IRST ANNUAL

OCTOBER 1975,

SIOUX FALLS,

SOUTH DAKOTA

GEOLOGICAL SURVEY 

PROFESSIONAL PAPER 1015
PROCEEDINGS OF THE

FIRST ANNUAL

WILLIAM T. PECORA

MEMORIAL SYMPOSIUM,

OCTOBER 1975,

SIOUX FALLS, SOUTH DAKOTA
WILLIAM T. PECORA
PROCEEDINGS OF THE

FIRST ANNUAL

WILLIAM T. PECORA

MEMORIAL SYMPOSIUM,

OCTOBER 1975,

SIOUX FALLS, SOUTH DAKOTA

P.W. WOLL and W. A. FISCHER, Editors

GEOLOGICAL SURVEY PROFESSIONAL PAPER 1015

Sponsored by

American Mining Congress

in concert with

U.S. Geological Survey

American Association of Petroleum Geologists

American Society of Photogrammetry

The Association of American Geographers

The Geological Society of America

Society of Economic Geologists

UNITED STATES GOVERNMENT PRINTING OFFICE: 1977
UNITED STATES DEPARTMENT OF THE INTERIOR 

Cecil D. Andrus, Secretary 

GEOLOGICAL SURVEY 

V. E. McKelvey, Director

The U.S. Geological Survey agreed to publish the proceeding of the 

first annual William T. Pecora Memorial Symposium in its Professional 

Paper series because the subject material is related to the mission of the 

Survey. The usual standards for this series have been modified to accommodate the variety of styles used by the participants in this symposium. All color 

illustrations are placed at the front of the book for economy in printing. They 

are identified by the names of the authors of the papers from which they 

are extracted.

Library of Congress Cataloging in Publication Data

William T. Pecora Memorial Symposium, 1st, Sioux Falls, S. D., 1975.

Proceedings of the First Annual William T. Pecora Memorial Symposium, October 

1975, Sioux Falls, South Dakota.

(U. S. Geological Survey professional paper; 1015)

Supt. of Docs, no.: I 19.16:1015

1. Prospecting Remote sensing Congresses.

I. Woll, Priscilla W. II. Fischer, William A., 1919- III. American Mining Congress. 

IV. Series: United States. Geological Survey. Professional paper; 1015. 

TN270.A1W54 1975 622M5 76-608272
COLOR ILLUSTRATIONS
VI FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

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FIGURE 11.—Florida Keys (Landsat).

COLVOCORESSES
VIII FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

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COLOR ILLUSTRATIONS IX

Residual Magnetic Anomalies

Interval =25 Gammas

FIGURE 8.—Residual total magnetic intensity map with Landsat interpretation superimposed. The +25 gamma contour is at the 

division between yellow and green; values increase toward the warmer colors and decrease toward the cooler colors in 

25-gamma increments.

BENTZ AND GUTMAN
X FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Bouguer Gravity Anomalies

Interval = 2.5 Milligals

FIGURE 9.—Bouguer anomaly map with Landsat interpretation superimposed. The zero milligal contour is at the division between 

yellow and yellow-ochre; values increase toward the warmer colors and decrease toward the cooler colors in 2.5-milligal 

increments.

BENTZ AND GUTMAN
COLOR ILLUSTRATIONS 

4.3° 44°

XI

Yemen

Arab

Republic

FIGURE 11.—Landsat-1 false-color mosaic of Yemen. Images 1082-07011, October 13, 1972; 

1082-07013, October 13, 1972; 1117-06562, November 17, 1972; and 1117-06565, November 17, 1972.

BENTZ AND GUTMAN
XII FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 6.—Great Kavir, September 20, 1972; false-color composite of ERTS-1 image EDC-010015.

KRINSLEY
COLOR ILLUSTRATIONS XIII

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FIGURE 7.—Great Kavir, May 12, 1973; false-color composite of ERTS-1 image EDC-010019.

KRINSLEY
XIV FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 9.—Machine-aided enhancement, of thermal-infrared 

imagery. (Daedalus Enterprises, Inc.)

EICHEN AND PASCUCCI

FIGURE 10.—Mineral occurrence overlay—synthesized overlay 

of analyses from Landsat aeromagnetic and gravimetric data.

EICHEN AND PASCUCCI

EXPLANATION

Black.—Swaths are known faults or coincidents of ERTS lineaments with aeromagnetic and gravity lineaments. 

Circular areas denote intersections.

Blue.—Swaths are coincidents of ERTS lineaments with aeromagnetic or gravity lineaments.

Circular areas denote intersections.

Major through-going lineament system. 

Light dots.—Areas of known mines.
COLOR ILLUSTRATIONS XV

FIGURE 12.—Composite map showing lineaments interpreted from Landsat (yellow), SLAR (red), and U-2 (black) photography.

EICHEN AND PASCUCCI
XVI FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 6A (above) and B (below).—The upper scene includes the area of the Ewaso N'Ciro depression, the 

southern half of Landsat image 1190-07054. The Yamicha lava plateau lies at the extreme northwest corner. 

The lower scene is the area east of Wajir, including Anomaly A, the southern half of image 1189-07000. 

These color composites were made by combining a blue image of band 4, a green image of band 5, and 

red images of bands 6 and 7 on an additive-color viewer and copying the scenes on Ektachrome film. Location and true orientation shown on figure 8 (p. 150). Scale about 1:1,000,000.

MILLER
Wl15-00

COLOR ILLUSTRATIONS

HI 1^-301 W1^-001

XVII

ull 13-301

IWI 15-30 *li 15 ?e 

020CT72 C N41-5I/U114-29 N N41-49/W|4-23 MSS D SUN EL39

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FIGURE 12.—False-color composite image of a Landsat scene of the region of the Great Basin south of Twin Falls, Idaho. Image

1071-17531, October 2, 1972.

HODGSON
XVIII FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

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FIGURE 13.—Landsat lineament mapped to scale on "The Tectonic Map of the United States." (Modified from USGS and AAPG, 1961.)

HODGSON
COLOR ILLUSTRATIONS XIX

100 KM 

I

FIGURE 6.—Simulated natural color Landsat image of the Nabesna quadrangle. Image made from mosaic of scenes 1692-20150

and 1692-20152 taken June 15, 1974.

ALBERT AND CHAVEZ
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FIGURE 7.—False-color image with sinusoidal stretch of the McCarthy quadrangle. Images made from mosaic of scenes 1350-20223 taken July 8, 1973, and 1709-20090

taken July 2, 1974.

ALBERT AND CHAVEZ
COLOR ILLUSTRATIONS

FIGURE 8.—Color combination of HH (green) and HV (yellow) imagery 

near Freeport, Texas. Marshy areas which produce high HV returns 

appear yellow.

DELLWIG AND MOORE

10 20 30 40 50 MILES

FIGURE 2.—Enhanced false-color composite of part of Landsat image 1125-05545. Location of the Saindak porphyry 

copper deposit is indicated by "S", new prospects located as a result of the digital processing experiment are 

shown at 5-c, 5-d, 6-d, 6-e, and 8-a. The light-toned patches at the crest of the volcano Koh-i-Sultan are 

altered rock resulting from fumarolic action.

SCHMIDT AND BERNSTEIN
XXII

38°N—£

II7°W 

I

FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

II5°W II4°W

L*

37 °N—

35C N

34°N—

II7°W II6°W II5°W II4°W

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II3°W

FIGURE 2.—False-color mosaic of 11 Landsat-1 MSS composites covering the area of study outlined in figure 1. Identification numbers for the frames used in this mosaic are shown in figure 3 (p. 255). See text for discussion of the MSS bands and 

printing filters used in producing the composites.

LIGGETT AND CHILDS
COLOR ILLUSTRATIONS XXIII

FIGURE 7.—Comparison of aerial photography (A), Landsat color image (B), Landsat color ratio image (D), and geological map 

(C), for Yerington, Nevada. The satellite materials are prepared directly from the CCT's. 7A, Ektachrome color print, taken 

from 20 km (RB 57, MX 248, August 11, 1973). 7B, Color infrared image made from CCT, 1397-18051, August 24, 1973, 

13 days later than the aerial photograph; Dicomed print using digital data in an enhanced mode (note increased contrast). 7C, Published geological map (Moore, 1969). 7D; Color ratio image made from the same CCT data as for 7fl, 

Dicomed print, using ratios R74, R64, and R54.

Note the similarity between the color patches on 7D and the geological patterns on the map, 7C, especially the areas 

of Ta (Alta volcanics)—open arrow, and Th (Hartford Hill volcanics)—solid arrow. Also Kg (granodiorite) and the porphyritic 

granodiorite (Kpg).

LYON

Opening remarks, by V. E. McKelvey _________________ 1

International implications of Landsat data from a geological viewpoint, by J. A. Reinemund _____________________ 3

Table 1. Other countries for which Landsat data have been provided by

the EROS Data Center _______________________ 4

2. Other countries having existing or planned facilities using the

Landsat system ________t_____________—_— 7

3. Landsat regional seminars and workshops in which the U.S.

Geological Survey has been involved _______________ 8

NASA plans for future earth resources missions, by William Nordberg 13

Table 1. Earth resources and environmental survey satellites—operating and in preparation ___________ — __________ 14

2. Earth resources and environmental survey satellites—planned

and in prospect ___________________________ 16

Application of remote sensing (Landsat data) to petroleum exploration (abs.), by M. T. Halbouty ________________ 19

xxv
Landsat application to resource exploration and gas planning,

by C. E. Brockmann ________________________-----_-- 21

Figure 1. Geological provinces of Bolivia _______________-----__---_-- 22

2. Geologic and geomorphological map from ERTS images _______ 24

3. Drainage interpretation from ERTS images ___________________ 25

4. Geological interpretations from Skylab image _________________ 26

5. Mineralogical map ____________________-_----_------------- 28

6. Gasline selective routes ___________________-_------_-------- 30

Table 1. Comparison of alternative gasline route ____ — ________________ 31

An overview of Canadian progress in the use of Landsat data in

geology, by A. F. Gregory and L. W. Morley _____________ 33

Table 1. Relative interest in remote sensing by user discipline, August 1975 35

2. Relative interest in remote sensing by economic sector, August 1975 36

3. Net sales of standard Landsat products for 3 years ending

September 15, 1975 _________________________- 36

4. Geological users of Landsat data, 1975 ______________________ 37

5. Net sales of standard Landsat products to recognized geological

users _______________________________________________ 37

Mapping and charting from Landsat, by A. P. Colvocoresses _______ 43

Figure 1. Map of Copper Creek, Australia, and ERTS imagery of the

	creek in flood ____________________--_---------_--—____ 44

2. Map accuracy improved by Landsat imagery _________________ 45

3. Thin cloud penetration capability of ERTS 1R sensor __________ 45

4. Water boundary delineation from ERTS ____________ — _______ 46

5. Space Oblique Mercator projection __________________________ 47

6. Nominal ERTS scenes, Florida _______________---__-__--_--_- 48

7. Seasonal mapping with ERTS _______________________________ VI

8. Lac Manicouagan, Canada ________ — _ — _____--____-_-__-____ 49

9. Comparison of nautical chart and ERTS image ________________ 50

10. ERTS correlation to nautical chart __________________________ 51

11. Florida Keys (Landsat) _________________ — — _------- VII

12. Gas flares in Saudi Arabia (Landsat) _____________ — ________ 52

13. DMSP image ________________________-__________ 53

14. Enlargement of a portion of ERTS image showing mirror response 54

15. The National Capital Region, Ontario-Quebec, Canada ___•_____ 55

16. Phoenix __________________________ — _________-_--___-__-_ 56

17. Arizona _________________________________________________ 57

18. Florida ___________________________________ 58

Relationship of mineral resources to linear features in Mexico as

determined from Landsat data, by G. P. Salas ____________ 61

Figure 1. Composite of Mexico from Landsat-1 imagery showing the

Neovolcanic Axis Metallogenetic Province ________________ 62

2. Structural interpretation of Landsat-1 imagery showing incidence

of faults, fractures, mines, and adits ______________________ 63

3. East Pacific rise and Nevolcanic Axis structure _______________ 64

4. Bouguer anomalies showing coincidence of strong gradient with

Sierra Madre Occidental _________________________ 65

5. Trend of orientation of silver deposits in Mexico showing apparent displacement of subprovinces _____________________ 66

6. Schematic geologic map of the Neovolvanic Axis Metallogenetic

Province of Mexico __________________________________ 67

7. Landsat-1 imagery of the Neovolcanic Axis of Mexico showing 

predominance of NW-SE and NE-SW trending faults and 

shorter fractures ______________________________________ 68

8. Structural map of Pachuca showing E-W and NVV-SE faults and

veins ______________________________________________ 71

9. Taxco mining district, State of Guerrero, showing vein control

by faults and fractures ______________________________ 72

10. El Oro-Tlalpujahua mining district _______________________ 73

XXVI
Landsat contributions to studies of plate tectonics, by Jan Kutina

and W. D. Carter ___________________________ 75

Figure 1. Tectolinear interpretation of a l:5,000,000-scale ERTS-1 mosaic

of the United States __________________________ 77 

2. Tectolinear interpretation of the eastern part of the United

States, set in context with some structural and metallogenic 

features of the Canadian Shield __________________---_----- 78

Landsat data contributions to hydrocarbon exploration in foreign

regions, by F. P. Bentz and S. I. Gutman _________________ 83

Figure 1. Index map of northern Africa showing Santa Fe Minerals, Inc.,

exploration area ___________________________-__---------- 84

2. Geology of Cairo-Suez District, after Said _. ________________ 85

3. Landsat-1 false-color mosaic of Egypt _______________________ VIII

4. Lineament interpretation of Landsat mosaic of Egypt ___________ 86

5. Star diagram illustrating relationships between mapped lineaments 87

6. Wrench fault tectonics as related to lineament interpretation ____ 87

7. Regional tectonics of Northeast Africa ________-__-_______---_ 87

8. Residual total magnetic intensity map with Landsat interpretation

superimposed _________________________-_____---__-_---- IX

9. Bouguer anomaly map with Landsat interpretation superimposed X

10. Index map showing Sante Fe Minerals, Inc., exploration area in

Yemen ____________________________________ 88

11. Landsat-1 false-color mosaic of Yemen _____________________ XI

12. Interpretation of lineaments, circular and tonal anomalies from

Landsat data _____________________________ 89

13. Circular anomalies and well locations _____________________ 90

14. Detail of streaks and tonal anomalies on Yemen coastal plain __ 91

Measurement of luminescence of geochemically stressed trees and 

other materials, by W. R. Hemphill, R. D. Watson, R. C. 

Bigelow, and T. D. Hessen ______________________________ 93

Figure 1. Photograph of laboratory fluorescence spectrometer ____________ 94

2. Photograph of Perkin-Elmer FLD, showing the optical head,

electronic console, and light collector ____________________ 95

3. Photograph of FLD optical head and light collector installed in

a basket mid-ship of a Bell Jet Ranger helicopter ___________ 96

4. Map showing location of Malachite Mine area, Jefferson County,

Colorado ___________________________________ 98

5. Map showing distribution of copper in soil and location of sample

trees growing in background and anomalous soils ___________ 98

6. Graph showing excitation spectra of Pinus ponderosa needles from 

geochemically stressed and background trees, Malachite Mine, 

Jefferson County, Colorado, as measured with a laboratory 

fluorescence spectrometer _______________________________ 99

7. Graphs of temporal luminescence of Pinus ponderosa and meteorological parameters. Maximum luminescence contrast between 

background and anomalous trees tends to occur during periods 

of minimum cloud cover _______________________________ 100

8. Graphs of temporal luminescence of Pinus ponderosa and meteorological parameters. Minimum luminescence contrast between 

background and anomalous trees tends to occur during periods 

of maximum cloud cover ________________________________ 101

9. Graph of temporal luminescence of Pinus ponderosa and meteorological parameters. Luminescence contrast of background and 

anomalous trees do not correlate with cloud cover conditions 

cited in figures 7 and 8 __________________________________ 102

10. Map showing location of geochemically stressed and background

trees in the Alpine Mill area, Douglas County, Nevada ______ 104

XXVII
Measurement of luminescence of geochemically stressed trees and other 

materials—Continued

Figure 11. Linear regressive analysis correlating FLD luminescence counts 

for specific trees with molybdenum concentrations from 20 to 

300 ppm ______________________________________________ 105

12. Geologic map of part of the Sespe Creek area showing location of a helicopter traverse and helicopter hovers _________ 106

13. Statistical plot showing correlation between relative luminescence 

and specific gravity of 29 crude oils at the following Fraunhofer 

lines: A, 396.8 nm; B, 422.7 nm; C, 486.1 nm; D, 518.4 nm; 

E, 589.0 nm; and F, 656.3 nm _____________________ 110

14. Map showing: (1) Dispersal of oil from natural seep off Coal Oil 

Point, Santa Barbara Channel, and (2) FLD luminescence responses from clear water, thin oil film, and heavy crude layer__ HI

Table 1. Luminescence (source-detector, solar, and depth corrected) of

10 bean plants expressed in terms of rhodamine WT equivalency 97

2. Mean and standard deviation of copper and zinc content of needle 

ash from 13 P/nus ponderosa growing in geochemically anomalous and background soils ________________________________ 99

3. Location, molybdenum content in ash, and luminescence, expressed 

in rhodamine WT equivalence, of geochemically stressed and 

background juniper trees in the Alpine Mill area _____________ 103

4. Luminescence of 10 phosphate samples measured with the laboratory fluorescence spectrometer at 486.1 nm in terms of rhodamine WT equivalence (source-detector, solar, and depth corrected) _____________________________________ 105

5. Luminescence of phosphate and gypsum samples, collected from 

the Santa Margarita Formation near Pine Mountain, California, 

and measured with the MPF-3 at 486.1 nm in terms of rhodamine WT equivalence (source-detector, solar, and depth corrected) ____________________________________ 106

6. Reflectance, FLD counts, and luminescence in terms of rhodamine WT equivalency (source-detector, solar, and depth corrected) of phosphate, gypsum, and background reference materials ____________________________________ 107

7. Reflectance, FLD counts, and luminescence in terms of rhodamine WT equivalency of phosphate, gypsum, and background 

materials _________________________________ 107

8. FLD counts and luminescence in terms of rhodamine WT equivalency of associated phosphate and gypsum materials in the 

Lakeland, Florida, area ____________________________ 108

9. Integrated excitation intensity of crude oils at specific Fraunhofer

wavelengths in terms of equivalency with rhodamine WT _____ 109

Use of ERTS-1 (Landsat-1) images for engineering geologic applications in north-central Iran, by D. B. Krinsley _____________ 113

