B. (1986). The Botanv of Manmoves. Cambridge, Cambridge University Press- 413p.
Tucker Abbott, R. (1 974). American Seashells: The Marine Mollusca of the Atlantic and Pacific Coasts of North America. New York, Van Nostrand Reinhold Company. 663p.
Varekemp, J-C. and Thomas, E. (2000). "Modem Rate of Sea Level Rise Exceeds Average Rate of the Last 2000 Years." On-line publication, National Oceariic and Atmospheric Administration: www.ncdc.noaa.gov/ogp/papers/varekamp.html.
Wagner, E. and Tarble de Ruiz, K. (1975). "Lagunillas: A New Archaeological Phase for the Lake Maracaibo Basin, Venezuela." Journal of Field Archaeolow. 2: 105- 1 18.
Waikely, A. and Black, LA. (1934). "An examination of the Degtjareff method for determinhg soi1 organic matter, and a proposed modification of the chromic acid titration method." Soi1 Science. 3 7:29-3 8.
Ward, L.G. and Ashley, G.M. (1 989). ccIntroduction: Coastal Lagoon Systems." Marine Geolow. 88:l8 1-1 85.
Warmke, G.L. and Tucker Abbott, R. (1961). Caribbean Seashells. Narberth, Livingston Publishing Co. 346p.
Waters, M.R. (1 992). Principles of Geoarchaeolopy: A North American Perspective. Tuscon, The University of Arizona Press. 398p.
Watts, W.A. (1975). "A late Quaternary record of vegetation from Lake Annie, south- central Florida." Geology. 3344-346'.
Weaver, C.E- (1989). Clam, muds, and shales. Developments in Sedirnento1og-y. 44. Elsevier, Amsterdam- 8 19p.
Whittig, L.D. (1965). X-ray deact ion techniques for mineral identification and mineralogical composition- In: Black, C.A. (ed.). Methods of Soi1 Andvsis, Madison, American Society for Agronomy. p. 671-696.
Wright, H.E. (1967)- "A square-rod piston sampler for lake sedirnents." Journal of Sedimentary Petrolov. 37(3):975-976.
Woodroffe, C.D. (1 98 1). "Mangrove Swamp S tratigraphy and Holocene Transgression, Grand Cayman Island, West Indies." Marine Geo1og.v. 4 1 :27 1-294.
Woodroffe, C.D. (1990). "The impact of sea-level rise on mangrove shorelines." Progress in Physicai Geography. 14(4):483-520,
Xianjue, W., Yuwei, C., Jianquan, L., Mingqing, W., and Yiyang, Z. (1 983). "REE Geochemistry of Sea-floor Sediments of the Continental Shelf of the East China Sea." Geochernistw. 2(4):3 18-327.
Appendix A - Particle Size Results
Upper table shows the particle size results by stratigraphie unit. The lower tabIe presents the particle size results for units I and LI in core 4. Sample numbers are listed adjacent to the unit number, and depths below the top of the core are included when multiple sarnples from the same unit were analyzed. Totals that do not equal 100 are due to rounding,
UNIT 1
UNIT 11
UNIT III
UNIT N
UNIT V
UNIT VI
Sampte
3 (84 - 88 cm) 4 5 6 8 9 IO I I
13 (58-62 cm) 13 (76 - 80 cm) 14
18 19 20
2 1 22 23 24 25 26 27
29 30
3 1 32
Sand
18 18 22 22 26 3 O 3 O 13
5 8 5
I3 12 13
4 22 17 15 42 22 48
15 18
66 60
Silt
3 2 3 0 24 29 24 20 32 35
29 3 O 30
29 26 23
32 24 2 1 27 24 3 O 22
33 28
19 16
Clay
50 52 54 49 50 50 3 8 52
66 62 6 5
58 62 64
64 54 62 58 3 4 48 3 O
52 54
15 24
Depth
UNIT 1 (84 - 88 cm) (88 - 92 cm) (92 - 96 cm)
UNIT II (58 - 62 cm) (62 - 66 cm) (66 - 70 cm) (76 - 80 cm) (80 - 84 cm)
Sand Clay
Appendix B - Mn noduies
A linear band of hard black nodules was discovered in sarnple 8. The band is 17 mm
long (Plate BI) and 4 mm in diameter (Plate B2) and is shaped Iike a half-cylinder (the
opposite halfof the cylinder was sheared-off during coring). The band is aligned roughly
20' from vertical. Individuai nodules are generally 150 pm to 250 pm in diameter (Plate
B3), and have a framboidai structure (Plate B4). These nodules are collectively
organized in a finger-like arrangement (Plate B5), and are oriented towards the centre of
the haif-cylinder. Each has a rough and pitted surface (Plate B6). The relatively Bat
surface at the bottom of the nodule clump in Plate BS marks the intefiace between the
sediment matrix and nodule band.
