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Master's Theses Graduate College
6-1988
Electrical Resistivity as an Approach to Evaluating Brine Electrical Resistivity as an Approach to Evaluating Brine
Contamination of Groundwater in the Walker Oil Field, Ottawa Contamination of Groundwater in the Walker Oil Field, Ottawa
County, Michigan County, Michigan
Janet A. Koehler
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Recommended Citation Recommended Citation Koehler, Janet A., "Electrical Resistivity as an Approach to Evaluating Brine Contamination of Groundwater in the Walker Oil Field, Ottawa County, Michigan" (1988). Master's Theses. 1185. https://scholarworks.wmich.edu/masters_theses/1185
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ELECTRICAL RESISTIVITY AS AN APPROACH TO EVALUATING BRINE CONTAMINATION OF GROUNDWATER IN THE WALKER
OIL FIELD, OTTAWA COUNTY, MICHIGAN
by
Janet A. Koehler
A Thesis Submitted to the
Faculty of The Graduate College in partial fulfillment of the
requirements for the Degree of Master of Science
Department of Geology
Western Michigan University Kalamazoo, Michigan
June 1988
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ELECTRICAL RESISTIVITY AS AN APPROACH TO EVALUATING BRINE CONTAMINATION OF GROUNDWATER IN THE WALKER
OIL FIELD, OTTAWA COUNTY, MICHIGAN
Janet A. Koehler, M.S.
Western Michigan University, 1988
Surface electrical resistivity successfully defined brine
contamination within a glacial drift aquifer in western Michigan.
The study site is in a residential area of eastern Ottawa County,
in the Walker Oil Field. A Schluraberger array with a maximum
current electrode separation (AB/2) of 316 meters (1037 feet) was
used. It was possible to detect geoelectric layers to about 30
meters (100 feet) below ground level, with the maximum current
penetration of about 1/10 (AB/2). On occasion, thick surficial
clay precluded detecting deeper geoelectric layers. Through use
of the INVERS computer program, fifty vertical electrical
soundings were interpreted and correlated with geological,
geophysical and water quality data. Low resistivity zones were
identified on several geoelectric sections within the glacial sand
aquifers adjacent to water wells in which relatively high levels
of chloride and specific conductance had been detected. The
conclusion is that these low resistivity layers represent
groundwater contamination zones.
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ACKNOWLEDGMENTS
I would like to extend a special thank you to Dr. Richard
Passero for his continual support and guidance during the course
of this study, and throughout ray academic career at Western
Michigan University. Also, I ara greatly indebted to Dr. William
Sauck whose geophysical expertise was invaluable to this study.
As my thesis committee members, I am grateful to Dr. W. Thomas
Straw and Dr. Gerry Clarkson for their constructive criticism of
ray work. I would like to thank Mr. David Westjohn for his
enthusiasm and encouragement, and for having critiqued ray report.
Special thanks is due to all those who helped me with my
field work, especially my good friends, Kent Meisel, Terry Wagner,
Kayleen Jalkut and Lula Palmer. Also I must thank Chuck Graff
and Jean Talanda for their drafting skills and their comradery. I
am grateful to the U.S.E.P.A. for allowing me to work under the
Walker Oil Field study.
Most of all I would like to thank my parents, Dr. James
Koehler and Genevieve Koehler, for their continual encouragement
and their love.
Janet A. Koehler
11
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Uni
International300 N. Zeeb Road Ann Arbor, Ml 48106
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O rder N um ber 1334190
Electrical resistivity as an approach to evaluating brine contam ination o f groundwater in the Walker Oil Field, O ttawa County, M ichigan
Koehler, Janet A., M.S.
Western Michigan University, 1988
Copyright ©1988 by Koehler, Janet A. All rights reserved.
U MI300 N. Zeeb Rd.Ann Arbor, MI 48106
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Copyright by Janet A. Koehler
1988
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TABLE OF CONTENTS
ACKNOWLEDGMENTS................................................... ii
LIST OF TABLES....................................................vi
LIST OF FIGURES..................................................vii
LIST OF PLATES.................................................... ix
INTRODUCTION....................................................... 1
HISTORY OF THE WALKER OIL FIELD................................... 4
REGIONAL SETTING.................................................. 10
Surficial Geology............... 10
Subsurface Geology............................................. 10
Surface Hydrology..............................................12
Hydrogeology................................................... 12
Groundwater Quality............................................14
STUDY AREA........................................................ 11
General Description............................................16
Surficial Geology..............................................16
Subsurface Geology.............................................18
Surface Hydrology..............................................22
Hydrogeology................................................... 22
Groundwater Quality............................................28
REVIEW OF ELECTRICAL RESISTIVITY USEDIN HYDROGEOLOGICAL PROBLEMS...................................... 36
PREVIOUS WORK IN THE WALKER OIL FIELD AREA.......................38
iii
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TABLE OF CONTENTS — Continued
ELECTRICAL RESISTIVITY
Definition..................................................... 39
Uses........................................................... 39
Factors Governing Resistivity of Rock Materials............. 40
Types of Electrode Configurations and Exploration Methods..44
Theory....................................................... 48
Field Methods................................................50
Data Reduction...............................................56
First Stage...............................................57
Second Stage..............................................60
Third Stage...............................................63
Interpretation of Field Data................................ 65
Geoelectric Section A .................................... 68
Geoelectric Section D.................................... 72
Geoelectric Section E.................................... 74
Longitudinal Conductance Map................. 77
Laboratory Procedures....................................... 79
CONCLUSIONS AND RECOMMENDATIONS.................................. 81
APPENDICES........................................................ 85
A. Equipment..................................................86
B. Soil Boring Data and Labpratory Results................... 90
iv
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TABLE OF CONTENTS — Continued
C. Apparent Resistivity Data..................................95
D. Archie's Law Calculations.................................134
E. Geoelectric Sections B, C, F, G, H, and 1................ 1)6
BIBLIOGRAPHY..................................................... 143
v
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LIST OF TABLES
1. Oil Well Record Sunmary for the Study Area................... 6
2. Brine Production and Disposal RecordSummary for the Study Area.................................... 8
3. Water Quality Data and Domestic Welland Soil Boring Depth........................................ 31
4. Electrical Resistivity Values of GeologicalMaterials (after Telford).................................... 43
vi
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LIST OF FIGURES
1. Location Map Showing Site Area Within TallmadgeTownship, Ottawa County, Michigan............................2
2. Detailed Map of the Study Area Showing Domestic Welland Cross Section Locations.................................. 3
3. Map Showing Location and Approximate Size of the Walker Oil Field (Michigan Department of Natural Resources, 1981)..............................................5
4. Site Map Showing Permit Numbers of Both Activeand Abandoned Oil Wells...................................... 7
5. Map Showing the Approximate Location of Ottawa County Relative to the Glacial Systems in Lower Michiganas Mapped by Leverett and Taylor, 1915......................11
6. Glacial Landforms in the Study Area (After Ten Brink,1975)........................................................ 17
7. Site Map Showing Drift Thickness Based on Oil WellRecord Data.................................................. 19
8. Site Map Showing Bedrock (Michigan Formation)Surface Based on Oil Well Record Data.......................21
9. Geological Cross Section Along the South Side of Leonard Street, Tallmadge Township, Ottawa County.................. 24
10. Geological Cross Section Along Private Drive Northof Leonard Street, Tallmadge Township, Ottawa.............. 25
11. Geological Cross Section Along 14th Street, Tallmadge Township, Ottawa.............................................26
12. Geological Cross Section Along Leonard Street Extension, Tallmadge Township, Ottawa.................................. 27
13. Groundwater Flow Direction Based on PotentiometricSurface of the Study Area...................................29
14. Isoconcentration Map of Chloride (mg/L) of DomesticWell Water (values collected by Wagner, 1988)...............32
vii
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LIST OF FIGURES — Continued
15. Map of Specific Conductance (umhos/cra) of DomesticWell Water (values collected by Wagner, 1988).............. 33
16. Schlumberger Electrode Arrangement.......................... 45
17. Uniform Three Dimensional Current Flow...................... 45
18. Distortion of Current Flow Lines When Crossing theBoundary Between Media of Differing Resistivity............45
19. Changes in Layer Thickness (h), and Electrode SeparationInfluence Current Flow Direction............................ 49
20. Map Showing the Locations of VESand Geoelectric Sections.................................... 51
21. Sample of Field Data......................................... 52
22. Hypothetical Schlumberger Field Curve ShowingCurve Segment Displacement.................................. 55
23. Sample of Study Area Field Curves............................58
24. Four Basic Relationships Between Resistivityand Thickness in a Three-Layered Subsurface................ 60
25. Map of Longitudinal Conductance (mhos)...................... 64
26. Arrangement of Sheet Electrodes Used in LaboratoryAnalysis of Soil Samples.................................... 79
27. Sketch of IC-69 Earth Resistivity Meter..................... 87
viii
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LIST OF ELATES
1. Geoelectric Section A
2. Geoelectric Section D
3. Geoelectric Section E
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INTRODUCTION
The purpose of this investigation was to determine the
effectiveness of surface electrical resistivity as a means of
detecting groundwater contamination from oil field brines in the
Walker Oil Field. Electrical methods have been utilized
frequently in defining subsurface geology and hydrology. Surface
electrical resistivity has not generally been employed in
populated areas where cultural phenomena limit the application of
resistivity surveys.
The area investigated is located within the northern-most
portion of the Walker Oil Field in Tallmadge Township, Ottawa,
County Michigan (Figure 1). More specifically, it occupies the
southwestern quarter of section 14 and the southeastern quarter of
section 15 of Township 7 North, Range 3 West. The site is bounded
by Sand Creek and its tributary to the north and west, 14th Street
to the east, and the southern border of section 14 and 15 to the
south (Figure 2).
1
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2
TallmadgeTownship
s tudy site
OttawaCounty
-t— ----10 2 miles
Figure 1. Location Map Showing Site Area Within Tallmadge Township, Ottawa County.
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3
1 8 0 S DOMEST I C WELL L O C A T I O N
SOIL B O U I N O L O CA T I O N
Figure 2. Detailed Map of the Study Area Showing Domestic Well and Cross Section Locations.
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HISTORY OF THE WALKER OIL FIELD
The Walker Oil Field includes portions of Kent and Ottawa
Counties. The field, discovered in 1938, encompasses 8560 acres
(Figure 3). More than 780 wells drilled in the Walker Oil Field
produce gas, oil and brine. Production peaked by 1940, and
cumulative production reached more than 4,000,000 barrels of oil
(Michigan Department of Natural Resources, 1981). The Walker Oil
Field was the most active Michigan oil field that year (Newcombe,
1940). Oil production has steadily decreased since the early 1940's.
Oil is produced from the Traverse Limestone in the upper part
of the Devonian Traverse Group. Within the study area the Traverse
Limestone ranges from 2 to 13 meters (8 to 42 feet) in thickness,
and the pay zone ranges from 1 to 6 meters (3 to 19 feet) (Table 1).
Ten oil wells were drilled in the study area. Four of these oil
wells currently produce oil and brine from depths of 566 to 625
meters (1858 to 2050 feet) below ground level (Figure 4). Six oil
wells have been plugged and abandoned. Most of the wells in this
portion of the Walker Oil Field have produced for 26 years.
Since the 1940's a small portion of Michigan oil field brine has
been used for road maintenance. The majority of this brine was
disposed of to surface pits. In the study area pit disposal was
used for nearly 35 years from 1940 through 1975. Pits consisted of
shallow unlined excavations in the existing soils located near pump
jacks and tanks. Surface application of oil field brine is a
possible cause of the degradation of groundwater supplies.
4
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OaiUil i t m u
tWKI Vfllf IdH
C'»t)a
• IIICM
0 N / - T Li i «.t
G O N
0
W Ci)
Walker Oil Field O N
Figure 3. Map Showing Location and Approximate Size of the Walker Oil Field (Michigan Department of Natural Resources, 1981).
gas field
oil field
oil and gas fields
112 miles
i
Table 1
Oil Well Record Summary for the Study Area*
EerraitNumber Drift MI MA CLD ELS ANT TRV
TRVLS PAY
TotalDepth
* 7318 118 57 249 681 538 149 66 10 8 1857.5
* 7695 94 126 215 690 535 142 73 14 8 1875
* 7824 125 55 275 682 525 153 59 8 6 1874
7887 100 75 240 605 510 174 60 14 7 1864
8424 132 55 273 698 514 148 69 42 6 1889
9385 190 0 240 741 534 115 55 8 3 1875
9851 120 35 310 682 508 163 187 34 11 2050
*13156 155 35 265 683 537 157 61 11 4 1888.5
13447 163 17 277 703 540 119 73 25 17 1892
21965 121 69 250 702 534 146 72 23 19 1894
* formation thickness and depth in feet
* active oil wells
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7
P R O D U C I N G O i l W i l l
A B A N D O N E D O i l W f l l
H O L D I N G T A N K S
O i l W i l l P E R M I T NO.
2 1 9 8 5
7 8 9 5
•̂ 96 5 1
4 4 7
8 4 2 4
Figure 4. Site Map Showing Permit Numbers of Both Active and Abandoned Oil Wells.
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Table 2
Brine Production and Disposal Record Summary for the Study Area (1949-81)
PermitNumber
ProducedOil
ProducedBrine
Brine To Brine To Pits Injection Wells
* 7318 9465.4 5905.8 2555.0 3350.8
* 7695 14099.9 6168.6 5383.8 784.8
* 7824 - no production records -
7887 22447.5 5110.0 3650.0 1460.0
8424 365.0 273.8 273.8 0.0
9385 2555.0 547.5 547.5 0.0
9851 1277.5 1825.0 1825.0 0.0
*13156 10541.2 2518.6 1733.8 784.8
13447 2555.0 547.5 547.5 0.0
21965 - no production records -
* production/disposal amounts in barrels
* active oil wells
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Due to the rising public concern over environmental degradation,
attention was focussed upon the dumping of waste brine on Michigan
lands (Herold, 1984). Special Order Number 1-81, under Act 61
(P.A. 1939, as amended), was, therefore, issued by the Supervisor
of Veils as a means of controlling oil field brine disposal
practices. Under Special Order Number 1-81 brine can be disposed
of by injection to an approved subsurface formation, through an
approved brine disposal well. Disposal of oil field brine to
pits, however, was banned. As a result of this regulation
subsurface injection has now become the dominant brine disposal
method in the Walker Oil Field. In the study area, disposal wells
apparently are absent, and it is assumed that since 1981 the brine
has been hauled from the well sites and disposed of elsewhere.
Based on production records, it is estimated that nearly
22,900 barrels of brine have been produced from this portion of
the Walker Oil Field (Table 2).
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REGIONAL SETTING
Surficial Geology
During the Wisconsinan Stage of Pleistocene glaciation
Michigan was covered with about 305 meters (1000 feet) of drift
deposited by moving ice fronts. In the Woodfordian Substage
periods of ice advancement and retreat developed several different
morainic systems and intervening outwash plains, till plains and
lacustrine deposits (Ten Brink, 1975).
In Ottawa County the Lake Border and the Valparaiso moraines
and associated outwash plains were formed (Figure 5). The Lake
Border and the Valparaiso morainic systems roughly trend north and
south through southwest Michigan. The sediments of these moraines
range in texture from clay to boulders. Interraorainal outwash
plain sediments range from clay to gravel size (Stramel, Wisler &
Laird, 1954).
Subsurface Geology
The Michigan Basin is the dominant structural geologic
feature in the state of Michigan. Rock units overlying the
Precarabrian basement generally thicken and dip toward the center
of the basin. In the deepest part of the Michigan Basin there are
approximately 4572 meters (15,000 feet) of Paleozoic rocks, with
minor thicknesses of Jurassic rocks. Paleozoic rocks at the Walker
Oil Field reach a maximum thickness of 2134 meters (7,000 feet)
(Lowden, 1964).10
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11
f > # ? <c # / % i
Figure 5. Map Showing the Approximate Location of Ottawa County Relative to the Glacial Systems in Lower Michigan as Mapped by Leverett and Taylor, 1915.
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-C3.
The Traverse Limestone produces oil in the Walker Field from
closure on two broad anticlines. Lowden (1964) proposes that
these structures are the result of the dissolution of the B-Salt
and A-2 Salt beds of the Salina Group, and the subsequent
deformation of the overlying units.
Surface Hydrology
The Walker Oil Field lies within the Grand River drainage
basin. The major stream in this basin is the Grand River, which
drains to the west along the southern margin of the field to Lake
Michigan. Sand Creek drains the western portion of the field and
flows within Tallraadge Township from Section 15 to the south to
its confluence with the Grand River.
Numerous smaller streams, lakes, springs and swamps also
exist within the Grand River drainage basin. Many of the low-
lying swampy areas are found adjacent to the Grand River, often
along the inside of meanders.
Hydrogeology
Nearly all residences within the Walker Oil Field depend on
groundwater through use of private wells. These wells produce
from both the glacial drift and bedrock. Drift wells are used
abundantly because of the good quality and quantity of groundwater
obtained from a relatively shallow depth of usually less than 30
meters (100 feet).
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Very few residential wells were completed in the bedrock
aquifer, the Marshall Sandstone. The Marshall Sandstone is often
encountered at 61 or more meters (200 feet) below ground level
and typically contains objectionable amounts of chloride and
dissolved solids.
In Ottawa County confined and unconfined aquifers are found
within the glacial drift. The unconfined aquifers are composed of
glacial sand and gravel units, at or near the ground surface. The
confined aquifers, also composed of glacial sands and gravels, are
overlain by thick impermeable clays and clayey tills.
Perched aquifers also exist in the area. They are usually
small, discontinuous, water-bearing sand and gravel lenses located
within the vadose zone that overlie impermeable clays and clayey
tills.
Mississippian bedrock units underlie the glacial deposits
and include the Michigan Formation, Marshall Sandstone and the
Coldwater Shale. In Ottawa County the Michigan Formation and the
Coldwater Shale are rarely aquifers. Locally they produce small
volumes of water usually of poor quality for domestic use. The
Marshall Sandstone is an important aquifer and produces large
volumes of water (United States Environmental Protection Agency,
1981). Though rarely used for domestic purposes, some industries
do use the Marshall Sandstone for cooling water needs.
The groundwater flow direction in the glacial materials is
different from the flow direction in the bedrock. Within the
drift groundwater flow varies throughout the county. In northern
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Ottawa County the groundwater flow direction is generally toward
the Grand River. In southern Ottawa County the flow direction is
expected to be toward Lake Michigan (United States Environmental
Protection Agency, Valker Oil Field Study, in progress).
Regional groundwater flow within the bedrock appears to be to
the east, in the direction of dip, toward the center of the
Michigan Basin (United States Environmental Protection Agency,
Walker Oil Field study, in progress).
Groundwater Quality
Drift wells in Kent and Ottawa counties were sampled during
the 1970's and 1980's by the local health departments, the
Michigan Department of Public Health and the Department of Natural
Resources. The water sampling was done to determine the quality
of the groundwater in domestic wells. Parameters tested for
included chloride and specific conductance.
Chloride and specific conductance data were available for
sixty six glacial drift wells located within the Walker Oil
Field. Depths of wells sampled varied from 9 to 24 meters (30 to
80 feet), with an average depth of 18 meters (59 feet). Chloride
values from these wells ranged from 5 to 1200 mg/L with an
average value of 270 mg/L. Specific conductance in 36 of these
wells showed values that ranged from 500 to 2600 Aimhos/cm,
(Michigan Department of Public Health files).
Similar water quality data were available for only nine drift
wells located outside of the oil field. Well depths varied from
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16 to 50 meters (52 to 165 feet), with an average depth of 34
meters (111 feet). Chloride values of the water samples ranged
from 1 to 46 mg/L, with an average value of 8 mg/L. Specific
conductance values varied from 310 to 580 yumhos/cra (Michigan
Department of Public Health files).
Water quality data were not consistent throughout these
counties. The data are skewed since there are many more chloride
and conductivity data available from within the Walker Oil Field
than from adjoining areas, however, there is a significant
difference between the water quality values within and outside the
field. The average chloride value is approximately 30 times less
outside the field. Specific conductances are also notably lower
outside the oil field.
Based on data from Huffman, 1977, 14 mg/L is a generalized
background chloride level for drift in Michigan. This value is in
keeping with the value of 8 mg/L noted in several wells from
outside the Walker Oil Field. No general specific conductance
background level for drift in Michigan has been determined.
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STUDY AREA
General Description
Land use in the study area consists mainly of farm and
residential properties. Sparse wooded areas exist adjacent to
Sand Creek. Most of the land is farmed, and current oil
production is limited to parcels within the planted and unplanted
fields.
The area is crossed by two main roads, 14th Street and
Leonard Street (Figure 2). Forty dwellings exist along these
streets, as well as the Tallmadge Township Hall and the Wesleyan
Church. Fourteenth Street receives brine applications in the
summer for dust control and Leonard Street is salted in the winter
for ice control.
Municipal water and sewage disposal are not readily available
in this area. Residents rely on private water supplies, and
domestic waste and sewage are disposed of through individual
septic systems. To improve the quality of the naturally occurring
hard water, nearly two thirds of the residents have water
softeners.
Surficial Geology
In this locale glacial landforms in the study area consist of
the Inner Valparaiso Moraine and the Sand Creek Outwash Plain
(Figures 5 and 6). Surface elevations range from about 195 to 212
meters (640 to 695 feet) above mean sea level, with the higher16
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■ M ilw m z m m z
• v * v:K>>m
sjs-ssjs
H p lB Kmm^atSsSSmBMf i r a M H l ic M iiP p il
m a f & f a
□ Sand CreekOutwash Plain and lacustrine deposits
Inner Valparaiso Moraine
Study area "boundary
Contour interval 10 feet
oH 500 feetFigure 6. Glacial Landforms in the Study Area (after Ten Brink, 1975).
elevations generally found on the moraine and the lower elevations
on the outwash plain. The land surface slopes gently toward Sand
Creek to the west. Sand Creek and its tributary stream are
incised in the western and northern portions of the site.
Oil well records in the area indicate that the drift
thickness ranges from 29 to 58 meters (94 to 190 feet) (Figure
7). Glacial materials consist of intercalated clay, sand and
gravel. For a detailed description see Hydrogeology subsection.
Subsurface Geology
Bedrock units identified on logs from Walker Oil Field
exploration drill holes include the Traverse Group, Antrim Shale,
Ellsworth Shale, Coldwater Shale, Marshall Sandstone and the
Michigan Formation.
The Middle Devonian Traverse Group is the oldest of the rock
units to be discussed in this report. It is composed of several
thick limestone, dolomite and shale sequences. Gas, oil and brine
are produced in the Walker Oil Field from the Traverse Limestone.
The pay zone in the study area is 1 to 8 meters (3 to 19 feet)
thick. Production is from 566 to 625 meters (1858 to 2050 feet)
deep (Table 1).
The Antrim Shale and the Ellsworth Shale, of Late Devonian
age, overlie the Traverse Group. The Antrim Shale is described as
a light to dark shale unit that ranges in thickness from
approximately 35 to 53 meters (115 to 174 feet). Gas is produced
from this shale unit in Michigan.
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19
PRODUCI NG O i l W f U
A 8 A N O O N t O O i l W i l l
* 21 DRIFT THI CKNESS t ) 150
10 FOOT CONTOUR I NTE RVA L
121
94118
125
190
• 100
Figure 7. Site Hap Showing Drift Thickness Based on Oil Well Record Data.
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The Ellsworth Shale is a dark silty shale that is not a
producer of petroleum in the state. The upper Ellsworth Shale
averages 6 meters (20 feet) in thickness and the lower rock unit
is about 145 meters (475 feet thick).
The Coldwater Shale is characterized on driller's logs as
dark mud and shale, limestone and red-rock. It is of Early
Mississippian age and it lies above the Ellsworth Shale. This
rock unit is the thickest of the six encountered, ranging from 184
to 226 meters (605 to 741 feet). The Coldwater Shale does not
produce oil or gas in Michigan.
The Marshall Sandstone lies above the Coldwater Shale. This
Early Mississippian rock unit is described as sandstone, shale and
mud. It ranges from approximately 66 to 94 meters (215 to 310
feet) in thickness. And it produces some oil, gas and brine,
though not abundantly.
The Michigan Formation of late Mississippian age underlies
the glacial drift. This formation, characterized as a dark mud or
shale, limestone, sandstone or gypsum, ranges from 0 to 38 meters
(126 feet) in thickness. The "Stray" Sandstone of the Lower
Michigan Formation is known to produce gas and is used for gas
storage.
Bedrock elevation data from oil well records were used to
produce a bedrock surface map (Figure 8). As contoured, this map
shows a northeastern to southwestern trending bedrock valley just
west of the intersection of 14th Street and Leonard Street.
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P R O D U C I N G O i l W i l l
A B A N D O N E O O i l W i l l
9 2 0 B E D R OC K I I I V A T l o N ( U t i ) #3 9 41 0 FOOT C O N T O U R I N 1 C R V A
CL.L»8 0.
5 8 3
• 8 8 7
l—l— I— |
Figure 8. Site Map Showing Bedrock (Michigan Formation) Surface Based on Oil Well Record Data.
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Surface Hydrology
Surface waters within the study site include Sand Creek and a
tributary, and a swampy area along Sand Creek. Sand Creek is a
perennial stream. Within Ottawa County it is about 21 kilometers
(13 miles) long and drains to the south into the Grand River.