Figure 1. Map showing the relationship of the desert basin sumps (playas)

and associated features to relief in Iran __________________ 114

2. Map showing interior watersheds of Iran: the Great Kavir and

the superposed boundary of the ERTS-1 (Landsat-1) images. _ H5

3. Map showing elements of the Great Kavir ________________ 116

4. Photograph of rough black salt ridges and pinnacles adjacent to

the dry-season road across the Great Kavir ______________ 118

5. Map showing existing Iranian road net and the proposed Great

Kavir road ________________________________________ 119

6. Great Kavir, September 20, 1972; false-color composite of ERTS1 image __________________________________________ XII

7. Great Kavir, May 12, 1973; false-color composite of ERTS-1

image ___ — __________ — _______________________________ XIII

XXVIII
Use of ERTS-1 (Landsat-1) images for engineering geologic applications in 

north-central Iran—Continued

Table 1. Hydrologic conditions along critical segments of the dry-season 

road across the Great Kavir as inferred from ERTS-1 images 

from September 2, 1972, to May 12, 1973 ____________ 120

Applications of remote-sensing technology for powerplant siting, by

Leo Eichen and R. F. Pascucci ________________---------- 123

Figure 1. Landsat satellite _________________________----------------- 124

2. Landsat image of New York City and vicinity ______ —— — ____ 125

3. Thermal infrared image recording of surface heat emissions ____ 126

4. Sketch diagram, typical side-looking airborne radar system _____ 127

5. Side-looking airborne radar image _______________---_---_-___ 128

6. Typical aeromagnetic map, Mineral, Virginia __________________ 129

7. Lineament analysis of Landsat image __________-___--_-_-_____ 130

8. Lineament analysis of SLAR imagery __________________________ 131

9. Machine-aided enhancement of thermal-infrared imagery ________ XIV

10. Mineral occurrence overlay—synthesized structural overlay of analysis from Landsat, aeromagnetics, and gravimetric data ______ XIV

11. Digitally processed land use data from Landsat observation ____ 133

12. Composite map showing lineaments interpretated from Landsat

(yellow), SLAR (red), and U-2 (black) photography ________ XV

13. Multispectral computer processed classification map of an area 

west of Koh-i-Dalil, Pakistan, showing five areas classed as 

"mineralized" ________________________-___--_-_-_-_-_--_- 134

Landsat-1 image studies as applied to petroleum exploration in Kenya,

by J. B. Miller ____________________________ 137

Figure 1. Index map showing regional features and areas of the Chevron

exploration license and option ____________________________ 138

2. Landsat image mosaic, Garissa-Wajir-El Wak area, Kenya, band

7 _____________________________________________________ 141

3. Landsat image mosaic, Garissa-Wajir-El Wak area, Kenya, band

5 _____________________________________________________ 142

4. Lineaments, rock unit boundaries, and other features as interpreted from the Landsat imagery ________________________ 143

5. Rock unit distribution, broadly defined from Landsat imagery

and other sources ______________________________________ 144

6. Landsat false-color composites. The upper scene includes the 

area of the Ewaso N'Giro depression. The lower scene is the 

area east of Wajir, including Anomaly A ___________________ XVI

7. Comparison of Landsat imagery structural features with crudely

represented geophysical data ___________________________ 149

8. Structural pattern derived from geophysical data over the northern part of the initial Chevron license _____________________ 150

Regional linear analysis as a guide to mineral resource exploration

using Landsat data, by R. A. Hodgson ___________________ 155

Figure 1. Chart showing sequence of Landsat data flow from acquisition

to application in minerals exploration ___________________ 156

2. Primary factors considered in use of Landsat data for analysis

and interpretation of regional linear geologic features ______ 157

3. Main features of the Landsat-1 MSS subsystem _______________ 158

4. Diagram showing configuration of the Initial Image Generating

Subsystem ____________________________________ 158

5. Diagram showing the main elements comprising a Landsat image 159

XXIX
Regional linear analysis as a guide to mineral resource exploration using 

Landsat data—Continued

Figure 6. Schematic diagrams showing the composite structural and physiographic aspects of lineaments _______________-___-___----- 159

7. Basic types of geologic structures ___________________------- 160

8. Orders of systematic linear features _________________________ 161

9. Sketch and structure contour map of Florence Pass lineament ___ 161

10. Smaller orders of linear geologic structures __________________ 163

11. Smallest order of linear geologic structure seen on Landsat imagery

by direct observation or by inference ___________-__-__--- 164

12. False-color composite image of a Landsat scene of the region in

the Great Basin south of Twin Falls, Idaho ________________ XVII

13. Landsat lineament mapped to scale on the tectonic map of the

United States _____________________________ __ __ __ __ _ XVIII

14. Sets of major lineaments visible on the 1974 band 7 USDA Landsat mosaic of the United States at scale 1:5,000,000 ______ 165

15. First-order lineaments of the United States taken from the band 

5 Mosaic of the United States as published in the July 1974 issue 

of Geotimes ____________________________________________ 166

16. Spurr's Silver Line and the platinum-nickel line of Thamm ____.. 167

17. Zonal distribution of platinum-nickel deposits along a Great Circle

in eastern Africa ______________________________________ 168

18. Sectional diagram showing various orders of fractures which may 

be genetically related and which may control the location of 

mineral deposits _______________________________________ 169

The application of remote sensing technology to assess the effects of 

and monitor changes in coal mining in eastern Tennessee, 

by A. E. Coker, A. L. Higer, and R. L. Rogers _________ 173

Exploration by petroleum independents using imagery and photos from

EROS and manned space surveys, by R. W. Worthing ______ 175

Tectonic deductions from Alaskan space imagery, by E. H. Lathram

and R. G. H. Raynolds _______________________ 179

Figure 1. Space image lineaments in Alaska _________________________ 182

2. Space image lineament pattern in North American Cordillera.____ 184

3. Lineaments and crustal fractures suggested in selected inductive

analyses ________________________________ — — _ 186

Computer-enhanced Landsat imagery as a tool for mineral exploration

in Alaska, by N. R. D. Albert and P. S. Chavez _________ 193

Figure 1. Map of Alaska showing location of the Nabesna and McCarthy

quadrangles ____________ —— ___ —— _____ —— ___ — _ — ___ 194

2. Map of the Nabesna and McCarthy quadrangles showing generalized geologic terranes ___________________ — ___________ 194

3. Map of the Nabesna and McCarthy quadrangles showing linear

features and mine locations ______________________________ 195

4. Map of the Nabesna quadrangle showing linear and circular features and color anomalies observed on computer-enhanced Landsat imagery ___________________________________________ 196

5. Map of the McCarthy quadrangle showing linear and circular

features _______________________________________________ 197

6. Simulated natural color Landsat image of the Nabesna quadrangle XIX

7. False-color Landsat image with sinusoidal stretch of the McCarthy quadrangle. _______________________________ XX

8. Breakdown of color anomalies seen on computer-enhanced Landsat imagery and their association with mineralized areas and 

geochemical anomalies in the Nebesna quadrangle _________ 198

XXX
Computer-enhanced Landsat imagery as a tool for mineral exploration in 

Alaska—Continued

Figure 9. Map of the McCarthy quadrangle showing known faults and their 

possible extensions as determined by linear and curvilinear features visible in the sinusoidally stretched false-color Landsat 

image of the McCarthy quadrangle _______________________ 199

Table 1. Number of significant mineral occurrences in the various linear

directions in the McCarthy quadrangle, Alaska ______________ 196

Evaluation of improved digital processing techniques of Landsat data 

for sulfide mineral prospecting, by R. G. Schmidt and Ralph 

Bernstein ______________________________ 201

Figure 1. Index map showing the Chagai District and Saindak, Pakistan-___ 202

2. Enhanced false-color composite of part of Landsat image 1125-

05545 _____________________________________ _ ___ _ _ XXI

3. Graphic summary of digital processing and data analysis performed in the experiment _______________________________ 204

4. The Saindak-Mashki Chah area of the western Chagai District, 

Pakistan, showing the control area near Saindak and the area 

where the digital-classification method was applied __________ 208

5. Classification map of an area west of Koh-i-Dalil showing five

areas classed as "mineralized" __________________________ 209

6. Comparison of digital-classification map made by using table 

"B" and geology mapped in field, Saindak porphyry copper deposit, Pakistan __________________________________________ 211

Table 1. Digital classification table "B" used in 1974 mineral evaluation

in the Chagai District, Pakistan __________________________ 206

2. Revised classification table "SSD" prepared in April 1975 ______ 207

3. Revised classification table "S" prepared in September 1975 ____ 207

A deeper look at Landsat-1 images of Umiat, Alaska, by A. F. Maurin

and E. H. Lathram __________________________________ 213

Figure 1. Index map of northern Alaska showing physiographic provinces, 

the area covered by Landsat image 1004-21395, and the area 

of oriented lakes previously studied by Carson and Hussey____ 214

2. Landsat image 1004-21395, band 7, of the Umiat area ______ 215

3. Ozalid print of positive transparency of Landsat image 1004- 

21395, band 7, showing contrast enhancement and location of 

detailed figures _________________________________________ 216

4. Direction diagram computed from the three heavy small circles

of figure 3 _______________________________ 217

5. Steps in erosion and opening process _______________________ 218

6. Another area studied using the erosion and opening process ____ 219

7. Structural interpretation by conventional geomorphologic study using outcropping anticline as a standard and the elliptical "path" 

concept _______________________________ 220

8. Two selected areas of Landsat image 1345-21344, band 7, with 

common orientation showing mushroom ice cakes in black 

lakes _____________________________________ 221

9. Experimental processing of part of the Northern Foothills shown

on Landsat image 1004-21395 ___________________ 221

Why Landsat? A management view, by J. R. Porter, Jr. ____________ 225

Regional and global geological studies using satellite magnetometer

data, by R. D. Regan __________________.._____ 229

XXXI
AIRTRACETM—An airborne geochemical exploration technique, by

A. R. Barringer ___________________________ 231

Figure 1. Nickel and copper in surface dust, Agnew, Western Australia __ 238

2. Two-dimensional model of the convective plume _______________ 239

3. Inflight analog record of particulate count, temperature, and vertical g, Arizona, February 6, 1975 __________________ 240

4. Contributions of global, continental, regional, and local backgrounds to near-surface particulate loadings _______________ 241

5. Effect of mixing activity on particulate loading ______________ 241

6. AIRTRACETM equipment mounted in a 206B Jet Ranger _____ 242

7. A test of linearity of laser analytical system for variations in loadings of USGS soil (XRG-6), silicon versus titanium _________ 244

8. A test of linearity of laser analytical system for variations in

loadings of USGS soil (XRG-6), zinc versus titanium ________ 245

9. Limerick prospect, near Bancroft, Ontario, AIRTRACE Mk III—

copper ————____________ —— __—— __ ———— ———— —— —— 246

10. Flight A AIRTRACETM activity contours Cu+Zn regression ____ 247

11. Flight B AIRTRACETM activity contours Cu+Zn regression ____ 247

12. Cement comparison of AIRTRACETM data and ground truth ______ 248

Table 1. Analyses of soils, plants, and vegetative particulates __________ 234

An application of satellite imagery to mineral exploration, by M. A.

Liggett and J. F. Childs _________ ____________— 253

Figure 1. Location map for the area of study showing generalized positions

of the Black Mountains and Nye County volcanic provinces.— 254

2. False-color mosaic of 11 Landsat-1 MSS composites covering

the area of study ___________________________ — _________ XXII

3. Index map showing Landsat-1 MSS frames used in the false-color

mosaic _________________________________________________ 255

4. Generalized map of the Cenozoic fault systems visible in the

Landsat-1 imagery _____________________________________ 256

5. Generalized map of the Cenozoic volcanic and plutonic rocks in

the study area _______________________________________ 257

6. Diagrammatic model relating right-lateral strike-slip movement 

on the Las Vegas Shear Zone to crustal extension in the two 

volcanic provinces ______^_______________________________ 259

7. Generalized chronology of strike-slip movement on the Las Vegas 

Shear Zone and normal faulting, igneous activity, and related 

mineralization in the Black Mountains and Nye County volcanic 

provinces ______________________________________________ 262

8. Late Cenozoic mineralization in relation to Cenozoic faulting in

the Back Mountains volcanic province ______________________ 264

9. Diagrammatic model illustrating the interrelationship of strikeslip and normal faulting in the Black Mountains volcanic province _________________________________________________ 266

Mineral exploration applications of digitally processed Landsat imagery,

by R. J. P. Lyon __________________________ 271

Figure 1. Channel-by-channel spectral plots for picture elements along

a raster line ___________________________-__------"-__- 272

2. Time series of averaged spectra and radiance and normalized

reflectance ________________________________________—__ 273

3. Yerington pit area, Nevada, aerial photograph _________ — _____ 276

4. Raw lineprinter output for channels 5 and 7, Yerington pit area,

Nevada ____________________________________________ 277

5. Effect of varying the tolerance level in STANSORT/CLUSTER 278

6. Clustering analysis using STANSORT/SEARCH ___________ 278

7. Comparison of aerial photography, Landsat color image, color

ratio image, and geological map of Yerington, Nevada ____— XXIII

XXXII
Mineral exploration applications of digitally processed Landsat imagery— 

Continued

Figure 8. Views of Goldfield, Nevada, site and Pine Nuts Mountains, Nevada, comparing vegetation cover _______________________ 280

9. Relation between regional structure, alteration zones, and Landsat R54 ratio image, Goldfield, Nevada ____________ 281

10. Locality map of Landsat-detected anomaly and the Mo-anomaly

in the vegetation, Mt. Siegel quadrangle. Nevada ____________ 285

11. Enhanced Landsat images of Karasjok, northern Norway ______ 287

12. Landsat analysis of Tifalmin, New Guinea, area ______________ 288

Table 1. Localities and results of case histories ________________________ 275

2. Typical ratio R54 values for Goldfield _________________ 282

3. Ratio comparisons for Goldfield, Nevada _____________________ 282

4. Means and interband ratios for some altered rocks and some unaltered rocks, Goldfield, Nevada __________________ 283

5. Published ratio values for some alteration minerals ___________ 285

6. Correlation between variables in data sets with increasing vegetation content ____________________________________ 289

7. Means and variability in data sets with increasing vegetation content ______________________________ 290

Tradeoff considerations in utilization of SLAR for terrain analysis,

by L. F. Dellwig and R. K. Moore _________________ 293

Figure 1. Two radar images of Phoenix, Arizona ______________________ 295

2. Interpretability vs. equivalent resolution for hard targets, roads,

	and other transportation _________________________________ 297

3. Comparison of square and rectangular cells ___________--__--- 298

4. Mono Craters, California, AN/APQ-97 SLAR imagery _______ 299

5. Bountiful, Utah, AN/APQ-97 SLAR imagery ____________ 300

6. Atchafalaya River basin, Louisiana, AN/APQ-97 SLAR imagery__ 301

7. Freeport, Texas, AN/APQ-97 SLAR imagery ____________ 302

8. Color combination of HH and HV imagery near Freeport, Texas-_ XXI

9. Phoenix, Arizona, AN/APS-94D SLAR imagery ____-____ 303

10. Denver-Colorado Springs corridor, Colorado, SC-01 SAR imagery 304

11. Price comparisons—photos vs. radar, spring 1975 ______________ 305

Worldwide indexing and retrieval of Landsat images, by F. F.

Sabins, Jr. _______________________________ 307

Figure 1. Location of COFRC Landsat index maps _____________________ 308

2. COFRC Landsat index map plotting routine _________________ 309

3. Portion of COFRC printout of Landsat-1 index tape ___________ 311

4. Landsat-1 index map of southern Africa, 0-73 days ___________ 312

5. Landsat-1 index map of southern Africa, 74-144 days _________ 312

6. Landsat-1 index map of southern Africa, 145-248 days ________ 313

7. Retroactive index map for first 248 days plotted from second index tape ___________________________________________ 313

8. Updated Landsat-1 index map, 249-478 days, plotted from second

index tape ____________________________________________ 314

9. Composite of 0% cloud cover index maps to indicate areas

lacking cloud-free images ________________________________ 314

10. Portion of COFRC world zone map for southwest quadrant (zone

3) _____________________________________________________ 315

11. Landsat mosaic of southern part of Sudan ___________________ 316

Intercrossing crustal structure and the problem of manifestation of 

its deep-seated elements on the surface, by V. I. Makarov 

and L. I. Solov'yeva ________________________ 319

Figure 1. Scheme of intercrossing structure of the Turan platform and Tien 

Shan based on the results of interpretation of space images, 

structural analysis of the relief, and geologic data __________ 322

XXXII!
Intercrossing crustal structure and the problem of manifestation of its deepseated elements on the surface—Continued

Figure 2. Scheme showing location of zones of higher seismic activity in

Northern and Central Tien Shan ________________-__---_--- 323

3. Some examples of interference between the elevation zones of

various trends ____________________________-__---__----- 326

4. Scheme of echelon-like structure of elevation zones __________ 326

Combined formalized processing of space image and geologic-geophysical data in connection with the study of deep structure 

of petroliferous platform regions, by P. V. Florensky, A. S. 

Petrenko, and B. P. Shorin-Konstantinov __________________ 339

Figure 1. Southern Russian plain. TV image obtained by the Soviet Earthorbiting satellite "Meteor" _______________________________ 340

2. Lower Volga region. TV image transmitted from the American

satellite ERTS-1 on 16 July 1973 __________________________ 341

3. Example of a composite profile of geologic-geophysical and photometric information ____________________________________ 342

4. Photometric scheme of the image shown in figure 2 __________ 342

5. Geologic map for the Lower Volga region ___________________ 343

6. Scheme of neotectonic movements of the Lower Volga region __ 343

7. Scheme of isolines showing the correlation coefficients for the

gravity and magnetic fields _______________________________ 347

8. Basement surface topography _____________________________ 348

9. Scheme of isolines showing the coefficients of correlation of the

gravity field with the optical density _______________________ 349

10. Scheme of lineaments _____________-_-____-_-____--------- 351

11. Zoning scheme for the crystalline basement of the Lower Volga 

region compiled from a complex of geologic and geophysical 

data and taking into account the results of deciphering and photometry of TV-space images _______________________________ 352

Table 1. Quantitative characteristics of the identified blocks ___________ 344

Geological studies by space means in the U.S.S.R., by V. G. Trifonov, 

V. I. Makarov, V. M. Panin, S. F. Scobelev, P. V. Florensky, 

and B P. Shorin-Konstantinov ________________________ 355

Figure 1. Large-scale space photo of Babadag-Karatau region of the central

part of the Tadjik depression ___________________________ 356

2. Structural-geologic map of the central part of the Tadjik depression compiled using space photos _________________________ 357

3. Scanner image of Eastern Fergana, Landsat-1, June 24, 1973, band

5 _____________________________________________________ 358

4. Geological interpretation of the image figure 3 ______________ 359

5. Scanner image of Eastern Fergana, Landsat-1, June 24, 1973,

band 6 ___________________________________ 360

6. Geological interpretation of the image figure 5 ______________ 361

7. Middle-scale photo of the Issik-Kul region ___________________ 362

8. Geological-geomorphological interpretation of figure 7 __________ 363

9. Large-scale photo of the eastern coast of Caspian Sea, Manghyshlak Peninsula, and Ustjurt _________________________ 364

10. Structural map of Manghyshlak and Ustjurt compiled using photos

from "Sojuz-8" and "Sojuz-12" ___________________ 365

11. Middle-scale space photo of Eastern Caucasus and Lower Kura

lowland ___________________________________________ 366

12. Correlation of lineaments deciphered on "Sojuz-9" photos and

zones of deep seismic deformations of Eastern Caucasus ____ 367

13. Small-scale scanner image of Caucasus, 18 satellite "Meteor,"

August 21, 1974, band 0.6-0.7 mkm _________________ 368

XXXIV
Geological studies by space means in the U.S.S.R.—Continued

Figure 14. Correlation of lineaments deciphered on TV and scanner "Meteor" 

images of Eastern Caucasus and epicenters of earthquakes 1911- 

1966 ___________________________________________________ 369

15. Scanner image of Lower Volga region, Landsat-1, July 16, 1973 369

16. Photometrical map of figure 15 in conditional figures without clouds 370

17. Schematic structural-geologic map of crystalline basement of 

Lower Volga region using geological and geophysical data and 

space photo interpretation ______________________________ 370

XXXV

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Opening Remarks to the First William T. Pecora Memorial Symposium

By Vincent E. McKelvey, 

Director, U.S. Geological Survey

Governor Kneip, Dr. Overton, Ladies, and Gentlemen:

It is a great privilege for me to be able to open 

this First William T. Pecora Memorial Symposium. 