INAA results on nine nodule clumps show that they are dominated by Mn (4.0%
to 29.6%) and Mg (6.4% to 3 1.3%), with smaller quantities of Al, Na, and Cl (Table B 1).
This is consistent with SEM-EDS analysis of individual nodules that show high Mn,
followed by Cl, Ca, Si, Al, K and Mg. SEM-EDS scans across the interior of several
cleaved nodules, however, reveal that they have a unifonn internal structure and contain
littie or no Fe (the cIurnps were not analyzed for Fe by INAA). This is in contrast to Mn
concretions reported fiom paleosols in northern Venezuela (Mahaney et al., 1999) and
fiom Aquic Argiudolls fkom Illinois (Cescas et al., 1970), which have altemating Fe-Mn
concentric layers and Fe dorninated nuclei respectively3.
The formation of ferromanganiferous and rnanganiferous nodules and concretions
can be understood by examining the Eh-pH (redox) diagram (Figure B 1). Afier primary
A concretion has internal structure (e.g. concentric layering), while a nodule does not (Bukeland, 1999).
1 O7
PIate BI Plate B2
Plate B3
Plate B5 Plate B6
Table B 1. Mn clump samples are listed 1 - 9. Al1 values in ppm unless othenvise noted.
minerals weather and release Fe and Mn (assurning a source of Fe and Mn is available),
periodic reducing and oxidizing conditions will result in the mobilization or precipitation
of these elements. To the right of the dashed line in Figure BI, Fe and Mn both
precipitate. To the left of the dash-dot h e , Fe and Mn rernain in solution. Between
these lines, Fe forms a precipitate while Mn remains in solution (Birkeland, 1999). The
mobilization or precipitation of Fe and Mn also depends on pH, with precipitates often
forming in alkaline conditions. Because of this, and the oxidizing-reducing conditions
necessary for their formation, Fe-Mn accumulations are commonly associated with
poorly drained soils (Arshad and Arnaud, 1980; Cescas et al., 1970).
The ongin of the Mn nodules at Los Buchillones is unclear. While Figure B1
shows that they surely formed in oxidizing conditions (unless the soil was highly
alkaline), the lack of Fe in the nodules is puzzling, especially given the high Total Fe
(3.77%) present in the associated sediment. Birkeland (1999) presents a diagram that
shows approximate soil-moisture redox conditions and resulting redoximorphic features
(Figure B2). In diis model, soil saturated for one or two days a year (and at near
Figure B2- Redox diagram (Birkeland 1999).
Figure 83. in this model, type 2 soils me saturated for a few days and are at near saturation for a few months each year, which results in the mobilization and precipitation of Mn (Birkeland 1999). The other soi1 types are saturated for different periods o f time, resulting in different (or no) redoximorphic features.
.Mn (rnmgrins + nodules)
saturation for severai months each year) will accumulate Mn but not Fe. At present, the
location of core 10 at Los Buchillones is submerged under 10 cm of water. If the lagoon
was once lower (as regional sea level studies suggest; Boardman et al., 1988), the
shoreline may have been in such a position that storm surges or high sprïng tides would
saturate the backshore one or two days each year, creating conditions appropriate for Mn
accumulation. The uniform internai structure of the Mn nodules also suggests repeated
oxidizing-reducing environments were not essential for their formation, and that the
necessary conditions for Mn accumulation rnight only needed to have been reached on a
few occasions.
The source of the Mn at Los Buchillones in unknown, but it may have orïginated
upslope rather than through the weathering of local primary minerais. The shape and
alignment of the nodule concentration irnplies the Mn accurnulated in a root channel or
rodent burrow, while its shallow depth (ca. 18 cm below the lagoon bottom) suggests its
formation was recent and could have been influenced by surficiai processes. One
possibility is that ~ n * was dissolved in surface m o f f and precipitated as the water
drained through the root channel or rodent burrow. Future research should examine the
heavy minera1 suite to determine whether a potential Mn source exists arnong the local
p rimary rninerals .
Appendk C - REE mean concentrations and standard deviations (S.D.) by unit.
UNIT1 N Mean S.D.
UNITU N Mean S.D.
UNIT III N Mean S.D.
UNIT IV N Mean S.D.
UNIT V N Mean S.D.
UNIT VI N Mean S.D.