s. e. hay, d. p. klein, f. m. boler, and m. brickey u.s ...brickey's gravity observations were...
TRANSCRIPT
PRINCIPAL FACTS OF GRAVITY OBSERVATIONS IN THE
DRAGOON MOUNTAINS NATIONAL FOREST AND GILA SAN FRANCISCO
RIVERS WILDERNESS AREAS, ARIZONA
by
S. E. Hay, D. P. Klein, F. M. Boler, and M. Brickey
U.S. Geological Survey Denver, Colorado 80225
Open-File Report 81-849
1981
This report is preliminary and has not been edited and reviewed for conformity with U.S. Geological Survey standards and nomenclature
Table of Contents
Page
INTRODUCTION 1
DATA COLLECTION 2
ELEVATION CONTROL 2
DATA REDUCTION 3
MAP COMPILATION 3
PRINCIPAL FACTS 4
REFERENCES 5
LIST OF FIGURES
Figure 1: Survey Areas 6
Figure 2: Residual Bouguer, Dragoon Mountains 7
Figure 3: Residual Bouguer, Gila San Francisco 8
APPENDICES
A Base Station Control 9
B Clifton Base Station Description 10
C Principal Facts and Elevation Control - Dragoon Mountains 11
\ D Complete Bouguer - Dragoon Mountains 15
E First Order Polynomial Surface - Dragoon Mountains 16
F Principal Facts and Elevation Control - Gila San Francisco 17
G Complete Bouguer - Gila San Francisco 21
H First Order Polynomial Surface - Gila San Francisco 22
Principal Facts of Gravity Observations in the
Dragoon Mountains National Forest and Gila San Francisco
Rivers Wilderness Areas, Arizona
Studies Related to Wilderness
The Wilderness Act (Public Law 88-577, Sept. 3, 1964) and related Acts
require the U.S. Geological Survey to survey certain areas on Federal lands to
determine their mineral resource potential. Results must be made available to
the public and be submitted to the Administration and the Congress. This
report presents the results of a geophysical survey of the Dragoon Mountains
Further Planning Area (RARE II) and the Gila-San Francisco Wilderness Study
Area, Arizona.
INTRODUCTION
This report presents the principal facts of new gravity observations in
the Dragoon Mountains Further Planning Area (RARE II) and in the area of the
Gila San Francisco Wilderness Study Area, and includes complete Bouguer
gravity and residual Bouguer gravity anomaly maps for the two areas. New
gravity data were obtained in November, 1979 and May, 1980 by M. Brickey.
Fifty-one gravity stations were established in the Dragoon Mountains area
within the area shown in figure 1. Sixty-nine gravity stations were
established in the Gila San Francisco River Wilderness Study Area also shown
in figure 1. The Dragoons survey area is bounded by lat 31°35'N«, to lat
32°20'N., and long 109°35'W., to long 110°25'W., and is located in the
Dragoon, Cochise, St. David, and Pearce 15' quadrangles. The Gila San
Francisco survey area is bounded by lat 32°45'N., to lat 33°15'N., long
109°15'W., to long 109°45'W., and is located in the Bryce Mountain, the
Clifton, the Safford, and the Guthrie 15' quadrangles. The Bouguer gravity
anomaly maps also include data from the Department of Defense (DOD), Boler and
others (1980), and Wynn (1980).
DATA COLLECTION
Brickey's gravity observations were made using a LaCoste-
Romberg^-' geodetic gravity meter G-24 and were tied to the DOD gravity base
stations in Safford or Clifton, Arizona for the Gila San Francisco survey, and
in Wilcox, Arizona for the Dragoon Mountains survey; all of which are part of
the International Gravity Standardization Net, 1971 established by the Defense
Mapping Agency Aerospace Center (1974) . A description of the Clifton base is
included in appendix A; descriptions of bases at Wilcox and Safford are
available from the DOD.