Bill Pecora was a remarkable man—a great scientist, a philosopher in the broadest sense of that term, 

and an inspiring leader. He considered himself to be a 

"field-boot" geologist and so characterized himself, as 

a matter of fact, in those terms in a speech here in 

1970 when the EROS Data Center was still on the 

drawing board.

But while he was, indeed, an outstanding "fieldboot" geologist, by taking the lead in forming the 

EROS Program and pressing hard for its development, he showed himself to be a visionary, both 

in his recognition of the possible applications of space 

technology to the study of the Earth, and of the need 

for it to help satisfy the requirement of a world 

pressing hard in the means of assessment.

Bill saw the rapidly accelerating needs for resources and for the preservation of environmental 

quality as well, and he saw the great potential in 

satellite observations for helping to provide the 

worldwide information needed to achieve both of 

those objectives. Much of Bill Pecora's vision has already been realized. NASA has provided the technology to acquire valuable satellite data, and the people of Sioux Falls, the Congress, and the Federal 

Administration have made it possible for the full 

community of scientists, technologists, and environmentalists to obtain and interpret and use the data 

through the Sioux Falls EROS Data Center. As papers here to be presented will show, new uses and 

applications of satellite imagery are being developed and formatted. Indeed, we have already had a 

glimpse of some of those applications in the description which Governor Kneip gave us of the activities

already in progress here in the State of South Dakota.

Many people and organizations have contributed 

to these achievements, but naturally I am proud of 

the part which the Geological Survey and the Department of the Interior have played in bringing 

about a program that has fostered international relations and improved interorganizational and interdisciplinary exchange and communication and is adding 

to our understanding of the Earth and its resources. 

These contributions flowed from Bill Pecora's imaginative leadership, and it is fitting, indeed, that this 

Symposium be named in his honor.

A word, now, about the William T. Pecora Symposium. This is, of course, the first of what we hope 

will be a long series devoted to the exchange of 

experience and knowledge in the application of remotely sensed data. Because of Bill Pecora's great 

interest in mineral resources and because of the 

exciting progress being made in the applications of 

Landsat data to mineral exploration, it seemed appropiate to focus this First Symposium on mineral 

and mineral fuel exploration—and we are glad that 

the American Mining Congress was able to take the 

lead in sponsoring it.

The next Symposium will be primarily sponsored 

by the American Society of Photogrammetry and 

will be held here in Sioux Falls next August 23-27. 

The theme will be "Mapping with Remote Sensing," 

a topic fundamental to all resource and environmental efforts. We anticipate that subsequent symposia will address other themes, such as wildlife 

preservation, forestry, water resources, and others. 

The Survey has no desire to direct the content of 

these symposia, but we do pledge continued support 

to the interested scientific societies to make this a 

forum for the development and exchange of knowledge in keeping with the vision of a truly great man, 

William T. Pecora.

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

International Implications of Landsat Data From a Geological Viewpoint

By John A. Reinemund, 

U.S. Geological Survey, Reston, Virginia 22092

INTRODUCTION

It is indeed a privilege and an honor for me to 

have a part in this William T. Pecora Memorial Symposium on the applications of remote sensing to mineral and mineral fuel exploration. Although I am certainly no expert on remote sensing, I have been 

continuously involved in the international program of 

the U.S. Geological Survey for about 20 years and 

have been a fascinated observer of the impact remote-sensing technology has had, both in our own 

program and in overall cooperation between the 

nations of the world.

Jt seems especially fitting that we should discuss 

the international implications of Landsat data at a 

symposium honoring Dr. Pecora. Not only was he 

primarily responsible for the Survey's strong effort to 

develop an earth resources satellite system, in cooperation with the National Aeronautics and Space 

Administration (NASA), but he was also vitally interested in the potential applications of that system to 

international resources problems. His interest in the 

international applications was a logical outgrowth of 

his participation in the Survey's international program 

more than 30 years ago, when he assisted in surveys 

for strategic minerals in Latin America (Pecora, 1944; 

Pecora and Fahey, 1949, 1950; Pecora, Klepper, and 

others, 1950; Pecora, Switzer, and others, 1950). His 

enthusiasm for international cooperation, and his 

recognition of the mutual benefits to be gained from 

joint studies of geological phenomena, in cooperation 

with scientists abroad, were to a considerable extent 

responsible for the steady growth in the Survey's program in international geology and the strong emphasis on international applications of Landsat data

which has characterized the Survey's efforts in remote sensing.

SIGNIFICANCE AND SCOPE OF THIS 

DISCUSSION

It is interesting to note that the problems with 

which Dr. Pecora and other Survey geologists (Dorr, 

1944; Johnston, 1947) were primarily involved in 

their Latin American work 30 years ago—the international supply of critically needed mineral raw materials—is once again a subject of intense international concern. This concern has been partly responsible for the worldwide interest in Landsat applications. Geologists in the industrialized countries recognize the need to greatly accelerate the exploration 

and assessment of world resources to help meet their 

nations' future import requirements, and they look to 

Landsat data as an aid in this process. Their interest 

was reflected at the meeting of the European Geological Societies in Reading, England, last month when 

10 percent of the 130 presentations dealt with Landsat applications to mineral investigations on five 

continents.

We here in the United States are also increasingly 

concerned, as discussed recently in a Conference on 

Requirements for Fulfilling a National Materials Policy 

(Promisel, 1974), for in the last 3 years our annual 

imports of energy and mineral raw materials have 

risen from about $4 billion or 11 percent of total 

needs to about $20 billion or 27 percent of total 

needs, and last year we imported more than half our 

requirements of 23 mineral commodities (Secretary 

of the Interior, 1975). But most developing countries 

are even more concerned with the need to increase
FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM 

TABLE 1.—Other countries for which Landsat data have been provided by the EROS Data Center

Afghanistan

Algeria

Argentina

Australia

Austria

Bangladesh

Barbados

Belgium

Bolivia

Brazil

Brunei

Bulgaria

Burma

Canada

Central African

Republic

Chile

China

Colombia

Costa Rica

Cyprus

Czechoslovakia

Dahomey

Denmark

Dominican Republic

Ecuador

El Savador

Ethiopia

Finland

France

Gabon

Gambia

Germany, East

Germany, West

Ghana

Greece

Guatemala

Guinea

Guyana

Honduras

Hungary

Iceland

India

Indonesia

Iran

Ireland

Israel

Italy

Jamaica

japan

Jordan

Kenya

Khmer Republic

Korea

Kuwait

Lebanon

Lesotho

Liberia

Libya

Luxembourg

Madagascar

Malawi

Malaysia

Mali

Mauritania

Mauritius

Mexico

Morocco

Nepal

Netherlands

New Zealand

Nicaragua

Niger

Nigeria

Norway

Pakistan

Panama

Paraguay

Peru

Philippines

Poland

Portgual

Rhodesia

Romania

Saudi Arabia

Senegal

Sierra Leone

Singapore

South Africa

South Vietnam

Spain

Sudan

Surinam

Swaziland

Sweden

Switzerland

Taiwan

Tanzania

Thailand

Trinidad

Tunisia

Turkey

United Arab Republic

United Kingdom

Upper Volta

Uruguay

U.S.S.R.

Venezuela

Yemen

Yugoslavia

ZaVre

Zambia

worldwide resources exploration and assessment, because they not only compete for access to raw materials for their own internal needs but are faced with the 

necessity of increasing raw-material exports to pay for 

imports of food, manufactured goods, and technology. 

And it is in the developing countries, where mineral 

surveys are generally not well advanced, that the use 

of Landsat data can be especially helpful to accelerate mapping, improve existing maps, and identify 

geologic conditions favorable for mineralization.

So it is that at this critical time, when industrial and 

and developing countries alike are faced with the 

urgent need for intensified resources studies, that the 

Landsat system, along with other satellite and aircraft 

systems, offers a new, powerful, and challenging tool, 

the full dimensions of which have not yet been realized. The worldwide interest in this tool is evident 

from the number of articles, meetings, and projects 

that deal with it. In our Geological Survey program 

last year, for example, 58 scientists from 35 countries 

attended the two international courses given here at 

the EROS Data Center, and 127 scientists from 24 

countries participated in seminars or workshops we 

conducted abroad. About 55 governments are currently sponsoring experimental applications of Landsat imagery, and most of these involve cooperation 

with one or more organizations in the United States. 

The EROS Data Center has supplied Landsat materials to 111 countries (see table 1), and already this 

year data for more than 50,000 Landsat frames have

been purchased by private and governmental users 

for areas outside the United States.

In this discussion I do not propose to describe or 

illustrate in detail the specific applications of Landsat 

data that are, or may become, internationally important. Many excellent presentations to follow in this 

symposium will do this far better than I could. However, I would like to comment briefly on some significant applications of Landsat data in other countries, 

on the basis of the rapid growth in the international 

use of Landsat data, on the more significant benefits 

of participation in the Landsat program, and on constraints that could prevent the most effective use of 

this new technology.

SIGNIFICANT INTERNATIONAL 

APPLICATIONS OF LANDSAT DATA

Geologists around the world are focusing most of 

their attention, in one way or another, on three major 

problems: Accelerating and intensifying the exploration and assessment of resources, as mentioned previously; protecting and efficiently utilizing the environment; and minimizing the effects of natural disasters. 

Landsat data have important applications in each of 

these problem areas, and the papers that follow illustrate these applications. Many of the recent applications were reviewed in the Tenth International 

Symposium on Remote Sensing of Environment held 

in Ann Arbor, Michigan (Environmental Research In-
INTERNATIONAL IMPLICATIONS OF LANDSAT DATA

stitute of Michigan, 1975), earlier this month. An initial 

evaluation of economic value of these applications 

was made last year by Lietzke (1974).

With regard to resources exploration and assessment, the principal applications of Landsat data have 

been in accelerating the mapping of unexplored territory and in improving existing maps. The cooperative 

mapping of high-relief mountain provinces such as 

the Himalaya Mountains, the Alps (Bodechtel and 

Lammerer, 1973) and the Andean Cordillera (Carter, 

1975), which will no doubt be illustrated later this 

morning by Dr. Carlos Brockmann, is especially significant because we have not previously been able to 

obtain synoptic and essentially distortion-free images 

of these provinces, which are so important for an 

understanding of mineral genesis. Equally significant 

is the application of Landsat data to study of the 

Precambrian shield areas, as has been described recently by Weecksteen (1974) for West Africa, Correa 

(1975) for Brazil, and Blodget, Brown, and Moik 

(1975) for Arabia. The use of Landsat multispectral 

techniques permits the identification and definition of 

contacts that are not readily located without the use 

of this new tool. And in studies currently underway, 

it has been possible to correlate the geology in the 

shield areas on the opposite sides of the Red Sea 

(Abdul-Gawad and Tubbesing, 1975) and to demonstrate the value of Landsat data characteristics in 

long-distance correlation of geologic units.

Extensive and highly significant revisions of structural maps are underway in many countries using 

Landsat imagery, and these are especially significant 

in prospecting for minerals and hydrocarbons. For 

example, a new map of Thailand is nearing completion as a joint effort by Prayong Angsuwathana of the 

Thai Department of Mineral Resources and S. J. 

Gawarecki of the U.S. Geological Survey, and a new 

map of Pakistan has been prepared by Kazmi 1 in 

which it has been possible to classify faults on age of 

movement.

A closely related and highly significant use of 

Landsat data in East Asia by Maurice Terman of the 

Geological Survey, as a contribution to a 35-nation 

cooperative Circum-Pacific Map Project (International 

Union of Geological Sciences, 1975), is in the evaluation of the relative accuracy of existing geologic maps. 

This demonstrates the value of Landsat data for 

checking geologic map accuracy as well as for improving and augmenting map detail.

1 Kazmi, A. H., 1975, Application of ERTS-1 imagery to recent 

tectonic studies in Pakistan: Unpub. rept. prepared for the 

Geological Survey of Pakistan.

Perhaps no use of Landsat data has created more 

interest recently than the identification of major 

structural lineaments, many of which seem to be related to the distribution of minerals and hydrocarbons 

(Lathram and others, 1973; Saunders and Thomas, 

1973). Several papers to be presented at this Symposium deal with this subject, and important work 

has been done in Australia and in several countries in 

Asia, South America, and North America. Some important known ore bodies, such as Broken Hill in New 

South Wales, seem clearly related to major lineaments, at least some of which reflect through-going 

structures of major dimensions in the continental 

crust. Agah (1975) has reported on lineaments across 

the Zagros Mountains in Iran that seem related both 

to facies changes in the sedimentary sequence and 

to hydrocarbon distribution. This line of research is 

of such widespread interest and importance that an 

international research project on correlation of structural data derived from satellite and other sources 

with distribution of known mineral deposits is now 

being considered under the International Geological 

Correlation Program jointly sponsored by the International Union of Geological Sciences and UNESCO.

An equally challenging use of Landsat data in the 

detection of ore deposits through digital-processing 

techniques is discussed in six presentations to follow, 

here in this Symposium. The work carried out by 

Schmidt in Pakistan is especially indicative of the 

impact and potential of Landsat data, when applied 

to a well-studied terrain, in which the extent and 

significance of the mineralization were much more 

apparent after digital processing of Landsat data. The 

technique of digital analysis to detect alteration in 

rocks and soil, and also changes in vegetation related 

to mineralization, may prove to be one of the most 

important applications for accelerating mineral exploration.

Geologists concerned with environmental studies 

and surficial phenomena are having spectacular success with Landsat data. The work of McKee and 

others (McKee and others, 1973; McKee, 1975), for 

example, in worldwide studies of sand seas, provides 

a basis for classification and evaluation of environmental changes in the principal desert areas that 

could not readily be made without Landsat data. In 

a recent study of Landsat applications in the Sahelian 

zone in Africa, Cooley and Turner (1975) demonstrated the usefulness in identifying and mapping 

laterite duricrust, locating areas favorable for ground 

water, classifying land for agricultural potential^ and 

many other highly significant uses. A series of environmental studies using Landsat data is being
FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

carried out cooperatively by Egyptian and United 

States scientists (Galal, 1975), and similar programs 

are underway or planned in several other African 

countries. Mapping effects of tin mining in shallowwater offshore areas has proved feasible using 

Landsat data along the coast of Malaysia; the United 

Nations is now studying the environmental effects of 

strip mining of tin on land in that country by use of 

Landsat data, comparable to studies of mining areas 

in the United States (Wier and others, 1973; Chase 

and Pettyjohn, 1973; Alexander and others, 1973). 

George Taylor of the Geological Survey, using 

Landsat data in western Brazil, identified an alluvial 

fan of such huge dimensions—half as big as the State 

of Iowa—that it has never before been recognized. 

The work in Iran to be described by D. B. Krinsley 

later in this Symposium, is an outstanding example of 

the application of the data in the interpretation of dry 

lake deposits, monitoring of desert environments, and 

engineering planning in areas typical of vast arid 

regions in the developing countries.

A most promising and significant application of the 

Landsat system is for the monitoring of natural disasters and the development of early warning systems, 

especially of flood and volcanoes. A recent study by 

Robinove (1975) on behalf of the Agency for International Development (AID) has demonstrated the 

excellent possibilities for using Landsat imagery in 

damage assessment for floods, drought, fire, and 

glacier movement, and the possible uses of the Landsat Data Collection System in warning of the danger of 

floods, earthquakes, volcanic eruptions, glacier movements, and water pollution. Monitoring of seismicity 

associated with volcanism (Ward and others, 1973) 

which is now underway in Central America, the 

United States, Alaska, Hawaii, and Iceland, using a 

total of 18 data collection platforms relaying through 

Landsat, may be prototype of a worldwide satellite 

volcanic monitoring system. The applicability to assessment of flood damages has already been demonstrated through studies of flooding in the Mississippi 

Valley and in Pakistan, and it is likely that programs 

of flood warning, monitoring, and damage assessment, 

using the Data Collection System and satellite 

imagery, will eventually be established in the world's 

major river systems, assuming an operational satellite 

system is established. Such a flood warning and assessment system may, in fact, be an adequate justification for an operational earth-resources satellite 

system.

BASIS FOR GROWTH IN INTERNATIONAL 

USE OF LANDSAT DATA

It seems pertinent to examine the basis for the 

remarkable growth in the use of Landsat data around 

the world. As I noted previously, this growth reflects 

the recognized value of the Landsat applications in 

the attack on major problem areas in geology and in 

other earth-science disciplines. But what are the special conditions under which international participation 

in the Landsat program has flourished, and what can 

we learn about the possibilities of future participation 

from a study of these conditions?

In my opinion the widespread use of Landsat data 

is mainly a result of three actions: The decision to 

develop Landsat as an international system with open 

participation in its use; the establishment of facilities 

and procedures here at the EROS Data Center for 

worldwide distribution of the data; and the efforts 

that have been made to transfer knowledge of 

Landsat technology to other countries.

The fundamental basis for the development of 

Landsat as an operational system has, of course, been 

the United States' insistence on unrestricted availability of the data and on international cooperation 

in its use. The United States position was reaffirmed 

by Dr. Kissinger on August 11 in Montreal when he 

stated:

Earth-sensing satellites . . . can dramatically help nations 

to assess their resources and to develop their potential. In 

the Sahel region of Africa we have seen the tremendous 

potential of this technology in dealing with natural disasters. The United States has urged in the United Nations 

that the new knowledge be made freely and widely available. . . . While we believe that knowledge of the earth 

and its environment gained from outer space should be 

broadly shared, we recognize that this must be accompanied 

by efforts to insure that all countries will fully understand 

the significance of this new knowledge.

The United States position was also defined more 

specifically with regard to the Landsat system earlier 

this month at Ann Arbor by Dr. Leonard Jaffe of 

NASA (Jaffe, 1975).

From the geological viewpoint, the NASA program 

of sponsoring cooperative research projects with 

scientists in other countries, to experiment with applications of Landsat data, has been of tremendous 

importance. Many of the presentations to follow contain results of those projects. Thirty-six countries 

participated in 95 cooperative research projects with 

Landsat-1 data, of which 54 projects involved geoscience applications, and 35 countries are participating 

in 39 projects with Landsat-2 data, of which 30 involve the geological sciences.
INTERNATIONAL IMPLICATIONS OF LANDSAT DATA

This NASA-sponsored program has not only demonstrated uses of the data and encouraged the participation of foreign scientists, but it has also given other 

countries a feeling of mutual involvement in the 

development of a new technology—a feeling that they 

are genuine participants and not mere bystanders. 

And it is interesting to note that, in most of the countries participating actively in the Landsat program, 

geological agencies have been very active. In fact, in 

about 40 percent of the 55 or so countries sponsoring 

Landsat applications, geological or mapping agencies 

are the lead agencies in Landsat cooperation.

Most important to continuing and practical use, in 

my opinion, is the availability of the data at modest 

cost through the EROS Data Center here in Sioux

Falls. This has revolutionized the planning of geologic 

programs around the world; for, except in areas of 

persistent cloud cover, it has given national and international agencies, private industry, and research 

institutions alike an assured source of data in a variety 

of formats and a facility to which they could turn with 

their problems. This availability of data, and guidance, 

will be vastly expanded, of course, as regional receiving stations and distributing facilities are established 

to augment those now operating in four countries and 

as national information centers are developed such 

as those already established in 17 Latin American 

countries through the joint efforts of the Inter-American Geodetic Survey (IAGS). the U.S. Geological Survey, and local country agencies (table 2).