Sand Creek is approximately 195 meters (640 feet) above sea level
at the confluence with its tributary and approximately 180 meters
(590 feet) above sea level at its junction with the Grand River.
The Sand Creek tributary is about 805 meters (half mile) in
length, and roughly bounds the entire study area on the north. It
descends from an elevation of 204 meters (670 feet) above sea
level in the northeast, to 195 meters (640 feet) above sea level
in the northwest where it drains into Sand Creek.
Hydrogeology
In this portion of the Walker Oil Field 19 well records are
available for 38 water wells and geologic logs are available for
ten oil wells. Oil well records provide details of the bedrock
geology. The overlying glacial materials are usually not
described, although the drift thickness of 29 to 58 meters (94 to
190 feet) was noted on the records.
In the study area domestic well depths vary from
approximately 9 to 49 meters (30 t'o 160 feet) below ground level.
Four soil borings were drilled and logged in this area of the
Walker Oil Field by Western Michigan University faculty in 1983.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
The boring logs provide descriptions of the glacial materials.
The purpose of installing these borings was to obtain additional
geological information in selected areas. Water well records, oil
well records and soil boring records were used to prepare four
geological cross sections (Figures 9-12).
A single aquifer composed of sand and gravel exists within
the drift. It is overlain by 6 to 18 meters (20 to 60 feet) of
clay and clay till. The thick clay-rich units often produce
confined aquifer conditions. Confined conditions were reported in
nearly all well records but were not observed in the shallow soil
borings. The static water level readings of the borings were
observed immediately after the completion of drilling and were not
allowed to stabilize prior to measuring. Confined groundwater
conditions may have been observed in the soil borings after
stabilization.
Discontinuous lenses of sand and gravel lie within the thick
clay-rich materials. In some cases these sand and gravel lenses
may be water-bearing and of sufficient quantity to sustain a
well. One such perched aquifer produces a non-potable water
supply from less than 6 meters (20 feet) below ground level in the
vicinity of 1587 Leonard Street.
Clay-rich material overlying the sand and gravel aquifer
differ across the study area. Inspection of the soil samples from
soil borings #1 and #2 indicate that the material overlying the
aquifer in the southeastern portion of the study area is
lacustrine in nature with intercalated clay tills. Soil samples
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with perm
ission of the
copyright ow
ner. Further
reproduction prohibited
without
permission.
W e s t
A
I 7 0 01 4 51 1 5 0 1 1 4 7 5 1 4 6 3
E a s t
A'
1 4 3 5 1 4 5 71 5 8 7SB 3
gravelyg-HP** clay clay
sand
sandy clay clay
sandT D 4 S f r
TO 61 I tTO 5 8 f t TO 5 9 I t TO 6 3 I tTD 6 3 I i
1— 6 00h-l 1 1 1
SOI I1 0 0 FEET
S A N D A N D G R A V E L [ H a S A N D Y C L A Y £ £ 3 G R A V E L Y C L A Y
POT E N T I OME T RIC 1 5 8 7 L E O N A R D STREET SB 3 SOIL B O R I NG NO. TO TOTAL WELL DEPTHSURFACE____________________________ AQDRE SS
Figure 9. Geological Cross Section Along the South Side of LeonardStreet, Tallmadge Township, Ottawa County, MI. See Figure 2 for A-A' Location.
fo4S
)
!
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ner. Further
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without
permission.
Z<
- 7 0 0
-6 20
W e st
B
Eas t
/B
14 8 4 1 4 3 0 SB 2
sandy clay
clay
sand gravel
sand
ID 68 It TD 6 7 I I
g r a v e l S A N D Y C L A Y S A N D A N D GRAVEL G RA V E L Y C L A Y
-3Z_ POTE NT I O M E T R I C 1 4 8 4 L E O N A R D STREET S 8 3 S O I L B O R I NG NO. 3 TD T O T A L WELL O E P T H
_________ SURFACE____________ _ _ _ _ _ A D D R E S S
Figure 10. Geological Cross Section Along the North Side of LeonardStreet, Tallraadge Township, Ottawa County, HI. See Figure 2 for B-B* Location.
roUi
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ner. Further
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permission.
S o u t h
C
N o r th
C '
1 2 1 8 0
sandy clay
sandTD 6 0 I t
I D 5 8 I t TD 5 5 I t
T D 7 5 I t .
» «-» I0 1 0 0 F E E T
S A N D Y C L A Y S A N D A N D G R A V E L
V POTE N T 10 M ET R 1C
S U R F A C E1 2 1 0 9 14 TH STREET
AOORESSSB 1 SOI L B O R I N G NO. 1 I D T O T A L WELL DE PTH
Figure 11. Geological Cross Section Along 14th Street, Tallmadge Township, Ottawa County, MI. See Figure 2 for C-C Location.
N iON
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W e s t E a s t
•7 0 0
■6 8 0
clay6 6 0
gravely clayv -— 6 4 0
sandsand62 0
TD 5 9 l l
' 6 0 0
□P O I E N I I O M E I R I C , 5 7 7 L E O N A R D S I R E E I
SUE f AC E ____ A D D R E S S
S A N D Y . G R A V E L Y CLAY
T D I O T A L W E L L D E P T H
Figure 12. Geological Cross Section Along Leonard Street extension, Tallmadge Township, Ottawa County, MI. See Figure 2 for D-D' location.
M
from Soil boring #3 and #4 show that in the northern portion of
the study area the lacustrine deposits are absent, and in general
the clay till directly lies above the sand and gravel aquifer.
The composition, thickness and areal extent of glacial
deposits vary significantly over a short distances (see Figure
9). This may account for abrupt changes in lithology and extent
of a particular glacial unit. However, several well drillers were
involved in the installation of the water wells in the area.
Differences in sampling techniques during drilling as well as
different degrees of detail and accuracy in compiling the well
logs, could also be factors in the variation of glacial materials
shown in the cross sections.
A map of the potentiometric surface was produced from
contouring the static water level data of the 19 water wells in
the study site, and the three wells from just outside the site
(Figure 13). From reviewing this map, it is suggested that a north-
trending groundwater divide exists in the area north of Leonard
Street. Groundwater flows away from the divide in both an
easterly and westerly direction.
Groundwater Quality
Water quality data were obtained by collecting water samples
from domestic wells and soil borings located within and just
outside of the Walker Oil Field during the summers of 1983 and
1984. Forty three wells and two soil borings were sampled. Water
samples collected from wells were tested for chloride by
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29
□eeo8 5 0 ST AT I C WATER I E V E L ( F T )
G R O U N D W A T E R F L O W 01 R E C T I O N
G R O U N O W A T E R D I V I D E
5 F O O T C O N T O U R I N T E R V A L
8 3
s«n
8 4 609530680
5 2 06ST □
Figure 13. Groundwater Flow Direction Based on the Potentioraetric Surface of the Study Area.
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titration, and were tested for specific conductance with a
portable conductivity meter (Wagner, 1988). Soil boring water
samples were collected in the summer of 1984. These water
samples were tested for chloride. Table 3 lists domestic well
and soil boring depth and location, as well as water quality
data.
The water quality data obtained from the well samples were
used to create two separate maps, a chloride isoconcentration map
and a specific conductance map (Figures 14 and 15). Several
important observations can be made from these maps, including the
following five:
1. The pattern of both maps is similar.
2. Three adjacent and discrete chloride plumes exist in
about the middle of the study area.
3. The plumes are elongate in shape.
4. The plumes appear to originate from or are associated
with several abandoned oil wells.
5. As drawn the central and the eastern-most plumes appear
to have moved in a westerly to southwesterly direction. The
western-most plume is likely to migrate in a westerly to north
westerly direction. The orientation of the plumes is related to
their locations with respect to the local groundwater divide
described in the groundwater flow map (Figure 13).
6. The central plume includes the highest concentrations of
chloride and specific conductance.
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Table 3
Water Quality Data and Domestic Well and Soil Boring DepthC h lo r id *
< "0 /L )Spec. Conductance
f*e tios/on)Depth
( i t ) Lo ca tio n
167 - Ur* 1376 Leonard
32 740 160 1365
140 960 40 1439 *
106 900 60 1424 •
190 1000 U * 1426
411 1600 67 1438/1430
136 1000 66 1492
165 1000 63 1435 •
496 3000 91 1451 *
100 725 61 1457
616 1900 69 1469
113 830 66 1475
722 2600 66 1480 •
642 - u r* 1494
662 2000 67 1600
M l 1600 63 1601
90 660 63 1609 *
404 1600 u r* 1810
906 1200 60 1625 *
190 - u r* 1626
66 610 92 1635
344 1600 78 1542
170 1200 61 1545
67 760 69 1577
962 1600 66 1667
83 - 160 1638 *
434 1700 76 1685 *
“ 1200 68 1723 *
166 - Ur* 1805 *
33 - 67 1624 a
293 1400 60 12109 14 th
424 1700 66 12116 a
66 725 63 12134 *
370 1200 78 12135
66 160 65 12160 '
190 1100 Ur* 12155
143 990 Ur* 12177
79 700 38 12160
66 660 u r* 12187
14 660 u r* 12303
6 676 u r* 12320
30 - 30 12463 a
76 76 12456
60 - 40 S o il Bor 1no e 1
- - 46 • • 2
- - 40 • • 3
60 — 40 • • 4
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32
30 □PR O D U C I N G O i l W E l l
• •
*□
i d!?<>□o a170|5 7
730
85 0
SO40/. 1 »ODV ^ -20 O—̂ 2 7 on0—
^ S ^ ? 5 :V 2 9 3uyo c X m ]
)C V '* 0D
83
1 3tO
Figure 14. Isoconcentration Map of Chloride (mg/L) of Domestic Well Water (values collected by Wagner, 1988).
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33
H O L D I N G T A N K S
NCE
V A L U E S ' / i m h o t / c m
5 0 0 / i m h o i ' c m CONTOUR I N T E R V A L
5 0 O« o O
00 □7 6 0
0 0
OOQ7 0 o D
66 O D
00 2 0 011 o o D
> * < 1 0 □1 8 0 C 20 6 0 0
7 2 « □1 7 0 0 |o D
<>□000I 8 0N.
7 4 0 D100,
9 OOQ5 00
Figure 15. Map of Specific Conductance Cumhos/cm) of Domestic Well Water (values collected by Wagner, 1988).
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
In the study area domestic well depth varies from
approximately 12 to 49 meters (38 to 160 feet), with an average
well depth of 18 meters (60 feet). The chloride contamination
appears to be separated into three discrete plumes. It is likely
that inconsistencies in chloride values, such as the two low
values on the north side of Leonard Street, are actually due to
sampling problems. Sampling problems may be due to such factors
as the uncertainty of well depth, as only about half of the
domestic wells had well logs prepared for them.
The chloride isoconcentration map indicates that levels of✓
chloride in the groundwater range from 14 to 722 rag/L. A
secondary Recommended Maximum Contaminant Level (RMCL) of 250
rag/L has been established by the United States Environmental
Protection Agency (U.S.E.P.A.) for chloride in drinking water
(Driscoll, 1986). This limit is based on the aesthetic quality
of the water.
Thirteen of the water samples tested for chloride detected
levels greater than 250 mg/L. The highest chloride levels were
within plumes in the middle of the study area, on either side of
Leonard Street. The lowest chloride levels were found in the
northeast, above the Sand Creek tributary, and in the northwest,
just below the tributary. Outside of the study area, just north
of the site on 14th Street, the lowest chloride level was
detected at 5 mg/L. It is inferred that chloride levels of
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35approximately 5 to 75 mg/L represent background levels (also see
Regional Groundwater Quality Section).
Specific conductance is considered an indication of the
amount of total dissolved solids. The U.S.E.P.A. has developed
an RMCL of 500 mg/L for total dissolved solids. The specific
conductance map, shows values ranging from 550 to 2600
Aunhos/cm. The highest specific conductance values were found in
the middle of the site along Leonard Street. The lowest values
were found in the northeast and the northwest, and east of 14th
Street. The locations of the high and low specific conductance
values are similar to those of the chloride values.
Two soil borings were sampled for chloride. The water
samples were collected from each boring immediately upon reaching
the water-bearing zone. Samples from soil boring #1 and #4 show
60 and 50 mg/L chloride, respectively.
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REVIEW OF ELECTRICAL RESISTIVITY USED IN HYDROGEOLOGICAL PROBLEMS
One of the earliest uses of DC resistivity in groundwater
application was exploring for potable water supplies. Often the
search for substantial water supplies involved defining the
boundary between the fresh-water and salt-water zones in a given
aquifer. Swartz, 1939, accomplished this in the Hawaiian
Islands.
Warner (1969) attempted to delineate the fresh-saline water
interface in the aquifers of several sites in New York and in
Texas. Apparently the surface resistivity method was able to
accomplish this task at most all sites except when the zone of
saturation, overlying the saline zone, was very thin with
respect to its depth below ground level.
Since the late 1960's surface electrical resistivity
surveys have been used abundantly in hydrology for groundwater
contamination studies. Cartwright and McComas (1968) conducted
a resistivity survey at an Illinois landfill which was
successful in detecting the direction and the distance of
contamination movement off the landfill site.
Fink and Aulenbach, 1974, were also able to define the
direction of groundwater flow from a resistivity study conducted
at a site in New York where sewage effluent was discharged onto
sand beds.
Electrical resistivity surveys were carried out at four
industrial and landfill sites by Stollar and Roux (1975).36
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Through three of the surveys the lateral extent of groundwater
contamination plumes was defined. One study was not successful,
though, due to such factors as deep water table, and
insufficient resistivity contrast between contaminated and
uncontaminated groundwater.
Many hydrogeological studies involving resistivity have
been conducted recently in the United States. Fretwell and
Stewart (1981) successfully defined the fresh-water/saline-
water contact in a limestone aquifer of a karst area of
Florida.
Bisdorf (1983a) employed this geophysical method to
trace geothermal zones within basalt and rhyolite flows
of the Newberry Caldera of Oregon. Bisdorf (1983b) was able
to map fresh water zones in terrace gravels of Idaho with the
electrical resistivity technique. Problems with cultural
features, however, did make site selection of the
resistivity stations less than optimal.
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EREVIOUS WORK IN THE WALKER OIL FIELD AREA
The Walker Oil Field area has been investigated by others in
the past in attempts to locate bedrock structures, and to define
areas of groundwater contamination. Lowden (1964) conducted a
gravity survey in the Field and was successful in locating salt
beds of the Salina Formation.
Wagner (1988) and Meisel (1985) conducted separate
hydrogeological investigations of the oilfield. Wagner studied
groundwater quality of domestic wells in several counties,
including Kent and Ottawa. She detected several areas where
sodium, chloride and specific conductance values were elevated,
which she suspects may be due to the production and disposal of
oilfield brines.
Meisel (1985) conducted an electrical resistivity study in
Kent county in an attempt to map groundwater contamination
associated with oilfield brines. The technique was not
particularly successful in defining zones of groundwater
contamination because of interference from conductive clays, but
did describe a complex shallow aquifer system.
A similar geophysical survey was attempted by Michigan
Department of Natural Resources (MDNR) previous to Meisel's
investigation. The survey was not completed in part because in
their opinion cultural interferences precluded the application of
DC surface resistivity techniques.
38
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ELECTRICAL RESISTIVITY
Definition
Resistivity is the bulk or three-dimensional property of a
substance which opposes the flow of electrical current. Surface
electrical resistivity is a geophysical technique in which an
electrical current is introduced at the ground surface between a
pair of electrodes, allowing for measurement of electrical
potentials at another pair of electrodes, and hence the
computation of an apparent resistivity at that location.
Uses
Surface electrical resistivity is a valuable means of
collecting geological and hydrogeological data from the
subsurface. Some of the geological data that are obtainable
from employing this geophysical method are as follows:
1. geological structures: folds, faults, intrusion
2. sedimentological features: large scale bedding,
gradation
3. lithological changes: general composition, litholo-
logical boundaries
4. glacial features: buried valleys, stream channels
5. natural resources: minerals and ores, geothermal
reservoirs, water supplies (Mooney, 1980).
39
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40The following aspects of the hydrogeological environment
are also described through surface electrical resistivity:
1. groundwater quality: fresh versus saline water
sources, inorganic contamination plume
2. glacial deposits: drift thickness, sand and
gravel zones (potential aquifers), clays (aquitards)
3. hydrology: perched aquifers, water table
4. fracture directions: study of directional variations
of resistivity.
In addition to geological and hydrogeological data,
surface electrical resistivity can supply information regarding
land use and cultural phenomena.
Factors Governing Resistivity of Rock Materials
Resistivity of consolidated and unconsolidated rock materials
is controlled by various parameters. Included among these
parameters are the degree of saturation and composition of water
retained in the pore spaces, porosity and compaction of rock
materials, and mineralogy (Dobrin, 1960).
Surface electrical resistivity is generally used to obtain
information about geologic materials existing below the water
table. Saturated materials are discussed in greater detail
herein than unsaturated materials.
In the zone of saturation, where most of the void spaces of
rock materials are 100% water-filled, the chemical make up or
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salinity of water contained in these materials is one of the most
significant parameters influencing resistivity. The value of
resistivity will be a function of the volume, mobility and the
dissociation of the dissolved ions in water (Dobrin, 1960).
The mode of transportation of an electrical current in the
saturated zone is through the dissolved ions in water. An
increase in salinity of pore water results in a decrease in
electrical resistivity, all other properties being constant.
The porosity of the saturated rock materials will directly
effect the amount of pore water contained in the rocks. An
increase in porosity, causing an increase in water saturation,
will commonly result in a resistivity decrease. Highly porous
clays will typically exhibit lower values of resistivity than will
sands and gravels, due to increased porosity. Massive limestone
having low porosity usually displays high values of resistivity.
Increasing water saturation up to about 50% results in a rapid
decrease in resistivity. Increasing from about 50% to 100%,
however, results in a slow decrease in resistivity (Mooney,1980).
Compaction of rock materials can affect the overall
resistivity values. An increase in compaction often results in a
decease in porosity, and therefore an increase in resistivity.
Geologically older rock units generally have high values of
resistivity due to compaction of sediments from increased
overburden (Dobrin, 1960). Igneous and metamorphic rock types are
commonly among those having relatively high resistivity values.
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Pore water characteristics are most significant in
determining resistivity of rock materials in the zone of
saturation. Rock mineralogy is often only of secondary
importance.
In the unsaturated zone, where only residual quantities of
pore water are retained, the dominant resistivity-controlling
influence is rock mineralogy. An electrical current introduced at
the ground surface will flow directly across the mineral grains of
the rock materials in this zone (Dobrin, 1960).
In unsaturated, unconsolidated, rock materials resistivity
values commonly vary from about 1 to 800 ohm-raeters (Table 4).3
Sandstone can reach approximately 6 x 10 ohm-meters, while clays
in the temperate environment show relatively low resistivity, 1 to
100 ohm-meters (Telford, Geldart, Sheriff & Keys, 1976).
Field work of the United States Geological Survey (U.S.G.S.)
including deep resistivity well logs, suggest that resistivity
values of the saturated shallow sand and gravels in the northern
Michigan Basin in Michigan, range from 100 to 300 ohm-meter (D.
Westjohn, personal communication). In southwestern United States
resistivity values are characterized from about 15 to 20 ohm-
meters (Zohdy, 1965).
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Table 4
Electrical Resistivity Values of Geological Materials (after Telford 1976)
Geological MaterialsResistivity Averages and Ranges (jl.m)
Alluvium and sands 10 - 800
Clays 1 - 100
Unconsolidated wet clay 20
Sandstone 1 - 6.4 x 108
Limestone 50 x 107
Shale (consolidated) 2 0 - 2 x 104
Saline waters (3%) 0.15
(20%) 0.05
Natural Waters (sediments) 1 - 100
Soil Waters 100
Surface Waters (sediments) 10 - 100
Meteoric Water 30 x 103
Sea Water 0.2
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44
Types of Electrode Configurations and Exploration Methods
Many types of electrode configurations or arrays can be used
when employing surface electrical resistivity. Most of the arrays
consist of four co-linear electrodes arranged so that the outer
electrode pair introduces the electrical current (I) into the
ground surface, while the inner pair measures the resulting
potential difference (V).
Resistivity values obtained from conducting an electrical
resistivity survey at the earth's surface are defined as apparent
resistivity values ( / ). These values are influenced by the
electrical current penetrating the many geoelectrical layers
making up the subsurface (see Theory section).
The two most common arrays presently used in the United
States in groundwater investigations are the Schlumberger and the
Wenner arrays (Zohdy, Eaton & Maybey, 1974). In the Schlumberger
set up the current electrodes (AB) and the potential electrodes
(MN) are kept laterally symmetrical about the geometricaI center
of the spread (Figure 16). The AB electrodes are expanded
continuously during the survey, while the MN electrodes are only
moved infrequently. In general the MN electrodes are kept close
together, such that MN is less than or equal to 1/5 AB
(Mooney,1980). The MN electrodes are expanded when the potential
drop falls below the precision desired. This array geometry
allows for detecting resistivity changes resulting from
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45
M -G>-
Figure 16. Schlumberger Electrode Arrangement.
A ----- ------ K
7 J* 1 / '
' I
Figure 17. Uniform Three Dimensional Current Flow.
Y®i I
/ * SOOJL'm
/ * 1 0 0 0 j i * m 2
»1 > ° 2
Figure 18. Distortion of Current F l o w Lines When f^rnssi — »E the Boundary Between Media of Differing Resistiv- ^ i t y .
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inhomogeneities present at the ground surface near the electrodes,
which can affect the overall apparent resistivity reading.
The following equation is used to determine the measured
apparent resistivity when using the Schlumberger array on a planar
surface or half space:
/ =^/4 . a
This equation is based on the array geometry, the electrode
separation, the applied current and the measured potential
difference.
The Schlumberger electrode configuration has the following
advantages over the Venner array:
1. The survey can be completed relatively quicker and
cheaper, as fewer personnel are required.
2. The array is less affected by near surface
inhomogeneities because the MN electrodes are expanded
infrequently.
3. This electrode configuration has a somewhat greater depth
of investigation and better resolution (Zohdy et al., 1974).
In the Wenner array set-up the AB and MN electrodes are kept
laterally symmetrical about the midpoint of the array. The
distance AM » MN - NB - a.
As opposed to the Schlumberger array, both the AB and MN
electrodes are expanded simultaneously. The equation needed to
(AB)2 - (MN)2(MN)
VI (1)
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determine the apparent resistivity values in employing the Wenner
array is as follows:
An advantage of the Venner array is that it measures a larger
potential difference signal than does the Schlumberger array. It
is, however, more easily affected by near surface inhoraogeneities
and telluric currents, due to the repeated relocation of the MN
electrodes (Telford et al., 1976).
Two common methods of surface exploration are vertical
electrical sounding (VES) and horizontal profiling (HP) methods.
In the VES method, there is a fixed center point around which AB
and MN electrodes are systematically expanded, thereby providing a
progressively deeper penetration of electrical current.
With the HP method the array is moved as a whole along a
given traverse at the earth's surface. A constant electrode
spacing is maintained throughout the survey. By moving the entire
array at each station of the survey, it is possible to note
lateral changes in resistivity at a certain depth.
Both Schlumberger and Wenner arrays can be used in either
sounding or profiling surveys. For this study the Schlumberger
array was used to conduct vertical electrical soundings. This
array was chosen to avoid problems with lateral inhomogeneities
expected to exist in glacial materials overlying the study area.
Vertical electrical soundings were needed in order to obtain
information about the subsurface at unknown depths.
(2)
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48Theory
Resistivity measurements collected at the earth's surface are
calculated assuming uniform resistivity and, therefore, isotropic
and homogeneous subsurface conditions. Since the subsurface is
actually not isotropic and homogeneous, results of four-electrode
resistivity surveys conducted on the earth's surface are referred
to as apparent resistivity (or f ) values. If a resistivity
survey is conducted over isotropic and homogeneous media, then the
true resistivity ( is determined. values are almost
exclusively measured under laboratory conditions.
Electrical current introduced into a homogeneous and
isotropic media will result in a uniform three dimensional current
flow pattern, semi-cylindrical in shape (Figure 17).
As mentioned previously, the earth is inhomogeneous and
anisotropic in nature. The current flow pattern will become
distorted under these conditions, with current concentrating in
low resistivity media. As current flow lines cross boundaries of
differing resistivities, the flow lines change. Current flow
lines bend toward the normal when crossing into higher resistivity
media, and bend away from the normal when crossing into lower
resistivity media (Figure 18).
The distortion of the flow lines cause a change in the
potential drop reading, resulting in a change in f (Figure 19).cl
The depth of current penetration is a function of the layering
structure of the earth, and the length of the AB/2 separation
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49
Figure 19
i— G >
a)I V s 11' l \
- A -
- - _
S •» — *— CD-
✓ i
- h -
B
b) * *r"■ V-v -g- 3 _ <• f A
12
c)
©-
7JV/ r ' ~ - ' i x r-v- *
d)
— © -
A
Changes in Layer Thickness (h) and Electrode Separation Influence Current Flow Direction.a) Little influence from layer 2 where h, > h„ andr < / ■ 1 21 2*b} current flow is greatly influenced by layer 2, but most of the current is concentrated in layer 2, where h < h2 andc; Current flow is greatly influenced by layer 2, where AB is large;d) little influence from layer 2, where current electrode is small (after Mooney, 1980).