Gravity loops were started and ended daily at these bases. The observed
gravity values were corrected for meter drift by a linear interpolation
between the base station measurements. Mean duration of these loops was eight
hours. Maximum recorded meter drift was 0.09 mgal over a nine hour loop, but
drift was seldom greater than 0.04 mgal on the average. Meter readings for
bases at Safford and Clifton, converted to milligals and corrected for earth
tides are plotted against observation time in appendix A. Characteristics of
this drift data are fair indicators of the uncertainties in the meter readings
for all stations.
ELEVATION CONTROL
Forty-two of the 51 station elevations in the Dragoon Mountains area were
obtained from bench marks, spot elevations, or section corners found on
1:62,500 scale U.S. Geological Survey topographic maps. The remaining nine
were estimated from contour intervals at known positions on the maps. Thirty-
'Use of brand names is for descriptive purposes and does not constitute endorsement by the U.S. Geological Survey.
four of the 69 station elevations in the Gila San Francisco area were
estimated from contour intervals at known positions on the maps. The others
were obtained from benchmarks, spot elevations, or triangulation points.
Tabulations of the elevation controls and uncertainties for each station in
the two survey areas are listed in appendix B (for the Dragoon Mountains) and
appendix F (for the Gila San Francisco).
DATA REDUCTION
Unpublished U.S. Geological Survey computer programs were used to process
and prepare Bouguer anomaly contour maps for the two survey areas. Station
coordinates were digitized from field maps and converted to geographic
coordinates. Observed gravity values were corrected for earth-tide and linear
meter-drift using the 1967 geodetic reference system (International Union of
Geodesy and Geophysics, 1967) and the 1971 Potsdam gravity value (Morelli,
1971). Computer terrain corrections were calculated from each station out to
166.7 km using the method of Plouff (1977). For corrections from 0 to 5 km,
30 second mean elevation data was used for the Gila San Francisco area and
fifteen second mean elevation data was used for the Dragoon Mountains area.
Both surveys used 1 minute elevation data for corrections from 5 to 21 km, and
3 minute elevation data for corrections from 21 to 166.7 km. An assumed
odensity of 2.67 gm/cmj was used for terrain corrections. Earth curvature
corrections and complete Bouguer (terrain corrected) anomaly values were
calculated. The complete Bouguer anomaly values were gridded at a 1 km
spacing using the method of Briggs (1974). The grids are contained within the
survey area boundaries mentioned previously, shown in Figure 1.
MAP COMPILATION
Station data which appeared to be in error (based on abnormally high
*1 km = 3281 feet
elevation and terrain correction errors and spurious anomalies), as well as
duplicate observations were deleted from the data set prior to compiling the
maps. The criteria used in deciding which station was to be kept in a given
group of duplicates are as follows: when not in error, U.S. Geological Survey
data had priority over DOD data, which in turn had priority over private
company data.
Computer plotted contour maps of the gridded data were produced using a
linear interpolation technique for positioning contours, with optional contour
smoothing with splines under tension (Cline, 1974). The contour maps produced
for this report make use of the smoothing option with spline factor sigma=3.
The first order least squares polynomial surface was generated and subtracted
from the complete Bouguer gravity values to give first order residual values,
which have been plotted as residual gravity maps (fig. 2 and fig. 3).
PRINCIPAL FACTS
The principal facts of the Dragoon Mountains data are tabulated in
appendix C. The tabulations include only Brickey's gravity data; however, the
gravity maps were generated from the total data available. The data are shown
contoured as a complete Bouguer gravity map in appendix D. Figure 2 shows a
residual Bouguer contour plot of the survey area, obtained by removing the
first order polynomial surface from the complete Bouguer grid (appendix D).
The first order polynomial surface is shown contoured in appendix E.
The principal facts of the Gila San Francisco Wilderness Study Area are
tabulated in appendix F. The data are shown contoured as a complete Bouguer
gravity map in appendix G. Figure 3 is the residual Bouguer contour plot of
the Gila San Francisco survey area, obtained by removing a first order
polynomial surface from the complete Bouguer grid (appendix G). The first
order polynomial surface is shown contoured in appendix H.