TABLE 2.—Other countries having existing or planned facilities using the Landsat system. 

Data receiving and distribution stations

Existing Planned

Canada

Brazil

Italy

Chile

Iran

Zaire

Data information centers

Latin America Other

Argentina

Brazil

Bolivia

Chile

Colombia

Costa Rica

Dominican Republic

Ecuador

El Salvador

Guatemala

Honduras

Nicaragua

Panama

Paraguay

Peru

Venezuela

Uruguay

Thailand

Indonesia

Iran

Italy (Food and Agriculture

Pakistan

Turkey

Organization)

Data collection platforms

Canada _ _

Guatemala

Nicaragua _ _

El Salvador .. _

33 _

2 __

7 _

4

1 _

do.

._ _ do.

1 Agreement formalized after this Symposium was held.

And the use of Landsat data has also been intensively fostered, of course, by the efforts to transfer 

remote-sensing technology to other countries through 

various means. AID has played an important role in 

sponsoring seminars abroad and participant training 

here at the EROS Data Center. The U.S. Geological 

Survey, mainly on behalf of AID, has helped conduct 

six seminars or workshops in Asia and the Far East, 

attended by more than 350 participants from 25 countries, and four seminars in Africa attended by 200 

participants from 16 countries (table 3). In addition, 

the Survey, in cooperation with IAGS, has helped

conduct seven seminars or workshops in Latin America involving several hundred participants from 

virtually all Latin American countries, including, earlier 

this year, an initial workshop in the use of the Landsat 

Data Collection System. The Survey has now conducted five international training courses here at 

Sioux Falls involving about 135 participants from 40 

countries. These activities have been augmented by 

the ten Symposiums on Remote Sensing of the Environment sponsored by the Environmental Research 

Institute of Michigan and by the meetings of Landsat 

investigators sponsored by NASA.
FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

TABLE 3.—Landsat regional seminars and workshops in which the U.S. Geological

Survey has been involved

Asia and Far East

1971__ Seminar/workshop on remote sensing in Southwest Asia, at Ankara, Turkey.

1972____ Seminar/workshop on remote sensing in Southwest Asia, at Tehran, Iran.

1973_ — _ Seminar on remote sensing in East Asia, at Bangkok, Thailand.

1973___ Seminar/workshop on remote sensing in East Asia, at Manila, Philippines

1974____ Seminar/workshop on remote sensing in East Asia, at Bangkok, Thailand.

1975___ Seminar/worksohp on remote sensing in East Asia, Lahore, Pakistan.

Africa

1973____ Seminar/workshop on remote sensing in the Sahelian zone, at Bamako, Mali.

1974___ Seminar/workshop on remote sensing in East Africa, at Nairobi, Kenya.

1975___ Seminar/workshop on remote sensing in West Africa, at Bamako, Mali.

1975_ — _ Seminar on remote sensing in West Africa, at Accra, Ghana.

Latin America (cooperative with Inter-American Geodetic Survey in Panama).

1971_ — _ First training course in remote sensing.

1972_ — _ Second training course in remote sensing.

1972_ — _ Remote sensing course for Latin America.

1973_ — _ Third training course in remote sensing.

1973____ First Pan-American Symposium on Remote Sensing.

1974_ — _ Workshop on multiband image manipulation and resource interpretation.

1975_ — _ Workshop on Data Collection System.

The United Nations has also contributed to the 

transfer of Landsat technology by sponsoring worldwide meetings, such as one held earlier this year in 

Canada, and regional meetings to review the progress 

on the use of the data (Chipman, 1975). It is especially 

gratifying to note the beginnings of technology transfer in Brazil, where the Brazilian Space Agency 

(INPE), in cooperation with the Committee on Space 

Research, conducted a meeting last year on space 

applications of direct interest to developing countries. 

It was attended by 28 scientists from 17 nations.

INSTITUTIONAL BENEFITS OF PARTICIPATION IN THE LANDSAT PROGRAM

I have already mentioned the advantages of using 

Landsat data in accelerating the exploration and assessment of resources, protecting and utilizing the 

environment, and minimizing the effects of natural 

disasters, which are in themselves an adequate justification for encouraging the widespread use of the 

Landsat system. But I believe there are additional 

benefits also for institutions and programs that participate in the use of Landsat data, especially in the 

developing countries. These may be summarized as 

follows:

1. More systematic observation and interpretation of 

resources data: As the Landsat data are systematic and multispectral, their use encourages 

standardization in handling, processing, and interpretation procedures, as well as for more

penetrating study than has commonly been 

applied to aerial photography. Proper use of the 

data imposes a discipline on the geologist that 

will probably (and hopefully) carry over into all 

aspects of his work.

2. Increased knowledge and use of data-processing 

techniques: Because the Landsat data are computerized, their use provides an opportunity to 

demonstrate the techniques and advantages of 

data processing and perhaps to hasten the use 

of data processing in handling other types of 

geologic data.

3. Development of photoreproduction and distribution capacity: In order to provide data for multiple uses and to permit the visual analysis of 

multispectral imagery, photoreproduction and 

distribution capability must ultimately be developed in user countries or in regional data centers. For example, Thailand has now developed 

such capability and is serving the needs of its 

own agencies and of the Mekong countries. This 

capability provides a basis also for issuing multicolor photo maps, such as the gridded image 

map of the Thailand Central Plain issued last 

month by the National Research Council of 

Thailand.

4. Better planning and monitoring of programs: It is 

now routine practice in many countries to utilize 

Landsat images for planning projects and 

plotting the progress of surveys or installations.
INTERNATIONAL IMPLICATIONS OF LANDSAT DATA

5. Promotion of interdisciplinary coordination and 

inter agency contacts: Because Landsat data are 

applicable to nearly all earth-science disciplines, 

most user countries have found it expedient to 

develop interagency coordinating mechanisms. 

In Thailand, for example, a National Committee, 

operating under the National Research Council, 

has been established to coordinate the Landsat 

program involving participants from 24 agencies 

and universities. A similar body functions vigorously in Turkey. This type of mechanism results 

in much closer coordination between agencies 

than existed previously.

6. Promotion of international cooperation: The many 

symposiums, seminars, workshops, and dataexchange mechanisms that are based on Landsat 

applications have provided a vast acceleration 

in earth-science cooperation and a new community of international remote-sensing specialists. 

As regional data centers and receiving stations 

are established, the process of cooperation will 

be advanced further and regularized.

It should not be inferred that these institutional and 

program benefits inevitably follow whenever a country uses Landsat data, but I think it is fair to say that 

developing countries participating extensively in the 

Landsat program have generally realized most or all 

of these peripheral benefits.

POTENTIAL CONSTRAINTS ON FUTURE 

USE OF LANDSAT DATA

In closing my remarks, I call your attention to possible constraints on the widespread and effective use 

of Landsat data in international geology, which we 

must seek to avoid. It would indeed be a tragedy if 

for various reasons we do not fully develop and 

utilize this magnificent technology to help with the 

major worldwide problems of geology and other 

earth sciences, and I feel that we should keep these 

possible constraints in mind.

Within the developing countries, the effective use 

of Landsat data in the future will depend on sustaining the initial interest that has been aroused because 

the technology is new and promising and avoiding 

bureaucratic controls that restrict and stifle the use 

of the data. The experience with the introduction of 

aerial photography in developing countries several 

decades ago shows that once the initial enthusiasm 

was dissipated, the use of photography by local geologists and agencies became very desultory, undisciplined, and nondefinitive. Moreover, in many countries, 

use of photography was restricted by bureaucratic

red tape and lack of interagency cooperation. Unfortunately, these same tendencies are already appearing in some countries and could prevent the full use 

of Landsat data.

Another potential constraint is the failure to complete the transfer of remote-sensing technology to the 

developing countries. Few developing countries are 

using the Landsat data adequately even in simple 

photographic mode; even fewer countries make effective use of the multispectral characteristics of the 

Landsat data, and scarcely any have the capacity for 

digital analysis that we now realize has such high 

potential. Yet already there are signs of weakening in 

the programs for training and transfer of technology, 

and too little emphasis is being given to assistance in 

the fundamental problems of establishing national 

institutions and programs that can take full advantage 

of remote-sensing technology. It is at least as important that international cooperation complete the process of technology transfer as that it fully explore the 

potential scientific applications of the Landsat system.

And finally, and perhaps of greatest concern, is the 

possible failure to continue moving forward toward a 

fully operational earth resources satellite system, 

either because of political and security restrictions on 

the operation of the system or because of failure to 

provide adequate funds for building the system. Having demonstrated the great value of satellite data in 

geology and other earth sciences, it would indeed be 

a tragedy if we could not develop a fully operational 

satellite system, with a full complement of ground 

receiving stations, multipurpose satellites, adequately 

distributed data collection platforms, and data distribution centers. Such a failure would be ironic in view 

of the newly evident need for greatly intensified exploration and assessment of world resources that was, 

I think, a major factor in the original concept of 

Landsat as visualized by Dr. Pecora.

It may be appropriate here to recall the words of 

the Honorable Harlan Cleveland, Director of International Affairs for the Aspen Institute, at a recent 

Conference on the Role of Professional Associations 

in an Interdependent World, in Washington. He said:

We are gathered here because in one way or another we 

want to be leaders in coping with interdependence. If each 

of us merely says what he or she came to say and departs, 

we will miss a great opportunity. To match the macroproblems we face together, we need to build an international 

consortium of the concerned, a community of continouus 

consultation about the human purpose our miraculous techniques and our professional practices .are going to serve. 

... If we miss this chance, here or soon, we who presume 

to leadership will deserve that devastatingly snide comment 

of Ciraudoux: 'The privilege of the great is to watch catastrophe from a terrace'.
10 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

I submit that promoting effective development and 

utilization of the Landsat and other satellite systems 

for use in attacking major problem areas in geology 

may be one way to help avoid watching catastrophe 

from a terrace.

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Presentations, Sec. A., p. 493-500.

Carter, W. D., 1975, Mineral resource investigations 

in South America using Landsat data: Michigan 

Environmental Research Inst, Internat. Symposium on Remote Sensing of Environment, 10th, Ann 

Arbor, October 6-10, 1975, Summaries, p. 146.

Chase, P. E., and Pettyjohn, W., 1973, ERTS-1 investigation of ecological effects of strip mining in 

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Earth Resources Technology Satellite-1, New 

Carrollton, Md., March 5-9, 1973, v. 1, Tech. 

Presentations, Sec. A, p. 561-568.

Chipman, Ralph, 1975, International and regional approaches to remote sensing for development: 

Michigan Environmental Research Inst., Internat. 

Symposium on Remote Sensing of Environment, 

10th, Ann Arbor, Oct. 6-10, 1975, Summaries, 

p. 209.

Cook, J. J., and Istvan, L. B., 1975, A cursory survey 

of the status of remote sensing activity for earth 

resources surveys and environmental monitoring 

in developing countries: Michigan Environmental 

Research Inst., paper commissioned for Nat 

Acad. Sci. Committee on Remote Sensing Development, 10 p.

Cooley, M. E., and Turner, R. M., 1975, Applications 

of ERTS products in range and water management problems, Sahelian Zone, Mali, Upper Volta, 

and Niger: U.S. Geol. Survey Open-File Report 

75-46, 68 p.

Correa, A. C., 1975, A regional mapping program and 

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Summaries, p. 151.

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Arbor, Michigan Environmental Research Inst.— 

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v. 256, no. 5515, July 24, p. 252.

International Union of Geological Sciences, 1975, 

Geological Newsletter: Internat. Union Geol. Sci. 

Quart. Jour., v. 1975, no. 2, June 30, p. 169-171.

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INTERNATIONAL IMPLICATIONS OF LANDSAT DATA 11

Lathram, E. H, Tailleur, I. L., Patton, W. W., Jr., 1973, 

Preliminary geologic applications of ERTS-1 

imagery in Alaska: Goddard Space Flight Center 

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Carrollton, Md., March 5-9, 1973, v. 1, Tech. 

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Lietzke, K. R., 1974, The economic value of remote 

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scale: Mich. Environmental Research Inst, Internat. Symposium on Remote Sensing of Environment, 10th, Ann Arbor, Oct. 6-10, 1975, 

Summaries, p. 134.

McKee, E. D., Breed, C. S., and Harris, L. F., 1973, A 

study of morphology, provenance, and movement 

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5-9, 1973, v. 1, Tech. Presentations, Sec. A, 

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Aeronautics and space report of the President: 

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Barbosa, A. L. M., and Frayha, Resk, 1950, Mica 

deposits in Minas Gerais, Brazil: U.S. Geol. Survey Bull. 964-C, p. 205-305, pis. 14-17, figs. 

6-38.

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and Myers, A. T., 1950, Structure and mineralogy 

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Am. Mineralogist, v. 35, no. 9-10, p. 889-901.

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Aug. 11-16, 1974, Proc, p. 79-84.

Robinove, C. J., 1975, Disaster assessment and warning with Landsats: Michigan Environmental Research Inst., Internat. Symposium on Remote 

Sensing of Environment, 10th, Ann Arbor, Oct. 6- 

10, 1975, Summaries, p. 116.

Saunders, D. F., and Thomas, G. E., 1973, Evaluation 

of commercial utility of ERTS-A imagery in 

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March 5-9, 1973, v. 1, Tech. Presentations, Sec. 

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Africa, using ERTS-1 multispectral images: Natl. 

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Wier, C. W., Wobber, F. J., Russell, O. R., and Amato, 

R. V., 1973, Fracture mapping and strip mine inventory in the Midwest by using ERTS-1 imagery: 

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Md., March 5-9, 1973, v. 1, Tech. Presentations, 

Sec. A, p. 553-560.

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

NASA Plans for Future Earth Resources Missions

By William Nordberg, 

NASA Goddard Space Flight Center, Greenbelt, Maryland 20771

ABSTRACT

Landsats have proven that Earth observations from 

space are capable of providing information which is 

useful in a number of applications that are of vital 

concern to society. These applications include the 

management of food, water, and fiber resources; 

exploration and management of energy and mineral 

resources; and protection of our life-sustaining environment.

However, in order to fully satisfy the needs for such 

applications, it will be necessary to: improve the 

present satellites and sensors, extract useful information from these observations more quickly and reliably, and improve the mechanism by which this information is transferred to end users.

A number of developments are now underway to 

improve sensors and observing systems. They include 

the third Landsat, to be launched in 1977, which will 

make high resolution images of surface temperatures 

to improve crop, other vegetation, and soil classifications. A Heat Capacity Mapping Mission (HCMM) is 

also planned for 1977 to map surface temperatures 

at hours of maximum and minimum heating. It is expected that soil moisture patterns, and soil or rock 

compositions, can be distinguished better with such 

a satellite than with Landsats which do not scan the 

Earth at times that are optimum for this purpose. A 

Thematic Mapper is now under development to make 

Earth surface images with a radiometric accuracy of 

about 0.5 percent in six spectral bands and with a 

spatial resolution of about 30-40 m. This instrument 

could be used for Earth observations by 1980; however, a satellite mission to fly this Thematic Mapper 

has not yet been approved.

Automatic identification and classification methods 

are being developed to extract information such as 

crop and forage acreages, amounts of runoff, and 

types of land use directly from the satellite observations. A number of Applications Systems Verification 

Tests are being conducted particularly in the areas 

of crop and land-use inventory and runoff prediction 

to demonstrate the direct transfer of space-acquired 

information to end users.

When speaking about plans for the future, it is not 

only desirable, but, I believe, also necessary to look 

back at one's accomplishments in order to establish 

the basis on which future developments can be, and 

should be, based. In the area of surveying the Earth's 

resources and environment from space, we can look 

back upon a very solid basis, indeed, which provides 

us with a clear understanding of the objectives and 

needs for future developments.

For more than a decade, weather satellites have 

made global observations of atmospheric and Earth 

surface conditions which could be applied to a better 

understanding of geophysical processes involving 

Earth resources and the environment. Recently, 

Landsats have proven that Earth observations from 

space are capable of providing information that is of 

vital concern to society; namely, for the management 

of food, water, and fiber resources, for the exploration and management of energy and mineral resources, and for the protection of our life-sustaining 

environment.

From this experience, we have learned that in the 

future it will be necessary to concentrate on three 

general activities:

13
14 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

1. To improve our spaceborne observing and measuring techniques, in order to make them more 

specific to the applications which they will be 

designed to achieve.

2. To provide for ground-based facilities and to organize ground operations such that specific 

useful information can be extracted more 

rapidly and more reliably than is now possible 

with the highly experimental Landsats.

3. To improve the mechanism by which the information that results from satellite observations 

filters down to the end-users and is integrated, 

not only in their day to day operations, but also 

in their planning and budget considerations.

This last aspect of our planning depends not only 

on past technical achievements and on the soundness 

of our technological approach to the future, but it also 

depends very strongly on economic and political considerations. I am very much concerned that our most 

diligent and competent technical plans for future 

Earth-observing systems will be fruitless and doomed 

to fail if users are not willing to make the necessary 

investments and commitments to reap the benefits of 

this new technology.

Let us now take a brief look at the present state 

of Earth resources and environmental surveys from 

space. Table 1 summarizes the types and purposes of 

both satellites that are now operating and satellites 

that are being built to firm launch schedules. Thematic 

maps can now be obtained, at least theoretically, 

every 9 days, of anywhere in the world (outside a 

circle of 10 degrees around each pole) with the two 

Landsats that are in orbit. These maps can be obtained from the images acquired by Landsats-1 and -2 

in four spectral bands of reflected solar radiation 

along swaths 185 km wide. But, Landsat-1, which was 

3 years old in July 1975, can transmit data only directly to receiving stations; it cannot store pictures on 

its tape recorders anymore. Therefore, observations 

every 9 days are possible only where such receiving 

stations exist. This is the case for North America, via 

three stations in the U.S. and one in Canada; over 

South America, via a Brazilian station; and over 

Europe and North Africa, via a station in Italy. Direct 

transmissions of observations over Southwest Asia, 

Southeast Europe, and Northeast Africa will soon be 

possible via a station that is being procured by Iran. 

A station to be located in Zaire will cover most of the 

remainder of Africa. Interest in such receiving stations 

has also been expressed by a variety of additional 

countries, so that thematic mapping every 9 days 

using two Landsats is expected to cover increasingly 

large areas of the world. Other areas, which are not 

within range of such receiving stations, must depend 

on the data stored on the tape recorders that still 

function on Landsat-2. Such coverage occurs, of 

course, much less frequently; namely, one to several 

times per year, depending on interest expressed by 

people in these areas.

In addition, observations relating to earth resources 

management and environmental protection are available from the operational weather satellite system 

that is maintained by the National Oceanic and Atmospheric Administration (NOAA). Aside from continuous 

observations of cloud formations and atmospheric 

temperature soundings for the purpose of weather

TABLE 1.—Earth resources and environmental survey satellites, operating and

in preparation

Operating as of October 1975:

Landsat-1, 1972_______________4-band thematic. 

Landsat-2, 1975______________Mapping (80-m resolution). 

NOAA-3, 1973_________________Sea surface temperature.

NOAA-4, 1974__________________Ice and snow (optical, 1-km resolution).

Nimbus-5 and -6, 1972 and 1975____Sea ice (microwave, 30-km resolution).

SATELLITE TRACKING____________Continuous gravity field. 

In preparation:

Landsat-C, 1977__________________4-band thematic mapping (80-m resolution).

Thermal mapping (200-m resolution). 