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
(Dobrin, 1960). A more detailed discussion of the theory of
electrical resistivity is found in Zohdy et al., 1974; Mooney,
1980; and Dobrin, 1960.
Field Methods
Figure 20 shows the locations of 56 VES's completed using the
Schlumberger array. It also indicates the locations of several
geoelectric sections (GSA - GSI). Each geoelectric section
consists of several VES's that are generally equidistant to one
another and are arranged in a straight line. In Geoelectric
Section C - F the geoelectric sections were oriented perpendicular«■to the proposed groundwater flow direction. This particular
orientation was chosen in order to define the lateral boundaries
of the groundwater contamination plume(s), expected to exist in
the shallow aquifer.
Both the current and potential electrodes were expanded about
the geometric center of the array. Each expansion was
approximately 1.46 times greater than the preceding length.
Current electrodes (AB) were expanded to large distances, ranging
from 100 to 316 meters (328 to 1037 feet)(Figure 21). Cultural
interferences such as buildings and fences, sometimes prevented
moving the electrodes all the way to 316 meters (1037 feet).
Typically the maximum AB/2 expansion was 147 meters (482 feet).
At a few VES's 100 meters (328 feet) was the largest separation
possible. The maximum MN/2 separation was 15 meters (49 feet).
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5 1
VES STATION12GEOEIECTR IC SECTION
S O I t BORING
ACTIVE! AB AN D O N ED O i l W E t l S
H O ID IN O TANKS
□
9OS H22 CR23
G S I3 0
□2*3 2
S 0 0
Figure 20. Map Showing the Locations of VES and Geoelectric Sections.
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52
Project! Tallm adge Township - O ttaw a C o .. Ht • VES H o .
Location: a p p ro x . 100 m w es t o f 1 4 th S t ! 250 m . Date! 8- 22-81 n o r th o f Leonard SC.
Operator! K o e h le r e t al Equip.Conditions: c lo u d y - h o t - damp
ForwardV / I
ReverseV / I
AD/2 ( “ )
MN/2 < - >
K V / I(JL)AvG.
A5-71 • m ) smoothed v a lu e s (jll'm )
4 .9 6 4 .7 0 1 .0 0 .1 5 10.2 4 .8 3 4 9 .3 60 .0
1.79 1.74 1.47 0 .1 5 22.4 . 1 .77 3 9 .6 48 .2
0 .688 0 .605 2 .1 5 . 0 .1 5 4 8 .2 0 .647 31.2 3 8 .0
0 .300 0 .317 3 .1 6 0 .1 5 1 04 .0 0 .309 32.1 39.1
0 .191 0 .191 4 .6 4 0 .15 2 25 .0 0 .191 4 3 .0 52.3
0 .131 0 .131 . 6 .81 0 .1 5 4 8 5 .0 0 .131 6 3 .5 77.3
0 .561 0 .505 6 .81 0 .5 145 .0 0 .533 7 7 .5 __0 .333 0 .336 1 0 .0 0 .5 3 13 .0 0 .335 104 .9 l n r>. o
0 .207 0 .207 14.67 0 .5 675 n O. 207 11Q 7
0 .123 0 .123 21.54 0 .5 1457.0 0 .123 179.2 187 .0
0.403 0 .398 21.54 1 .5 4 8 4 .0 0 .401 194.7
0 .208 0.231 31.62 1 .5 1045.0 0 .2 2 0 229 .9 230 .0
.0 .0 8 8 0 .116 4 6 .4 1 1 .5 2 2 5 3 .n n m 2 220 n
0 .038 0 .043 6 8 .13 1 .5 4 85 8 .0 0 .041 199.2 197.00 .133 0.133 68.13 5 .0 1450.0 0 .134 194.3
0 .043 0 .043 100.0 5 .0 3134 .0 0 .043 134.8 135.0
0 .012 0 .021 146.7 5 .0 6753 .0 0 .033 222 .8
0 .015 * 0 .015 215.4 5 .0 14570.0 0 .015 218 .6
0 .035 0.031 215.4 15 .0 4 8 3 5 .0 0 .033 1 5 9 .6
' 0 .022 0.021 116.2 15.0 10450.0 0 .022 2 29 .9
■E lfiV fltl in - i« -a p r m ----68 R I
Figure 21. Sample of Field Data.
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At the majority of the VES's only a five meter (16 foot) maximum
separation was used.
At each electrical sounding the current electrode separation
was increased, and external voltage was applied across the current
electrodes, causing an electrical current to flow through the
earth. The resulting electrical potential (V) was then measured
between two potential electrodes, and the apparent resistivity was
calculated.
This procedure was repeated at each station of a sounding.
When the electrical potential reading had dropped to a very small
value, it was necessary to expand the MN electrodes. The accuracy
of the measured electrical potential was improved by expanding the
MN electrodes when the value of MN approximated l/20th the AB/2
value.
Apparent resistivity measurements were made before and after
the expansion of the MN electrodes, while the AB electrodes
remained stationary. Calculated apparent resistivity values at
each station of each VES were plotted against the respective AB/2
values on log paper to generate field curves of apparent
resistivity. Data points that appeared to be inconsistent with
the field curve were repeated to check their validity.
An average of the forward and reverse V/I readings was then
calculated for each station of a given VES. Apparent resistivity
values were computed using formula 1 (see Types of Electrode
Configuration and Exploration Methods section). The V/I values
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were read directly from the resistivity meter. On the field data
sheet K equals the following:
K - #74 . (AB)2 - (MN)(3)(MN)
After collecting about 17 apparent resistivity readings at a
given VES, the field equipment was moved approximately 50 meters
(164 feet) to the next VES site and the entire process was
repeated.
Apparent resistivity readings were collected before and after
expanding the MN electrodes, while keeping the AB electrodes
fixed. This procedure caused an overlap of points, and
segmentation of the apparent resistivity curve. When surface
materials near the MN's are homogeneous, both apparent resistivity
values collected before and after expanding the MN's are similar,
and the resulting curve segment is slightly displaced to the right
(Figure 22). When the surrounding surface materials are
heterogeneous, the values of apparent resistivity readings before
and after the MN expansion are quite dissimilar. This results in
a large curve segment offset to the left of the previous segment.
Use of the Schlumberger apparent resistivity method, therefore,
allows the user to interpret the effect of surface inhomogeneities
adjacent to the MN electrodes. As noted in Figure 21, two
apparent resistivity measurements were collected at AB/2 = 6.81,
21.54, 68.13 and 215.4 meters (22, 71, 224, and 707 feet,
respectively).
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55
log p0
log L
Figure 22. Hypothetical Schlumberger Field Curve Showing Curve Segment Displacement.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
56
To avoid recording potentials caused by electrochemical
activity between the metal contacts of the electrodes and
electrolytes of the soil, two precautions were taken:
1. Non-polarizing Cu-CuSO^ potential electrodes
were used.
2. A reversing switch was used to change the direction of
current between the metal stakes, used as current electrodes.
Thus the signal polarities were alternately reversed and
the constant spurious potentials were canceled out (Dobrin,
1960).
Data Reduction
In order to interpret the significance of the collected field
data, the following three stages of data reduction were
followed:
1. Each apparent resistivity curve was smoothed and visually
inspected.
2. Trial subsurface resistivity models were examined through
the use of the computer program RESIST, and the program INVERS
was used to refine the model to best fit the field curve.
3. A longitudinal conductance map and several geoelectric
sections were constructed.
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57
First stage
To simplify an apparent resistivity curve, inconsistencies in
the curve had to be adjusted and smoothed through. Resistivity
data from Schlumberger soundings, represented by unconnected curve
segments, were shifted and joined together to form one continuous
field curve.
All 54 apparent resistivity curves were segmented.
Segmentation of Schlumberger apparent resistivity curves was
caused by plotting the double readings of apparent resistivity
collected at subsequent MN separations, while the AB/2 spacings
remained constant (see Field Methods Section).
Cusps, abrupt changes in the curve shape, also had to be
smoothed. Nine curves appeared to have cusps. The cusps are
expected to have been caused by buried cultural factors or leakage
of electrical current. Smoothing through the curve segments and
the cusps of each apparent resistivity curve helped to clarify the
particular shape of the curve, allowing for their interpretation.
Through a cursory visual examination the minimum number of
geoelectric layers, their relative apparent resistivity values,
and the curve types were inferred. The number of geoelectric
layers were discerned by noting the rises and falls of the
apparent resistivity curves. In Figure 23, for example, VES #2a
is depicted by five geoelectric layers, assumed from the initial
inspection. It is possible, however, that more than five
geoelectric layers may in fact exist in the subsurface due to
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58
Tallmadge Twp. - Ottawa Co., HI 2aapprox. 25 m so. o il tank serv. rd;100 m west 14th St. 9-17-83
IC - 69 (loaner)
very damp - cool - cloudy ___
Figure 23. Sample of Study Area Field Curves.a) Segmentation of the field curve;b) Same curve after smoothing.
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factors such as suppression, in which a given geoelectric layer
may not be uniquely represented on the particular apparent
resistivity curve. A geoelectric layer may be suppressed if its
thickness is small when compared with its depth of burial. Thus a
thin geoelectric layer might be averaged with thicker geoelectric
layers lying above or below it. To improve the reliability of the
inferences made for visual examination of apparent resistivity
curves, supplemental geological, hydrogeological and groundwater
quality data were utilized as control, to yield a better
understanding of the makeup of the subsurface.
A rough estimate of the apparent resistivity value of each
curve segment was read from the ordinate axis on the curve plot.
Apparent resistivities from VES #2a are noted as 220, 75, 135, 70
and 200 ohm-meters (Figure 23). These values are crude
approximations of apparent resistivity values only, as each
geoelectric layer is influenced by the geoelectric layers
surrounding it.
The type of each apparent resistivity curve was determined by
the relationship between the resistivity and thickness of the
geoelectric layers (Figure 24). If more than three layers
characterize the subsurface, the curve types can be combined to
represent the particular geology. VES #2a, made up of five
layers, denotes an HKH-type curve.
The 54 apparent resistivity curves reviewed were judged to
have from three to seven geoelectric layers. The majority
consisted of five such layers, representing the HKH-type curve.
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60
1)
2)3)
4)
Figure 24.
where > < 4 H-type curve
where ' i < > K-type curve
where / i > A > ^3 Q-type curve
where ' i < < ^3 A-type curve
Four Basic Relationships Exist Between Resistivity and Thickness in a Three-Layered Subsurface:1) Represents a minimum or H-type curve,2) Represents a maximum or K-type curve,3) Represents a descending or Q-type curve,4) Represents an ascending or A-type curve
(after Zohdy et al, 1974).
Second Stage
The number of geoelectric layers and layer resistivity values
were obtained through visual inspection of the apparent
resistivity curves. Layer thickness was estimated by reading the
values from the. abscissa of each resistivity curve plot. These
data were combined to create a initial model of the subsurface
used with the interpretational computer program, RESIST. The
RESIST program generated a theoretical curve, based upon the input
initial model, which was then superimposed on to the field curve.
The initial model was modified when needed, by the user to improve
the fit between the curves. RESIST, therefore, acted to improve
the initial model of each apparent resistivity curve from the
first stage of data reduction.
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RESIST was utilized when reviewing only the first few
apparent resistivity curves. With the exception of double
checking the rough model gathered from visually reviewing a few
atypical curves, the RESIST program was eventually discontinued,
in order to expedite the curve evaluation process. In the opinion
of this write, the model obtained in visually inspecting the
apparent resistivity curve (First Stage) was usually sufficient to
use as the initial model in the second computer program, INVERS.
INVERS is a computer program designed to determine a layered
earth model whose calculated apparent resistivity curve closely
agrees with the curve of the field data (Mooney, 1980). The trial
model (obtained from RESIST) layer resistivity and thickness
values were input into the INVERS computer program, representing
the initial layered earth model. The program then determined an
apparent resistivity curve for these data, which was compared with
the field curve. A root mean square (RMS) error value was then
computed, based on the dissimilarities between the curves. The
average RMS was 4.8% for this research.
The initial model was iteratively adjusted automatically
until the model had passed through 15 iterations, until the RMS
error began to increase (diverge), or until the RMS error fell
below a pre-set cut-off value (Mooney, 1980). To improve the RMS
error between the final calculated layered model and the field
data model, the process was repeated, with the user making
adjustments to the new model. Geological data was used as control
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f o r c o m p a r i s o n w i t h t h e s o u n d i n g s d o n e n e a r w a t e r w e l l a n d s o i l
b o r i n g l o c a t i o n s . T h e m o d e l w a s g r e a t l y i m p r o v e d w h e n t h e l a y e r
t h i c k n e s s e s o f g e o l o g i c a l f o r m a t i o n s , f o r e x a m p l e , w e r e k n o w n .
T h e INVERS c o m p u t e r p r o g r a m o f f e r s a m e a n s o f t y i n g i n
s u p p l e m e n t a l g e o l o g i c a l i n f o r m a t i o n , b y a l l o w i n g e i t h e r o r b o t h
t h e r e s i s t i v i t y a n d t h i c k n e s s o f o n e o r m o r e g e o e l e c t r i c l a y e r t o
b e h e l d f i x e d w h i l e t h e o t h e r p a r a m e t e r s w e r e a l l o w e d t o v a r y .
A l s o c a l c u l a t e d i n t h e INVERS p r o g r a m f o r e a c h g e o e l e c t r i c
l a y e r w e r e t h e D a r Z a r r o u k p a r a m e t e r s , l o n g i t u d i n a l c o n d u c t a n c e
( S ) a n d t r a n s v e r s e r e s i s t a n c e ( T ) . S » t h i c k n e s s / r e s i s t i v i t y f o r
a m in im u m r e s i s t i v i t y l a y e r , a n d T - r e s i s t i v i t y x t h i c k n e s s f o r
a m ax im u m r e s i s t i v i t y l a y e r . T h e s e p a r a m e t e r s w e r e u s e d t o d e f i n e
a p a r t i c u l a r c u r v e s e g m e n t o f a n a p p a r e n t r e s i s t i v i t y c u r v e . By
h o l d i n g c o n s t a n t t h e S p a r a m e t e r f o r c u r v e s e g m e n t s r e p r e s e n t i n g
a r e s i s t i v i t y m in im u m , a n d t h e T p a r a m e t e r f o r c u r v e s e g m e n t s
r e p r e s e n t i n g a r e s i s t i v i t y m axim um l a y e r , t h e c o m p u t e d t h e o r e t i c a l
c u r v e w o u l d n o t d e v i a t e g r e a t l y f r o m t h e f i e l d c u r v e . S e v e r a l
l a y e r e d e a r t h m o d e l s , t h e r e f o r e , c o u l d b e p r o d u c e d f r o m t h e s am e
f i e l d d a t a .
A l l a p p a r e n t r e s i s t i v i t y c u r v e d a t a w e r e r u n t h r o u g h t h e
INVERS c o m p u t e r p r o g r a m , w i t h t h e e x c e p t i o n o f VES # 8 . A l a y e r e d
e a r t h m o d e l o f l e s s t h a n o r e q u a l t o 10% c o u l d n o t b e d e t e r m i n e d
t h r o u g h t h e INVERS c o m p u t e r p r o g r a m . I t i s p o s s i b l e t h a t a b u r i e d
c o n d u c t o r , s u c h a s a p i p e l i n e , e x i s t s i n t h e s u b s u r f a c e i n t h e
v i c i n i t y o f VES # 8 . T h e VES # 8 s o u n d i n g c u r v e a p p e a r s t o b e
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anomalous in character and was, therefore, not included in the
data used to interpret the subsurface of the study area.
Third Stage
The interpreted resistivity data obtained from INVERS
computer models were used to construct nine geoelectric sections
(Elates 1-3 and Appendix E). Data from domestic wells, oil wells,
soil borings and from water samples were correlated with adjacent
vertical electrical soundings and were incorporated into the
geoelectric sections. Based upon the curve similarities these
data were extrapolated to the next adjacent sounding in a
continuous manner. The method of constructing the sections was
similar to that used in preparing geological cross sections.
The longitudinal conductance (S) map was created by adding
the S values at each VES, exclusive of the highly variable
surface layer, as noted in the output from INVERS (Appendix C).
where h^ represents the sum of the thickness of the geoelectric
layers, and denotes the sum of the resistivity of the
geoelectric layers. The S values then were plotted and contoured
at 0.2 mho contour interval (see Interpretation of Field Data -
Longitudinal Conductance Map) (Figure 25).
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64
0.47 10 N Gl T UDI N A L CONDUCTANCE 0 VAL UES(mhot)-EXCLUSIVE 07
FIRST LAYER
A C T I V I / A 8 A N O O N E D O l L WELLS
• » H O L D IN G TANKS
.2 mho CONTOUR INTERVAL
1.080.07
,0.10
'1.38*
1.2
Figure 25. Map o£ Longitudinal Conductance (mhos).
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Interpretation of Field Data
True resistivity values of field-collected soil samples, were
measured and calculated in the laboratory. These values were used
to verify the interpreted resistivity values that were calculated
by the computer program INVERS, for the different geoelectric
layers. This was especially important for the dry and saturated
sands and gravels of the drift aquifer. An overall good
correlation exists between the interpreted resistivity and true
resistivity values. Sometimes, however, the interpreted
resistivity values differ from the true resistivity values. This
appears to occur when more than one geoelectric layer was
represented by a single interpreted resistivity value. For
details on the method of laboratory testing refer to the Lab
Procedures section.
Water quality data from domestic well and soil boring
sampling were included in the respective geoelectric sections for
added reliability. Chloride was one of the parameters tested for.
Values of chloride ranged from 14 to 722 mg/L, with background
levels equal to about 75 rag/L or less (see Ground Water Section).
In general areas of elevated chloride concentrations correspond to
areas of low resistivity. Low chloride concentrations are also
associated with areas of high resistivity.
The interpreted resistivity of the saturated zone was
determined by two different methods:
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1. The computer model INVERS assigned resistivity
values to the geoelectric layer representing the zone of
saturation within the constraints of the fixed parameters
associated with geological control data.
2. Specific conductance values of domestic well water were
combined with Archie's Law, to determine reasonable aquifer
resistivities for some of the sand-gravel units.
In addition to chloride, water samples from domestic wells
were also tested for specific conductance. Specific conductance
values were converted to resistivity values and were then applied
to Archie's Law. Archie's Law can be written as follows:
^FMN " H2(/0 ^where “ formation resistivity, ^ 2 0 “ resistivity of the
interstitial water, i6 - porosity, m - matrix cementation factor.
Calculation of Archie's Law resulted in determining the average
aquifer formation resistivity from the depths at which the
domestic wells were screened. Archie's Law calculations can be
found in Appendix D.
Porosity values of glacial materials can vary greatly. Most
porosity values of unsorted tills would be expected to fall within
the range of 25 to 45%, with the higher values representing the
clay-rich till (Davis & DeWiest, 1966). The value of 30%, used in
Archie's Law in this study, typically represents clean sands and
gravels, such as those composing the drift aquifer in the study
area. Kwader (1985) points out that matrix cementation factors
for most unconsolidated quartz sand aquifers range from
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1.3 to 1.4. For this study a value of 1.35 was used, to represent
the matrix cementation factor.
Eorosity, as with water quality, is not expected to remain
constant across a given geoelectric section. The formation
resistivity values calculated from Archies's Law were used as
estimates only. These values were, therefore, allowed to
fluctuate when no control data were available.
It is possible that the water quality data collected from
sampling these wells may not be representative of the actual
groundwater quality of the aquifer. Some of the well screens are
completed partly into the contamination zone and partly into the
overlying fresh water zone. It is likely, therefore, that the
specific conductance data collected from water samples are lower
than that of the actual groundwater quality. The resistivity
values calculated from Archie's Law may represent the maximum
resistivity and thickness values for this low resistivity zone.
The INVERS-generated resistivity values are much lower than those
derived from Archie's Law, and may describe the minimum
resistivity and thickness values for this layer. The real
resistivity and thickness values are unknown, and may lie between
values described by these two models.
Three geoelectric sections are described in the
Interpretation of Field Data Section. Model A represents computer
generated resistivity values of the saturated zone, and Model B
represents the same geoelectric section calculated by INVERS, but
with the aquifer resistivity constrained to the value calculated
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from Archie's Law, based on water conductivity assumed porosity of
30%, and cementation factor of 1.35.
Geoelectric Section A
Geoelectric Section A is based on eight vertical electrical
soundings (VES's), one water well record, one soil boring and two
oil well records (Plate 1). Both models A and B show several
distinct geoelectric layers. The first layer below ground level
is characterized by interpreted resistivity values that range from
about 75 to 1400 ohm-raeters. These heterogeneous surficial
materials are interfingered with unsaturated sands.
Below the surficial materials lies a clay unit in both
models. Model A shows that the layer appears to thicken from
about 0.6 meters (two feet) at VES #1 to nearly 12 meters (40
feet) at VES #3b, and is represented by interpreted resistivity
values of 11 to 65 ohm-raeters. In Model B the clay-rich zone is
very thin, ranging from 0.6 to about 3 meters (2 to 10 feet), and
is characterized by interpreted values of 21 to 96 ohm-meters.
True resistivity values of 48 to 68 ohm-meters were noted in the
laboratory. Below this point in the geoelectric section the two
models have few similarities and will, therefore, be described
individually.
In Model A a water-bearing sand and gravel unit exists
beneath the clay-rich unit. It is denoted by interpreted
resistivity values of from 19 to 700 ohm-meters, with resistivity
values of 80 ohm-meters or less denoting isolated clay-bearing
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zones. Static water level data indicate that this sand and gravel
unit represents a portion of both the unsaturated and the
saturated zones. Laboratory values of 45 and 68 ohm-meters
describe the sand and gravel materials. The soil boring and the
domestic well completed in this zone were sampled and tested for
chlorides, showing levels of 50 and 75 mg/L, respectively. These
are of background chloride levels, not indicative of groundwater
degradation.
Low interpreted resistivity values, ranging from 8 to 16 ohm-
meters define the resistivity layer underlying the sand and gravel
unit. This layer averages about 8 meters (25 feet) in thickness.
No water quality data, or detailed geological or geophysical
information, were available to describe this geoelectric layer, or
those underlying it. The low interpreted resistivity values of
this layer suggest that it represents either a clay-rich layer, or
perhaps a zone of groundwater contamination. Better control data
are needed in order to make this distinction.
This conductive layer is continuous across most of the
section except at VES #3B. At VES #3B no geoelectric layers are
detected at a depth greater than that of the sand and gravel
unit. The reason that these deeper layers are not detected may be
the result of only a shallow depth of electrical current
penetration, when employing the surface resistivity method, caused
by the thick low resistivity layer above. Alternately, the low
resistivity layer underlying the shallow clay might not be
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continuous to the northwest, and it might not exist beneath
sounding #3b.
Underlying the deep low resistivity layer is a unit with
interpreted resistivities that vary from 151 to 440 ohm-meters. It
is continuous from VES #1 to #3A. Well record data from oil
wells located about 50 meters (164 feet) southeast of VES #1
suggest that bedrock in the vicinity of Geoelectric Section A may
be detected within this deepest resistivity layer. This
geoelectric layer may presumably describe either the top of the
Michigan shale and limestone, or the deepest portion of the
glacial overburden above the bedrock. Based on similar
resistivity values between this deepest geoelectric layer and the
layer below the shallow clay unit, this layer likely depicts sand
and gravel glacial materials.
In Model B a sandy-clay zone is detected below the clay-rich
zone. Geological control data indicate that this geoelectric
layer is made up of unsaturated sands and clays. Interpreted
resistivity values range from 117 to 291 ohm-meters. Laboratory
values from SB #4 show true resistivity values ranging from 48 to
200 ohm-meters.
Beneath the sand and clay unit lies a geoelectric layer
represented by interpreted resistivity values of 57 to 82 ohm-
meters between VES #3B and 3', and 31 to 36 ohm-meters between VES
#2B and IB. No control data are available to define the north
western portion of this layer. Soil boring #4, completed in the
low resistivity portion of this geoelectric layer, indicates that
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at least the upper portion is composed o£ saturated sand and
gravel. True resistivity values were calculated to be 45 to 48
ohm-meters. A water sample detected 50 mg/L chloride, which is
within the inferred background chloride level. These data do not
support that the upper portion of this low resistivity zone
represents a zone of groundwater degradation. Additional
geological and water quality data would be needed in order to make
any conclusions about this layer.
No geological, water quality or lab data were available to
describe geoelectric layers underlying the low resistivity layer
mentioned above. Only inferences can be made with regard to the
nature of these layers. The geoelectric layer underlying the low
resistivity layer varies from 108 to 305 ohm-meters. At VES #1A
neither the low resistivity zone mentioned above nor this
relatively high resistivity zone are detected. One medium
interpreted resistivity value of 74 ohm-meters has been assigned
to represent approximately 27 meters (90 feet) of rock material.
This resistivity value and thickness are anomalous and do not fit
the model. It is inferred that the overlying low resistivity
layer and the relatively high resistivity layer are being
represented by one medium resistivity value.