SELECTED REFERENCES
Boler, F. M., Klein, D. P., Christopherson, K., and Hoover, D., 1980, Gravity
observations - Clifton-Morenci area, Greenlee County, SE Arizona: U.S.
Geological Survey Open-File Report 80-96, 18 p.
Briggs, I. C., 1974, Machine contouring using minimum curvature: Geophysics,
v. 39, no. 1, p. 39-48.
Cline, A. K., 1974, Scalar and planar-valued curve fitting using spline under
tension: Communications of the Association for Computing Machinery, v.
14, no. 4, p. 218-223.
Defense Mapping Agency Aerospace Center, 1974, World Relative Gravity
Reference Network, North America, Part 2: DMAAC Reference Publication 25,
with supplement updating gravity values to the International Gravity
Standardization Net 1971, 1635 p.
Grant, F. S. and West, G. F., 1965, Interpretation theory in applied
geophysics: New York, McGraw-Hill Book Co., p. 236-239.
Hammer, S., 1939, Terrain corrections for gravimeter stations: Geophysics, v.
4, p. 184-194.
International Union of Geodesy and Geophysics, 1967, Resolution no. 1, XIV
General Assembly: Bulletin Geodesique, v. 86, p. 367.
Morelli, C., 1971, The International Gravity Standardization Net 1971 (IGSN
71), International Association of Geodesy, Publication speciale no. 4.
Plouff, D., 1977, Preliminary documentation for a FORTRAN program to compute
gravity terrain corrections based on topography digitized on a geographic
grid: U.S. Geological Survey Open-File Report 77-535, 45 p.
Wynn, J. C., 1980, Principle facts for gravity stations and base station net
in the Silver City 1° x 2° degree Quadrangle, Arizona and New Mexico:
U.S. Geological Survey Open File Report no. 80-...(in press), p.
Ill1 110
33
32(
10 0 10 20 30
0 10 20 30 /tO 50 fii i i KM
HILES
GILASAN FRANCISCO
WILDERNESS STUDY
AREA BOUNDARY
DRAGOON MOUNTAINS
FURTHER PLANNING AREA . (RARE II) BOUNDARY
iSXTombstone
i-33'
32*20'
32'
31*35
110'2
111 110'
Figure 1. Index map showing location of this report.
32:15: 0
32: 0: 0
31:45: 0
Figure 2. Residual complete Bouguer anomaly contour map of the Dragoon Mountains survey area. The boundary of map is the boundary of the study area. Contour interval, 2 mgals.
33:15: 0
33: 0: 0
32:45: 0
Figure 3. Residual complete Bouguer anomaly contour map, Gila San Francisco Wilderness Study Area. Contour interval, 2 mgals.
DIAL READING, IN MGALS
ro ro03 0> 00 CO o> 03
K>O
CO C»>00 VO 00 Oo o
OJ
oro
':..:"!:i :.:::-. ,..-.::: I-::;.:.:..-.:.-:.:-:: . ' : ..: . :::. ; :::.. :::..:.:::..::L!:::I!.L--J..^: :;: j^L..j.;^:_j-» £ J^I:.-::;;L.:::;:^-I__; o
'! :"'..». i
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1
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" "" """"""
;;: = ;::.-!;.:i;;::.-:r:;- ..:f:r:.:;::I::::-J:i?:j'::; -:"H:>i::i:i!::: -i.^-^a^_-L«.^.:i^4-..:..- ^- -^i-ii;:-:......--:!:-:: :::
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.: ;::::: !..:::. '.:U:'. ::.':::~:'r.::'.: : : " " "" """" '
^S-rrri^M'^i-r'i"^"!!^"Q' > c^^nnnrriiii'-viii..!.-?.-^:
< : r*^^:]^:+i^i\::-:\~'".\ [] p - . £yO : : :--. .^ -.-.:-~r:~~::-\ : :. |L . ^ g :: ;::::::::.(.::::-:;.. ;:::;:.. .;;;:
* . r *.*. T^ . "7 *rT"T?"~T T T" . 7T ^ T""~ . ~;1, . .. . j . . j. TT
.:.:LL;?;;i;:.l.:u_:!-lIl.::i;'::ii:H::ii"!i.:uu:i:l::.I:IIJ:
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APPENDIX B
U.S. GEOLOGICAL SURVEY GRAVITY BASE STATION
STATE/COUNTRY Arizona
NEAREST TOWN Clifton
ELEVATION
1156.7 m
DATE
STATION DESIGNATION Clifton
LONGITUDE
109°12.6 f W
OBSERVED GRAVITY 979154.40 mgals (1971)
LATITUDE 32°57.48 f N
TOPOGRAPHIC MAP(S)
York Valley 15 f .