Panchromatic imaging (40-m resolution).

APPLICATIONS EXPLORER-A, 1977____"Heat capacity" mapping (500-m resolution). 

Nimbus-G, 1978______________Ocean color and temperature (500-m

resolution).

Sea ice and sea state. 

Air pollution. 

Seasat-A, 1978_________________Sea ice and sea state.

TIROS-N, 1978____________________Global atmosphere and sea surface observations.
NASA PLANS FOR FUTURE EARTH RESOURCES MISSIONS 15

forecasting, these satellites also provide global maps 

of surface temperatures and images of snow and ice 

cover in the visible and infrared spectrum with about 

1-km resolution. NOAA-3 and -4 are operating now, 

and, as Goon as one of these satellites fails, it will be 

replaced by a new one, to keep two in operation at 

all times.

Microwave sensors on Nimbus-5 have mapped the 

extent and, to a cetrain degree, the structure of polar 

sea ice and of the Greenland and Antarctic ice sheets, 

since December 1972.

Another significant geophysical result was obtained 

through tracking more than 30 satellites during the 

last 10 years. Analyses of perturbations of the orbits 

of these satellites have made it possible to determine 

the Earth's gravity field on a global scale with a spatial 

resolution that would be economically prohibitive by 

any other means.

Now, I should like to turn to our plans for the immediate future. These involve satellites and missions 

which are being readied for launch during the next 

few years. Our highest priority is to supplement the 

thematic mapping, which has been so eminently successful with the first two Landsats, with images of 

surface temperatures. The multispectral scanner, 

which will be flown on the third Landsat in 1977, will 

include a fifth band to measure and image radiation 

emitted by the Earth's surface in the 10.5- to 11.5-/*m 

wavelength range. It is expected that surface temperature maps with a spatial resolution of about 200 m can 

be obtained from these measurements. Adding this 

temperature mapping capability to the Landsat system 

is expected to improve significantly our capability of 

classifying crops, vegetation, and soils.

Experiments conducted with Skylab and with aircraft flights have shown that for some applications, 

higher spatial resolutions than those of Landsat-1 and 

-2 are desired, especially for urban land-use mapping 

and for the detection of transient phenomena. The 

Return Beam Vidicon (RBV) cameras which have seen 

very little use with Landsats-1 and -2 will be reconfigured for this purpose on Landsat-C. Instead of 

three cameras in three spectral bands, two panchromatic cameras will be used to cover the same 185-kmwide swath that the multispectral scanner (MSS) 

covers, but the cameras will provide twice the spatial 

resolution of the MSS, namely about 40 m.

The potential of deriving soil moisture and surface 

composition information for both agricultural and 

hydogeological purposes, is being further pursued 

with the socalled "Heat Capacity Mapping Mission" 

(HCMM), which is expected to fly on the first applications explorer satellite in 1977. In contrast to the observatory class spacecraft of the Nimbus or Landsat 

type, which carry many or very complex instruments, 

each applications explorer will carry only one relatively simple instrument. The HCMM, for example, 

will only carry a 10.5- to 11.5-/im temperature mapping 

radiometer, with a spatial resolution of about 500 m. 

For reference purposes, a visible radiation channel 

of the same spatial resolution will also be included. 

The advantage of such a mission is that the orbital 

characteristics can be chosen to suit one and only one 

objective. In this particular case, the objective is to 

map surface temperatures at hours of maximum and 

minimum heating; that is, during early afternoon and 

early morning hours.

The surface temperature extremes, measured at 

those times, will provide a better indication of the 

heat capacity of the ground than the Landsat-C temperature maps which must be obtained at mid-morning 

and late evening in order to accommodate the other 

four spectral bands. It is expected that soil moisture 

patterns and soil or rock compositions can be distinguished better with the HCMM mission than with 

Landsat. Coverage with the HCMM will be such that 

each area of the Earth will be observed at least once 

every week during consecutive morning and afternoon 

passes from which heat capacity determinations will 

be attempted. Data can be read out only via direct 

transmission to ground stations and the format of the 

transmissions will be compatible with Landsat data 

acquisition stations.

Probably the last of the big, complex Earth-viewing 

observatories before the advent of Spacelab will be 

Nimbus-7 (called Nimbus-G before launch). Aside 

from making such measurements as the global radiative energy budget, solar ultraviolet radiation, and 

global ozone distributions for the purpose of continuously monitoring these important environmental 

parameters, Nimbus-G will demonstrate the feasibility 

of monitoring air and water pollution from space. 

Inferences concerning water quailty, including nutrient 

content will be attempted from measurements of 

water color with a coastal zone color scanner (CZCS). 

The scanner will map water surfaces in six spectral 

bands ranging from shortwave blue to the nearinfrared with a spatial resolution of about 500 m. In 

contrast to Landsat images, these measurements will 

be conducted in spectral bands which are particularly 

sensitive to the signatures of various water characteristics, such as sedimentation, chlorophyll, various 

types of pollutants, and bottom features. It is expected 

that observations in all major coastal zones of the 

world will be made twice every week with the CZCS 

on Nimbus-G. Test flights of the Nimbus CZCS on a
16 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

U-2 aircraft over the N.Y. bight, have shown clearly 

the dumping of acid wastes by barges and the drift 

patterns of the resulting pollution. Similar aircraft 

tests were conducted with U-2's off the west coast 

of Florida to determine the feasibility of detecting and 

mapping the occurrence of red tides with Nimbus-G.

Both Nimbus-G and Seasat will continue the monitoring of sea ice with microwave sensors. But, in 

contrast to Nimbus-5 and -6, the passive microwave 

sensor on Nimbus-G and on Seasat will provide 

simultaneous images at five different wavelengths 

with spatial resolutions ranging from 25 km at the 

short wavelengths to 200 km at the longest wavelength. In addition to ice mapping, these observations 

will also permit the measurement of sea state and sea 

surface temperature, regardless of cloud cover. Seasat-1 will also carry an imaging radar for the purpose 

of sea state and sea ice observations; however, because of data handling limitations on this satellite, it 

appears very unlikely that substantial amounts of 

radar observations will be made by Seasat over land 

surfaces.

The TIROS-N system to be placed in operation in 

1978, is intended to improve the operational observations now made with the NOAA satellites and will 

include perhaps even such environmental monitoring 

as sea ice, solar radiation, and atmospheric composition.

Now, I should like to turn to the missions which are 

not yet in preparation but which we think will be 

absolutely necessary to provide the information that 

is needed for efficient earth resources management 

and environmental planning (table 2). We believe that 

the key to Landsat follow-on missions will be the 

development of a new thematic mapper. This instrument would perform measurements with greater 

radiometric accuracy than the MSS on Landsat. Six 

spectral bands will be more appropriately placed and 

afford greater spatial resolutions than the MSS. The 

spatial resolution will be 30-40 m in all but the surface 

temperature measuring bands, and a radiometric accuracy of about 0.5 percent is expected to be

achieved. A spectral band in the near-infrared range 

around 1.6 //m would be included. This band is particularly important for agricultural and vegetation surveys. We are planning to initiate the full development 

of this instrument during the next fiscal year. However, a satellite mission to fly this Thematic Mapper 

has not yet been approved.

Another significant part of the planning for Landsat 

follow-on missions must be the redesign and reorganization of the data acquisition, information extraction, 

and data utilization scheme. Landsat-1 and -2 observations had been analyzed for a great variety of 

purposes by many hundreds of individual investigators 

in more than 40 countries. Many governmental organizations, especially in the U.S., Canada, and Brazil, 

have applied these observations as aids to their operations, such as sea and lake ice surveys, preparations 

of environmental impact statements, runoff predictions, flood potential assessments, updating or 

improvement of navigational charts and geological 

and general purpose maps, especially in sparsely 

populated or rapidly changing areas. In addition, 

several tens of thousands of individuals and organizations from all over the world have ordered Landsat 

data for their private purposes from the EROS Data 

Center in Sioux Falls. However, all of this happened 

many months or even years after the observations had 

been taken. The present Landsat data processing and 

information extraction scheme is not suited for efficient operational applications. For follow-on systems 

we cannot use the mail to ship raw data tapes from 

outlying data acquisition stations such as Alaska and 

California to a central processing station. In fact, we 

must decentralize the conversion process from raw 

data tapes to image tapes or hard copies, to the 

greatest extent possible. This will be facilitated by an 

all digital processing system. Worldwide data will be 

transmitted from the satellite to the U.S. via a tracking and data relay satellite and local data should be 

acquired by direct transmission to acquisition stations 

which should be placed to cover all major land masses 

of the Earth.

TABLE 2.—Earth resources and environmental survey satellites, planned and in prospect

Planned:

Landsat-D, 1980_______________.Thematic mapper.

Applications Explorer-C (Magsat), 1980__Magnetic survey. 

Prospected—mid-1980's:

Seasat follow-on ____________________Sea state, icebergs, and ocean currents.

Climate Monitoring______________Land use, radiation budget, and stratosphere.

Shuttle/Spacelab Experiment._______Radar surveys.

Gravsat_____________________Gravity field surveys.

SEOS___________________Geosynchronous environmental surveys.
NASA PLANS FOR FUTURE EARTH RESOURCES MISSIONS 17

In the U.S., data should be distributed via efficient 

communications links to decentralized processing stations which would generate those images, and apply 

those information extraction algorithms, that are 

suited to their patricular applications. Those who 

must acquire and process data in real time for operational purposes must now work with NASA and help 

plan the data acquisition, processing, and information 

extraction schemes for Landsat follow-on systems.

We are also planning another applications explorer 

mission for Earth survey purposes. The third such 

mission, to be launched in 1980, is planned to carry 

sensors to map the magnetic field of the Earth. Measurements with the Orbiting Geophysical Observatory 

(OGO), almost 10 years ago, have proven the feasibility of extracting latitudinal and longitudinal variations of the solid Earth magnetic field from orbital 

magnetometer measurements. Similar measurements 

from a Magsat, which would be designed specifically 

to map the field of the solid Earth, would be much 

more accurate and provide higher resolution than the 

OGO measurements. The results would serve to improve our understanding of the crustal structure of 

the planet, if not provide supplementary information 

for geophysical exploration.

Beyond Landsat follow-on and the Magsat missions, 

all our plans are highly speculative and not even in the 

firm proposal stage. In table 2, they are summarized 

as prospective missions. They include the possible 

survey of ocean conditions, such as sea ice, sea state, 

hazards to navigation, oil spills, and marine resources 

on an operational basis. Undoubtedly, satellites will 

have to be flown to make observations that are necessary to monitor and detect climate trends. Such 

observations include the survey of land use and 

concomitant albedo changes. The Spacelab on the 

"Shuttle" space transportation system will provide an 

inexhaustable facility for testing new observing techniques, particularly Earth survey radars. A set of 

sattelites whose orbital motions will be critically 

monitored, may be used to make an accurate survey 

of the Earth's gravitational field. Finally, the ultimate 

Earth survey test might be a Synchronous Earth Observing Satellite (SEOS) which would provide essentially continuous observations of Landsat quality, over 

almost'an entire hemisphere.

In conclusion, I should like to note that our technical 

base for planning future Earth-observing missions is 

well established. Our objectives for future missions are 

highly focussed and the technical feasibility of the 

missions we are planning, and those that we are 

dreaming about is clearly demonstrated. The hard 

facts of life are, however, that in today's environment, 

neither the best and most competent technical 

planning nor the most dedicated enthusiasm will 

suffice.

What is needed is an unequivocal concensus that 

the new systems which we are planning and which 

we wish to implement are not only feasible, but are 

also beneficial. This consensus must particularly include those who are considered the utlimate beneficiaries, namely, the end-users of this new technology. The broader this consensus is and the stronger 

commitments are made on the part of the users, the 

sooner we can expect that our plans and hopes for 

such new systems will be fulfilled.

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Application of Remote Sensing (Landsat Data) 

to Petroleum Exploration

By Michael T. Halbouty, 

Consulting Geologist and Petroleum Engineer, Houston, Texas 77056

ABSTRACT

The Landsat project is the most significant mission ever flown by NASA. 

The program has afforded the opportunity for the mineral and energy industries in the United States to improve the Nation's domestic resource base 

in a shorter time and at a more reasonable cost than would have been possible without the Landsat data.

Properly interpreted information from these images could save corporations millions of dollars in unnecessary exploration and development efforts 

and at the same time provide possible geologic clues which could lead to the 

discovery of tremendous reserves. The more the Landsat data are used, the 

more innovations for their use will be established.

Landsat data have broad use in the minerals/fuel field, including the 

following general applications:

1. Detection of large-scale geologic structures that were previously unknown and which may be significant with respect to the localization of 

hydrocarbons. Such features are commonly not recognizable on traditional aerial photographs.

2. The possible detection of very subtle tonal anomalies that may represent 

alteration of the soils resulting from mini-seeps of gas from hydrocarbon reservoirs.

3. The potential for detecting natural marine oil seeps with consequent 

improvement in efficiency of offshore exploration.

4. Detection of outcrops of important minerals and metals, especially in 

hostile environments.

5. The monitoring of ice distribution and movement in Arctic areas, such 

as may affect transport of materials in and out of the Arctic, the cost 

of seismic exploration in arctic sea ice areas, and the safety of exploration and production operations.

6. The monitoring of oilfield development and transport facilities, such as 

the Alaskan pipeline and an assessment of this development upon the 

environment.

7. The potential for improved communication and decisionmaking within 

petroleum companies.

19
20 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

The proper use of Landsat imagery affords the explorationist a most 

rapid and inexpensive tool which could add immeasurably to his existing 

geological knowledge.
PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Landsat Application to 

Resource Exploration and Gas Planning

By Dr. Carlos E. Brockmann,

Director, Landsat/Bolivia 

Servicio Geologico de Bolivia, La Paz, Bolivia

ABSTRACT

The Bolivian Landsat Program is a multidisciplinary 

research project aimed at developing the applications 

and use of Landsat, Skylab, and other remote-sensing 

imagery for the inventory and development of the 

natural resources of Bolivia. Under our Petroleum 

Exploration Subprogram, preliminary studies are being undertaken for the general delineation of the 

potential petroleum areas on the Chaco-Beni Plain at 

the margin of the Brazilian Shield. By interpretation 

of the morphology and drainage of the region, we 

were able to define the presence of anticlines that 

will be subject to verification by seismic exploration.

Under the Mining Exploration Subprogram, a direct 

relation was found to exist in the morphostructural 

zones of the Cordillera and the Altiplano (Highlands) 

between the faulting and settling of the igneous 

bodies from which mineralization has originated. 

Tonal anomalies, geomorphology, and structural features have defined potential areas for mineral prospecting.

Interpretations of Landsat imagery, Skylab photos 

and pHotoindexes enabled the selection of several 

alternatives in the design of the route of the proposed 

Santa Cruz-Puerto Suarez gasline. The proposed alternative routes are not as long as the existing railroad length. At the present time standard elevation, 

distance and bearing surveys of the proposed routes 

have not been made.

INTRODUCTION

The Bolivian Government is interested in obtaining 

basic and necessary information on the natural resources of the country, and for this reason Landsat 

and Skylab remote-sensing data are being actively 

evaluated and used.

The Bolivia Landsat Program was created in order 

to make proposed multidisciplinary studies with the 

participation of the Geological Service of Bolivia, 

Yacimientos Petroliferos Fiscales Bolivianos (National 

Oil Company) and Bolivia Mining Corporation 

(COMIBOL), the principal institutions that conduct research in geology, soils, forestry, and land use; studies 

are also being undertaken in agronomy in coordination with the Ministry of Agriculture. Hydrologic work 

is accomplished jointly with the Meteorologic and 

Hydrologic Service, and the Military Geographical 

Institute is in charge of the cartographic research.

Due to the success obtained from the developed 

research activities, the Bolivia Landsat Program is 

now systematically conducting operational work in 

different zones of the country.

GEOLOGIC PROVINCES IN BOLIVIA

There are six geologic provinces in Bolivia from 

east to west as follows (fig. 1):

I. Brazilian Shield.

II. Chaco-Beni Plain.

III. Subandes Belt.

IV. Eastern and Central Cordillera.

V. Altiplano (Highlands).

VI. Western Cordillera.

/. Brazilian Shield

The Brazilian Shield is located in the eastern section of the country; it is considered to be a gently 

sloping erosion surface that has an average altitude

21
22 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

•»

N

FIGURE 1.—Geological provinces of Bolivia. Scale 1:8,000,000. I, Brazilian Shield, II, Chaco-Beni Plain; III, Subandes Belt; IV,

Central and Eastern Cordillera; V, Altiplano; and VI, Western Cordillera.

of 300 m above sea level. It is formed by Precambrian It is known that metallic and nonmetallic ore deand Cambrian granitic and metamorphic rocks with posits exist in this zone but, as yet, they have not been

erosional remnants. extensively explored or developed.
LANDSAT APPLICATION TO RESOURCE EXPLORATION AND GAS PLANNING 23

//. Chaco-Beni Plain

The Chaco-Beni Plain lies between the Brazilian 

Shield and the Subandes Belt on the east and west, 

respectively. It is a major geotectonic unit where thick 

beds of sedimentary rocks have accumulated and lie 

unconformably on the crystalline basement. In general, it has a slight regional slope at the north with a 

slight fold in the western section. The plain is considered to be an important area for the accumulation 

of oil.

///. Subandes Belt

The Subandes Belt is located between the ChacoBeni Plain and the Eastern and Central Cordillera. It 

is formed by a series of parallel ridges which coincide 

with narrow longitudinal anticlines, generally cut by 

thrust faults along which rocks of different ages outcrop along their strike. The depressions or valleys 

correspond to synclines. This area is one of the best 

known petroleum provinces in Bolivia.

/V. Eastern and Centra/ Cordillera

The Eastern and Central Cordillera, also known as 

a Paleozoic block, is characterized by major uplift 

with altitudes that can approach 6,400 m. A main 

characteristic of this province is the noticeable relief 

inversion where the high topography coincides with 

synclinal structures and depressions coincide with 

anticlines.

The central and western sections of this geologic 

province are intruded by granitic rocks and are highly 

mineralized.

V. A/tip/ano

The Altiplano forms a well-defined geologic province which is considered to be a "Rift" block basin 

that formed in conjunction with the "Uplift" type 

movements of adjacent blocks that occurred during 

the Tertiary. Later, denudation of the high parts occurred forming an extensive pediment plain.

There are mineral deposits along the boundaries of 

this geologic province.

V/. Western Cordillera

The Western Cordillera is the result of vertical 

movements associated with intense volcanic activity 

in the late Tertiary; an alined volcanic chain exists 

forming mountains with elevations that are generally 

more than 5,000 m in height.

RESULTS OF THE GEOLOGICCEOMORPHOLOGIC INTERPRETATIONS

IN THE CHACO-BENI PLAIN

PETROLEUM EXPLORATION

Yacimientos Petroliferos Fiscales Bolivianos is in 

charge of the Petroleum Exploration Subprogram, 

which is aimed at delimiting, in an adequate manner, 

petroleum potential areas in the Chaco-Beni Plain and 

Subandes Belt. These areas have proven to be petroleum provinces in the middle and southern part 

of the country. The project also attempts to provide 

new structural information on faults and lineaments 

that can be correlated with existing geologic data of 

the fields in actual production.