One high interpreted resistivity value of 630 ohm-meters was
noted below the above-mentioned zone at VES #1 and a value of 91
ohm-meters was detected at VES 3'. These geoelectric layers
likely define the bedrock surface, describing the limestone and
the sandy shale members of the Michigan Formation, respectively.
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Geoelectric Section D
Ten soundings were correlated with six water well records,
three oil well records and one soil boring record in Geoelectric
Section D (Plate 2). Both Model A and Model B similarly
characterize five geoelectric layers, while only three different
geological units may in fact exist. At the surface are several
thin discontinuous geoelectric layers denoted by interpreted
resistivity values that range from 84 to 2796 ohm-meters. These
layers represents heterogeneous surficial materials.
Below the surface layer is a clay-rich unit interspersed with
sand and gravel. This clay-rich unit is characterized by low
values of interpreted resistivity, varying from 7 to 77 ohm-
raeters, and is laterally continuous across the section.
Calculated true resistivity values for sandy clay materials range
from 185 to 244 ohm-meters; clay is characterized by a value of 41
ohm-raeters. An anomalously low value of interpreted resistivity
within this clay-rich unit is detected at VES #48. The
significance of this low resistivity layer is unknown due to
inadequate geological control.
Underlying the clay-rich unit is a sand and gravel unit
intercalated with clay. The sand and gravel unit appears to be
subdivided into three distinct geoelectric layers. The first of
these layers can be described as a clay-rich sand unit. Static
water level data suggest that this unit encompasses both the
unsaturated and the saturated zones. Interpreted resistivity
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values range from 100 to 660 ohm-meters. True resistivity values
range from 89 ohm-meters, to 954 ohm-meters. Two domestic wells
and one soil boring were completed i n this zone. Chloride levels
detected in water samples from the wells were 113 and 165 mg/L,
somewhat higher than the supposed background level. No water
samples were collected from SB #3.
Beneath the clay-rich sand unit is a geoelectric layer
characterized by low interpreted resistivity values. These values
range from 4 to 32 ohm-meters in Model A, from 22 to 53 ohm-meters
in Model B. This geoelectric layer is about 396 meters (1300
feet) in length, and averages approximately 4 meters (12 feet) in
thickness in Model A, and 14 meters (45 feet) in Model B. It is
described as a sand and gravel unit in the log of oil well #9851,
as it is in the logs of three o f the domestic wells. Water
samples from the domestic wells that are at least partially
screened in this low resistivity zone, demonstrate elevated levels
of chloride, ranging from 352 to 515 mg/L. From these data it is
inferred that this geoelectric unit represents a zone of
groundwater contamination.
The proposed plume within the sand and gravel unit is not
detected at VES #49 in either of t h e two models. Two possible
reasons for its absence are as follows: (1) this low resistivity
layer may not be detected by surface electrical resistivity due to
the thick overlying clay at VES #49, which would allow only for a
shallow depth of current penetration, or (2) simply that this
layer does not extend laterally this far to the northwest.
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At VES #12 only the upper boundary of the inferred plume is
detected. The lower boundary is interpolated from adjacent
soundings. Relatively higher resistivity values were observed
within this zone at VES #11 and #12. Insufficient geological data
exist to interpret these values. Perhaps the concentration of
dissolved solids is lower in the vicinity of these soundings.
Underlying the inferred plume is a geoelectric layer
characterized by interpreted resistivity values of from 125 to 300
ohm-meters. In Model A it is described by the well log for oil
well #9851 as sand and gravel. No geological data are available to
correlate with these depths in Model B. None of the soundings
delineated the bedrock surface.
Geoelectric Section E
Geoelectric Section E was prepared using twelve vertical
electrical soundings that are correlated with three well records
and one soil boring (Plate 3). Five geoelectric layers are
interpreted in both Model A and B, while only three principal
geological units likely exist. Values of interpreted resistivity
were similarly assigned in both models to all but the deepest
conductive layer. The discrepancy in layer thickness and
interpreted resistivity values between the two models of this
layer is a function of the method of interpretation (see Types of
Electrode Configurations).
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The near surface resistivity layer is heterogeneous in
nature. Below it lies a layer that is characterized by low values
of interpreted resistivity, varying from 15 to 88 ohm-meters. It
is continuous across the section and thickens toward the middle of
the section. The accompanying geological data indicate that this
is a moist sand and clay unit. True resistivity values of from 28
to 51 ohm-meters were calculated for this unit.
Beneath the sand and clay unit two geoelectric layers are
detected which constitute one geological unit, a clay-bearing
gravel and sand. The first of these two layers is relatively
thick and continuous across the section. Interpreted resistivity
values ranging from 100 to 998 ohm-meters define this layer. True
resistivities were computed as follows: clay - 31 ohm-meters; dry
sand - 978 to 2212 ohm-meters; moist to saturated sand - 46 to 86
ohm-raeters. Static water level information suggest that this
layer represents the lower region of the vadose zone, and the
upper portion of the phreatic zone. A soil boring was completed
in this zone. No water quality data were available from this
boring.
Within this zone low values of interpreted resistivity of 100
to 140 ohm-meters were detected near VES #31, and #24 through #26
in both Models A and B. These relatively low values may be
interpreted as suggesting a localized increase in clay content of
the gravel and sand materials. It can also be inferred from the
low interpreted resistivity values that this interval depicts
groundwater contamination.
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The second of the two resistivity layers representing this
same gravel and sand unit is described by anomalously low
resistivity values, varying from 7 to 22 ohm-meters in Model A,
and 15 to 83 ohm-meters in Model B. This layer exists
approximately 9 meters (30 feet) below the potentiometric surface
and is at least 366 meters 1200 feet in length. It averages about
6 meters (18 feet) in thickness in Model A and about 12 meters
(40 feet) in thickness in Model B. It is fairly uniform in
thickness in Model A, but seems to pinch out to the southeast
between VES #26 and #27. In Model B the thickness of this layer
varies greatly across the geoelectric section. These low modeled
resistivity values for the sand and gravel unit appear to
characterize groundwater contamination. Two domestic wells within
this zone tested for chloride showed levels of 411 and 722 mg/L.
These levels are far above background chloride levels, lending
support to the possibility of a contamination plume.
At VES #27 through #29 resistivity values range from 66 to
125 ohm-meters in both Model A and B. This portion of the sand
and gravel unit apparently has not been impacted by chloride
contamination (Figure 15) or else the impact has been minimal.
Lower chloride values of 138 mg/L detected from sampling a nearby
domestic well support this suggestion.
Underlying the inferred contamination plume is the last
resistivity layer indicated by surface geophysical methods in this
section. No geological data are available to describe this lower
layer, which has values of interpreted resistivity ranging from
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100 to 375 ohm-raeters. It is possible that this deepest
resistivity layer detected actually portrays the lower zone of the
same sand and gravel unit that contains the inferred contamination
plume. Interpreted resistivity values of this unit are similar to
those of Geoelectric Section D, which was run parallel to this
section. In Geoelectric Section D geological data were available
which showed that the deepest resistivity layer was the same
aquifer material as that above the inferred contamination plume.
No data were available for bedrock depth in this section.
Longitudinal Conductance Map
As described in the third stage of the data reduction
section, longitudinal conductance (S), is expressed as
S = ^ h^/ f , where h^ = the sum of the thickness of the
geoelectric layers, and f = the sum of the interpreted
resistivity of the geoelectric layers of a. given VES (see
Electrical Resistivity). The map of longitudinal conductance was
created by adding together all the longitudinal conductance values
at each vertical electrical sounding. The summed S values are a
good indicator of the total amount of conductive material
investigated by a VES, and are independent of any particular
subsurface interpretive model. The INVERS computer modeling
program computes the S values of each geoelectric layer, as well
as other parameters (Appendix C). The S values for all
geoelectric layers at each VES were added and plotted at the
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respective VES stations (Figure 20). These values were then
contoured at 0.2 mho increments (Figure 25).
All fifty five of the S values were plotted. VES #31,
however, represents an anomalous value of S. At VES #31 the S
value is calculated as 0.085 mhos. Values from several nearby
data points range from 1.10 to 1.38 mhos. Since this value is
inconsistent with five surrounding data points, the author has
chosen to ignore this data point with regard to contouring the
map of longitudinal conductance (Figure 25). The cause of this
relatively low S value appears to be related to the thinner nature
of the inferred groundwater contamination plume at VES #31.
S values from within the study area ranged from 0.04 to 2.19
mhos. High values of S correspond to low values of interpreted
resistivity. This map roughly defines four such zones. Three
high longitudinal conductance zones are located along Geoelectric
Sections C, D, E, and F, and roughly trend S-SW. Another high
longitudinal conductance zone lies along Geoelectrical Section A,
and it trends W-NW (Figure 16). The contamination plumes depicted
in the chloride and specific conductance water quality maps
generally correspond with the zones of high S values in the
southwest portion of the study area (Figures 14 and 15). This
correlation between water quality and geophysical data support the
possibility of these zones representing localized groundwater
contamination.
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The highly conductive area intersecting 14th Street supports
a localized north-westward groundwater flow direction in this
area, related to the inferred groundwater divide. It is
depicted uniquely on this map. Further study should be
conducted in this area to verify the existance of this zone and to
determine its significance.
Lab Procedures
Several soil samples, collected with the split spoon sampler
from the soil borings, were lab-tested for resistivity.
Resistivity was calculated by measuring the length and diameter of
the soil sample and by measuring the current and the voltage.
Clay soil samples, being cohesive in nature, retained the
cylindrical shape of the sampling device. The unconsolidated sand
and gravels were packed into a small glass beaker before the
resistivity value could be calculated. Four wire screens were
used as AB and MN electrodes (Figure 26).
S
01 L
I________
Figure 26. Arrangement of Sheet Electrodes Used in Laboratory Analysis of Soil Samples.
<3
<8>
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Resistivity in the laboratory was calculated by using the
following equation: / - (V/I)*(A/L). The resistivity calculated
in the laboratory approximates the true resistivity, and any
differences arising from sample disturbance between the time of
collection and the time of laboratory measurements. This is true
because the sample was measured and the current distribution was
controlled.
Soil samples may have lost moisture during their storage
period in the laboratory. In order to compensate for this loss,
those samples that were considered moist or wet during sample
collection were checked before laboratory analysis. If necessary
they were saturated with deionized water and were retested.
Lab-calculated true resistivity values were used to aid in
interpretation of apparent resistivity field data and the
geoelectric sections. See Appendix B for laboratory calculated
values of true resistivity.
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CONCLUSIONS AND RECOMMENDATIONS
1. The surface electrical resistivity survey successfully
defined zones of groundwater contamination of a drift aquifer
within the study area. The shape of the plumes, and the lateral
and vertical margins were delineated.
2. Also identified by the electrical resistivity survey was
a conductive zone in the northeastern portion of the study area.
The significance of this zone is not clear, however, as there
were no geological data available for this portion of the study
area.
3. In general five geoelectric layers were detected in
several of the geoelectric sections. A heterogeneous dry sand
material is inferred to exist at the surface in the study area.
Interpreted resistivity values for this zone ranged from 60 to
3000 ohm-meters.
(a) A moist to dry clay was detected below the surficial
materials, with interpreted resistivity values varying from about
7 to 85 ohm-meters.
(b) A sand and gravel zone was identified below the clay
material. It appears that one interpreted resistivity range
from 100 to 1000 ohm-meters characterizes both the lower portion
of the unsaturated zone and the upper portion of the saturated
zone.
(c) A low resistivity layer was detected within the sand and
gravel aquifer in several geoelectric sections. It is
81
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characterized by interpreted resistivity values that vary from
about 4 to 85 ohm-meters. Water quality data from domestic wells
and geological data from soil boring logs, water and oil well
records, all indicate that this zone is a brine contamination
plume.
(d) Below the brine plume, very little if any water quality,
geophysical or geological data were available for correlation
with the geoelectric layers. Interpreted resistivity values
ranged from 60 to 600 ohm-meters. The bedrock surface was not
clearly defined in the geoelectric sections.
4. In general employing this geophysical technique allowed
for detecting geoelectric layers to about 30 meters (100 feet)
below ground level, or approximately 1/10 the AB/2 separation.
In a few vertical electrical soundings, however, thick clay
layers located near the surface prevented the detection of
underlying geoelectric layers. Relatively deeply buried
geoelectric layers were not identified in these instances because
the electrical current introduced at the surface was not able to
penetrate deep enough into the subsurface to detect the
conductive zone below the water table.
5. In conducting the surface electrical resistivity survey,
many problems and inconveniences were encountered due to cultural
factors. These cultural factors often acted to limit the maximum
expansion of the electrode array and distort a few of the
apparent resistivity sounding curves (VES #3) for example.
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83
6. Two different interpretational models were constructed
for each of Geoelectric Sections A, D and E. The first, allowing
more freedom for program INVERS, resulted in very low
resistivities and small thickness values for much of the aquifer
layer (Model A). In the second case the aquifer resistivities
were constrained to higher values compatible with the measured
water resistivities s calculated by Archie's Law, holding $ =
30%, and cementation factor (ra) - 1.35 (Model B). This resulted
in greater thickness for the aquifer layer. Both solutions are
geophysically correct, by the principle of equivalence, and only
independent thickness or in situ resistivity data could constrain
the solution.
7. It is recommended that a few small diameter wells be
completed in the highly conductive zone located in the
northeastern portion of the study area. This would allow for
obtaining geological and water quality data that can be used to
correlate with the geophysical data, in order to determine if the
zone represents a groundwater contamination plume, perhaps, a
clay-rich layer.
8. It is recommended that soil borings be drilled to depths
sufficient to penetrate all units of possible interest in the
problem area, commensurate with the depth of investigation of the
VES's. In this case they should have been approximately twice as
deep, in the range of 30 to 37 meters (100-120 feet), so that the
calibrated VES done at the same location could have all main
layer thicknesses constrained.
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9. Even better for calibrating the VES's at control
boreholes would be an open-hole resistivity log which should give
the geoelectric layer boundaries and their resistivities, thus
constraining very well the calibration VES. If a natural gamma
log were available, it also would help to define the contacts
between clay and coarser clastic units and give an independent
check of the drilling record.
10. Further surface electrical resistivity work at this site
should be geared toward determining lateral, particularly
downstream, limits of the plume. The contour maps shown here
have the contours rather arbitrarily closed, particularly at the
distal "ends" of the plume.
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APPENDICES
85
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Appendix A
Equipment
86
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Equipment
Several different pieces of equipment were used in conducting
the surface electrical resistivity study, among which were the
following:
IC - 69 Earth Resistivity Meter (Figure 27)
external battery pack
current and potential electrodes
approximately 350 meters (107 feet)
of insulated wire
leads, and wire reels
two-way radios
miscellaneous equipment
IC-69 Earth Resistivity Meter (Johnson Keck)
microammeter
range switch
current switch
ohmmeter dial
:0— Q -
••-
-v
external battery pack attachment
electrode attachment
null meter
self potential dial
Figure 27. Sketch of IC-69 Earth Resistivity Meter.
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microammeter - measures the amount of current generated; tests the
strength of some of the internal batteries.
range switch - decimal multiplier of the resistance readings from
the ohmmeter dial.
current switch - induces an electrical current into the ground
through current electrodes; FORWARD and REVERSE positions allow
the direction of the current to alternate between the electrodes.
ohmmeter dial - yields the resistance value (ohms) of a given
reading when multiplied by the range switch value.
external battery pack attachments - point of cable attachment to
the external batteries; employed when the current electrode
contact resistance was very high.
electrode attachments - point of attachment of wire leads from
from the current and potential electrodes to the instrument
terminals.
null meter - microammeter used in taking resistance readings.
self-potential dial - nulls out the electrochemical activity
between electrodes and the surrounding soils.
external battery pack - adds 10 45-volt batteries to the four
internal 45-volt battery supply; these supplemental batteries can
be added to the power supply one at a time.
current and potential electrodes - used to induce electrical
current into the ground and to measure the voltage drop,
respectively; current electrodes are made up of two 1/2-inch by
60 inch steel rods. Potential electrodes consist of 1-inch x 18
inch hollow PVC stakes; each stake contains copper sulfate that is
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in contact with the surrounding soils through the porous wooden
stake tips. These non-polarizing electrodes virtually eliminate
electrode-generated potentials that could occur between
electrodes.
two reels with about 320 meters (1050 feet) of wire each, two reels 35 meters (115 feet) of wire; wire leads; - used to expand
the distance between electrodes, allowing for a variety of AB/2
and MN spacings; two wooden and two small plastic reels were used
to facilitate the carrying and dispensing of varying amounts of
wire to both AB and MN electrodes.
two - way radios - three radios were used to facilitate
communication between the operator of the IC-69 equipment and the
field crew at large AB/2 spacings.
miscellaneous equipment - several different tools were kept on
hand for minor repairs, clean up and storage of the equipment.
These included Allen wrenches, screw drivers, extra wire, metal
brushes, metal tape, tape measure, metal stakes, metal clips, data
forms, calculator, and graph paper; also hammers and salt water
were carried into the field to increase current by reducing the
resistivity of the ground surrounding the electrodes, thereby
making better contact with the electrodes when necessary.
These equipment were used for the two consecutive summers of
1982/83. Western Michigan University's IC-69 unit was used
through out the majority of the survey. However, a Keck unit was
loaned to us when the other unit malfunctioned, as noted on the
data sheets.
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Appendix B
Soil Boring Data and Laboratory Results
90
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91
Soil Boring and Laboratory Results_____ Soil Boring #1 - Wagner____
Geological Sampling Laboratory-ProducedDescription___________ Interval Resistivity Results
brown clay 3.5 - 5'f = 6 7 ~ A ~ • m
= 625 m
brown clay gray clay w/ gravel 8.5 - 10'
? = 4 8 _n_ • m y > l S - 204 _/!.• m
moist.brown and gray clay w/ sand .lenses
13.5 - 15' y = 144 ~n.- m
18.5 - 20' = 145 _o.. mwet brown sand
brown sand with some gravel
23.5 - 25's = 589 m
y = 1249 - A . ■ ra
28.5 - 30' " f ^ = 1435 -/!• m
33.5 - 35' * 387 s i . - m = 1034 _/L • m
wet gravel and sand 38.5 - 40' y =165 m
• tg ■ true resistivity of lab-saturated material
= true resistivity of material as collected in field
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92
Soil Boring and Laboratory Results_____ Soil Boring #2 - Church_____
Geological Sampling Laboratory-ProducedDescription__________ Interval Resistivity Results
moist sandy brown and gray clay w/ cobbles 3.5 - 5' Y t = 39 -4.. m
moist soft sandy gray clay w/ some
gravel 8.5 - 10' E00CMnV*
13.5 - 15 / = 29 ~ n ~ • m t
moist stiff gray clay w/ some sand 18.5 - 19
19.0 - 20= 51 -J2. • m
/ = 1865 -A • m
dry brown sand 23.5 -25' y = 978 J L . - m
gray silty clay
28.5 - 30' Y t = 31 _/z. • m
33.5 - 35' f t = 2212 _o_- m
brown clay/dry brown sand
moist brown sand 38.5 - 40' = 46 . / i - m
wet brown sand 43.5 - 45' Y t = 8 6 ^ L - m
= true resistivity of material as collected in field
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93
Soil Boring and Laboratory Results_____ Soil Boring #3 - Quick_____
GeologicalDescription
SamplingInterval
Laboratory-Eroduced Resistivity Results
stiff brown sandy clay w/ some cobbles 3.5 - 5' f = 244 J L ' ra
soft sandy brown and gray clay w/ some
coarse sand8.5 - 10' / = 185 -A-' m
13.5 - 15' y = 238 Ji. • mmoist brown sand t
brown sandy clay w/ gravel 18.5 - 20'
insufficientsample
stiff gray clay w/ some sand
23.5 - 25' y - 4 1 -A-* m
and gravel28.5 - 30' / = 383 _/L* m
brown and gray sand33.5 - 35' Y - 954 _/!. • m
wet brown and gray fine sand 38.5 - 40' y = 8 9 - A - ' m
/ = true resistivity of material as collected in field
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94
Soil Boring and Laboratory Results- Soil BorinR #4 - Ellis_____
Geological Sampling Laboratory-Produced0 Description___________ Interval Resistivity Results
red and brown sandy clay
3.5 - 5' ^ = 200 — 0. • ni
8.5 - 10' u •p* 00 3moist red clay w/ gravel
moist sandy clay 13.5 - 15' ^ = 6 0 _/!_• m
stiff gray clay w/ some gravel 18.5 - 20' = 53 —£-• m
stiff gray clay w/ interbedded
sands 23.5 - 35' y = 68 — m
28.5 - 30' = 45 —ri- • rnwet gray and brown sand
sample not returned 33.5 - 35' --
wet gray and brown sand and gravel 38.5 - 40' y = 48 — A • n
y' = true resistivity of material as collected in field
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Appendix C
Apparent Resistivity Data
95
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96
ITERATION NO. 15, VES NO. 1LATER THICKNESS ELEV RHO THICKSRES THICK/RES1 1.44 677.0 573.5 823.0 0.00252 0.33 672.3 11.0 9.1 0.07563 4.37 669.5 242.9 1061.0 0.0180"4 2.04 655.2 24.0 48.8 0.08505 • 8.12 648.5 390.0 3165.6 . 0.02086 3.79 621.9 16.0 60.6 0.2367.. 7 . 609.5 440.0 • ■"'Tirp’v.
SPACING MODEL RHO FIELD RHO1.00 539.8 534.01-47 ___ 485.7 ..517,0 _
2.15 379.2 357.03.16 233.4 232.04.64 116.1 118.06.81 74.9 77.210.00 80.7 77.014.68 95.2 93.621.54 108.1 111.031.62 120.2 115.046.42 132.8 135.068.13 143.3 156.0100.00 173.1 158.0146.73 210.9 223.0RMS ERROR = 4.613
ITERATION NO. 15, VES NO. 1ALATER. 1 .• 2
3 ...•= . 4 . • • 567 .
THICKNESS ELEV0.662.023.961*967.987.60.
679.0676.8670.2657.2650.8624.6599.7
RHO65.217.3158.0 18.9411.0 9.0151.2
THICK*RES43.3 34.9625.537.03280.668.4
THICK/RES0.01020.11640.02510.10340.01940.8447
SPACING 1.00 v 1.47 2.15, 3.16 4.64 6.81 10.00
1.4..6 Ju.
MODEL RHO50.739.429.827.0 , 31.440.251.0 62.1
FIELD RHO50.639.4 29.926.632.439.549.565.5
2 1 . 5 431.6246.4268.13100.001 4 6 . 7 8
I ?-383.890.690.386.087.0
71.4 82.692.490.8 84.687.8RMS ERROR a 2.201
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97
ITERATION NO. 15# VES NO. IBLAYER
1234 S'
THICKNESS ELEV1.942.587.419.72
SPACING-l.OO.
678.0 671.7 663.2638.9607.0V 'V.MODEL RHO110.9
RHO THICKCRES 111.8 216.455.0 141.8700.1 5139.78.0 77.4216.0 - •
THICK/RES0.01730.04690.01061.2214
>.15 09 a i 05.!
i o : S o : ‘ ill:14*68 156.121.54 •; • 179.!111 •46.42 '■■■. ! 15 2 • 6;;~-~r t no-
FIELD RHO113. C11:1 '97.4
V -"'4 v, •■•V
life:.:
, 68.13m-r* 108.2y 100.00 -v- 79.8 ;RMS ERROR = • 3.516
192.9 *
...