OBSERVER METER REFERENCE STATION REFERENCE VALUE
DESCRIPTION/SKETCH(Revised April, 1979; Boler, 1980)
Station-'site is located at the Clifton Airport (Greenlee County Airport) at the southwest corner of red brick building, under wall phone. The airport is approximately 10 miles south of Clifton.
Greenlee County Airport
hanga]
Station
restroom
red brick bldg.
concrete steps
10
APPENDIX C
EXPLANATION FOR PRINCIPAL FACTS LIST
*»ate: 11/06/60
^ea: Dragoons
"»ata Source: M. Rrickey/ 1979
bASE STATION LIST
STATION LATITUDE LONGITUDE ELEVATION GRAVITY BASEdea min dea min ft observed CODE
rflLCOX 32 14.57 109 53.53 4183.0 979083.11 3
TERRAIN CORRECTIONS
Hand Correction: none.Computer Correction: Plouff zones A through Z.Digitized terrain data spacing for computer terrain corrections is 15 secondsTC columns of principal facts list contain total computer correction.
11
ELEVATION CONTROL AND UNCERTAINTIES
Table of Elevation Control Codes and Uncertainties
type of control
contour soot elev* spot elev** bench interpolatn pre- 1970 brn pre-1970 blk mark
post-1970 blk
uncertainty(fraction of the 0.5 0.3 0.1 <1 ft contour i nterval )
contour interval in ft
elevation uncertainties given as coderuncert ai nty in ft
7.99 o<f
* This column refers^to spot elevations printed in black on USGS auadrangle maps nuMished after 1970 or in brown on maos published before 1970. Soot elevations are determined hy photoarammetrv or third or ^ower order leveling at section corners^ wellsr tpianqulation points prominent topographic features* etc.
**.TMs column refers to soot elevations printed in black on USGS quad rangle maps published before 1970. The elevations have been field checked
12
Date: 11/06/80 pagePRINCIPAL FACTS
Area? DragoonsData source: M. Brickey/ 1979
STATION LATITUDEdeq win
OR-DR-OR-OR-DR-
DR-DR-OR-OR-OR-
OR-DR-DR-DlD2
D30405r»6D7
D809D10DllD12
D13014D15D16017
DlflD1902002102?