With these objectives, an evaluation of the ChacoBeni Plain section was done on the Rogaguado LakeSan Borja images within the coordinates 65°00'- 

67°00' W. longitude and 12°30'-15°30' S. latitude, at 

a scale of 1:1,000,000, covering an approximate area 

of 62,900 km2 . Work was done on Landsat images 

1045-13563 and 1045-13570, bands 5 and 7, corresponding to 0.6-0.7- and 0.8-1.1- /xm wavelengths of 

the electromagnetic spectrum.

Among the most important features that were 

mapped are lakes which were not represented in any 

existing map of the region. Some of the lakes have 

rectangular and square shapes, the edges of which are 

alined on N. 43° E. and N. 21-45° W. strikes (fig. 2).

On the basis of previous observations and by correlating existing geologic data of the zones with studies 

of satellite images, it was possible to deduce that 

there is a great influence of the Brazilian Shield on 

the Quaternary sediments of this zone, which have a 

varied thickness ranging from 441 to 812 m. The 

boundary between the Brazilian Shield and the adjacent Quaternary basin is clearly displayed and 

defined by drainage patterns and subdued topography. 

Some surface patterns could be related to the potential accumulation of oil.

Similarly, the drainage interpretation of the zone 

of Cobija-Puerto Heath was obtained from the 1191- 

14082 and 1191-14084 images, within the coordinates 

67°30'-69°30' W. longitude and 10°00'-13°30' S. latitude, using band 7 only in order to observe and 

delineate adequately the drainage system and areas 

of flooding (fig. 3).

Drainage anomalies, such as the deflection of 

streams, alinement of river valleys, lakes, and topography, made it possible to locate apparent anticlinal 

structures, the axes of which strike west-northwest, 

roughly parallel to the Subandes Belt in this region.
24 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

65° 00

I2°30

I3°00

I3°30'

I4°30'

I5°00'

I5°00'

67°DO'

66e30' eefoo

EXPLANATION

Rivers 

Lakes 

— ——— moments

FIGURE 2.—Geologic and geomorphological map of the San Borja-Mamore River and Rogaguado Lake region of Bolivia

made from ERTS images. Scale 1:1,900,000.

Straight river courses trending northeast-southwest 

and south-southwest appear to strike along lineaments 

which are apparently related to faults. Recently obtained seismic reflection data have confirmed the 

presence of two faults which coincide with the lineaments previously mapped on Landsat-1 imagery.

Similar geologic photointerpretation was conducted 

on Skylab photos on the Santa Cruz area where the 

most important petroleum and gas fields are presently 

being exploited (fig. 4).

The Santa Cruz area is located in the transition 

zone of the piedmont toward the subandean ridges,
LANDSAT APPLICATION TO RESOURCE EXPLORATION AND GAS PLANNING 25

66°30

10°DO'

10*30'

«°00

.-4--

EXPLANATION

Rivers

Drainage deflections

Faults or lineaments

Probable anticlines

Settlements with airfield

.—— International border

,2°30

|3°00

I3°30

69*30 69°00

FIGURE 3.—Drainage^interpretation from ERTS images of the Cobija-Puerto Heath and Rio Madre de

Dios-lxiamas River area. Scale 1:2,400,000.

where subdued topography, uniform lithology, and 

low dips make it difficult to obtain adequate photogeologic information using conventional aerial photographs.

Using photograph, SL-2-A-339, bands 1-5, with its 

large area synoptic view, it was possible to correlate 

major structural features, with diverse geological 

data, and has permitted us to define new potential

petroleum areas. Eleven anomalies were found to be 

correlated with subsurface anticlinal structures as 

corroborated by the wells drilled in the Cedro and 

Moreno anticlines.

In summary, we can conclude with the fact that 

hyperaltitude images for studies of vast areas, let us 

obtain a panoramic view of the area and make it
26 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

EXPLANATION

Capital of province

Highway

Railroad

Rivers

Flooded area 

Gas well 

Dry well

'I 1 \*/

y

Subsurface probable anticline

Wedging out probable; arrow 

indicates direction of wedging

Dips

Lineaments

* x * x x I Crystalline basement 

U JL JU (Brazilian Shield)

FIGURE 4.— Geological interpretations from Skylab image SL-2-A-339 of the Santa Cruz-Montero-Buena Vista

area of Bolivia. Approximate scale 1:800,000.

possible to correlate structural and geologic data imagery interpretation aimed at locating new favorwhich are basic to petroleum exploration. able areas for exploration and exploitation of mining

resources. 

MINING EXPLORATION Because Qf ^ sca, e limitations of Landsat imagery

The Mining Exploration Subprogram is conducted for visual interpretation, the conventional mineral reby the Mining Corporation of Bolivia using Landsat source evaluation methods were modified. Generally,
LANDSAT APPLICATION TO RESOURCE EXPLORATION AND GAS PLANNING 27

mining exploration methods are conducted at large 

scales ranging from 1:1,000 to 1:5,000, and generally 

close to known exploration and mining sites. However, new maps at 1:250,000 scale are being prepared 

for the purpose of establishing regional genetic relations of the mineralized bodies, their host rocks, 

structures and, where present, alteration zones.

Results of the Landsat imagery interpretation are 

important because it was possible to identify lineaments related to faults, tonal anomalies, and geomorphic anomalies which, when correlated to the 

existing information, let us delimit new potential 

mining areas.

To establish a methodology which could let us 

evaluate the mineralized zones from different points 

of view, the geomorphic characteristics, tonal differences, and drainage patterns were studied and considered to be fundamental criteria.

Tonal anomalies are denned as being the delimitation of zones with tonal characteristics that are 

different from the surrounding area and which may 

be related to intense zones of weathering, contact 

aureoles, vegetation concentration, facies variations 

of certain formations, and hydrothermal alteration.

Geomorphic anomalies are shapes that vary from 

the general tendency of the landscape and which are 

generally related to endogenic processes, such as 

magmatism and diapirism.

Tectonic-Structural anomalies are zones affected 

by the intersection of faults and lineaments, generally 

of regional character, and related to the emplacement 

of igneous bodies. They are generally represented by 

straight courses of streams and valleys.

FIELD RESULTS

With the purpose of proving the relationship of 

existing mineralization with anomalies defined by 

Landsat interpretation, fieldwork was performed in 

the area covered by Landsat image 1010-14033, selecting the best denned zones. The field results can 

be summarized as follows (fig. 5):

1. The Structural Anomaly of Patacamaya is located 

15 km to the northeast of the town of the same 

name on the Tapacari lineament at its intersection with the Achuta lineament. There are 

several mineralized subvolcanic bodies along 

the Tapacari lineament.

Field verification tests were negative at the 

lineaments intersection, due possibly to thick 

cover of Quaternary sediments that exist in the 

zone.

2. Structural Anomaly of Huayllamarca is located on 

the ridge of the same name. It corresponds to 

a fault zone where a direct relation between 

the anomalies, longitudinal faults, and diapirous 

rocks were determined. There we found copper 

minerals in the form of sulfates and carbonates.

3. Geomorphic Anomaly of Laurani is located close 

to the town of Sica Sica. It coincides geologically with a subvolcanic body, where dacites and 

andesites are known; this igneous body appears to be related to the Colquencha-Laurani 

and Achiri-Umala lineament intersection which 

strike northwest and southeast, respectively.

Fieldwork showed a direct relation between 

the anomaly and igneous activity with strong 

hydrothermal alteration and mineralization consisting of copper, silver, and lead minerals that 

are actually being exploited.

4. Tonal Anomalies of Sica Sica are located 10 km 

from the town, where fieldwork has determined 

the presence of sedimentary rocks with discordant red tones in contact with Paleozoic 

rocks with gray tones. The objective of this 

reconnaissance was to identify a possible alteration zone as the zone is located along the intersection of two regional faults. No evidence of 

mineralization was found.

5. Geomorphic Anomalies of Antaquira are located 

southwest of the town of Caquiaviri, where the 

direct relation between a longitudinal fault, a 

synclinal structure and subvolcanic intrusive 

rocks was found. Copper mineralization was 

found for the first time in the fault and joints 

that comprise the zone.

CONCLUSIONS

It was proven that mineralization can be found 

associated with longitudinal faults in the structural 

anomalies (Huayllamarca and others) identified on 

Landsat images.

The geomorphic anomalies are important as they 

always coincide with intrusive bodies and/or subvolcanic bodies, which are generally mineralized.

When systematic and sufficient detailed fieldwork 

were accomplished on major lineaments, these areas 

became interesting for mineral and petroleum exploration.

Even though the present example of tonal anomaly 

did not provide the expected positive result, there is 

evidence in other studied zones that tone has a relation with mineralization processes.
28 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

eroo'w

17°30'S

18°00'S

EXPLANATION

———— Lineaments-Faults

— —— Probable lineaments 

t o^y Subvolcanic bodies

C •>

\ / Geomorphic anomalies

FfCURE 5.—Mineralogical map. Approximate scale 1:1,250,000.

PRELIMINARY SELECTION OF THE SANTA 

CRUZ-PUERTO SUAREZ GASLINE ROUTE

OBJECTIVES

The principal objective of the present work was to 

study the applicability of the Landsat imagery for the

location of the most direct route of the Santa CruzPuerto Suarez gasline in relation to the actual existing 

railroad and to design several alternative routes.

Methodology and matena/s used.

In ^order to comply with the proposed objectives 

and due to the scanty cartographic information of the
LANDSAT APPLICATION TO RESOURCE EXPLORATION AND GAS PLANNING 29

area, the Landsat-1 imagery that covers the zone with 

a maximum of 30-percent cloud cover was selected 

and supported by a Skylab space photograph. We 

also used a photoindex of available aerial photographs that cover the study area.

Images 1240-13415, 1240-13421, 1005-13344, 

1005-13350, 1111-13243, bands 5 and 7, photograph 

SL-2-190A-339, bands 2 and 6, and the photoindex 

of the South Robore area, were used due to the lack 

of satellite images of this section at the time the work 

was begun. The study was undertaken at a 1:250,000 

scale, using the Santa Cruz-Corumba railroad as a 

reference to prepare the corresponding map.

As the study area contains peculiar geomorphologic 

features, the first general physiographic map of the 

zone was prepared. In it we attempted to delimit the 

boundary of the Brazilian Shield in relation to the 

Chaco-Beni Plain, the Chiquitos Ridges, and other 

important geomorphologic features that could affect 

the selection of the preliminary route. Lagoons, rivers, 

creeks, hills, sand dunes, and especially the "Izozog 

Banados (swamps)" and the "Otuquis Banados (headwaters)", lowland areas that are subject to temporary 

flooding, were all decisive in the selection of the 

route that the gasline should have.

STUDY AREA DESCRIPTION

Generally, the Brazilian Shield in this zone is expressed as a peneplane where isolated granitic rocks 

and metamorphic rock outcrops exist and are 

separated from the San Jose, Robore, and Quimone 

Ridges by a poorly drained depression filled with 

Quaternary sediments (fig. 6).

The Chaco-Beni Plain corresponds to a poorly 

drained alluvial plain covered by low vegetation in 

the area of the Izozog Banados and Otuquis Banados. 

In these areas there are a great number of small 

braided rivers and scattered temporary lagoons, 

which are characterized by being located in topographic depressions with poor drainage.

The interpretation work was performed with 

images obtained during the period of the lowest stage 

of the rivers. The use of images, taken mainly at the 

end of the rainy season, is considered necessary for 

the accurate mapping of the flooding areas.

PRELIMINARY ALTERNATIVES OF THE ROUTE

Considering the locations of Santa Cruz city and 

the gasfields in exploitation as a starting point for 

the gasline to the town of Puerto Suarez and taking 

as basic parameters the longitude route and physiographic conditions of the area for the construction

and maintenance of the route, the following alternatives were designed:

1. Co/pa Field-Puerto Suarez alternative

Two routes [subalternatives] were considered for 

the portion of this alternative from the Colpa Field 

to Pozo del Tigre station. The alternative continues 

then as a single route to Puerto Suarez.

North Alternative

Approximate distance: 604.4 km.

Average altitude: Colpa Field 345 m above mean sea level.

Striking directly south-southeast from the Colpa 

Field for a distance of 138 km we can arrive at the 

Pozo del Tigre station. Field conditions along this 

route are good and characterized by gentle topography with adequate drainage where soils are generally 

limy-clayey sand. However, it is necessary to indicate 

that in the first stage of it, the Piray and Grande 

Rivers would have to be crossed. Their meandering 

courses must be studied in detail from existing supplementary information.

South Alternative

Approximate distance: 607.1 km.

Average altitude: Pozo del Tigre 272 m above mean sea

level. 

Colpa Field 345 m above mean sea level.

This alternative was designed with a southeast 

strike and an approximate distance of 140.7 km between the Colpa Field and Pozo del Tigre station, 

where the gasline crossing the Grande River would 

parallel the actual railroad bridge.

This subalternative has the advantages of being 

located farther away from the town of Warnes and 

of crossing the Grande River in an area where geologic information obtained for the bridge construction 

is available. Another positive characteristic for this 

section would be the fact that the route would parallel 

the railroad, facilitating by this way tube material 

transportation and would avoid new path construction. However, problems can be foreseen on the route 

right-of-way, as there is intense agricultural activity 

in the area.

Common Point

From Pozo del Tigre station, the route is common 

for both subalternatives and parallels the railroad 

with an east-southeast strike displaced from it an 

approximate distance of 2 km to the south. The purpose for this was to reduce the distance to the surroundings of the Musuruqui station (74.8 km distance, 

358 m altitude) where the north edge of the Izozog 

Banados is flooded and marshy during the rainy season. Total lengths of these proposed sections of gas-
30 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

MUZURUOUI

2

C?

Ridges

Hills

Lakes

Rivers 

Railroad

EXPLANATION

____ Alternative South, Colpa gas field Pto. Suarez 607.1 km. 

____ Alternative North, Sta. Cruz-Pto. Suarez 591.9 km. 

———— Direct Route Santa Cruz-Pto. Suarez 574.1 km. 

_..— Rio Grande Oil Field Pto. Suarez 539.5 km.

FIGURE 6.—Gasline selective routes. Approximate scale 1:3,500,000.

line are 215.8 and 218.8 km for the north and south 

subalternatives, respectively.

As it can be noticed, the proposed designs to the 

Musuruqui station do not present much variation in 

relation to the railroad. It is from this point that we 

propose the route to go south of the San Jose Ridge 

in a direct line to near the town of Robore.

The chosen route in this section is supported by the 

fact that the area is well drained; there are few, if 

any, rock outcrops and the soils are generally sandy 

having formed by the erosion of the San Jose Ridge. 

The route will go through a smooth plateau with a 

uniform altitude in the east section where it is presumed that sufficient soil thickness would be found 

for the excavation of the gasline trench.

Making a comparison of this route with the actual 

railroad in the same section that lies between Musuruqui and Robore, there appear to be several negative 

factors: (1) the construction of the bridge over the 

Quimome River indicated that there is insufficient soil 

thickness for the excavation of the trench, a factor 

that would increase the construction cost; (2) this zone 

is characterized by bad drainage in which temporary 

lagoons appear during the rainy season; and (3) the 

most important factor, if this route paralleling the 

railroad is selected, is related to the distance as it is 

13 km more than the distance proposed south of the 

bridge.

2. Santa Cruz city-Puerto Suarez route

This route was designed to collect the gas from 

the different production fields surrounding Santa 

Cruz city.
LANDSAT APPLICATION TO RESOURCE EXPLORATION AND GAS PLANNING 31

North Alternative

Santa Cruz city-Pozo del Tigre station-Puerto Suarez.

Distance: 591.9 km.

Altitude: Santa Cruz 465 m above mean sea level.

Puerto Suarez 220 m above mean sea level.

There is a distance of 125.5 km from Santa Cruz 

city to the common point of the Pozo del Trgre station where an alluvial plain is the main landscape. It 

consists mainly of limy sand that extends along the 

main route already designed from Puerto Suarez.

As a restriction for the selection of this alternative, 

it must be indicated that a suitable crossing of the 

Grande River must be chosen where its course is only 

slightly meandering. Also, to be considered is the 

construction of the feeder gaslines from the producing areas to the common point in the vicinity of Santa 

Cruz city.

Direct Alternative

Santa Cruz city-Puerto Suarez 

Distance: 574.1 km.

Generally, it must be indicated that this alternative 

would go first through the similar terrain described 

previously but with a significant problem. The Izozog 

Banados is considered to be a potential problem 

area, both for the construction and maintenance of 

the line, especially during the rainy season.

3. Grande River Field-Puerto Suarez alternative

Distance: 539.5 km.

Altitude: Rio Crande Field 338 m above mean sea level. 

Puerto Suarez 220 m above mean sea level.

This possible route was delineated because the Rio 

Grande Field is the biggest deposit of gas reserves in 

the country, and the route would be the most direct to

the town of Puerto Suarez. The design route, however, would cross the Izozog Banados, a total distance 

of 92 km. This potentially difficult terrain constitutes 

the most serious restriction that must be considered.

CONCLUSIONS

The area maps prepared for this study are the most 

up-to-date information available for the study of the 

selection of the route for the gasline. Landsat imagery, 

due to its regional coverage and geometric accuracy 

along with the multispectral factors, has enabled us 

to obtain the information of extensive areas both 

quickly and economically in comparison with the more 

conventional aerial methods.

RECOMMENDATIONS

• To make an aerial reconnaissance at a low altitude, 

combining the existing aerial photographs with 

Landsat imagery.

• To make a new study with Landsat-2 imagery to 

obtain more information with the multitemporal 

coverage in order to delineate more accurately 

the area influenced by temporary flooding.

• To study in detail the course of all the rivers that 

would have to be crossed in order to select the 

most suitable points for the construction of the 

bridges.

• To make an economic study on each one of the 

alternatives detailed before, relating distance to 

construction and maintenance. These factors will 

help the ultimate selection of the route.

TABLE 1.—Comparison of alternative gasline routes

Comparative sheet

Alternatives

Colpa Field-Puerto Suarez: 

North Alternative

South Alternative

Santa Cruz city-Puerto Suarez: 

North [Route] Alternative

Direct [Route] Alternative

Rio Crande [River] Field — Puerto Suarez

Railroad Route: 

Santa Cruz-Puerto Suarez

Distance 

(km)

604.400

607.100

591.900

. _ 574.100

539.500

630

Railroad km 

difference

-25.600 

-22.900

-38.100 

-55.900 

-90.500

Distance 

evaluation

XXX 

X X

XXX 

X X X X 

X X X X X

X

Physiographic 

evaluation

X X X X X 

X X X X X

X X X X 

X 

X

X X

Construction 

and maintenance

X X X X 

X X X X

X X X X 

X 

X

XXX

Total

12 

11

11 

6

7

6

x x x x x Excellent

x x x x Good

xxx Regular

x x Bad

x Very Bad
32 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

SELECTED REFERENCES

Anonymous, 1975, Technical report of the Thematic 

Cartographic Project of the Department of La 

Paz: La Paz, ERTS Program''Bolivia, Servicio 

Geologico de Bolivia, Office rept., July.

Brockmann, Q. Carlos, 1974, Preliminary alternatives 

of the Santa Cruz-Puerto Suarez gasline route: 

La Paz, ERTS Program/Bolivia, Servicio Geologico de Bolivia, Office rept., October.

Claure, H., 1974, ERTS imagery research for mining 

exploration: La Paz, Mining Corporation of 

Bolivia for ERTS Program, Servicio Geologico 

de Bolivia, Office rept., June.

Luizaga, S., 1975, Information on the revised Anomalous Zones detected through the technological 

satellite ERTS-1: La Paz, Servicio Geologico de 

Bolivia, Office rept., March.