1:8h i . •
ITERATION NO. 15* VES NO. 2IYER THICKNESS ELEV RHO THICKfrRES1 0.37 680.0 1100.0 409.92 1.67 678.8 134.1 224.33 0.98 673.3 10.9 10.74 10.51 670.1 152.1 1598.85 5.59 635.6 16.0 89.46 617.3 243.0
SPACING HOOEL RHO FIELD RHO1.00 388.8 408.01.47 210.0 202.62.15 131.1 124.83.16 91.9 92.84.64 64.3 69.06.81 55.2 50.010.00 62.6 55.414.63 74.4 83.021.54 83.1 100.031.62 36.5 34.646.42 89.0 74.363.13 99.0 104.3100.00 119.5 125.6
THICK/RES0.00030.01250.08920.06910.3492
RMS ERROR = 9.717
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
ITERATION NO- 15, VES NO. 2aLAYER THICKNESS ELEV RHO THICK*RES1 1-59 . 682-0 238-0 377.52 3.33 676.8 39.0 129.83 7.12 665-9 510-0 3623.74 8.10 642.5 8.0 64.75 616.0 200.0
SPACING MODEL1RHO FIELD RHO1.00 229.6 219.01.47 215.5 222.02.15 185.4 190.03.16 139.1 142.04.64 95.2 93.06.81 73.0 76.610.00 38.4 87.714.63 109.3 109.021.54 127.5 1 25.031.62 130.7 136.046.42 114.9 122.068.13 90.5 87.4100.00 • 73.5 72.1146.73 87.2 94.5RMS ERROR = 4.233
ITERATION NO. 15, VES NO. 28LAYER
1 2. 345
THICKNESS ELEV0.99 683.0 RHO234.74.82 679.8 45.7- 11.27 663.9 300.49.09 . 627.0 9.0597.1 263.6
SPACING MODEL RHO FIELD RHO1.00 208.4 225.01.47 175.5 163.02.15 128.0 121.03.16 84.5 91.54.64 63.0 62.86.81 62.2 60.210.00 73.8 70.414.63 91.6 95.221.54 103.3 112.031.62 115.3 114.046.42 107.4 103.068.13 90.6 90.1100.00 32.4 31.5146.73______93.3 ______94.J5__
RMS ERROR = 4.400
THICK*RES 232.5 220.2 3384.1 81.8
THICK/RES0.00670.03530.01401.0130
THICK/RES0.00420.1056-0.03751.0100\
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
99
• vITERATION NO. 15, VES NO. 3 LATER THICKNESS ELEV RHO
1231.322.55 680.0675.7667.3
1582.420.0100.2
THICKSRES2033.750.9
SPACING1.001.472.153.16 4.64 6.8110.0014.6321.54
MODEL RHO 1459.9 1272.2925.6490.7 171.157.949.459.4 70.2
FIELD RHO1382.01461.0983.0485.0171.0 55.0 47.6 63.5 71.4RMS ERROR = 5.962
ITERATION NO. 15* VES NO. 3*LAYER THICKNESS ELEV RHO THICK*RES1 0.30 683.0 498.0 143.72 0.99 682.0 1787.0 1762.23 5.02 673.8 26.0 130.44 12.41 662.3 164.9 2046.35 8.29 621.6 9.8 81.36 594.4 171.0
SPACING MODEL RHO FIELD RHO1.00 393.7 908.01.47 973.1 997.02.15 918.7 987.03.16 681.5 703.04.64 359.3 342.06.81 130.2 133.010.00 55.0 56.314.63 53.5 54.721.54 63.6 62.831.62 70.6 67.946.42 71.3 \ 72.168.13 63.6 X 69.7100.00 71.0 \ 72.1146.78 82.8 . . 81.0RMS ERROR = 2.619
THICK/RES0.00030.1273
THICK/RES0.00060.00060.19290.07530.8452
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
100
ITERATION NO. 3, VES NO. 3ALAYER THICKNESS ELEV RHO THICKSRES THICK/RES1 0.13 633.0 136.0 17.8 0.00102 0.98 682.6 1100.0 1081.6 0.00093 6.42 679.3 30.0 192.9 0.21404 11.51 658.3 80.0 920.8 . 0.14395 11.01 620.5 14.0 154.1 ' 0.78626 584.4 276.0
SPACING MOOEL RHO FIELD RHO1.00 . 534.8 502.01.47 586.2 575.02.15 552.5 551.03.16 413.1 463.04.64 224.9 239.06.81 91.1 81.710.00 45.7 45.514.68 42.7 42.721.54 46.7 47.231.62 49.3 50.046.42 50.7 50.268.13 56.3 56.0
100.00 70.4 68.9146.78 92.3 94. 5
RMS ERROR = 4. 970
ITERATION NO. 15. VES NO. 38 LAYER.. THICKNESS... ELEV RHO THICKSRES THICK/RES
1 0.05 633.0 60.52 0.69 632.3 1000.03 1.99 630.6 320.04 11.33 674.0 24.05 635.2 177.0
SPACING MODEL RHO FIELD RHO1.00 550.7 509.01.47 583.3 618.02.15 543.2 . 550.03.16 430.5 478.04.64 280.2 270.06.81 142.6 126.010.00 60.6 60.114.68 36.2 46.6. 21.54 38.6 43.231.62 49.6 47.046.42 64.9 56.368.13 83.0 75.1100.00 102.6 97.2146.78 122.0 122.0
2.9638.7637.8 2 33.9
0.00030.00070.00620.4928
RHS ERROR = 10.964
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
101
ITERATION NO. 15, VES NO. 4LAYER THICKNESS ELEV RHO THICK*R£S1 1.41 685.0 215.7 304.22 6.05 680.4 38.3 231.63 5.70 660.5 403.0 2298.84 5.59 641.8 16.7 93.35 623.5 119.1
SPACING MODEL RHO FIELD RHO1.00 205.4 207.01.47 189.0 194.02.15 156.4 153.03.16 111.1 106.04.64 71.3 75.46.31 54.6 55.510.00 56.5 53.214.63 68.2 65.521.54 . 82.2 36.731.62 92.0 97.246.42 94.7 94.668.13 93.4 97.4100.00 94.4 92.6146.78 99.9 107.0RMS ERROR = 4.357
ITERATION NO. 1* VES NO. 5
THICK/RES0.00650.15900 . 0 1 4 20.3349
LAYER THICKNESS ELEV 1 0.61 688.02 1.70 . 686.03 1.30 680.44 , 12.40 676.25' 635.5
RHO73.925.0199.0854.040.0
THICKSRES45.142.5258.710539.6
THICK/RES0.00330.06300.00650.0145\
\SPACING 1.00 1.472.153.16 4.64 6.8110.001 4 . 6 321.5431.6246.4268.13100.00
MODEL RHO57.746.939.942.054.375.6105.2142.6184.2220.4234.1209.7151.1
FIELD RHO60.048.233.039.152.377.3105.0140.0137.0230.0230.0197.0135.0RMS ERROR = 5.057
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
102
ITERATION NO. 15. VES NO. 6LATER THICKNESS ELEV RHO THICK*RES
1 0 . 5 8 6 3 5 . 0 5 5 8 . 9 3 2 2 . 92 0 . 8 8 6 8 3 . 1 5 0 . 0 4 A . 0
•.•3. , . • 4 . 5 8 6 8 0 . 2 . 2 0 0 . 9 9 2 0 . 4. 4 - . 1 3 . 5 5 : 6 6 5 . 2 6 7 6 . 0 9 1 6 2 . 3
s 5 : 6 2 0 . 7 1 7 4 . 7
THICK/RES0.00100 . 0 1 7 60 . 0 2 2 8 -0.0200
SPACING > MOOEL RHO FIELD RHO1 . 0 0 3 4 0 . 5 3 3 2 . 01 . 4 7 2 1 0 . 4 2 3 5 . 0
. 2 . 1 5 . 1 2 7 . 3 . 1 1 2 . 03 . 1 6 1 1 2 . 7 1 1 0 . 04 . 6 4 , . 1 3 2 . 3 ... 1 3 4 . 06 . 8 1 \ 1 6 2 . 5 1 7 0 . 0
1 0 . 0 0 2 0 1 . 3 - ... 2 1 5 . 01 4 . 6 8 ' 2 4 9 . 4 2 5 3 . 02 1 . 5 4 2 9 9 . 3 2 9 7 . 03 1 . 6 2 3 3 4 . 0 3 0 8 . 04 6 . 4 2 3 3 5 . 0 3 1 3 . 0 ,6 3 . 1 3 2 9 8 . 7 2 9 7 . 0
1 0 0 . 0 0 2 4 6 . 5 2 6 0 . 01 4 6 . 7 8 2 0 6 . 6 2 2 3 . 0
RMS ERROR = 6 . 4 1 6
ITERATION NO. 11, VES NO. 9LAYER THIC KNE3S ELEV RHO TH1 1.31 690.0 71 3.92 0.77 635.7 9.03 11.34 633.2 1100.64 4.67 646.0 s . a5 630.6 346.1
SPACING MODEL RHO FIELD RHO1.00 663.9 635.01.47 530.1 550.02.15 426. S 414.03.16 239.0 263.04.64 110.3 105.06.31 30.1 77.010.00 102.2 97.014.68 133.7 130.021.54 133.6 175.031.62 225.4 242.046.42 250.6 304.063.13 245.5 279.0100.00 214.5 132.0146.78 137.7 169.0215.44 192.5 189.0316.23 222.3 261.0RMS ERROR = 9.504
944.5 7.0 12473.9 37.4
THICK/RES 3.0013 3.0356 0.3103 0.5S42
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
103
ITERATION IMO. 1 5 , VES NO. 10
LAYER T H I C K N E S S ELEV RHO THICKSRES1 0 . 6 3 6 9 1 . 0 3 2 . 0 5 1 . 72 3 . I S 6 8 8 . 9 3 3 . 0 1 0 3 . 33 1 0 - 0 0 6 7 8 . 6 4 0 0 . 0 4 0 0 0 . 14 3 . 4 - i 6 4 5 . 8 1 0 0 . 0 3 4 0 . 65 7 . 3 9 6 3 4 . 6 3 . 9 3 0 . 56 6 0 3 . 8 2 8 0 . 0
• SPACING MODEL RHO FIELD RHO1 . 0 0 5 6 . 3 6 9 . 41 . 4 7 5 5 . 4 5 6 . 12 . 1 5 4 5 . 6 4 4 . 33 . 1 6 4 2 . 2 4 0 . 84 . 6 4 4 6 . 5 4 3 . 66 . 8 1 5 3 . 6 5 6 . 0
1 0 . 0 0 7 7 . 6 7 3 . 81 4 . 6 3 1 0 0 . 1 9 5 . 02 1 . 5 4 1 2 0 . 4 1 2 1 . 03 1 . 6 2 1 2 9 . 1 1 5 5 . 04 6 . 4 2 1 1 7 . 9 1 4 6 . 06 8 . 1 3 8 9 . 7 3 9 . 0
1 0 0 . 0 0 5 4 . 3 5 3 . 31 4 6 . 7 8 6 0 . 4 6 7 . 5
R MS ERRaR‘ = 9 . 7 9 5
IT ERA TI GN N G . 1 5 , VES NO. 1 0
LAYER T H I C K M E S S ELEV RHO THICK*RE51 0 . 7 4 6 9 1 . 0 8 3 . 5 6 1 . 52 2 . 2 6 6 9 8 . 6 2 5 . 7 5 8 . 03 1 4 . 3 3 6 3 1 . 2 3 0 0 . 4 4 4 6 9 . 24 6 3 2 . 4 2 5 . 0
S PACI NG MODEL RHO F I E L D RHO1 . 0 C 6 9 . 5 6 9 . 41 . 4 7 5 6 . 9 5 6 . 12 . 1 5 4 4 . 6 4 4 . 83 . 1 6 3 9 . 7 4 0 . 94 . 6 * 4 5 . 0 4 3 . 66 . 8 1 5 3 . 9 5 6 . 0
10 . 0 0 7 8 . 4 7 3 . 81 4 . 6 3 1 0 0 . 7 9 5 . 02 1 . 5 4 1 2 1 . 4 1 2 1 . 03 1 . 6 2 1 3 2 . 0 1 5 5 . 04 6 . 4 2 1 2 3 . 2 1 4 6 . 06 3 . 1 3 9 3 . 9 3 3 . "
1 0 0 . 0 0 5 3 . 7 5 3 . 3
RM5 EE 3DR = 7 . 5 2 1
THICK/RES0 . 0 0 7 70 - 0 9 5 40 . 0 2 5 00 . 0 3 4 12 . 0 3 8 6
THI C. K/ R5S0 . 0 0 3 30 . 0 8 7 7C . C 4 9 5
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
104
ITERATION NO. 15* VES NO. 11LATER THICKNESS ELEV RHO THICKSRES THICK/RES1 0.73 639.0 2795.9 2027.5 0.00032 0.76 686.6 475.1 361.2 0.00163 0.43 684.1 25.9 12.4 0.01854 17.41 682.6 150.0 2511.4 0.11415 3.37 625.4 22.0' 74.3 0.15306 614.4 207.2
SPACING MOOEL RHO FIELD RHO1.00 2108.0 2173.01.47 1470.8 1340.02-15 773.4 834.03.16 312.2 306.04.64 142.4 145.06.81 122.4 110.010.00 129.9 133-014.63 135.1 163.021.54 134.8 137.031.62 129.3 122.046.42 126.3 124.063.13 134.0 141.0100.00 150.3 147.0
RMS ERROR = 7. 131
ITERATION NO. 10, VES NO. 11LAYER THICKNESS ELEV RHO THICK*RES THI CK/ RES
1 0 . 72 6 3 9 . 0 2 7 9 6 . 0 2 0 1 0 . 6 0 . 0 0 9 32 0 . 7 9 6 3 6 . 6 4 3 0 . 0 3 7 9 . 4 0 . 0 0 1 63 0 . ? 7 6 3 4 . 0 3 3 . 0 3 3 . 1 0 . 0 2 3 04 1 4 . 6 6 6 3 1 . 2 16 5 . 0 2 4 1 9 . 0 0 . 0 3 3 95 5.55 5 3 3 . 1 3 0 . 0 1 7 5 . 6 0 . 1 9 4 36 6 1 3 . 9 2 2 3 . 0
SPACI NG MOOEL RHO FI ELD RHO1 . 0 0 2 1 0 1 . 5 2 1 7 3 . 01 . 4 7 1 4 6 5 . 0 1 3 4 0 . 02 . 1 ? 7 7 8 . 1 8 3 4 . 03 . 1 6 3 1 4 . 4 3 0 5 . 04 . 6 4 1 4 1 . 5 1 4 5 . 06 . 3 1 1 2 1 . 3 1 1 0 . 9
1 2 . 0 0 1 3 1 . 5 13 3 . 01 4 . 6 ? 1 3 ? . 5 16 3 . 92 1 . 5 4 1 3 7 . 6 1 3 7 . 02 1 . 6 2 1 2 9 . 7 1 2 2 . 04 6 . 4 2 1 2 4 . 7 1 2 4 . 06 3 . 1 3 1 3 3 . 2 1 4 1 . 0
I O C . 0 ' 1 ? 2 . 9 1 4 7 . 0o m; E’ r o ? = 5 . 6 5 0
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
105
ITERATION NO. 4, VES NO. 12LAYER THICKNESS ELEV RHO TH1 0.69 689.0 ’ 408.02 9.56 636.7 39.03 9.00 655.4 660.04 625.8 53 32.0
SPACING MODEL RHO FIELD RHO1.00 238.5 283. 01.47 191.3 196.02.15 102.1 104.03.16 56.1 53.34.64 43.9 44.76.81 43.1 43.810.00 46.9 47.614.63 56.4 54.521.54 72.1 62.931.62 90.9 J 98.246.42 106.0 124.068.13 109.2 120.0100.00 95.8 109.0146.73 70.8 94.5
280.2 373.3
5939.S
RMS ERROR = 9.981
i t e ° a t i o ,m NJ « c * - f v = r> 1 ?LAYER THICK NESS ELEV •2 Hu TH
1 0 . 5 ? 6 3 9 . C 49 3 . 0 -
2 9 . 8 0 6 3 5 . 7 3 9 . 13 9 . 32 6 5 4 . 6 6 6 0 . 0 .4 6 2 2 . 4 5 3 . 0
SPACING MODEL RHO FIELD RHO1 . 0 0 2 3 3 . 4 2 3 3 . 01 . 4 7 1 9 1 . 3 19 5 . 92 . 1 5 1 0 2 . 1 10 4 . 03 . 1 5 5 6 . 1 5 3 . 34 . 5 4 4 3 . 9 4 4 . 76 . 3 1 4 3 . 3 4 3 . 3
10 . 0 0 4 6 . 7 4 7 . 51 4 . 5 3 5 5 . 3 5 4 . 52 1 . 5 4 7 1 . 9 5 2 . 93 1 . 6 2 9 2 . 2 9 3 . 24 6 . 4 2 1 1 3 . 7 1 ? K A
* U * • -
6 ■: . 1 1 1 2 9 . 3 J* ■' 9 ■1 ' •s «•« ; w • v j 1 1 4 . 1 1 C -3 . 91 4 6 . 7 3 9 5 . 1 9 4 . 5
THICK-.5ES 235.2332. 9
5 AS 0.1
ERROR = 5 . 3 9 5
THI CK/ RES0.00170.2451.0.0135
t h : c < / ~n 0 n 1- . - V -C . 2 5 10.014
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
X i n ̂X J. i/ .f W | I wf V".D
; LAYS* THICKHSSS ELEV
« j . i j
RHO rHICK*RES THICK/RES, 1 0,29 689.5? 1461,0 416.6 ■ 3-. 0002
2 5,7 3' 583,1 45.3 256.7 3-, 176 83 12,54 669,3 365.? 3549,3 3',02894 '5 .52' 534.8 9 .? 49.4 3.6123
.. 5' ' 515,7 145,3 :
SPACING MODEL RMQ FIELD RHO--------------
1.20 185.1 272,31.47 59.3 62.22.15 • 49.2 45,83,16 47.7 42,34.64 49.6 45.3•5.31 55.7 54,317,22 65,3 53.914.58 • 85.1 97.521,54 125,4 113,331,52 119.3 125,345,42 119.3- 119.368.13 135.R 99.3
1 95.c ?7 , 2<45.78 •j M f i :■ i . 5
RMS. ERROR = 7 . 1<>5
I TERATI ON NO . 4 , VES NO. 13
LAYER THICKNESS ELEV RHO1 0 . 29 6 5 9 . 0 1 4 7 1 . 02 4 . 3 3 6 3 3 . 0 4 0 . 0-> 9 . 7 1 6 7 2 . 0 3 7 3 . 04 1 2 . 9 0 6 4 0 . 2 2 3 . 93 5 9 7 . 9 1 3 6 . 3
S PACING MGOEL RHO FI ELD RHD1 . 0 0 1 9 2 . 4 2 0 2 . 01 . 4 7 6 7 . 0 6 2 . 22 . 1 5 4 4 . 4 4 6 . 33 . 1 6 4 3 . 3 4 2 . 04 . 6 4 4 5 . 2 4 5 . 36 . 3 1 5 4 . 1 5 4 . 3
i o . o o 6 3 . 4 S 3 . 91 4 . 6 5 3 7 . 7 3 7 . 52 1 . 5 4 1 0 7 . 0 1 1 3 . 03 1 . 5 2 1 1 9 . 9 1 2 5 . 04 - 5 . 4 2 1 1 7 . 5 1 1 9 . 76 3 . 1 2 1 0 5 . 1 9 3 . 3
1 /■> ' ± • -V 9 6 . 5 9 7 . 21 4 - 5 . 7 5 9 3 . 7 1 0 1 . 0
R‘4S ERROR = 4 . 5 1 6
THICK*RSS 423.* 1 9 5 . 3
3 6 2 1 . 4 2 9 5 . 7
T HI C K/ R £ S 0 . 9 0 3 2 0 . 1 2 1 90.32 60 0.56:9
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
107
I T E R A T I O N NO. I S , VES NO- 14
LAYER THICKNESS ELEV RHO T HI C K* 3 5 S THI CK/ RES1 0 . 7 7 6 9 0 . 0 1 9 7 . 1 1 5 0 . 9 0 . 0 0 3 92 . V« 6 . 4 7 6 8 7 . 5 * * 4 1 . 9 2 7 1 . 3 0 . 1 5 4 3
. 3 1 0 . 6 8 6 6 6 . 3 6 5 0 . 0 . 6 9 3 9 . 3 0 . 0 1 6 44 w 8 . 0 0 6 3 1 . 2 6 . 3 2 - f r 5 4 . 1 1 . 1 3 3 75 6 0 5 . 0 1 2 5 . 0
SPACING MODEL RHO FI ELD RHO1 . 0 0 1 5 9 . 4 1 6 1 . 0
. 1 . 4 7 1 2 3 . 4 1 2 2 . 02 . 1 5 3 4 . 1 3 4 . 53 . 1 6 5 5 . 4 6 0 . 04 . 6 4 4 9 . 7 >♦5. 46 . 9 1 5 1 . 6 5 3 . 6
1 0 . 0 0 6 1 . 4 6 5 . 31 4 . 6 3 7 9 . 5 3 1 . 92 1 . 5 4 1 0 3 . 3 9 9 . 03 1 . 6 2 1 2 6 . 6 1 1 9 . 04 6 . 4 2 1 4 0 . 1 1 3 4 . 0
-• 6 8 . 1 3 „ 1 3 5 . 3 1 4 9 . 01 9 0 . 0 0 / 1 1 3 . 6 . 1 1 3 . 0
, 1 4 6 . 7 3 iy 9 1 . 6 - 8 7 . 8
fr R M S ’. E R3&.0R k. 5-093
I TERATI ON NO. 1 5 , VES NO. 1 4
» f tvcp t u T r KN p SS ELP V RH2 THICK*RESL A p t h i .k h . ss .l v ? .oor|
? - P t ? f : l s !5.o S / t i s4 m ? I I I : ! i i : l - i t s : ? s . $ «
5 7 5 . 4 1 7 5 . 0
SPACING MODEL RHO P I P L3 RHO1 . 3 0 1 5 7 . 3 1 5 1 . 91 . 4 7 1 3 5 . 9 1 2 2 . 0
■ 2 . 1 5 9 1 . 1 8 4 . 53 . 1 6 5 4 . 3 6 3 . 04 . 5 4 4 1 . 2 4 5 . 46 . 3 1 4 6 . 9 5 3 . 6
1 C . 0 ? 6 3 . 1 6 5 . 31 4 . 6 5 35.4 8 1 . 32 1 . 5 4 1 1 0 . 3 9 9 . 03 1 . 6 2 1 3 2 . 0 1 1 3 . 04 o . 4 2 1 4 1 . 3 1 3 4 . 96 3 . 1 3 1 3 1 . 9 1 4 9 . 0
1 2 0 . 0 0 1 0 9 . 4 1 1 2 . 21 4 6 . 7 3 9 2 . 2 3 7 . 3
RMS ERROR = 3.436
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
108
TER*IIOT. MO, 1 5 , v r s MO. 15
aver n i r : * c j r s ' s ~ 'ELr v~ . . . . rHTC:^ Rr s -~ r H I ^ K ' /R E 5 ~1 3 , 5 5 5 8 ? , ? 4 5 2 , 1 2 5 2 . 2 31, 0 0 1 27 4 , 3 5 ' 5 6 7 . 2 4 3 , 3 1 7 4 . 4 3'. 1 3 9 33 : 1 3 , 3 1 6 7 2 . ? , 4 3 3 , 3 . 4 3 3 2 , 2 : 3', 0 2 5 34' 5 , 4 9 . 6 4 3 , 0 9 , 3 2^" 4 9 . 3 3 , 6 * 8 35. y *sr.';Zlr® 6 2 2 . 1 2 3 5 . 2 , / / '
SPAJIMS MODEL RHO FIELD; RHO1 . 3 0 2 6 1 . 3 2 8 9 , 3 :1 . 4 7 1 5 3 . 7 1 5 3 , 3 •2 . 1 5 7 6 . 1 7 4 . 63 . 1 6 53 . f i 4 4 , 24 , 6 4 4 9 , 5 3 9 , 86 . 9 1 5 9 . 2 5 3 . 4
13', 30 " ' 7 4 , 6 7 2 , 6. 1 4 , 6 8 •i:: 9 6 , 3 1 3 5 , 0v - v 2 1 . 5 4 1 1 6 . 7 1 3 3 . 0 - ,.v
3 1 , 6 2 1 2 9 , 1 1 3 6 , 04 6 , 4 2 . ' 1 2 7 , 3 1 2 5 , 36 8 , 1 3 . 1 1 5 . 6 1 1 3 . 0
103>,33 1 1 3 . 0 .. : 1 3 3 , 0 f1 4 6 , 7 8 - 1 2 1 . 5 •... 1 3 5 , 0
SMS, ERROR, s; 1 0 , 2 4 7
ITERATION N j• 15, VES NO. 15LA'fER THICKNESS SLSV RHO THICKER? 3 THlCK/ R=S
1 G . - j l $39.3 453.9 ZZ$m,2 2.74 637.0 26.33 8,52 67 8.0 451.4 384 3.0 0.01894 16103 650.0 25.0 400.7 0.64115 597.5 257.6
SPACING MODEL RHO FIELD RHC1.00 273.7 239.01.47 161.7 153.02.15 73.9 74.63.14 41.9 44.24.64 43.3 3 9.56.31 56.3 52.4
, ^ s - -* f > 7 £1 • j » -J • ‘ £ • ~14,6 2 99.0 105.021.5 4 119.5 133.331.62 130.746.4 2 127.1 126.353.12 114.3 110.0102.02 109.5 10 9.114o.7 ’ 123.2 125.?