023024025026027
4041424344
4546474849
505152
3231313131
3132323131
3131313232
3232313131
3131313131
3131313131
3132323232
3232323131
3.8157.5556. 8456.7656.00
53.77?.470.73
59.0953.44
53.6651 .1050.115.501.29
1.29l.?8
56.9258.6756.05
51.6750.805?. 4958.6757.80
58.0255.305?. 7054.0154.30
55.634.753.133.044.76
4.770.421.28
52.3451.24
LONGITUDEdeq
-109-110-110-110-109
-109-109-109-110-109
-109-10°-109-100-110
-110-109-109-109-109
-109-109-109-109-110
-110-110-no-10°-109
-109-109-10°-110-110
-110-110-t09-109-109
mi n
59.531.331.333.08
56.46
?5. 1«?59.1759. 6^0.42
59.02
58.1457.3954.6356.300.79
0.7657.74^4.6857.8652.82
53.8359.5557.2654.872.80
1.102.241.55
59. 2*53.04
57.8658.6758.960.760.68
1.690.77
56.74S5.69S7.90
ELEVATIONft code
4854.05610.06546.05253.05004.0
5018.04780.05464.06272.07118.0
6760.06662.05618.04290.04759.0
4731.04643.04^03.04*1°. 04490.0
4*70.05132.05780.04451.04975.0
5470.74865.04838.07071.04625.0
489^.04421.04745.04560.04886.0
4725.04980.04766.05030.05445.0
122222
2121322
22243
13222
22123
31321
13333
33311
G Robserved
979049.9107*9*4.81978914.56979006.60979013.39
979010.50979054.38979004. 8*978944.0797*873.03
Q78894.3097*900.2^978972.39979084.29979046.25
979043.35979059.6997*050.0497*033.90979048.42
979020.79979009.4897*963.88979056.69979025.42
978996.0°979029.62979027.91°7«877.55079035.18
970021.15970Q76.53079055.52979059.8207*052.66
97POS9.5*079034.51979050.30979000.300789*7.81
A V I T Y BASEtc
2.093.5914.254.032.27
1.711.524.8112.0515.67
13.8916.014.390.170.84
0.820.910.641.750.38
0.891.233.280.471.56
3.S81 .491.93
15.820.49
5.070.321.590.510.88
0.551 .491.754.382.80
Cha CODE
-147.11-157.03-159.65-155.08-163.91
-163.51-145.82-148.77-151.79-160.91
-163.16-156.60-158.12-150.65-154.29
-15*. 88-147.70-160.09-152.62-161.56
-159.52-154.18-161.26-159.08-156.76
-154.72-155.83-155.20-159.83-164.26
-150.37-149.41-147.59-155.31-144.94
-14*. 03-150.99-147.70-168.40-156.16
33333
33333
33333
33333
33333
33333
33333
33333
13
Date: 11/06/80PRINCIPAL FACTS
Area: DragoonsData source: M. Rrickey, 1979
paqe
STATION
029 D30 D31032033
035036 D37 038
LATITUOEdep mi n
3131313131
3132323232
51.6554.1955.9855. 4159.63
58.870.410.^03.434.74
LONGITUDFdeg
-110-110-110-110-110
-110-109-110-110-109
mi n
0.923.510.011.101.17
2.7754.903.592.60
54.92
ELEVATIONft code
4Q67.04733.05323.04^60.05040.0
4732.04323.04S51.04707.04P23.0
33311
33343
GRAVITYobserved
979017979036978995979021979032
9790409790679790S69790S5979083
.38
.87
.08
.31
.31
.59
.13
.46
.02
.88
tc
1.350.814.993.031.93
1.450.310.610.520.13
BASEcba COOE
-157-155-160-157-148
-157-158-15^-151-154
.18
.65
.41
.07
.09
.67
.80
.53
.84
.07
33333
33333
14
APPENDIX D
32:15: 0
32: 0: 0
31:45: 0
Complete Bouguer map, Dragoon Mountains survey area, 2.67 g/cnH; contour interval, 2 mgals.
Reduction density,
15
APPENDIX E
m
32:15: 0
32: 0: 0
31:45: 0
First order polynomial surface, Dragoon Mountains survey area. Contour interval,
2 mgals. Stations are shown as 0.
16
APPFNDIX F
EXPLANATION FOR PRINCIPAL FACTS LIST
Hate: 11/06/80
Area: Gila San Francisco Arcs
n ata Source: M. Brickey,19QO
BASE STATION LIST
STATION
CLIFTONSAFFORO
LATITUDE deq min 3£ 57.48 32 51.13
LONGITUDF deo min 109 12. oO 109 39.22
ELEVATION ft
3794.9 3130.0
GRAVITY BASEobserved CODE979154,40 1979206.13 2
TERRAIN CORRECTIONS
Hand Correction: none.Computer Correction: Plouff zones A through Z.Dinitized terrain data soacing for computer terrain corrections is 30TC columns of principal facts list contain total computer correction.
seconds.