Oblitas G., Jaime, Salinas E., Carlos, Davila E., Juan, 

Cabrera V., Arturo, and Hidalgo F., Manuel, 1973,

Summary of the petroleum geology of Bolivia: 

La Paz, Yacimientos Petroliferos Fiscales Bolivianos, 92 p.

Vargas, Carlos, 1973a, Drainage interpretation of the 

ERTS images of the Cobija- Puerto Heath-Madre 

de Dios River-Ixiamas area: Yacimientos Petroliferos Fiscales Bolivianos: La Paz, ERTS Program Bolivia, Servicio Geologico de Bolivia, 

Office rept., September.

————1973b, Results of the geologic-geomorphical 

study of two ERTS images of the San Borja 

Zone-Mamore River-Rogaguado Lake-West of 

Bolivia: La Paz, Yacimientos Petroliferos Fiscales 

Bolivianos, Office rept., August.

————1975, Geologic-physiographical interpretation 

of the Skylab photograph corresponding to the 

Santa Cruz-Montero-Buena Vista area: Yacimientos Petroliferos Fiscales Bolivianos: La Paz, 

ERTS Program Bolivia, Servicio Geologico de 

Bolivia, Office rept., February.
PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

An Overview of Canadian Progress 

in the Use of Landsat Data in Geology

By A. F. Gregory, President 

Gregory Geoscience Ltd., Ottawa, Canada,

and L. W. Morley, Director 

Canada Centre for Remote Sensing, Ottawa, Canada

ABSTRACT

During the past 3 years, Canadian geologists have 

been assessing the geological use of Landsat data in 

the context of a vast but relatively well known hinterland. Although few in number, these geologists 

comprise the largest single class of users of Canadian 

Landsat data. In particular, a few oil and mineral 

exploration companies and consultants appear to use 

as many images as the other 90 percent of the geological users, excluding reference collections.

Most Canadian geological users have a relatively 

long and broad experience with Landsat data. Visual 

interpretation of black and white prints is the principal method of analysis. There has been little research 

into automated processing; however, a major advance 

in digital classification of arctic terrain is imminent.

Practical applications are related primarily to reconnaissance for geological structure and disposition 

of surficial materials. Half of the users claim a modest 

to large benefit from use of Landsat data but cannot 

identify specific dollar benefits.

The level of development of practical geologic 

applications in Canada is greater than predicted in a 

pre-ERTS forecast. Visual interpretation of Landsat 

images will soon become a prime tool, in conjunction 

with others, for geological reconnaissance. The technique will be especially valuable in poorly explored 

arid areas where vegetational cover is sparse. Automated processing will remain in the research stage 

until specific low-cost methodologies are developed.

LANDSAT IN A CANADIAN CONTEXT

Canada, with a territory covering nearly 3.9 million 

square miles, is the largest country in the Western

Hemisphere and the second largest in the world. 

Canadian terrain is extremely diverse, comprising 

almost semitropical areas in southern Ontario and 

southern British Columbia, great mountain arcs, wide 

fertile prairies, a vast lake-strewn interior, and seemingly endless stretches of northern wilderness and 

tundra. Eighty-nine percent of this area is not settled; 

indeed 95 percent of all Canadians live in 10 percent 

of the area comprising an irregular fringe along the 

border with the United States of America.

From a geologist's viewpoint, Canada is composed 

of 17 geological provinces in four main categories: 

continental shelf, platform, orogen, and shield. Geologically, the youngest provinces are the Atlantic, 

Pacific, and Arctic Continental Shelves. They comprise slightly deformed sediments and volcanics, 

mainly of Mesozoic and Cenozoic age. The St. Lawrence, Interior, Arctic, and Hudson Platforms comprise thick, flat-lying Phanerozoic strata over 

crystalline basement. The Appalachian, Cordilleran, 

and Innuitian Orogens are mountain belts of deformed 

and metamorphosed sedimentary and volcanic rocks, 

mainly of Phanerozoic and Proterozoic age, and 

granitic intrusions. The remaining seven geological 

provinces comprise the Canadian Shield which is composed of Precambrian rocks. The Grenville, Churchill, 

Southern, and Bear provinces embrace Proterozoic 

orogenic belts. The Superior, Slave, and Nain 

provinces comprise metasedimentary and metavolcanic rocks of older Archean age, including the oldest 

continental crust known in Canada.

The mineral industry is one of the most important 

sectors of the Canadian economy. The value of mineral production in 1974 was $11.6 billion, of which 

fossil fuels represented 44 percent, metals 42 percent,

33
34 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

nonmetallics 8 percent, and structural materials 6 percent. Much was exported, mainly to the United States, 

Britain, and Japan. Principal mineral products were 

oil, natural gas, nickel, copper, iron ore, zinc, asbestos, cement, and sand and gravel. Of the major 

geological provinces, the Interior Platform yields in 

value about 40 percent of all mineral production, 

mainly fossil fuels, and the Canadian Shield about 35 

percent, mainly metals.

Recorded Canadian history began with the quest 

for these and other riches in the New World. The 

search for economic gain was a particular stimulus, 

and indeed is a continuing theme, throughout Canadian 

history although the nation became a reality just over 

100 years ago. Despite its vast area and relatively 

young age as a nation, Canada has been well explored and mapped at reconnaissance scales. For 

example, an updated coverage of black and white 

aerial photographs is maintained for all of Canada, 

at scales between 1:63,360 and 1:15,000. The whole 

country has been surveyed and mapped with high 

standards at a scale of 1:250,000, thus presenting a 

relatively detailed depiction of relief, river systems, 

transportation facilities, forest cover, and centres of 

population. Bedrock geology has now been mapped 

over 95 percent of the nation at reconnaissance scales 

of 1:250,000 and smaller, although only about 20 percent of the overlying Quaternary sediments have been 

mapped at similar scales.

A vast but relatively well-known hinterland, thus, is 

the context in which Canadian geologists have assessed the geological use of Landsat data. The experiences reported here reflect involvement in the ERTSLandsat program from early planning in the United 

States through direct readout of data at our own 

receiving station to current research and applications 

(Morley, 1971). The information comes from sources 

too numerous to acknowledge here, including industrial, academic, and government members of the 

Working Group on Geoscience of the Canadian Advisory Committee on Remote Sensing, staff and files 

of the Canada Centre for Remote Sensing, and contributions from private companies.

DEVELOPMENT OF CANADIAN

GEOLOGICAL INTEREST IN THE

LANDSAT CONCEPT

HISTORY

Over the past 60 years, but especially since 1945, 

photogeology has made significant contributions to 

the science and practice of geological mapping. In the 

early 1960's, the term "remote sensing" was adopted

when other parts of the electromagnetic spectrum 

were used. Of course, geophysics had been developed 

earlier for other wave bands but, in this paper, such 

techniques are not considered as remote sensing 

(Gregory, 1972). During the past few years, space 

platforms have added new dimensions to the remote 

sensing of geology (Gregory and Moore, 1976).

The late Professor H. L. Cameron was probably 

the first Canadian geologist to demonstrate the possibilities of synoptic, small-scale photography and 

other novel methods of remote sensing. By the early 

1960's, he was using stereoscopic, time-lapse methods 

to study early space photography for the National 

Aeronautics and Space Administration (NASA). In 

1963, he briefly reviewed his work in a paper to the 

First Seminar on Air Photo Interpretation in the Development of Canada (Cameron, 1964). At the same 

seminar, W. A. Fischer of the USGS reviewed his 

pioneer work in geological remote sensing and emphasized the broadening spectral capabilities (Fischer, 

1964).

The enthusiastic but practical presentations of these 

two specialists were responsible for awakening the 

interest of Canadian geoscientists to the potential of 

remote sensing in all its aspects. The combination of 

that seminar with personal experiences in geophysics 

and photogeology lead the authors of this paper to 

initiate remote-sensing projects in 1964 and eventually 

to establish a remote-sensing section within the Geophysics Division of the Geological Survey of Canada.

By early 1967, serious consideration was being 

given to possible Canadian involvement with the resource satellites that were being planned in the United 

States by the Department of the Interior and NASA. 

In 1968, one of us (LWM) initiated planning for Canadian participation in remote sensing while the other 

(AFG) reviewed contemporary planning in the United 

States. It is interesting to note that at that time, geological applications of satellite data were expected to 

be significant, especially for structure and geomorphology, although of lesser importance than applications 

related to land use, forestry, surface water, agriculture, etc. Training, research, and development of 

applications were considered to be prime needs 

(Gregory and Morley, 1969).

Following a national review and recommendations 

presented in 1971, the Canada Centre for Remote 

Sensing was established with Dr. Morley as founding 

director. In 1972, he also became chairman of the 

Canadian Advisory Committee on Remote Sensing 

while Dr. Gregory was appointed chairman of that 

committee's Working Group on Geoscience.
AN OVERVIEW OF CANADIAN PROGRESS 35

CANADIAN EXPECTATIONS FOR REMOTE 

SENSING OF GEOLOGY BY SATELLITES

Timely acquisition and interpretation of data from 

Landsat-1 was recommended by the previous Working Group on Geology (1971, p. 10). However, that 

working group reported the main geological need to 

be for airborne sensing, particularly aerial photography. It was concluded that for use in Canada, satellite 

data "will provide valuable new information about 

the surficial geology of Canada, which is incompletely 

mapped at any scale. However, these data will add 

only supplementary information on gross structure 

and bedrock geology, most of which has been mapped 

at scales smaller than 1:250,000 and much at larger 

scales" (ibid, p. 11). It was further concluded that 

"there are few geologic requirements for continuous 

repetitive surveys" (ibid, p. 11), atlhough their use 

was foreseen for seasonal and temporal analyses, e.g., 

studies of terrain, erosion, and sedimentation.

Because of the limited availability of Landsat data 

during the year following launch of the satellite on 

July 23, 1972, expectations of Canadian geoscientists 

changed little. Most geoscientists continued to view 

Landsat as very experimental. However, a few geologists used standard photogeologic techniques on 

Landsat images and reported potential, low-cost applications for mapping structural geology, particularly 

linears, and for planning exploration projects. Seasonal enhancements of geological features suggested that 

the original expectation of little requirement for repetitive data was incorrect (Working Group on Geoscience, 1972 and 1973).

The advent of Landsat fired unrealistic geological 

expectations, especially among nonqeoscientists, both 

in Canada and abroad (Gregory, 1973, p. 88). However, practicality grew over the following year as 

relevant results of Landsat analyses became available.

USERS OF CANADIAN LANDSAT DATA

BASIS OF ANALYSIS

The following analyses of Canadian users of 

Landsat data are based on three sets of data: (1) The 

current Canada Centre for Remote Sensing 'National 

Air Photo Library (CCRS 'NAPL) computer listing of 

sales of standard Landsat products for the 3 years 

ending September 15, 1975; (2) returns from a questionnaire on the geological use of Landsat data which 

was mailed in early August 1975; and (3) the current 

CCRS computer listing of scientists and engineers

with an interest in remote sensing, as of August 22, 

1975.

NUMBER OF USERS

As of August 1975, 3307 separate persons and organizations had registered an interest in Canadian 

remote sensing by returning a report to the Canada 

Centre for Remote Sensing. While there is, undoubtedly, some overlap in representation between individuals 

and organizations, this number reflects a solid base of 

participation in remote sensing in Canada.

Among the 3307 listings, there was much greater 

interest in remote sensing applied to the geosciences 

(1078) than to any other single scientific discipline or 

practice. A breakdown of user interest (table 1) shows 

that range of interests as well as the overlap in them. 

Contacts (i.e., letters, visits, and telephoned enquiries) 

at the User Services Section of the Canada Centre 

for Remote Sensing confirm a continuing major interest in remote sensing applied to the geosciences 

(30-40 percent of all contacts each month).

Major and more-or-less equal interest was expressed by representatives of companies, federal and 

provincial governments, and educational institutions 

(table 2).

SALES OF CANADIAN LANDSAT DATA

Interest is not a very satisfactory way of defining 

users of Landsat data. Another current indication of 

use, which is hardly more precise, is a cumulative 

list of customers who purchased Landsat data through 

the National Air Photo Library (NAPL). On this list 

of 536 customers, 205 (38 percent) could be identified 

as having a major geological base, i.e., a geological

TABLE 1.—Relative interest in remote sensing by 

user discipline, August 7975

Category Number Percent

Total Interest _________________ 3307 100

Agriculture (including Soils) ____________ 694 20

Atmospheric Sciences ________________ 348 10

Cartography/Photogrammetry ___________ 643 19

Fisheries _____________________ 373 11

Forestry _____________________ 697 21

Geography __________________ 674 20

Geology ____________________ 1078 32

Glaciology/lce Reconnaissance __________ 389 11

Hydrology ___________________ 616 18

Oceanography/Marine Science __________ 414 12

Wildlife/Livestock ______________ 461 13

NOTE: Sums exceed listed totals because of multiple interests 

expressed by a single individual or organization.
36 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

TABLE 2.—Relative interest in remote sensing by 

economic sector, August 7975

Category

Educational Institutions

Federal Government Agencies

Provincial Government Agencies

Foreign Government Agencies

Private Individuals

Municipal Government Agencies

Regional Government Agencies

International Organizations _ .

Total

Number

752

692

664

- _ 539

124

110

29

20

7

2937

Percent

26

24

23

18

4

3

1

1

0

100

TABLE 3.—Net sales ot standard Landsat products for 

3 years ending September 75, 7975

Product Total net Net geological Percent 

sales sales geol.

B & W prints

Colour prints

B & W transparencies ___ 

Colour transparencies ____

Total

60,016

7,209

18,354 

3,185

88,764

32,506

1,925

1,471 

531

36,433

54.2

26.7

8.0 

16.7

41.0

NOTE: These figures represent net sales external to the National 

Air Photo Library and the Canada Centre for Remote 

Sensing. They do not include images of Canadian terrain 

sold by EROS (U.S. Geological Survey) in Sioux Falls, S.Dak. 

or by ISIS (a private company) in Prince Albert, Saskatchewan. It is possible that these latter sales are equal to or 

greater than sales reported here.

survey, an oil or mining company, or a consultant. The 

next largest identifiable groups of users were foresters (45), library and information services (41), and 

geographers (39), each with 7 to 8 percent of the 

number of customers. However, there is a large group 

of individuals and otherwise unidentifiable purchasers 

(155 or 29 percent), which was not amenable to classification.

A semiquantitative estimate of the number of geological users was made from a computer printout of 

net sales (i.e., excluding images generated for internal 

use at the CCRS and NAPL) of standard Landsat 

products* in Canada up to September 15, 1975 

(table 3). This analysis indicates that 41 percent of net 

sales were made to identified geological users. However, there were uncertainties in classifying customers 

as nongeological; hence the statistics are minimal 

although the trends are real.

Standard Landsat products are 9x9 inch prints and transparencies, both colour and black and white.

CLASSES OF GEOLOGICAL USERS

A precise breakdown of purchasers by subdiscipline 

within the geosciences is difficult to achieve. However, the results of a questionnaire prepared in support of this paper permit a semiquantitative analysis. 

Of the 173 questionnaires sent to selected purchasers 

with an identifiable geoscience interest, 70 (41 percent) were returned by December 31, 1975. These 

returns (table 4) show that mineral exploration companies (45 or 64 percent) are the largest users of 

Landsat data among Canadian geological users, 

excluding the major collection in the Geological 

Survey of Canada.

The industrial sector was represented by returns 

from 52 companies and consultants. Of these, 4 companies concerned with oil and gas exploration, 1 

company concerned with mining exploration, and 3 

consulting companies reported that they each analyze 

over 100 Landsat scenes per year. One company in 

each class reported using over 500 scenes per year. 

Indeed, these 8 major users, by their own reports, 

appear to use more images annually than all other 62 

users combined.

The computer listing of sales by NAPL (table 3) 

provides another means of assessing the classes of 

purchasers within the geoscience community. Of the 

36,433 standard products sold to recognized geological users (table 5), about half (18,022) comprise 

black and white prints in a national collection at the 

Geological Survey of Canada. The balance (18,411 

standard products) was sold to the various users noted 

previously. The figures in table 5 confirm the conclusion that in terms of number of users, number of 

images purchased, and number of scenes analyzed, 

the mineral exploration companies are by far the 

largest users of Canadian Landsat data for geological 

applications. Similar companies also appear to be 

major users of Landsat data in the United States 

(Sabins, 1974) and Australia (U.K. Remote Sensing 

Society Newsletter No. 7, p. 14, Nov. 1975).

RANGE OF EXPERIENCE

Of the 70 users returning questionnaires, 31 percent (22) started using satellite data in 1972, immediately after the launch of Landsat-1; 40 percent (28) 

began their use in 1973; 23 percent (16) in 1974; and 

only 6 percent (4) started in 1975. Of these same 

users with experience in Canada, 24 percent (17) have 

experience with Landsat data for other parts of North 

America, and 21 percent (15) have similar experience 

for other parts of the world.
AN OVERVIEW OF CANADIAN PROGRESS 37

TABLE 4. — Geological users of Landsat data, 7975

Annual use (scenes

Class 10 10-50 50-100 100-500

Geological survey and 

research: 

(a) Gov'ts _ _ 1 33

(b) Universities 441

Mineral exploration: 

(a) Oil and gas 3 3 3 3

(b) Ore 7 12 7

(c) Combined 2 1

Consultants and 

contractors 13 2

Not specified _ 11

Total 16 28 16 5

per year)

Un500 known

1 1 

1 1

1

3 2

Total

7 

9

14 

28 

3

7 

2

70

TABLE 5. — Net sales of standard Landsat products to recognized geological users 

[Excluding a national collection at G.S.C.]

Class BWPRT* CPRT* BVVTRA*

Oil and gas exploration 

companies _ 3448 164 414

Mining exploration 

companies 4020 486 229

Consulting and contracting 

companies 2192 154 187

Federal agencies 2463 755 244

Provincial agencies 1373 323 309

Academic institutions 941 37 88

Other 47 6 -

Net Products 14,484 1925 1471

National collection, G.S.C. _

Total products sold to recognized geological users:

CTRA* Total

200 4226 

85 4820

95 2628 

72 3534 

65 2070 

12 1078 

2 55

531 18,411 

_ _ 18,022

_ _ 36,433

Percent 

of total 

net 

products

22.9 

26.2

14.3 

19.2 

11.2 

5.9 

0.3

100

CPRT = colour prints. 

BWTRA= black and white transparencies. 

CTRA = colour transparencies.

LEVEL OF CANADIAN TECHNOLOGY FOR 

GEOLOGICAL INTERPRETATION

Most users (93 percent of the 70 respondents) commonly use visual interpretation based on standard 

photogeologic techniques. The remainder reported 

rare or nil use of such techniques. Enlargements and 

projections are commonly used for interpretation at 

scales as great as 1:250,000. Two major users and 

seven smaller users reported working at scales as

large as 1:50,000. Thirty-six percent (25) of the users 

reported that they had tried seasonal enhancements, 

but only 13 percent (9) noted that they did so commonly. Ten users (14 percent) reported using machine 

assistance, 6 did so commonly. Comparable figures 

for digital processing are 6 and 1. Of the seven users 

reporting common use of machine and digital assistance, only one purchases more than 100 scenes per 

year.
38 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Most users (62 or 88 percent) use black and white 

prints while about half have used colour prints (37), 

enlarged prints (38), or black and white transparencies 

(32). The strong preference by geological users for 

black and white prints extends to all classes of such 

users (table 5). Few users (<1 percent) have worked 

with computer compatible tapes (CCT's) or enlarged 

transparencies, although 70 mm transparencies have 

been more widely used (21 percent). All four MSS 

bands and colour composites are the preferred materials for 40 percent (28) of the users while the remainder prefer band 6 either alone or in conjunction 

with band 5 and/or band 7. Band 4 receives less 

use although it is ordered frequently.