R*S ERROR = 6.252
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
109
I T E R A T I O N NO. 1 5 , V £ 3 NO. 16
Y zP. THICKNESS ELEV RHO THICK JsRES1 0.43 692.0 531.7 277.42 2.53 690.4 3 9.9 13 4.93 7.24 631.8 300.0 2172.14 2.09 653.1 44.0 . 92.15 9.00 651.2 700.0 6300.06 621.7 72.0
SPACING MODEL RHO FIELD RHO1.00 255.3 265.01.47 133.5 126.02.15 66.4 72.33.16 53.6 53.94.64 62.0 52.66.31 79.7 80.810.00 102.9 106.014.63 123.3 126.021.54 152.7 142.031.62 173.2 165.046.42 134.3 139.069.13 173.2 204.0100.00 150.4 160.0146.7 3 114.5 115.0
THICX/RSS 0.0003 0.0659 0.02*1 0 • 0475 0.C129
RMS ERROR = 347
ITERATION NO. 4, VES NO. 17LAYER
1 23456
THICKNESS ELEV RHO 0.61 691.0 280.01.71 639.0 19.92. 23 693.4 120.05.46 676.1 . 740 . 010.00 653.2 200.0625.4 62.1
SPACING MODEL RHO FIELD RHO1.00 176.1 16 3.01.47 106.1 110.02.15 53.9 52.13.16 37.3 40.04.64 43.6 43.46.81 59.4 55.5
10.00 81.4 74.514.63 108.5 101.021.54 137.2 137.031.62 159.9 177.046.42 166.2 198-068.13 149.6 156.0100.00 117.1 100.0146.78 87.0 81.0
THICK*RES 171.9 34.1 267.1 4038.7 2000.0
THICK/RES0.00220.03580.01350.00740.0500
RMS ERROR = 8.435
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
ITERATION NO. 15* VES NO. 13LAYER
123456
. .THICKNESSI ELEV • -RH0 THI CK*RES1 . 1 0 6 9 0 . 0 1 1 5 . 0 1 2 6 . 30 . 4 3 6 3 6 . 4 3 0 . 0 1 4 . 53 . 6 2 6 3 4 . 8 1 2 3 . 0 4 4 5 . 17 i 0 0 6 7 2 . 9 3 5 0 . 0 5 9 5 0 . 2
1 2 . 0 0 6 5 0 . 0 4 0 0 . 0 4 8 0 0 . 46 1 0 . 6 7 0 . 1
THI CK/ RES0 . 0 0 9 50 . 0 1 6 20 . 0 2 9 4Q. QQ320 . 0 3 0 0
SPACING1.001 . 4 72 . 1 53 . 1 6 4 . 6 4 6 . 3 1
10 .00 1 4 . 6 3 2 1 . 5 4 3 1 . 6 2 V 4 6 . 4 2 X 6 6 . 1 3
100.00 1 4 6 . 7 3
MODEL RHO 1 0 3 . 8
- 1 0 1 . 29 1 . 78 3 . 09 7 . 3
' 1 1 9 . 61 5 4 . 1
i. 1 9 9 . 22 4 6 . 62 3 0 . 62 8 1 . 5
, 2 3 8 . 2/ 1 6 8 . 1 ' 1 0 9 . 5
FIELD RHO1 0 5 . 01 0 9 . 0
8 9 . 78 5 . 29 9 . 7 , ,
HOiO"."«'1 4 8 . 0200.02 5 2 . 03 1 3 . 03 0 6 . 02 5 9 . 02 1 3 . 01 0 3 . 0
RMS ERROR = 7 . 5 1 1
I TERATI ON NO. 1 5 * VES NO. 1 9
LAYER THICKNESS ELEV RHO THI CK*RES THI CK/ RES1 0 . 7 3 6 3 8 . 0 1 2 0 . 0 3 3 . 2 0 . 0 0 6 12 0 . 1 3 6 3 5 . 6 3 5 . 0 6 . 4 0 . 0 0 5 23 4 . 2 3 6 3 5 . 0 1 3 0 . 0 5 4 9 . 9 0 . 0 3 2 54 9 . 1 1 6 7 1 . 1 9 0 0 . 0 S 2 0 1 . 3 0 . 0 1 0 15 6 4 1 . 2 1 1 0 . 0 .......
SPACING MODEL RHO' FI ELD RHO1 . 0 0 1 1 0 . 3 1 0 3 . 01 . 4 7 1 0 4 . 9 1 1 0 . 02 . 1 5 1 0 4 . 6 1 0 1 . 03 . 1 6 11 2 . 4 1 0 3 . 04 . 6 4 1 2 7 . 3 1 3 3 . 06 . 3 1 1 5 1 . 1 1 5 4 . 0
1 0 . 0 0 1 3 3 . 5 1 5 3 . 01 4 . 6 3 2 3 7 . 1 2 2 3 . 02 1 . 5 4 2 8 3 . 1 2 5 5 . 03 1 . 6 2 3 0 5 . 2 3 0 7 . 04 6 . 4 2 2 3 6 . 2 3 2 4 . 06 3 . 1 3 2 3 0 . 4 2 2 5 . 0
1 0 0 . 0 0 1 6 9 . 1 1 5 7 . 01 4 6 . 7 3 1 3 1 . 6 1 3 5 . 0
RMS ERROR = 5 . 4 4 3
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Ill
ITERATION NO. VES NO. 20LATER THICKNESS RHO1 0.62 683.0 294.02 5.03 631.0 47.93 664.3 173.1
SPACING MOOSL RHO FIELD RHO1.00 202.6 200.01.47 137.9 141.02.15 84.6 83.93.16 60.1 53.34.64 55.3 57.46.31 59.4 53.210.00 70.1 69.214.63 86.3 89.121.54 105.3 103.031.62 124.3 125.0RMS ERROR = 2 - 1 6 9
182.5243.5THICK/RES0.00210.1060
ITERATION NO. VES NO. 21LATER THICKNESS ELEV RHO1 1.09 637.0 361.02 3.64 633.4 50.03 0.23 671.54 25.00 670.7 4000.05 588.7 600.0
THICKCRES393.0132.032.2100000.0
THICK/RES0.00300.0723-0.0016“0.0063' ;
. SPACING MODEL RHO1.00 325.31.47 277.22.15 201.73.15 126.24.64 37.36.31 92.510.00 125.814.63 130.321.54 257.431.62 361.446.42 493.8
.... - 58.13 646.5100.00 794.8146.78 897.5
FIELD RHO336.0282.0191.0133.0 85.2 39.7116.0153.0225.0361.0574.0760.0931.0912.0
RMS ERROR. = 9.273
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
112
ITERATION NO. 6, VES NO. 22LATER THICXNESS ELEV RHO th:1 0.67 687. 0 299.82 3.57 684.3 41.63 673.1 156.2
SPACING MODEL RHO FIELD RHO1.00 215.4 221.01.47 148.4 142.02.15 33.0 39.43.16 58.0 59.14.64 53.2 52.76.31 60.5 53.110.00 73.9 73.914.63 90.3 97.921.54 107.1 102.0
201.7148.2
RMS ERROR * 3.832
ITERATION NO. 15» VES NO. 23TER THICKNESS ELEV RHD THICX*RES1 0.65 638.0 2270.7 1470.02 0.50 635.9 423.1 211.73 1.04 634.2 24.0 25.04 12.45 630.3 438.9 ' 6087.75 5.16 640.0 25.0 129.16 20.02 623.0 216.0 4324.17 557.4 57.0
SPACING 1.00 1.47 2. IS 3.16 4.64 6.81 10.00 14.63 21.54 31.62 46.42 68.13 100.00 146.73
MODEL RHO1565.7993.3450.0156.996.3113.6155.0193.1222.4229.0205.6163.7124.295.1
FIELD RHO 1432.09 3 6 . 0 4 3 1 . 3154.091.5113.0156.0205.0251.0215.0195.0168.0 125.094.5
RMS ERROR 5.436
THICX/RES0.00220.0858
THICX/RES0.00030.00120.04340.02550.20630.0927
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
113
ITERATION M3. 15, VES NO. 24layer thi cknes s elev
1 1 . 1 7 6 6 5 . 02 5 . 8 9 6 8 1 . 2345
9 . 8 26.01
6 6 1 . 86 2 9 . 6.£09*9.
RHO IHICK»RES 8 4 . 6 9 9 . 2
- J i^ 0 ______ 1.64,81 4 0 . 0
7 . 02 B l s Z -
1 3 7 4 . 4 4211
t h i c k / r e s31. 013 9
___0j 2102 _3', 0701 3 , 8 5 8 3
SPACING MODEL RHO FIELD_MO_1 . 3 01.4.72 . 1 53 . 1 64 . 6 4S'. 81
13.00 1 4 . 6 8 2 1 . 543 1 . 6 24 5 . 4 26 3 . 1 3
1 0 3 . 0 01 4 5 . 78
7 9 . 87 2 . 9 3.1,1. 4 7 , 3 37,7 -15.X3 8 . 44 5 . 6
J53, 4_ 5 3 . 15 9 . 36 1 . 77 2 . 59 3 . 3
8 1 . 27 3 . 0
_5J.8_ 4 7 , 63 8 . 0 Jl'.X3 9 . 4 4 5 . 2
_5 3 ».75 7 . 56 3 . 1
.59.6. ,7 2 . 19 4 . 5
RMS. ERROR s: 3 . 13 2
ITERATION NO. 1S> VES NO. 24 LAYER THICKNESS ELEV
345
1.30 7.46 S. 29 26.33
635.0 631.7 657.2630.0 543.6
RHO9 3 . 132.2 139.930.0236.8
THICK.~R£S83.32 4 0 . 01159.7739.9
THICK/RES0.0114C.23130.05930.6777
SPACING I. 00 1.472.152.16 4.64 6 . 8 110.0014.6821.5431.324o.4263.12
100.00146.73
MODEL RHO31.372.659.546.633.935.33 9 . 144.352.257.6 5 9.9.62.372.392.6
FIELD RHO31.2 73.C 5'3. 347.633.027.139.445.250.757.563.159.$...
72.194.5R‘1S ERROR = 2.335
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
114
iteration; no. is, ves no‘. 25layer t h i c k n e s s elev RHO THICIURES THICK/RES
1 3 . 8 $ 6 8 3 . 0 3 1 9 . 3 2 7 2 . 9 3 . 0 0 2 72 0 . 2 9 6 8 5 . 2 2 3 . 3 5 . 5 3'. 013 83 6 . 5 1 6 8 4 . 3 3 4 . 7 2 2 6 . 2 3 . 1 8 7 44 7 . 1 2 6 6 2 . 9 1 3 3 . 3 7 1 1 . 7 3 . 0 7 1 25 . 4 . 7 3 6 3 9 . 6 1 5 . 3 7 3 l 3 3 . 3 1 3 56 6 2 4 . 2 1 3 3 . 3
' SPACING ... : HODEL RHO FIELD RHOi . a a 2 5 7 . 5 : 2 4 3 . 31 . 4 7 1 9 2 . 4 1 9 9 . 02 . IS 1 1 5 . 1 1 2 4 . 33 , 1 6 6 3 . 9 5 4 . 84 . 6 4 4 1 . 2 4 3 . 6
. 6 . 8 1 3 8 , 6 4 3 , 31 3 . 0 0 4 1 , 0 4 3 , 4 -
. . . . 1 4 . 6 8 . 4 5 . 7 4 5 . 02 1 . 5 4 5 3 . 6 5 3 . 43 1 . 5 2 5 4 . 2 5 5 , 34 6 . 4 2 5 7 . 9 5 6 . 86 8 . 1 3 6 4 . 2 6 5 . 3
1 0 3 . 3 0 7 2 . 8 7 2 . 1
RMS. ERROR s. 4 . 6 7 8
ITERATION NO. 15, VES NO. 25LAYER THICKNESS ELEV RHQ THICK--*R5S THICK/RES1 0.97 683.0 313.7 277.1 0.0027
2 0.60 635.1 19.6 11.8 2 - ^ 0 33 8.04 633.2 33.2 315.5 0.20434 4.37 656.8 100.0 437.1 0.94375 17.17 640.8 45.0 772.3 0.33176 534.5 100.0
SPACING MOOEL RHQ FIELD RHC1.00 258.4 243.01.47 193.4 199.02.15 115.1 124.C3.16 60.2 54.34 • 6 ̂ 41.4 4 3.6o.21 39.7 40.310.00 41.7 40.4
14.59 4 5.2 45.021.54 49.3 50.431.62 54.2 55.346.42 53.4 56.96^.13 64.3 6 5.3
1 j 0 .0 c 72.2 72.1"MS ERROR = 4.331
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
ITERATION: NO. ■ 6 , VES N0‘. 26
11
layer t h i c k n e s s elev RHO THICK#RES THICK/RES1 0 . 7 2 : 6 8 9 . 0 7 5 0 . 9 5 3 7 . 0 3*, 0 0 1 32 0 . 4 1 6 8 6 . 7 1 7 . 8 7 . 2 at. 0 2 2 93 . 2 r 63 6 8 5 . 3 ' , 5 5 . 9 . 1 4 9 , 8 3', 0 4 8 34 1 1 . 1 7 6 7 6 . 5 1 1 2 . 0 . 1 2 5 1 , 2 . 3 . 0 9 9 7S •" 1 . 6 S 6 3 9 , 9 ....... 2 2 . 0 ' 3 6 . 2 at. 0 7 4 86 6 3 4 . 5 1 3 2 . 2
SPACING MODEL RHO FIELD RHO1 . 0 0 5 2 3 . 7 5 1 5 . 01 . 4 7 3 3 3 . 0 3 3 9 . 02 . 1 5 1 5 7 . 2 1 5 8 . 03 . 1 6 7 2 . 3 7 3 . 94 . 6 4 ' ’ 5 8 . 1 5 9 . 16 . 8 1 6 4 . 3 6 4 . 9
J. 1 0 . 0 0 . . 7 3 . 8 - 7 2 , 4 .
1 4 , 6 8 8 2 . 9 8 4 . 1-...... 2 1 . 5 4 ....... , Q 0^ 0 8 8 , 1 - .........
3 1 . 6 2 ’ 95.2 . 9 7 . 1_ . 4 5 . 4 2 - ........' 1 0 1 pi .... 1 0 1 . 0
6 8 . 1 3 1 0 3 . 8 1 3 7 . 01 0 0 . 3 0 1 1 6 . 8 1 1 9 . 01 4 6 . 7 8 1 2 3 . 0 __ 1 .2 2 ,0 ...
RMS. ERROR 3: 1 . 5 6 6
ITERATION n o . 1 5 » VES NO. 2 6
LAYER THICKN ESS ELE1 C. 7 1 6 3 9 . 02 0 . 4 1 6 8 6 . 73 5 . 7 0 6 8 5 . 34 1 0 . 6 7 6 6 6 . 65 3 . 8 7 6 3 1 . 66 6 1 8 . 9
RHO7 5 0 . 0
1 8 . 0 66.1112.1 4 8 . 1
1 3 2 . 0
THI CK* R: S5 3 0 . 4
7 . 33 7 7 . 0
1 1 3 6 . 11 3 6 . 0
THI CK/ RES 0 • COO 9 0 . 0 2 2 7 0 . 0 8 6 2 0 . 0 9 5 2 0 . 0 8 0 6
S P I C I N G MODEL RHO FI ELD RHO l . O C 5 1 9 . 9 5 1 5 . 01 . 4 7 3 2 3 . 2 3 2 9 . 02 . 1 5 1 5 5 . 6 1 5 9 . C3 . 1 6 7 4 . 3 7 0 . 94 . 6 4 6 0 . 6 5 9 . 16 . 3 1 6 4 . 1 6 4 . 9
1 0 . 0 0 6 9 . 8 7 2 . 41 4 . 6 3 7 7 . 0 8 4 . 12 1 . 5 4 8 4 . 7 3 3 . 13 1 . 6 2 9 1 . 7 9 7 . 14 6 . 4 2 9 3 . 5 1 0 1 IC6 3 . 1 2 . 1 S 6 . 4 . . 1 0 7 . 0
10C- . O0 1 1 4 . 6 1 1 3 . 0145.7 3 121. 12-.-
RMS ERROR * 3 . 7 3 0
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
ITERATION NO. 15, VES NC. 27LAVER
2 *•... 3 . ■
' 4
THICKNESS ELEV 0 . 3 0 6 9 0 . 0A . 15 . 6 8 9 . 09 . 7 0 ' 6 7 5 i 4
6 4 3 . 6 ,
SPACING 1.00 1 .4 7 . 2 . 1 5
' ' 3 . 1 6 4 . 6 4 6 . 8 1 10.00
1 4 . 6 8 • 2 1 . 5 4
3 1 . 6 2 4 6 . 4 2 6 8 . 1 3 100.00
1 4 6 . 7 8
MODEL RHO- - 7 9 . 6
4 3 . 6 . 3 5 . 6 -
— '35. 7-^4 8 . 56 3 . 68 3 . 2
1 0 3 . 71 1 9 . 91 2 5 . 91 1 9 . 61 0 6 . 394.5
RHO 3 9 2 . 8
3 2 . 1 3 3 9 . 2
8 2 . 8
THICK*RES1 1 6 . 11 3 3 . 3
3 2 8 9 . 3 -
THICK/RES0 . 0 0 0 80 . 1 2 9 2
' 0 . 0 2 8 6
FIELD RHO7 9 . 44 3 . 93 5 . 3
- 3 6 . 4 ......-3 9 . 64 7 . 26 2 . 67 9 . 3
1 0 9 . 0 1 2 7 . 0 .1 2 8 . 01 1 6 . 01 0 3 . 0
9 4 . 5RMS ERROR 2 . 8 3 1
I-TES A iL S lL i? . «_1.5 ,
l ay e r
23
THICKMESS ELEV 0-«-33 6 9 3 . 0
6 8 9 , 0 6 7 5 . 6
. 4 , 0 91 3 , 3 9
RHO. rHICK#RES -3 9 .5 .3 U 6 j j _
3 2 . 03 1 8 . 0
1 3 1 . 03 3 0 4 . 8
THICK/RES 1', 0 0 0 7
3*, 12 7 9
SPACING-
— ---- ri4,iy
MODEL RHO FIELD RHO■ 1 * 3 0 7 9 , 7 7 9 . 4
1 . 4 7 4 3 . 5 4 3 . 82 . 1 5 3 5 . 5 .35.^3. .. .........3 . 1 6 3 5 . 7 3 6 . 44 . 6 4 3 9 . 6 3 9 . 66 . 9 1 4 8 . 6 „ 4 7 . 2 ____ _______ _______________
1 3 , 3 0 6 3 . 7 6 2 . 61 4 . 5 8 8 3 . 1 7 9 . 32 1 . 5 4 ______1 . 33 , 6 . . . 1 0 9 . 3 ____________________________3 1 , 6 2 1 1 9 , 7 1 2 7 . 04 6 . 4 2 1 2 5 . 7 1 2 8 , 06 8 . 1 3 1 1 9 . S . . 1 1 6 , 0 _____ _ ____ ________________
103'. 00 1 0 6 . 4 1 0 3 . 01 4 6 . 7 8 9 5 . 6 9 4 . 5
RMS ERROR s 2 . 9 4 9
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
117
ITERATION- NO. 15. VJS_JJ p , 2.8.l a y e r t h i c k n e s s elev
1 0 . 531 6 9 2 . 0RHO- THICK»RES 1 7 0 . 3 8 5 . 6
t h i c k / r e s3'. 0 0 3 3
2 2 . 8 33 1 2 , 1 34
6 9 3 , 46 8 1 . 16 4 1 . 3
2 6 . 5 ,■ 7 5 3 . 3
6 5 . 8
7 5 : 29 0 9 7 . 4
3', 1 0 6 8 3', 0 1 6 2
SPACING MODEL RHO FIELD RHO1 . 3 3
s 1 , 4 7 . 2 . 1 5
9 6 . 26 3 . 3 3 9 . 7
9 5 . 4 6 1 , § 3 8 . 7
3 . 1 64 . 6 46 . 8 1
3 5 . 94 2 . 75 7 . 8
3 5 . 34 3 . 45 7 . 5
1 3 , 3 01 4 . 6 82 1 . 5 4
8 3 . 51 1 3 . 11 4 4 . 4
7 8 . 31 3 6 . 01 4 4 . 0
3 1 , 6 24 6 . 4 26 8 . 1 3
1 7 7 . 31 9 6 . 91 9 3 . 8
1 8 6 . 02 3 5 . 01 9 2 . 0
103'. 30 1 4 6 . 7 3
1 5 7 , 21 1 3 . 9
1 5 3 . 01 1 5 . 0
RMS. ERROR s: 2 . 671
i t e r a t i o n : no . 1 5 , VES NO*. 29 •
l ay e r t h i c k n e s s elev1 3 . 6 2 6 9 4 . 02 2 . 0 7 6 9 2 . 0
. RHO THI 6 6 9 . 3
5 1 , 3 .
CK#RES416' .0
. _ 1 3 5 , 5
THICK/RES 3’. 3 0 0 9 3 ' , 0 4 0 5
3 9 , 3 54 9 , 3 3 '5
6 8 5 . 26 5 4 . 56 2 4 1 0
4 3 8 . 09 9 8 . 01 2 5 . 0
3 8 1 4 . 09 2 8 2 . 3
31. 0 2 2 9 3', 0 09 3
SPACING MODEL RHO FIELD RHO1 . 3 0 1.. 47 2 . 1 5
4 2 7 . 7 2 6 1 . 01 3 2 . 7
4 3 3 . 02 5 9 . 01 3 2 . 0 _
3 , 1 64 . 6 46 . 8 1
8 7 , 1. 9 5 . 81 2 5 . 1
8 9 . 6 , 9 0 . 7 1 2 7 , 0 _
1 3 . 0 01 4 , 6 82 i . 5 4
1 6 4 . 42 1 1 , 12 6 2 . 0
1 7 2 . 02 1 1 . 0 2 5 1 . 0
3 1 . 6 24 6 . 4 26 8 . 1 3
3 3 7 , 03 2 6 . 83 3 3 . 8
3 3 3 . 03 3 4 . 03 1 6 . 0
1 0 3 . 3 01 4 6 . 7 8
2 4 4 . 81 8 3 . 0
2 4 5 . 01 7 6 . 0
RMS. ERROR S: 2 . 9 5 4
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
iiFRwiSai so, 9, T s r ' \ y r 5 3
LAy5R' rHISKMSSS ELEV RHO THICK »R5S THICK/RES1 3 , 6 3 f a s . ? 1 8 2 , 7 11 O ' ““ ■ > , W S 5 ~2 5 , 63> 6 3 3 , 9 3 2 , 3 181 . 0 9>,173&.
_ 3 8 , 3 1 6 6 2 . 5 2 3 1 . 1 1 9 2 0 . S 3- .0362r*s' 4 ; B , 19 ■ - 63S~3 “ 7.2 57.2 1,1697^- • 5... '• ' 623,4 128,7
S ? A M ‘.’G MODEL RMO FIELD RHO1.3Z 129.4 128.21,47 9 2’. 2 ' 91,7 ..................*2 ,15 56,e 56.33.16 43.7 43,5
• 4,64 37.3 3T.8 ...6.81 , 42.P 39.8
13.20 47.5 47.9’ :: K: 14,68 - -'■'••v 58,4 •: " ' 54,5
21,54 > A 6 8 . 4 ̂68,3 iv:r- "I 31,62 „ t 72,2 77.9
46,42“ 67.4 73.6'..69‘,13 58.° . 53,7
103,30 55.7 56.4’14 - -v.:.. 64 ,7 / ••• . 67,5 -'-..i:''
• RMS, ERROR s 4. 154 ' • "^:'V ::
ITERATION NO. IE, V£S NO. 21LAYER THICKNESS ELEV • RHO THICK*RES THICK/RES1 1-33 S33.0 67.6 65.7 0.02902 0.99 - 678.5 15.4 "* 15.2 0.0642.3 5.83 .675.2 55.7 324.9 0.1043■i . Z - 5 ? 656.1 :. 140.1 1053.0 0.05395 • 17.84 . 631.3 ,29.0 . 517.3' 0.6151 \6 ........ - 572.8 205.4 — ■
SPACING 1.00 1.47 : 2.15 3.16 ‘ 4.646.31 10.00 14.68 .21.54 31.62 46.4 2 68. 13 100.00
DEL RHO FIELD RHD46.1 45.3 •43.9 45.040.0 39.935.8 35.5'34.9 " 34.938.7 38.745.6 45.753.6 54.061.0 60.065.3 64.365.3 69.370.7 66.7' 92.7 35.0RMS ERROR = 2.415
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
119
—Vi-Onfti lvi ' , -1V-,---W $——lfr.8:
layer t h i c k m e s s elev
W w g J 4 _ a . -..* — --1— .
RHO THICK#RES THICK/RES'.i 1 , 1 3 . 6 8 3 . 0 4 9 , 1 54._3__ 3., 0 2 3 52 2 , 09 * 6 7 9 , 3 2 5 , 0 5 2 , 2 3 ' , 08353 5 , 0 3 6 7 2 , 5 5 7 , 0 2 8 6 , 8 0*, 0 9 8 34 8 . 7 9 5 5 5 . 9 1 4 0 , 0 1 2 3 0 , 4 , 3<j362ff5 * 4 , 1 5 : 6 2 7 , 1 7 , 0 2 9 . 1 2<, 5 9 3 4 ,6 6 1 3 , 5 2 0 5 , 0
s p a c i n g MODEL RHO FIELD RHOV
- - . 1,00 . 4 6 . 3__ 4 5 . 31 . 4 7 4 3 , 8 4 5 , 02 . 1 5 3 9 , 9 3 9 , 9 •3 . 1 6 . . 3 5 , 9 . .... .........3 5 , 5 ____4 , 6 4 3 5 . 1 3 4 , 96 , 8 1 3 8 , 6 3 8 , 7 .
........... 1 0 , 3 0 . . . . .. 4 5 , 4 . 45,71 4 , 6 8 5 3 , 6 5 4 , 02 1 , 5 4 6 1 . 2 6 0 , 1
------ 3 1 , 5 2 . - _____ 6 5 , 4 _ --------- 6 4 , 8 _ .4 6 , 4 2 66,6 6 9 , 86 3 . 1 3 7 2 . 5 6 5 , 7
. . 1 0 0 , 3 2 . 6 2 . 7 .... 8 5 , 2 . . .