17
ELEVATION CONTROL AND UNCERTAINTIES
Table of Elevation Control Codes and Uncertainties
type of control
contour soot elev* spot elev** bench interpolatn pre- 1970 brn pre-1970 blk mark
post-1970 blk
uncertainty(fraction of the 0.5 0.3 0.1 <1 ft contour interval)
contour Interval in ft
elevation uncertainties given as coderuncertainty in ft
80 1:40.00 2:2a.OO 3: 7.99 ft
* This column refers to spot elevations orinted in black on USGS Quadrangle maps ouMished after 1970 or in brown on maos published before 1970. Soot elevations are determined by photoarammet rv or third or lower order leveling at section corners, wells? triangulation ooints prominent topographic features? etc.
** This column refers to soot elevations printed in black on USGS quad rangle maps published before 1970. The elevations have been field checked
18
Date: 11/06/80 paqePRINCIPAL FACTS
Area: Hila San Francisco Area Data source: M. BHckey,1980
STATION
SAFFPRDSAFF-SAFF-SAFF-SAFF-
SAFF-SAFF-SAFF-5AFF-SAFF-
SAFF-SAFF-SAFF-SAFF-SAFF-
SAFF-SAFF-SAFF-SAFF-SAFF-
SAFF-SAFF-SA pF-SAFF-SAFF-
SAFF-SAFF-SAFF-SAFF-SAFF-
SAFF-SAFF-SAFF-SAFF-SAFF-
SAFF-SAFF-SAFF-SAFF-SAFF-
1234
56789
1011121314
1.516171819
20212223'
24
2526272829
3031323334
3536373839
LATITUDEdeq
3232323232
3232323232
3232323232
3232323232
3232323232
3333333333
3333333232
3232323232
mi n
51.1355.6356.2756.3956.12
55.7256.6254.5655.2358.14
57.3657.4355.^755.9455.25
55.5555.0752.0655.1655.53
56.1056.1455.7056.3554.57
3.193.656.404.305.01
6.515.784.89
53.835^.39
59. <»555.3756.2756.0256.31
LONGITUDEdeq
-109-109-109-109-109
-109-109-109-109-109
-109-109-109-109-109
-109-109-109-109-109
-109-109-109-109-109
-109-109-109-1 09-109
-109-109-109-109-109
-109-109-109-109-109
mi n
39.2238.5638.1135.5736.21
36.2932.7834.1537.7941.55
41.0341.9842.6040.9140.80
40.0339.8640.4423.3723.47
23.5524.1023.2122.7823.05
24.8927.6?32.1°37.3438.76
38.1433.0231.3618.2618.98
17.8716.2318.6517.2417.87
ELEVATIONft
3130.03925.04410.04505.05000.0
4890.04040.04140.03P10.04100.0
3990.03900.03445.03670.03545.0
3625.03540.03127.04600.04570.0
4485.04644.04460.04565.04680.0
4000.04140.04844.04935.05091.0
4300.04938.05215.03605.03685.0
3820.05078.03920.03980.04020.0
code
51111
11111
11111
11111
15111
11332
12131
13111
GRAVITYobserved
979206.14979172.67979142.07979140.95979108.95
97°117.95979166.83979162.639791Q4.57979160.38
979174.05979181.42979194.00979188.049791Q2.82
979169.51979192.22979205.84979124.68979129.12
979138.09979125.37979138.69979130.34°79111.76
97°172.39979159.12979118.23979101.77979093.79
979143.00979107.29979090.64979175.71979173.18
979162.81979080.34979159.209791S4.56979151.54
tc
0.371.713.512.442.71
3.551.623.922.421.50
1.281.811.051.351.23
l.«71.410.460.770.76
1.111.711.19l.*91.11
2.365.161.091.501.26
3.201.202.740.580.55
0.497.75l.«21.522.16
cha
-160.11-150.95-151.66-148.34-150.11
-146.30-151.38-144.47-134.66-156.45
-148.50-152.04-159.41-151.60-153.45
-151.76-153.93-161.77-158.91-156.78
-153.32-156.00-153.59-155.85-165.90
-156.50-159.25-165.92-173.64-173.51
-171.71-170.28-167.61-172.55-171.11
-174.24-167.99-165.49-166.50-166.89
BASECODE
22222
22222
22222
22222
22222
11111
111i1
11111
19
Date: 11/06/80 pagePRINCIPAL FACTS
Area: G i 1 a San Francisco Area Data source: M. Brickey,1980
STATION
SAFF-SAFF-SAFF-SAFF-SAFF-
SAFF-SAFF-SAFF-SAFF-SAFF-
SAFF-SAFF-SAFF-SAFF-SAFF-
SAFF-SAFF-SAFF-SAFF-SAFF-
SAFF-SAFF-SAFF-SAFF-SAFF-
SAFF-SAFF-SAFF-SAFF-
4142434445
46474849SO
5152535455
S657585960
6162636465
66676869
LATITUDEdeg
3232323233
3333333332
3232323232
3332323333
3333333332
33333333
mi n
58.6057.8258.6559.8/41.11
1.350.200.611 .64
55.52
56.4655.6455.0456.3357.01
0.2759.5858.511.8b2.04
2.860.871.933.73
59.39
2.805.062.182.94
LONGITUDEdea
-109-109-109-109-109
-109-109-109-109-109
-109-109-100-109-109
-109-109-109-109-109
-109-109-109-109-109
-109-109-109-10"
mi n
29.8829.0927.7225.7326.88
25.5227.39P9.01?9.6026.57
24.7727.8927.6726.4125.28
24.1?24.2024.1324.4330.89
30.8030.5332.6932.60'21.95
?5.55?6.6927.2328.53
ELEVATIONft
5656.04657.05505.04569.05008.0
4448.05608.06069.06337.03904.0
4418.03778.03705.03968.04005.0
4256.03777.04180.04418.07004.0
638«.06635.04733.05006.03350.0
4510.04693.04815.05538.0
code
22222
22224
44441
32325
23224
2222
G Pobserved
979057.8997Q128.60979071.33Q79136.63979106.43
979139.73979057.27979031.47979013.70979170.41
979136.09979176.69979178.96979167.50979165. 85
979150.31979185.2597Q156.84979145.23078960.24
979011.40978988.23979116.93979098.04979205.94
979136.68979120.44970116.3697906b.94
A V I T Ytc
6.652.086.882.903.30
4.356.007.2410.111.46
3.851.692.302.824.10
4.321.725. SO1.91
19.70
8.2014.372.042.642.91
4.313.222.755.86
cba
-161.41-153.93-156.85-153.12-158.43
-157.87-167.75-165.30-165.58-154.56
-157.08-155.55-156.40-153.31-152.50
-157.31-152.63-151.72-157.31-170.07
-168.45-167.89-165. «5-171.20-155.99
-159. ?6-168.77-162.06-167.19
BASECODE
22222
2222?
2222?
22222
22??2
?2?2
20
APPENDIX G
33:15: 0 -
33: 0: 0
32:45: 0
o vo
Ul
o
w o
o vo
Ul
o
Complete Bouguer map, Gila San Francisco survey area, density, 2.67 g/cm3; contour interval, 2 mgals.
Reduction
21
APPENDIX H
33:15: 0
33: 0: 0
32:45: 0
First order polynomial surface, Gila San Francisco survey area, Contour interval, 2 mgals. Stations are shown as 0.
22