RMS. ERROR s: 2 . 4 7 4
ITERATION NO. 15, VES NO. 32LAYER THICKNESS ELEV RH31 0.67 537.0 144.3
2 S. 36 534.3 42.03 9.92 557.4 298.04 10.72 624.3 11.05 589.6 269.0
THICK*RS596.7351.32957.2117.9
THICK/RES0.00460.19900.03330.9745
SPACING MODEL RHO FIELD RHO1.00 113.8 117.01.47 38.6 35.92.15 64.3 65.03.16 50.9 52.24.64 46.2 45.26.31 46.5 45.0
10.00 50.3 50.114.68 60.0 59.4 .* 21.54 72.9 73.531.62 84.3 34.346.42 83.5 83.663.13 35.3 90.8100.00 83.3 73.5
RMS ERROR = 4.325
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
120
ITERATION NO. 15, VES NO. 33LAYER• 1 ..
• 2 ‘7- .... .345 • ••
THICKNESS ELEV RHO THICK*RES THICK/RES0.66 .688.0 242.2 160.3 0.00275.81- ■ 685.8 ... 45.3 262.8 0.128310^46... 666.8 - 320.8 '3354.0... 0.032620.20 632.5 30.0 606.0 0.6733566.2 164.1
SPACING MODEL RHO -. 1. 00 177.81.47 127.3... 2#15 - - 31.8'3.16 58.14.64 52.36.31 55.7..1C . 0 0 ..... 66,1. .. ..14.68 82.621 .54 100.331.6 2 112.146.42 111.968.13 102.1100.0 0 94.8
FIELD RHO175.0130.0 82.3' •56.5 '51.0 58.3 69.851.0-96.0103.0117.0102.094.0
RMS ERROR 3.125
rTFRTTroN-rjT-ir~■ r"S’ no. n .................... -....... ....layer t h i c k-iess elev rh? th tc:<*pes thick/res” 1 DT5T- TBTT**....... 742.5 ~ 162.2.........KZ>*27~'2 5.87 655.° 45,4 266.3 3,12943 10.55 566,6 235.2 353?.5 3.tfll54---- • 5.15 -631,9 ? , U 30 41.3 ' 0.64475 615,7 164.5
SPa : I v 3 MODEL RMQ f i e l d rmoi.?3 177.9 175.3
— r m ------- n 7 7 3--------1 3 2 7 2 —2.15 81.B 52.33.15 53.1 55.55754-------- 527*-------- 5T7S---5.91 55.7 53.3
12,?3 66.2 69,8— IT7frr-------- 8275--------8IT T
21.54 122.4 96. d31.52 112,2 108.245772-------rrr.'7------- i 1775“03,13 122.1 172.2
102.03 95.1 94.3
RMS. ERROR s-. 3 , 1 6 9
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
121
ITFRATi as VO, I f VRS MO. 34
LAVER I HI WVSSS ELEV RHO THICK^RSS TH1CK/RSS1
34
-5 -
3 . 5 1-5. -52-9 , 3 14 , 5 3
530,3 -536,-3- 5 6 3 . 2 541.>3
-52-5-S-3-
4 4 4 . ?- 6 7 . 9 -3 5 9 , 0
8,7•452,3-
2 2 6 . 4— 3 7 4 . - 9 -2 9 0 2 . 0 -
3 7 . 0
3'. 00 u -4 .081-2- a , 0 2 3 t 3 , 5 7 6 6
-SPftSSWS — PI ELD R^O-1.00 1 . 4 7
— 2 . 1 5 - 3 . 1 6 4 . 5 4
~ 6 t 8 1 — 10.00 1 4 , 6 0
—21-r54— 3 1 , 5 2 4 5 , 4 2 -
- 6 9 ^ 1 4 — 100,00 1 4 5 , 7 8
2 5 3 . 01 5 7 . 1
- 97 - . - 9 -7 7 . 97 6 . 0
-8-2-T-2-9 6 . 1
1 1 4 , 6428-1-4-1 2 7 . 61 1 1 , 5
- 9 3t &-9 0 . 2
101.0
2 5 0 . 0 160,3
- 9 7 , 4 -76,.07 5 . 8
- 8 5 . 3 -9 3 , 0
1 1 6 . 0 4 2 3 * 0 -1 2 4 . 01 1 3 . 0
- 4 7 . - 2 -8 7 . 8
101.0
RMS, ERROR s : 2 , 3 9 2
I TERATI ON NO. VES NO. 3 5
LAYER THICKNESS- ELEV L ■ ' 0 . 2 7 6 9 1 . 0
■ . 2 • 7 . 4 5 6 3 0 . 13~; 1 0 . 7 8 ' 6 5 5 . 7
4e 1 2 . 9 0 6 2 0 . 35 7 3 . 0
RHO T H I C K * 3 5 S3 5 4 . 1 9 5 . 0
3 8 . 1 2 8 3 . 74 0 6 . 1 4 3 7 6 . 0
1 4 . 61 9 9 . 9
1 8 3 . 8
THI CK/ RES 0 . 0 0 0 8 " 0 . 1 9 5 8 . 0_.J)265__
0 . 3 8 1 0
SPACI NG 1.00 1 . 4 7 2 . 1 5
.. 3 . 1 5 4 . 6 4 6 . 3 1 10.00
1 4 . 6 3 2 1 . 5 4 3 1 . 6 2
. 4 6 . 4 2 6 3 . 1 3 100.00
146.73 2 1 5 . 4 4
MODEL RHO7 0 . 54 6 . 04 0 . 529.54 0 . 24 3 . 2
, 5 0 . 26 3 . 19 0 . 3 9 6 . 9
1 0 6 . 4 1 0 5 . 2
9 3 . 49 3 . 5
1 1 1 . 5
FIELD RHO 7 0 . 74 5 . 54 1 . 63 3 . 3 4 0 . 04 3 . 55 0 . 36 0 . 7 7 3 . 99 9 . 3
1 1 3 . 01 0 3 . 0
9 7 . 234.5
117.05 MS ERROR =. 2.783
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
122
ITERATION VO, 7, VES NO, 35
l a y e r t h i c k n e s s e l e t ^ RHO- THICKvRES THTcK/RES.1 0,27 681,0 354,0 95.0 0‘, 0008
,.,••2 .. 7,45! • 680,1 v 38,0 283,2; 3', 1958 73 f2T, 9t 655,7 406,0 7428,8 3', 02 6 94 6,13 - 619,9 7.0 42,9 0', 87735 599,8 203,3
i .SPACING MODEL RHO FIELD RHO
. . . . ^ z z .7075 70,7
1.47 46,0 45,52,15 43,5 41,6
. 3 ,16 ....39,5 38,8'i •,,, 4,64 43,2 43,0j.- 6,91 . 43,1 43,5
13, 08- 50', 2 50,314.69 63,1 60,721,54 83,3 78,9-
• 3i, 62- .. 96,9 ' ' 99,3! • 45,42 ■ 106.4 113,0! : ;. . (58,13.: 105,2 103,0
100', 0(0 9874 97,2146,78 98,5 94,5.215,44 111,7 117,0 - -
I ’-V RMS, ERROR. ?r ' 2 , 7 8 1
ITERATION NO. 15, VES NO. 36LAYER
123 . , .4 ’ .5
“ THICKNESS ELEV \ RHO THICK*RES THICK/RES 0.41 630.0 ,429.4 175.1 0.00095.43 678.7 \ 66.1 359,3
12.39 660.8 „ . 6?9,9 n’SIU11.75 613.5 r 13.0 211.4 0.65265B0.0 374.5
SPACING ‘ MODEL RHO FIELD RHO
1.001.472.153.16 •4.64 6.8110.0014.6321.5431.6246.4263.13100.00146.78215.44
Hi:!80.372.774.7 34.51.0 5.1135.9 170.4197.3203.4 134.1157.4 152.3177.9
loirS8 5.374.7 70.452.7 102.0137.0190.0195.0205.0185.0155.0152.0131.0RMS ERROR = 3.322
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
123
ITeT atTDM M3. 15, VES MO. 36LAYER THICKNESS ELEV RH 3 THICK»RES THICK/RES
1 . 0 . 4 12 5 . 4 2 :
' 3 1 3 . 1 9 1
6 8 3 , 06 7 8 . 76 6 3 . 9 :
4 2 9 . 8 5 6 , 1
6 3 3 . 0 .
1 7 5 , 2. 3 5 8 , 37 9 1 1 , 7
3', 0 0 0 9 3-, 0 8 2 3 " ) 3 U 0 2 2 3 -fit
4 4 . 6 35
6 1 7 . 66 0 2 . 4
7 . 2 3 6 8 . 8 \
3 3 . 3 3', 6 4 2 8 |
SPACl MB 1'. 30
MODEL RHO 1 8 8 . 6 ’
FIELD RHO 1 9 2 . 0
1 , 4 7 2> 15 3 . 1 6
1 1 3 , 58 3 . 37 2 . 7
1 3 8 , 08 5 , 87 4 . 7
4 . 6 4 6 . 8 1
13 ' . 00
74*,78 4 , 6
1 3 5 . 1
7 3 . 48 2 . 7
1 3 2 . 01 4 . 6 62 1 . 5 43 1 . 5 2
1 3 5 . 81 7 3 . 31 9 7 . 2
1 3 7 . 01 6 3 . 01 9 5 . 0
4 6 . 4 2 6 8 . 1 3
103-. 00
2 0 3 , 21 8 4 . 11 5 7 . 6
2 3 5 . 01 8 5 . 01 5 5 . 0
1 4 5 , 7 82 1 5 . 4 4
1 5 3 . 11 7 8 . 1
1 5 2 . 01 8 1 . 0
RMS. ERROR m 3 . 3 4 4
ITERATION NO. 15» VES NO. 37LAYER THICKNESS ELEV RHO THICKSRES THICK/RES. 1 0.68 678.0 233.8 162.6 0.00292 4.50 -• 675.3 43.2 194.3 0.10423 - 12.82 661.0 603.6 7737.4 0.02124 22.26 618.9 20.0 445.2 1.11305 545.9 . 201.1
SPACING MODEL RHO FIELD RHO1.00 178.0 181.01.47 123.5 125.02.15 32.4 3 2.93.16 58.4 59.54.54 54.6 54.66. SI 63.2 5 2.0'10.00 32.0 77.314.69 109.2 106.021.54 140.1 133.031.62 165.4 174.046. 4 2 175.0 19 6.068.13 160.2 164.0100.30 127.3 122.0146.78 • 104.7 94.5215.44 107.1 117.0RMS ERROR = 5.203
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
124
ITERATION >13. 1 5 , VES NO. 37
LAYER THICKNESS ELEV RHO THICK*RE5 THICK/RES1 0 . 6 5 2. 4 , 8 1 3 a . 95
6 7 8 . 0 6 7 5 . 86 6 0 . 1
2 4 1 . 0 4 6 . 1
4 2 5 . 0
1 5 8 . 42 2 1 . 5 4 0 2 . 4
3- ,0027 31, 1 34 4 0'. 0 0 2 2
4 1 2 , 4 4. 5 :-“ . 7 i 45«-6W .r
6 5 7 , 0 \ 6 1 6 , 1
v - r 5 9 1 . 7
6 0 0 . 05 . 8
: v 2 0 0 . 0
7 4 6 5 1 25 0 . 9
3', 0 2 0 7 1 , 0 9 4 7
SPACING MODEL RHO FIELD RHO. Udd
1 . 4 7 2 . 1 5 v
1 2 6 . 7 , 8 2 . 2
1 8 1 , 0 1 2 5 . 0
■ 8 2 . 93 . 1 6 4 . 6 4
• 6 . 8 1
5 9 , 95 6 . 36 4 . 1
5 9 . 55 4 . 6 6 2 . 0
■1 0> 0 01 4 . 6 82 1 . 5 4
8 1 . 91 0 8 . 51 3 9 . 1
7 7 . 31 8 6 . 01 3 3 . 0
•
3 1 . 6 24 6 . 4 26 8 . 1 3
1 6 5 , 51 7 5 . 41 6 0 . 2
1 7 4 . 01 9 6 . 01 6 4 . 0
i a a > 0 01 4 5 . 7 82 1 S . 4 4
1 2 8 . 11 0 5 . 01 0 7 . 3
1 2 2 . 09 4 . 5
1 1 7 . 0
RMS. ERROR 9- 5 . 3 4 7
ITERATION NO. 1 2 , VES NO. 38 \ A
...... .
LAYER THICKN1 r . 0 32 4.173 14.584 2 0 . 1 0
........5:;::. .•
ESS ELEV677.0 673.6 659.96 1 2 . 1
‘ — 546.2 _
SHQ THICK*RES 191.1 197.6 67.3 280.4726.3 10589.6 29.0 582.81 4 7 . 3
THICK/RcS0.00540.06190.02010.6930
SPACING MODEL RHO FIELD RHO1.00 177.1 174.01.47 158.9 164.02.15 131.2 129.03.16 104.4 105.04.64 92.4 91.46.31 100.5 102.010.00 . 127.0 128.014.68 166.5 16C.C21.54 210.3 203.031.62 245.1 253.046.42 252.3 271.068.13 220.9 216.0100.00 166.1 160.0 •
146.78 125.6 128.0215.44 117.0 117.0RMS EPRCR = 2.945
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
125
ITERATION MO, 9. VES NO*. 38
LAYER THICKNESS ELEV_______ RHO,_EHI£K_*RfS THICK/RESI : vT,.l . 1 , 0 3 6 7 7 , 0 - 1 9 1 . 3 1 9 6 , 9 3*,0054 •
2 4 , 2 1 6 7 3 . 6 v ^ 6 7 . 7 2 8 5 . 3 3 , 0 6 2 33 1 5 . 1 4 6 5 9 f _8_ 7 2 5 . 5 ___10&8.2,%_____ 3 - , 0 2 M . _4 5 , 4 5 6 1 3 . 1 7 . 3 - 3 8 . 2 3 , 7 7 9 75 5 9 2 . 2 1 6 4 . 2
SPACING MODEL RHO FIELD RHO _ U M ________ m l * _______ 1J4...0_
1 , 4 7 1 5 3 . 9 1 6 4 . 02 . 1 5 1 3 1 • 1 1 2 9 . 03 . 1 6 1 0 4 . 4 10 5 . 04 j 64- : - 9 2 , 5 ' ’ . ' : 9 1 . 4
V 6 . 8 1 1 0 0 , 4 1 0 2 . 01 3 . 0 0 1 2 6 . 7 1 2 8 . 01 4 , 6 8 1 6 6 , 2 1 6 0 . 02 1 , 5 . 4 2 1 0 , 2 2 0 3 , 0
3 1 , 6 2 2 4 5 . 4 2 5 3 , 04 6 , 4 2 2 5 3 , 2 2 7 1 , 06 8 , 1 3 2 2 1 . 6 2 1 6 , 0
1 0 3 y 00 1 6 5 . 8 1 6 0 . 01 4 6 , 7 8 1 2 4 . 7 1 2 8 . 02 1 5 . 4 4 1 1 7 . 8 U 7 . 0
RMS. ERROR s 2 . 9 1 6
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
126
ITERATION NO. 15, VES NO- 39LATER THICKNESS ELEV RHO TH1 0.35 675.0 854.2 .•2 . 1.32 673.9 66.33 2.78 669.5 940.74 5.62 660.4 185.65 7.77 642.0 920.16 - 5.35 616.5 14.0 • i7 598.9 229.2
SPACING MODEL RHO FIELD RHO1.00 . 237.0 237.01.47 126.5 126.32.15 109.2 110.13.16 135.9 133.14. 64 179.3 178.16.81 230.2 233.110.00 277.3 278.014.63 311.3 303.021.54 326.4 326.031.62 319.3 317.046.42 234.7 283.063.13 224.9 235.0100.00 175.4 166.0146.78 164.4 169.0RMS ERROR » 2.347
296.6 \ 88-4 2615.6 1042.5 7148.0 75.0
THICK/RES 0.0004 0.0198 0.0030- 0.0302 0.0084 0.3824
ITERATION NO. 15, VES NO. 39LAYER- THICKNESS ELEV- RHO THICK*RES THICK/RES.1: 0.35 675.0 352.4 296.2 0.00042 1.32 673.9 66.3 88.4 0.01933.. 2.77 669.5 943.8 2611.9 0.00294 5.60 - 660.4 185.6 1039.9 0.03025 7.62 642.1 920.0 7014.4 0.00336 13.29 617.0 34.0 452.0 0.39107 - 573.4 230.6
SPACING MODEL RHO FIELO RHO1.00 235.9 237.01.47 126.5 ■ 126.32.15 109.2 110.13.16 135.9 133.14.54 179.9 173.16.31 230.2 239.110.00 277.4 273.014.68 311.3 303.021.54 326.4 326.031.6 2 319.9 317.046.4 2 234.7 233.066.13 224.9 235.0100.00 ■175.4 166.0146.73 164.4 169.0
RMS ERROR.* 2.345
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
127
ITERATION NO. 15, VES NO. 40LAYER THICKNESS ELEV1 0.85 673.02 0.54 670.2
RHO THICK*RES THICK/RES505.9 427.6 0.001710.0 5.4 0.0540
3 11.814 13.345
66 8.5 629.7 585.9939.910.3352.0
11692.7143.60.01191.2398
SPACING1.001.472.153.16 4.64 6.8110.0014.6321.5431.6246.4268.13100.00146.73
MODEL RHO397.5285.9160.236.280.6108.6149.5198.7248.6282.7273.4227.0155.9115.1
ERROR = 1
FIELD RHO341.0342.4165.177.2 73.4109.0151.0204.0268.0234.0263.0226.0157.0115.0,435
ITERATION: NO. 1 5 , VES NO*. 41
LAYER, THICKNESS ELEV RHO THICK#RES THICK/RES . 1 1 . 2 9 6 7 5 , 0 2 5 4 . 1 328*. 8 3'. 0 0 5 1
.. 2 . 1 U 5 : . . 6 7 0 . 8 2 1 . 0 2 4 *r 2 3' .054B3 1 4 , 9 § : 6 6 7 , 0 8 4 0 , 0 1 2 5 5 5 . 7 3 - . 01784 4 , 9 9 * 6 1 7 , 9 1 1 . 0 5 4 . 8 3 , 4 5 3 8
_ 5 _____ :___ 631^6______ 252^0____________________________
SPA?ijl-S __.MQD_SLLRHQ: F I ELD RHO1 . 0 01 4 4 72 . 1 5
„ 2 3 7 , 0 2 1 1 . 5 1 6 6 r 3
2 3 3 . 02 1 0 . 0 1 7 3 . 0
3 . 1 6 1 1 5 . 3 1 1 5 . 04 . 6 4 9 0 . 1 8 7 . 16 . 8 1 1 0 3 . 1 1 0 3 . 0
1 0 . 0 0 1 3 9 . 2 1 4 5 . 01 4 . 6 8 1 8 6 . 2 1 8 9 . 02 1 . 5 4 2 3 7 . 1 2 3 2 . 03 1 . 5 2 2 7 8 . 9 2 6 6 . 04 6 . 4 2 2 9 2 . 2 2 9 5 . 06 8 . 1 3 2 6 5 . 2 2 8 0 . 0
1 0 0 , 0 0 2 1 4 . 9 2 1 3 . 01 4 6 . 7 8 1 8 1 . 5 1 7 6 . 02 1 5 . 4 4 1 8 3 . 2 1 8 9 . 0
RMS. ERROR =• 2 . S 5 4
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
128
i t e r a t i o n : m o * i s . ves n o . 42\
layer t h i c k n e s s elev ! 1 ' 0 , 7 7 6 7 0 . 0
2 0 . 8 2 6 7 5 . 5
RHO . THlCKftRES 9 7 . 3 7 5 . 3
1 8 4 . 1 1 5 1 . 1
THICK/RES 3', 038 3 31, 0 0 4 5
3 1 * 9 54 1 3 . 5 55 8 . 9 7
6 7 2 . 8 6 6 6 . 46 2 1 . 9
3 3 . 96 5 0 . 1
1 1 . 0 * /
6 6 . 3 8 8 3 5 1 9
96 L 6
3*. 0 5 7 7 3', 0 2 08 3 . 8 1 5 1
6 5 9 2 . 5 4 8 3 . 0
SPACING U M 1 ■ 47
MODEL .RHO 1 0 3 . 9 1 0 8 . 7 ,
FIELD RHO . 1 0 4 , 0
1 0 9 . 0I' 2 * 1 5
3 , 1 6 ! 4 . 6 4
1 0 2 * 9 : 9 3 . 2
1 0 8 . 0 • 1 8 6 , 8
9 1 . 4, 6 . 8 11 3 > 5 01 4 . 6 8
. 96*0 , 1 1 9 . 0 1 5 5 ; 3
, . 9 5 , 8 1 2 2 . 0 1 4 9 . 0
2 1 , 5 4 I ■ 3 1 . 6 2 ; ! 4 6 . 4 2
. . . . . 1 9 3 7 , . ..
2 2 1 ; 1 > •. • .-;2 2 1 i 6 ■
1 8 6 * 0 / ' 2 2 8 . 0 '
2 3 4 . 06 8 * 1 3
1 0 3 . 3 01 4 6 . 7 8
1 9 0 * 91 5 1 . 51 3 8 . 9
1 9 1 . 81 5 8 . 01 2 8 . 0
2 1 5 . 4 4 1 6 2 . 0 1 7 5 . 3
RMS. eRROR s: 3 . 858
ITERATION NO. 15. VES NO. 43 'LAYER THICKNESS ELEV RHO THICXvRES1 0.91 690.0 193.8 182.52 5.15 677.0 65.0 335.03 10.91- 660.1 600.0 6543.64 8.97 624.3 11.0 98.55 594.9 490.0
THICK/RES0.00460.07930.01820.8176
SPACING1.001.472.153.16 4.64 6.9110.0014.4321.3431.6246.4268.13100.00146.79215.44
•MODEL- RHO179.0154.7121.393.8 81.385.9103.3132.3 15 2.3133.1131.0156.5132.2 135. *»163.2
FIELD RHO176.0145.0115.0 99.9 93.2 94.0131.0123.0 1 5 ?■ . 0 17 9.0139.0169.0123.0122.0 189.0
RMS ERROR = 6.936
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
129
ERftTlOW MO. 15, \IE& NO. 44
yer thickness elev rho thiciures t h i c k/res1 a . 85 6 8 2 . 0 1 7 8 . 2 1 5 1 . 0 3 ' . 0 0 4 B2 \ 4 , 7 5 ' 1 1 1 . 6 7 * 4 v 1 3 . 1 5 :
6 7 9 , 26 6 3 . 6
■-•':'«f'625l3 ' . ■
3 1 . 75 4 5 . 6
l i . 0
1 5 0 . 6 6 3 6 7 . 2
1 4 4 1 6
3*. 1502 3', 0 2 1 4 i ; 1 9 5 1
5 ' • . 5 3 2 . 2si.\
4 8 3 . 2
SPACING MODEL RHO. FIELD; RHO1 , 0 0 " 1 4 8 * . 9 1 4 6 . 01 . 4 7 1 1 7 . 5 1 2 1 . 0...... ^ .
■ " " ' 7 9 . 0...... ....... ... . — ..m m .. — .»
3 > 1 6 5 1 . 5 5 0 , 54 : 6 4 4 2 ‘f 0 4 2 . 8 «
- 6 * 8 1 ^ 45>7 4 6 . 0 :1 3 : 0 0 5 8 . 5 5 6 . 3 *1 4 . 6 8 . 7 8 . 4 7 3 . 5 _2 1 . 5 4 1 0 2 . 1 9 8 . 33 1 . 6 2 1 2 4 . 1 1 3 0 . 04 6 . 4 2 1 3 6 . 4 _ 1 5 1 . 06 3 . 1 3 1 3 2 . 4 1 3 7 . 0
1 0 3 . 0 0 1 1 7 . 2 1 1 6 . 0I4£aj_8 . ... U 0 . 3 _ 8 7 . 82 1 5 . 4 4 1 2 7 . 3 1 4 6 . 0
M S i.£RR0.8,.sj 8j 321
ITERATION NO- 14, VES NO- 45LAYER
1• 234
56
THICKNESS ELEV 0-72 635-05.94 632.63.23 663-1.02 652.5.47 626.2611.6
*P*LXM MODEL RHO 715.21.47 493.42.15 274.83.16 150.74.64 111.46.81 100.510.00 94.214.63 92.221.54 97.231.62 102.846.42 100.06S.13 92.0100.00 92.0146.73 107.5
RHO THICK*RES THICK/RES969.1 699.7 0.0007101.8 605.0 0.058437.9 122.3 0.0352345.0 2766.3 0.0232:.6.0 26.8 0.7457250.0FIELD RHO712.0495.0277.0149.0111.0
102 .0 .94.091.198.9 102.099.1 93.590.9 103.0RMS ERROR = 1.031
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
130
ITERATION NO. 15, VES NO. 46LAYER THICKNESS ELEV RHO THICK*RES THICK/RES1 1.16 693.0 1081.0 125 8.4 0.00112 2.37 679.2 269.9 639.6 0.00633 19.55 671.4 40.0 742.0 0.46374 610.5 109.1
SPACING1.001.472.153.16 4.64 6.8110.0014.6821.5431.6246.4268.13100.00
MODEL RHO 1005.7897.1708.1477.5232.1151.6 78.551.447.5 51.860.6 71.582.3
FIELD RHO980.0930.0775.0430.0262.0 149.075.4 59.254.054.155.669.631.5RMS ERROR 6.794
ITERATION; VO, 5# VES N‘0, 47LAYER . T K i : « VESS ELEV RHO rH!CK#R2S THICK/RES
1 9 , 4 4 6 8 5 , 3 5 8 6 , 3 2 5 9 . 4 3 , 0 0 0 9• 7 1 3 . 0 3 6 8 3 . 5 5 2 . 4 5 2 4 . 3 3' . lH0fi - .
3 7 , 6 5 • 6 5 3 , 3 3 3 5 , 3 2 5 6 1 . 9 3 . 0 2 2 3 ;4 4 , 9 9 6 2 5 , 7 3 , 9 . 4 4 . 4 3 , 5 5 9 65 6 3 9 . 3 2 8 5 . 9
SPAOl.VS MODEL RHO FIELD R4D• - . 1 . 3 0 2 5 3 . 3 , 2 4 1 , 0
r.- 1 , 4 7 1 2 8 , 5 1 4 3 , 0... 2b15 7 1 . 4 \ 6 5 . 33 . 1 6 5 7 , 1 5 5 , 44 , 6 4 . 5 4 , 8 5 4 , 8
•• 6 . 8 1 , _ 5 5 . 5 5 8 . 31 3 , 3 0 5 9 , 0 6 1 , 71 4 , 6 8 • 6 6 , 7 6 8 , 2
...' 2 1 . 5 4 V S'-ytfr 7 3 ; 3 V . - : 7 4 . 7. 3 1 , 5 2 8 9 . 4 8 5 , 7 -
• 4 6 , 4 2 9 5 , 1 9 9 , 16 3 . 1 3 9 7 . 4 9 7 . 2
1 0 3 , 1 ? 5 , 5 1 3 5 , 01 4 5 , 7 8 1 2 5 , 3 1 2 2 , 3
... . 1 1 5 . 4 4 . L*ii* . 1 63,J5
RMS. ERROR s 4 . 4 4 ? .
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
131
ITERATION NO. 6» VES NO. 47LAYER THICKNESS ELEV RHO THICK*RES THICK/RES1 : : -O.A4 - 685.0 - ' 586.0 259.4 0.0008. 2 9.96 683.5 52.4 521.9 0.18993 7.27 650.9 334.0 2428.4 0.02134 14.49 627.0 25.8 373.8 0.5618
• ---579.5 ^ — 283.9 -
SPACING MODEL RHO - FIELD RHO1.00 .250.4- ----241.0 -1.47 123.5 140.02.15 71.3 65.33.16 57.1 55.44.64 54.8 54.86.81 55.5 58. 310.00 59.0 61.714.68 66.7 63.221.54 79.4 74.7 ~31.62 89.3 86.746.42 95.0 99.165.13 97.4 97.2100.00 - 105.6 105.0146.78 125.8 122.0215.44 154.6 160.0
RMS ERROR * 4.447
ITERATION NO. IS, VES NO. 48LAYER. THICKNESS ELEV RHO THICK*RSS1 1.03 633.3 873.2 901.12 3.15 679.6 74.2 234.03 4.57 -669.3- .. 7.0 - 32.04 11.46 654.3 275.0 3152.15 29.24 616.7 35.1 1027.7-Av. 520.7 :_ _200.0 ...
SPACING MODEL RHO FIELD RHO \1.00 763.9 753.01.47~ 622.8“ .. 643.0 • ....2.1-5 411.7 406.03.16* 209.4 211.0.. . 4.64 93.9 92.56 . 31^.---- 48.0 ---- 48.0*". • ..•■•••10.00 27. 5 28.5 ■ .. V ■:
• 14.68 22.0 20.321.54 27.0 24.3...31.52 — ---- 35.0 ' .... 38-7 ....46.42 46.3 54.153.13 56.7 52.3
100.00 66.3 62.7
THICK/RES 0.0012 0.0425 - 0.6532 • 0.0417 0.8321
RMS ERROR a 5.392
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
ITERATION NO. .15* .' VES NO. 43 .LAYER THICKNESS ELEV RHO1 1.02 T 4 683.0 872.4
2 ^3.13 .J^:679.6/-v;;^:-:76.7, . - . 3 . . . , . , 5 . 3 4 6 8 9 . 4 . / 7 . 6• 4: • -12.21 631.9 - -V ;'275.0.."S ,6.00 .?■» 611.8..... 14*9
6 "■ ■ ■:■■ ■ ■ ■ ' > 592.1.•• vr.r - .300.0
132
THICKSRES 893.2 240.0 • 40.43358.7 . 89.1
.'THICKER ESa . 0.0012 .0.0408 0.7039. r, 0.0444 -7- .. 0.4038 • .
SPACING MODEL RHO1.00 .761.71.47 619.72.15 408.33.16 203.54.64 94.76.81 48.710.00 27.514.69 21.2.I 21.54 25.831.62 34.946.42 46.363.13 59.7100.00 76.0
FIELD RHO758.0643.0406.0211.092.543.028.5 . 20.324.839.754.152.8 62.7
. 7-ssker-r
RMS ERROR = 3.789
i t f r .m i O'J *Jo . 1 5 , VES rfO. 49
LA/SR rHKX'IESS ELEV RH? THTC1 1 , 7 5 63 3 . 1 2 7 3 . 37 "19 ,77"" 6 7 7 , 7 3 7 . 33 6J9.4 3 0 3 . 3
SPACING MODEL RHO FIELD RMO1 , 9 0 2 6 2 , 6 2 5 9 , 91 . 4 / .........2 4 3 , 9 2 4 5 . 92 . 1 5 • 2 1 7 , 9 2 3 7 , 93 . 1 6 1 6 4 . 5 1 5 3 . 9-------- 4 - 5-4 - - 1 3 2 , 7 - ---------- 9 7 . 7 ' "6 . 3 1 6 3 , 1 6 4 , 4 ^
1 3 , 30 4 4 . 3 5 1 , 31 4 . 6 b 4 1 , 6 47 7 92 1 , 5 4 4 5 , * 4 7 , 53 1 . 5 2 5 4 . 2 5 4 . 34 S . 42 7 <5.6 6 7 , 86 3 , 1 3 9 3 . 7 9 1 , 9
1 2 3 . 3 3 122.'*' 1 1 3 . 0146.70 I 3 '.. I 1 5 2 , <>
<*RSS thick/res 4 7 4 , ̂ 3-. 07657 3 1 . -t--------3- ,514? ’
P H 5. i.R-JCR = 6,877
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
133
ITERATION NO. 12# VES NO. 50LAYER THICKNESS ELEV RHO1 0.21 673.0 483.02 2.34 677.3 36.33 4.79 668.0 100.14 15.69 652.3 20.05 597.5 500.1
THICK*RES 103.0 1 04. 6 479.4 333.9
THICK/RES0.00040.07700.04730.3347
SPACING1.001.472.153.16 4.64 6.S110 .0014.6321.543 1 . 6 246.4263.13
100.00146.73215.44
EL RHO FIELD RHO54.0 54.441.0 39.639.5 40.241.1 40.145.2 44.350.9 51.355.0 56.053.9 54.747.3 45.743.2 44.947.3 47.363.6 63.533.1 24.6120.7 123.0161.6 160.0RMS ERROR = 2.350
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Appendix D
Archie's Law Calculations
134
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
135
Vail Addraaa
Archie's
Spaclf. Cond. Dooaatic Vail H,0
Cumhoa/ea)
Law Input
RaalatlvltyH O(i*»)
Data
RaaiatlvityFran
(jl?M )12303 14 IH 350 18.2 92.512320 14 IH 375 17.4 88.41303 Laoaard 660 15.2 77.212160 14 IH 700 14.3 72.61457 Laonard 12124 14 IH
725 13.8 70.1
1383 Laonard 740 13.5 68.61577 Laonard 760 13.2 67.11533 Laonard 810 12.3 62.51475 Laonard 830 12.0 61.012150 14 IH 830 11.8 59.912187 14 IH 860 11.6 58.91424 Laonard 900 11.1 56.41423 Laonard 960 10.4 52.812171 14 IH 990 10.1 51.41432, 1426, and 1433 Laonard
1000 10.0 50.8
12155 14 IH 1100 9.1 46.21523, 1345 and 1723 Laonard 12133 14 IH
1200 8.3 42.2
12109 14 IH 1400 7.1 36.11501, 1542 and 1587 Laonard
1600 6.3 32.0
1683 Laonard and 12115 14 IH
1700 3.9 30.0
1428 and 1310 Laonard
1800 5.6 28.4
1463 Laonard 1900 5.3 26.91500 and 1451 Laonard
2000 5.0 25.4
1484 Laonard 2600 3.8 19.8
Archla'a Law
whara / “ poroalty) • 30X
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Appendix E
Geoelectric Sections B, C, F,G, H, and I
136
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
137
-SJ r
a
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oz<JiUU
oz<e i
W!|»!■!»
za0
o•Io
1 1 A I1 V IS N V IW IA O IV 1111
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OE
OE
IEC
IIMC
S
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TIO
N
138
IM t> O
S 10 > +
III <0 > +
ozoz3o
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z<1(1zououiz
<>
W VO fc
H A I 1 V3S M V 3 W 3A09V 1333
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GiO
HfC
ltlC
S
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TIO
N
139
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GE
OC
II C
IK
1C S
EC
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N
140
11AI1 V i l N V 1W 1 A O IV l i l i
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141
IS
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3 M
ftn
mmm
»3 I *
f f ? f ? i § 3 2 S fJ--- 1__1___ I__IH » n i n n v iw ia o iv t i n
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OIQ
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IHC
1I
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IPX
142
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; •
5 •>
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• SS 5s •> *•
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o o O o o• • • • •I I i T i J I
1IAI1 V II NVIW IA O IV I I I !
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
BIBLIOGRAPHY
Bisdorf, R. J. (1983a). Schlumberger soundings nearNewberry Caldera, Oregon. (United States Geological Survey Open-File Report, 83-825). Washington, DC: U. S. GovernmentPrinting Office, 1-51.
Bisdorf, R. J. (1983b). Schlumberger soundings on the Snake River Plain near Nampa, Idaho. (United States Geological Survey Open-File Report, 83-412). Washington, DC: U. S.Government Printing Office, 1-56.
Bisdorf, R. J. (1985). Electrical techniques for engineering applications. Bulletin of the Association of Engineering Geologists, 22, 421-433.
Cartwright, K., & McCoraas, M. R. (1968). Geophysical survey in the vicinity of sanitary landfills in northeastern Illinois. Ground Water, 16, 23-30.
Davis, P. A. (1979). INVERSE [computer program], St. Paul, Minnesota: Minnesota Geological Survey. (Interpretation of resistivity sounding data: Computer programs for solutions tothe forward and inverse problems, Information Circular 17).
Davis, S. N., & DeWiest, R. J. M. (1966). Hydrogeology New York: Wiley.
Dobrin, M. B. (1960). Introduction to geophysical prospecting.(2nd ed.), New York: McGraw-Hill.
Dorr, J. A., & Eschman, D. F. (1970). Geology of Michigan. Ann Arbor: University of Michigan Press.
Driscoll, F.G., (1986). Groundwater and Wells. (2nd ed.),St. Paul: Johnson Division.
Fink, W. B., & Aulenbach, D. B. (1974). Protracted recharge of treated sewage into sand part II: Tracing the flow of contaminated ground water with a resistivity survey. Ground Water, 12, 219-223.
Fretwell, J. D., & Stewart, M. T. (1981). Resistivity study of coastal karst terrain, FL. Ground Water, 19, 156-161.
Hamrick, R. J. (1978). Dolomitization patterns in the Walker Oil Field, Kent and Ottawa Counties, Michigan. Unpublishedmaster's thesis, Michigan State University, Lansing, MI.
143
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Herold, J. E. (1984). The use of oil field brine on Michiganroadways■ Lansing: Michigan Department of NaturalResources, Geological Survey Division.
Huffman, G. C. (1977). Ground water data for Michigan. (United States Geological Survey Open-File Report, 79-332). Wa Washington, DC: U. S. Government Printing Office, 1-75.
Kunetz, G. (1966). Principles of direct current resistivityprospecting. Berlin: Gebruder Borntraeger.
Kwader, T. (1985). Surface borehole geophysical methods inground water investigations second national conference andexposition. National Water Well Association Conference Proceedings. Denver, 833-841.
Leverett, F., & Taylor, F. B. (1915). Pleistocene of Indiana and Michigan, and the history of the Great Lakes. (United States Geological Survey Monograph, 53). Washington, DC:U. S. Government Printing Office, 1-529.
Lowden, J. (1964). A combined geologic and gravity analysis ofWalker Oil, Michigan. Unpublished master's thesis, Michigan State University, Lansing, MI.
Meisel, K. E. (1985). The use of electrical resistivity todelineate a brine contamination plume in the Walker Oil Field,Kent County, Michigan. Unpublished master's thesis, Western Michigan University, Kalamazoo, MI.
Merrick, N. P. (1977). A computer program for the inversion of schlumberger sounding curves in the apparent resistivity domain. Hydrogeological Report 1977. Sydney: New SouthWales Water Resources Commission.
Michigan Department of Natural Resources, Geological SurveyDivision. (1983). Michigan's oil and gas fields,1981: Annual statistical summary, 36.
Mooney, H. M. (1980). Handbook of engineering geophysics. 2 ,
Electrical resistivity. Minneapolis: Bison Instruments,pp. 27.1-34.19.
Newcombe, R. B. (1940). Developments in Michigan during 1939. American Association of Petroleum Geologists Bulletin, 24, 974-993.
Passero, R. N. & Sauck, W.A. (1988). Groundwater contamination studies in the Walker Oil Field, Kent and Ottawa counties,MI. Unpublished manuscript, Western Michigan University,Geology Department, Kalamazoo, MI.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Stollar, R. L., & Roux, P. (1975). Earth resistivity surveys - a method for defining groundwater contamination. Ground Water. 13, 145-150.
Stramel, G. J., Wisler, C. 0., & Laird, L. B. (1954). Water resources of the Grand River area, Michigan. Michigan Department of Natural Resources. (Geological Survey Division, Circular 323). Lansing: Michigan Department ofNatural Resources, 1-40.
Swartz, J. H. (1939). Part II - Geophysical Investigations in the Hawaiian Islands. Transactions of the American Geophysical Union, 20, 292-298.
Telford, W. M., Geldart, L. P., Sheriff, R. E., & Keys, D. A. (1976). Applied geophysics. New York: Cambridge University Press.
Ten Brink, N. W. (1975). Surficial geology and landforms of east central Ottawa County, Michigan. Unpublished report, Grand Valley State College, Allendale, MI.
United States Environmental Protection Agency. (1981). Hydrogeology for underground injection control in Michigan: part 1. Underground Injection Project. Kalamazoo: Western Michigan University, United States Environmental Protection Agency.
Wagner, T. A. (1988). Ground water quality in the Walker Oil Field. Unpublished master's thesis, Western Michigan University, Kalamazoo, MI.
Warner, D. L. (1969). Preliminary field studies using electrical resistivity measurements for delineating zones of contaminated ground water. Ground Water, 7_, 9-16.
Westjohn, D. 1987, United States Geological Survey, personal communication.
Zohdy, A. A. R. (1965), Geoelectrical and seismic refraction investigations near San Jose, California. Ground Water, 3 41-48.
Zohdy, A. A. R., Eaton, G.P., & Maybey, D.R. (1974). Application of surface geophysics to ground-water investigations.IN Techniques of Water-Resources Investigations of the United States Geological Survey, (Book 2, Chapter Dl), Washington DC: U. S. Geological Survey, 1-59.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
PLEASE NOTE
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LEFT TO R IG H T, TOP TO BOTTOM , W ITH SMALL OVERLAPS
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(not available on microfiche). A xerographic reproduction has been provided for paper
copies and is inserted into the inside of the back cover.
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University Microfilm s International
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NW
MODELr- 700VES VESVES
498- 680320
26*- 660
24*
- 640 16580
177- 620
- 600
L 580
276 171
MODEL B700
- 680 33
- 660 82
225640
- 620164
600 108191
- 560Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
GEOELECTRIC SECTION A
VES VES SB OWR VES VES WWR
2b 2a 4 7695 1b 1a 12180
- 6 5 -11239*
161
510700
298
50 m g/l
200216 151
263
246161 128188
37
281 74?266 288
V
\ 132
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
OWR VES VES WWR VES OWR
7695 12180- 6 5 -112 6011J*55*161 243
24700
390
440216 151
128
117
305281
74?
186
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
; SAND m SAND AND GRAVEL BEDROCK
320 RESISTIVITY (ohm-metor) 50 mg/t CHLORIDE CONCENTRATK
VES VERTICAL ELECTRICAL SOUNDINGS 5 L STATIC WATER LEVELS
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
H SANDY CLAY— — •
— — • CLAY SCREENED INTERVAL 1 I IH—I |0 115
FEET
'tTRATION SB SOIL BORING OWR OIL WELL RECORD WWR WATER WELL RECOR)
LS * RESISTIVITY VALUES HELD CONSTANT
\
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
NL WELL RECORD WWR WATER WELL RECOR) ^ ,
PLATE 1
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PLEASE NOTE:
Oversize maps and charts are filmed in sections in the following manner:
LEFT TO RIG H T, TOP TO BO TTO M , W ITH SMALL OVERLAPS
The following map or chart has been refilmed in its entirety at the end of this dissertation
(not available on microfiche). A xerographic reproduction has been provided for paper
copies and is inserted into the inside of the back cover.
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an additional charge.
University M icrofilm s International
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V /
2UJ
<UJ</>
<UJ
£oCD<I— UJ UJu.
NW
r- 700
- 680
- 660
- 640
- 620
600
r- 580
- 560
- 540
520
r 700
r- 680
- 660
MODEL A
VES49
MODEL B
OWR9851
VES48
VES47
SB3
WWR1587
586270
52
37335
275 352 mg
300286
300
270 74
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
GEOELECTRIC SECTION D
WWR VES VES WWR VES OWR VES WWR VES1587 33 15 1451 14 13447 13 1501 12
452243-
40* 454245
400 365650 660
352 mg/l 8*
495 mg/l 32*391 m g/l
145
235 125
165
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
VES OWR WWR 10 9385 1435
WWR1501
WWR1475
WWR1463
VES VES
2796
^ 5 ^ ~.=?6r:
82-408- 33
400■5Z.150*
100660
■U3 m a/l 165 m g/l515 mg/l32*391 m g/l
207
279I
300
165*
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
i- 700 MODEL B
2a2V )
z<ll]2£om<til
- 680
- 660
- 640
- 620
- 600
h 580
- 560
- 540
- 520
~H7T270 74
37*
275 334
300
284
S5E
200
*- 500
SAND m SAND AND GRAVEL o°o° GRAVEL
270 RESISTIVITY (ohm-meter) 352 m g/l CHLORIDE CONCENT
VES VERTICAL ELECTRICAL SOUNDINGS SZ. STATIC WATER LEVEL
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
1471
45451 650
373321
2. 660
25*
53
30 136258
125164
VEL SANDY CLAY CLAY GRAVELLY CLAY BEDROCK SCREENED INTERVAL
ORIDE CONCENTRATION SB SOIL BORING OWR OIL WELL RECORD WWR WATER WELL RECORD
C WATER LEVELS * RESISTIVITY VALUES HELD CONSTANT
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
ZEST2796'
300■2.
165*
660
25*
53228
INTERVAL
WELL RECORD
I M I- I IoFEET 85
PLATE 2
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
PLEASE NOTE
Oversize maps and charts are filmed in sections in the following manner:
LEFT TO R IG H T, TOP TO BO TTO M , W ITH SMALL OVERLAPS
The following map or chart has been refilmed in its entirety at the end of this dissertation
(not available on microfiche). A xerographic reproduction has been provided for paper
copies and is inserted into the inside of the back cover.
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an additional charge.
University M icrofilm s International
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ET AB
OVE
MEAN
SE
A LE
VEL
| FE
ET
ABOV
E ME
AN
SEA
LEVE
L
NW
r- 680
- 660
I - 640
- 620
- 600
- 580
l - 680
- 660
- 640
- 620
U 600
MODEL A VES 39
920
14*
228
MODEL B
920
34*
VES38
164
29
VES37
200
20*
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
241191
68425
186
600726
239—191-
68
186
725 604
/
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
GEOELECTRIC SECTION E
VES36
369
WWR1484
VES35
VES31
WWR1430
VES24
SB2
VES25
319"85'354' 48
25* 353866
100
140140600 406
itsy722 mg/l •411 mg/l 100
287205
200
2088429!
66 38 5 6
I ' S L
140140610 406
18*
/30*
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
VESVESWWRVESVESVES
m75131920 5840{
750318112
10099I
138 mg/l83132
12!
669•3951 B r
750339112100
6683125132
100
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
SE
VESVESWWR 1432pSI ̂ 4 7 0 -
VES27
■395751
408750318
112
998
138 mg/l 66132 125
669•395 —5132
408750339
112
99883
125132
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
\
MODEL B
2y2V )
2<LU3E2oCD<LU
r - 680
- 660
- 640
- 620
- 600
- 580
- 560
* - 540
920
34*
29
239—191—
186
725 604
20*
201164
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
. \
88
323810C
140140610 406
29*18*
375 200
30*101
205
287
SAND SAND AND GRAVEL SANDY CLAY CLAY 3 5 GRAVELLY CLAY
8 54 RESISTIVITY (ohm-meter) 722 mg/1 CHLORIDE CONCENTRATION SB SOIL BORING
VIS VERTICAL ELECTRICAL SOUNDINGS 3 . STATIC WATER LEVELS * RESISTIVITY VALUES HELD CONSTANT
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
\
665■395 ------
32271£F
750339112100
83
13245
100
SCREENED INTERVAL
WWR WATER WELL RECORD
I I I I I IFEET 85
TANT
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
■395 _51
408750339
998
6683
125
FEET
PLATE 3
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
VNW
83a$
680
- 640
620
- 600
L 580
660
660
- 600
- 560
I- 540
I
MOOEL B
\ / \ /
MOOa AVES3 498"1767^^=^
GEOELECTRIC SEC’
VES2b
-k e h e i26* 46
296165
177
263276 171
164
191
266
108
91
SANO AND GRAVEL BEDROCKp
'M| SANDY CLAY
320 RESISTIVITY (ohm -m atar) 30 m g /l CHLORIDE CONCENTRATION SB SOIL B
VES VERTICAL ELECTRICAL SOUNDINGS H. STATIC WATER LEVELS • RESISTIVITY VAL
|1334190 © 1988 KOEW
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
GEOELECTRIC SECTION A
VES VES WWR
la 12180 --
VESVES OWR
7605VES
112
55*161 243ft*510 TO— Wjj
700206411 73mj/1 390
200 440216 151
263
161 246 128188
117
37305
2B174T266 288
186
132 630
SCREENED INTERVALCLAY
0 115FEET
WATER WELL RECOR)SB SOIL BORING OWR OIL WELL RECORD
PLATE« RESISTIVITY VALUES HELD CONSTANT
388 KOEHLER, JANET A.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
VNW
i
- 960
- 940
U00EL A
VES40 OWR6651
VES46
VES47
S8 WWR VES3 1667 33
GEOELECTRIC SECTION D
VES VNffi15 1451
VES14
•452'
40* 42270
400ISZ. 6S<
335275 495 mg/1
235 122300
286 165
300
2•s
o9
- 520
270
451
321
3 7*
275 25*334
30020 30 258
35
164
200
2I I I SAND H H I SAND AND GRAVEL p»3 j| CRAW- [g » j| SANDY CLAY CUY CRAWLLY d
270 RESSTM7Y (d u n - lM la r) 332 mg/l CHLORIDE CONCENTRATION
VES VERTICAL ELECTRICAL SOUNDINGS SL STATIC WATER LEVELS • RESISTIVITY VALUES HELD CONSTANT
1334190 (c )l988 KOEH
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
ON Dve s cm14 13447
VES13
VES12
WAR1475
VES WVffi11 1463
VES OWR WVW 10 9385 1435
•82—.
33r-475.
400150*3656S0 100
-113 m g/l 115 m g/l22m g/l 391 m g /l
207145
125
650 ■2.373 165*
660
25*
228
136
125
GRAVELLY CLAY = BEDROCK W M SCREENED INTERVAL |-i ih- io
FIET
OWR OIL WELL RECORD WAR WATER WELL RECORD PLATE 20 0 CONSTANT
KOEHLER, JANET A.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
FEET
AB
OVE
MEAN
SE
A LE
VEL
I FE
ET
ABOV
E ME
AN
SEA
LEVE
L
GEOELECTRIC SECTION E
fm SAND AND GRAVEL SANDY CUY
054 FESSnvmr (ohm-m«t«r)
3 . STATIC WATER LEVELS
1334190 ©1988 KOEHLEF
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
TRIC SECTION E
VESVESVES
1432
143075t*
20400
3928* 790
310112
too
140
130 mg/1
132 129
'MO-
408
790112
140
132
30*
100
105
287
r > 3 clay p q g gravelly c lay t s screened interval i-i-i- 1110 89
JONCENTRATICN SB SOIL BORJNO WVfi WATER HELL RECORD
LEVELS • RESISTIVITY VALUES HELD CONSTANT PLATE 3
KOEHLER, JANET A.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.