In summary, the analytical technique in common 

use among geologists at this time appears to be visual 

interpretation of black and white prints. Very little 

research seems to be directed to machine and computer assistance for geological applications, although 

there are a few notable exceptions.

CURRENT GEOLOGICAL USES OF LANDSAT

DATA

GENERAL

Interpretation, or the extraction of information 

about the surface of the Earth, is the prime use of 

Landsat data. Such use may be in support of research to increase scientific knowledge or in support 

of practical applications to meet economic and social 

goals (Gregory and Moore, 1976). Practical applications are commonly assumed to have a high probability 

for imminent return on investment. The distinction is 

judgmental and lacks clarity. Other uses, such as 

reference collections, illustrations, educational displays, and works of art have not been assessed, 

although the first, in particular, requires large numbers of images.

During the past 3 years, much of the use of Landsat 

data fell into the category of research as Canadian 

geologists strove to define potential applications, particularly for use in geological mapping. However, only 

13 percent of the respondents to the 1975 questionnaire considered that they were conducting research 

currently. Hence there has been a steady growth in 

the practical application of Landsat data. Accordingly, 

we have attempted to sort and outline the various 

Canadian uses of Landsat data under the two categories of research and practical application.

RESEARCH

Currently available results of research show a 

primary concern with the development of techniques

to identify and map geological structures and the disposition of major classes of rock. Standard photogeologic techniques were extended to the specific 

geometry and data for Landsat, with emphasis on 

texture and pattern. Thus, early visual studies established that many Canadian geological provinces have 

characteristic bulk textures and that geological lineaments and structures may be well expressed in 

Landsat data (Gregory and Moore, 1975 and 1976; 

Palabekliroglu, 1974aand b; Moore and Gregory, 1974; 

and Slaney, 1974). Similar analyses suggested practical applications in hydrogeology (Ozoray, 1974). The 

utility of temporal (or seasonal) analyses was demonstrated by Moore and Gregory (1974). Optical Fourier 

spectra were used by Arsenault and others (1974) to 

select and enhance linear features. In addition, they 

showed that holographic filtering could be used to 

detect simple characteristic shapes.

Spectral discrimination for geological purposes 

does not appear to have received adequate research 

in Canada, at least outside the bounds of commercial 

proprietary knowledge. Spectral discrimination of 

vegetational anomalies and possible applications in 

mineral exploration have been considered (see, for 

example, Working Group on Geoscience, 1974), but 

to date no success or systematic use has been confirmed. However, a most significant development has 

been reported in the spectral discrimination of terrain 

classes in the Canadian Arctic (Boydell, 1974, and 

subsequent personal communication). This evaluation 

shows that multispectral analysis of Landsat data, 

using CCT's and the Bendix MAD unit, could comprise 

a potentially more rapid and relatively accurate alternative to the conventional methods of preparing 

preliminary terrain maps by airphoto analysis. At the 

present stage of development, the validity of terrain 

classes is dependent upon detailed knowledge of the 

terrain and is not absolute, thus hindering general 

extrapolation and regional mapping. This research, 

however, is being continued by the Terrain Sciences 

Division of the Geological Survey of Canada.

A strong interest in ice reconnaissance was indicated by major users of Landsat data in the oil and 

gas industry. Attendant research has focussed on 

breakup and freezeup patterns in the Beaufort Sea 

and on the measurement of floe size and rates of 

movement during those periods.

PRACTICAL APPLICATIONS

No practical applications of Canadian Landsat data 

are currently documented in the literature. This reflects, in part, the newness of such applications in that 

case histories are still subject to field investigation
AN OVERVIEW OF CANADIAN PROGRESS 39

and, in part, the common commercial requirement for 

protection of proprietary rights with respect to methodology and results. The questionnaire previously 

mentioned, however, shows that Landsat images are 

being widely, intensively, and systematically used by 

mineral exploration companies and consultants. The 

practical objectives of such applications are relatively 

simple, as revealed by respondents to that questionnaire. A regional overview of geology is the prime 

requisite of 86 percent of the users, 67 percent are 

particularly interested in analyzing linears, and 41 

percent in the selection of targets for more detailed 

investigation (c.f., Sabins, 1974; Collins and others, 

1975, for U.S.). Secondary objectives included spectral 

discrimination of rock types and alterations (27 percent), which surely was mainly experimental, and the 

use of images as base maps for planning and managing exploration projects (26 percent). About 13 percent of the respondents reported using Landsat images 

for each of the following: recording environment in 

the vicinity of producing sites, regional overview of 

logistical factors, and classification of materials. The 

principal information derived from the Landsat data 

comprises: geological structures (66 percent), disposition and classification of rock units (46 percent), and 

surficial geology (34 percent). Other types of information, each reported by less than 10 percent of the 

respondents, include information related to soil type, 

erosion and sedimentation, terrain classes, surface 

water, land use, construction aggregate, ground water, 

natural disasters, and waste disposal. Other interesting uses, each reported by one respondent, were: 

spectral discrimination of zones of subsidence and 

correlation with aeromagnetic data.

While published case histories are lacking at present, there are several Canadian projects to which 

Landsat data are known to have made major or prime 

contributions. For example, they have been used to 

assess the structural framework of metallogenic 

provinces (linear analyses), to define structural and 

lithologic targets for diamond exploration in Africa 

and Canada (linear and spectral analyses), to plan 

alternate routes for a pipeline (mapping of welldrained ridges formed by glacial fluting), to classify 

mine wastes at a scale of 1:50,000 (spectral analyses), 

and for geological mapping to locate rock types, folds, 

and faults of importance in oil and gas exploration. In 

addition, as noted previously, there are active projects 

for mapping ice conditions related to oil and gas exploration in the Beaufort Sea and for forecasting 

snow and ice cover to assist in planning mineral exploration in northern Canada.

BENEFITS FROM USE OF LANDSAT DATA

Respondents to the questionnaire reported that the 

major benefits which they recognized from their use 

of Landsat data were:

1. Acquisition of geological information that is not 

readily available otherwise (64 percent);

2. Acquisition of supporting information to be integrated with other data (53 percent); and

3. Saving in time in assessing the regional geology 

(48 percent).

About 20 percent of the respondents reported that 

their use of Landsat data had resulted in a lower cost 

for assessing regional geology, had assisted in reduction of area for detailed study, and had assisted in 

mineral prospecting. Unfortunately, from a scientific 

viewpoint, a successful application of Landsat data 

in mineral exploration is least likely to be disclosed 

publicly. About 14 percent of the respondents reported 

receiving additional nongeologic information that was 

not readily available otherwise.

Ninety-three percent of the respondents reported 

that their use of Landsat data had contributed to their 

geoscience programs; 43 percent (30) considered the 

contribution to have been modest; 8 percent (5) considered it large, while 43 percent (30) considered it 

minimal; and 7 percent did not answer. Specific cost 

savings could not be identified by 41 percent (29), 

while 13 percent (9) consider there was no measureable saving, and 46 percent (32) did not answer the 

question.

These responses about benefits confirm the view 

that Landsat data, in conjunction with other types of 

data, are employed extensively in the regional 

reconnaissance which precedes more expensive, detailed methods of exploration. As is well known, many 

different geological, geophysical, and geochemical 

techniques are employed in compiling the information 

that eventually leads to a mineral discovery. Thus, it 

is simplistic and unrealistic to credit a discovery to a 

single methodology. It is equally unrealistic to expect 

an identifiable cost benefit to be assigned to a specific 

use of Landsat data. However, it is significant that 50 

percent of the respondents, including 6 of the 8 major 

users, claim a modest to large benefit .from their use 

of Landsat data.

FORECAST OF TRENDS

The utilization of Landsat data will continue to follow the typical use curve that describes the temporal 

development of new technology. With respect to visual 

photogeologic interpretation, the use of Landsat data 

has rapidly risen to "Panacea Peak," fallen into
40 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

"Sanity Slump," and is now beginning to climb 

"Reality Rise" toward the "Plateau of Practicality." 

However, the geological goals of practical spectral 

discrimination and automated processing have yet to 

be defined, and regular low-cost production has not 

been achieved.

Further research in these latter fields will be 

hindered by the fundamental limitations of surficial 

obscuration (lichens, vegetation, and overburden) and 

the lack of the third dimension, depth. Such limitations 

suggest that major support for this research must be 

obtained from organizations concerned with surficial 

mapping (e.g., governments and universities) rather 

than from mineral exploration companies which have 

equal or greater concerns with depth. Nevertheless, 

there are compositional contrasts of geoscience interest (e.g., gossans, alteration zones, and vegetational 

anomalies) that can serve to focus further research 

by means of spectral and automated analyses. The 

subsequent development of practical applications will 

be guided by the fact that these techniques, like all 

other methods of exploration, will not be specific but, 

rather, will undoubtedly present a multiplicity of 

anomalies for field checking.

Visual interpretation of Landsat images will continue to receive increasing acceptance as a tool, in 

conjunction with others, for developing concepts to 

guide mineral exploration and geological mapping, 

both in Canada and abroad. Landsat images will soon 

become a prime tool for regional geological reconnaissance, especially for poorly explored, arid and 

semiarid areas. This will probably become true even 

if Landsat were to fail in the near future. However, 

much additional experience must be accumulated before geologists can confidently associate mineral deposits with features on Landsat images. In particular, 

the ubiquitous linears will require classification and 

analysis before their geological significance can be 

fully understood. In this growth of practical applications, transparencies will be substituted for prints in 

laboratory analyses because of the inherently greater 

resolution; however, prints will be preferred for annotation and field studies. Improved instrumentation will 

be developed to assist such analyses.

Spectral discrimination and automated processing 

will evolve very slowly until substantial funding and 

dedicated programs are developed in support of geological applications. A major and practical advance in 

terrain classification by automated methods appears 

imminent. However, because of complex interrelationships between bedrock, soil, water, and vegetation, automated pattern recognition will remain 

unattainable for all but the simplest geological goals

(Gregory, 1973, p. 89; Sabins, 1974) and even there 

may be too expensive for practical application. While 

Landsat data have the advantage of uniform raked 

illumination, minimum geometric distortion, synoptic 

view, and worldwide coverage, it is primarily the 

related low cost of purchase and analysis that has led 

to their widespread adoption for regional reconnaissance. Spectral discrimination and automated processing will not be adopted for regular use until their 

current high costs are reduced. Indeed, as Kite (1975) 

has noted, it remains to be shown that such methods 

will be significant for mineral exploration and geological mapping. Perhaps the most useful future 

development for geoscientists will simply be an increase in resolution to 2 or 3 times that currently 

attained with Landsat.

CONCLUSIONS

Canadian interest in Landsat data is widely spread 

and more-or-less equally divided among companies, 

educational institutions, and government agencies.

Geoscientists have had a long, continuing, and major involvement with the Canadian Landsat program. 

However, at present only about 10 percent of the 

geoscientists have a strong commitment to the activity.

Current data defining sales and use of Landsat data 

show that identified geoscience organizations are 

major, if not the principal, users of Landsat data. 

Excluding reference collections, mineral exploration 

companies and consultants are the principal users.

Most (71 percent) geological users of Landsat data 

have been using such data since 1973 at least; the 

remainder started more recently but primarily in 

1974. Nearly a quarter of the Canadian users have 

experience with Landsat data for other parts of the 

world.

Visual photogeologic interpretation of black and 

white prints comprises the principal Canadian method 

of analysis. Digital processing and machine assistance 

have not really been assessed for geological applications, and little relevant research has been reported.

Most Canadian research has been directed to the 

development of visual techniques to meet specific 

requirements for the analysis of texture and patterns 

in Landsat images. However, there has been a major 

advance in the digital classification of Arctic terrain.

Practical applications are not yet documented in 

the literature. However, known examples are related 

primarily to reconnaissance for geological structure 

and disposition of surficial materials. Half of the geological users of Landsat data claim a modest to large 

benefit from such use but cannot identify a specific 

dollar benefit.
REFERENCES 41

In view of the major geoscience involvement, increased support is warranted for research into digital 

and automated methods of processing Landsat data 

to meet geological objectives. In particular, this should 

include temporal change detection, spectral discrimination and ratioing, and directional filtering, if 

warranted by developments in linear analysis.

The level of development of practical geologic applications in Canada is greater than predicted in a 

pre-Landsat forecast. Visual interpretation of Landsat 

images will soon become a prime tool, in conjunction 

with others for regional exploration, particularly in 

arid regions. Automated processing will remain in the 

research stage until low-cost methodologies are developed to meet specific geological objectives.

Because the specific Canadian context comprises 

a large, well-mapped terrain, the conclusions reached 

here should be extrapolated with caution to other 

different and less-explored terrains.

REFERENCES

Arsenault, H. H., Sequin, M. K., Brousseau, N., and 

April, G., 1974, Le traitment optique des Images 

ERTS: Canadian Symposium on Remote Sensing, 

2d, Guelph 1975, Proc., v. 2, pp. 488-493.

Boydell, A. N., 1974, Evaluation of the potential uses 

of Earth Resources Technology Satellite 

(ERTS-1) data for small scale terrain mapping 

in Canada's North: Internet. Soc. Photogramm. 

Comm. VII, Symposium on Remote Sensing of 

Environment, Alberta 1974, Proc., pp. 329-340.

Cameron, H. L, 1964, Photo interpretation in geotechnical investigations: Canada Interdept. 

Comm. on Aerial Surveys, Seminar on Airphoto 

Interpretation in the Development of Canada, 

Proc., pt. 4, pp. 10-20.

Collins, R. J., Petzel, G. J., and Everett, J. R., 1975, 

An evaluation of ERTS data for petroleum exploration (abs.): University of Kansas Space 

Technology Centre, Case History Research Conference on Remote Sensing, Lawrence, Kansas, 

pp. 8-10.

Fischer, W. A., 1964, Geological interpretation from 

airphotos: Canada Interdept. Comm. on Aerial 

Surveys, Seminar on Airphoto Interpretation in 

the Development of Canada, Proc., pt. 4, pp. 

21-31.

Gregory, A. F., 1972, What do we mean by remote 

sensing?: Canadian Symposium on Remote Sensing, 1st, Ottawa 1972, Proc, pp. 33-37.

————1973, A possible Canadian role in future global 

remote sensing: Can. Aeronautics and Space 

Jour., v. 19, no. 3, pp. 85-92.

Gregory, A. F., and Moore, H. D., 1975, The role of 

remote sensing in mineral exploration with special reference to ERTS-1: Canadian Inst. of 

Mining and Metallurgy Bull., v. 68, no. 757, pp. 

67-72.

————1976, Recent advances in geologic applications 

of remote sensing from space: Internal Astronautical Fed. Astronautical Congress, 24th, Baku 

1973, Astronautical Research: 1973, pp. 1-18.

Gregory, A. F., and Morley, L. W., 1969, Remote 

sensing and the solid-earth science, in Background papers on the Earth Sciences in Canada: 

Geol. Survey of Canada Paper 69-56, pp. 170- 

179.

Kite, R. L., 1975, Research on techniques for photographic enhancement of ERTS imagery for geologic applications (abs.): University of Kansas 

Space Technology Centre, Case History Conference on Remote Sensing, Lawrence, Kansas, pp. 

28-30.

Moore, H. D., and Gregory, A. F., 1974, Temporal 

analyses of ERTS-1 images for forest and tundra 

and their significance in visual interpretation of 

geology: Canadian Symposium on Remote Sensing, 2d, Guelph 1975, Proc., v. 1, pp. 47-58.

Morley, L. W., 1971, Canada's approach to remote 

sensing: Internal Symposium on Remote Sensing 

of the Environment, 7th, Ann Arbor, Mich. 1971, 

Proc., v. 1, pp. 3-18.

Ozoray, G., 1974, Lineament analysis using ERTS-1 

images of Alberta: Internat. Water Resources 

Assoc. Internat. Seminar and Exposition on Water 

Resources Instrumentation, Chicago 1974, Water 

Resources Instrumentation, pp. 456-466.

Palabekiroglu, S., 1974a, The value of ERTS-1 

imagery for mineral exploration: Canadian Symposium on Remote Sensing, 2d, Guelph 1975, 

Proc., v. 2, pp. 464-470.

————1974b, ERTS-1 imagery: The valuable tool of 

geoscientists: Internat. Soc. Photogramm. Comm. 

IV Symposium on Remote Sensing and Photo 

Interpretation, Proc., pp. 597-609.

Sabins, F. F., Jr., 1974, Oil exploration needs for 

digital processing of imagery: Photogramm. Engineering, v. 40, no. 10, pp. 1197-1200.

Slaney, V. R., 1974, Satellite imagery applied to earth 

science in Canada: Internat. Soc. Photogramm. 

Comm. IV Symposium on Remote Sensing and 

Photo Interpretation, Proc., pp. 555-572.
42 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Woolnough, D. F., 1975, Theoretical accuracies of 

space mapping for Canada: The Canadian Surveyor, v. 29, no. 3, pp. 267-276.

Working Group on Cartographic and Photogrammetry, 

1974, Report of the Working Group on Cartography and Photogrammetry, in Canadian Advisory 

Committee on Remote Sensing, 1974 Report: pp. 

48-49.

Working Group on Geology, 1971, Resource satellites 

and remote airborne sensing for Canada: Report 

No. 6, Geology: Ottawa, Dept. of Energy, Mines 

and Resources.

Working Group on Geoscience, 1972, Report of the 

Working Group on Geoscience, in Canadian Advisory Committee on Remote Sensing, 1972 Report: Ottawa, Dept. of Energy, Mines and 

Resources, pp. 77-80.

————1973, Report of the Working Group on Geoscience, in Canadian Advisory Committee on 

Remote Sensing, 1973 Report: Ottawa, Dept. of 

Energy, Mines and Resources, pp. 72-83.

————1974, Report of the Working Group on Geoscience, in Canadian Advisory Committee on 

Remote Sensing, 1974 Report: p. 85.
PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Mapping and Charting from Landsat

By Alden P. Colvocoresses, 

U.S. Geological Survey, Reston, Virginia 22092

INTRODUCTION

Although I once was a mining engineer, I have been 

a mapmaker for the past 25 years, and my work is 

no more related to the oil and mining industry than 

it is to any other map-using group.

Mapmakers, as well as others, now have a satellite 

in orbit known as Landsat—previously known as 

ERTS (Earth Resources Technology Satellite)—by 

which we can map the Earth at the smaller scales in 

image form. Since there is a wealth of written data 

available, I have no intention of trying to cover 

Landsat mapping in any detail. Those of you who 

want more information are invited to drop me a note, 

or see me personally, and I will be happy to respond. 

A few of the more pertinent references are appended 

to this paper.

To me, mapping is fundamental to man's efforts to 

understand and live on this planet, and as persons 

concerned with exploration for petroleum and other 

mineral resources, I am sure you will agree. But what 

and how well can we map with Landsat? By the use 

of photographs I will illustrate some of the things that 

can be done and leave it to you to decide to what 

extent Landsat mapping can be applied to your specific problems.

LIMITATIONS

First, let me cover what we cannot do with Landsat. 

Objects too small to be recorded by the 79-m (260-ft) 

Landsat picture element cannot be seen on the 

imagery. Although the capture of specific detail is 

affected by contrast and shape, most features smaller 

than 8 or 10 acres, unless they are very high contrast 

or linear features such as roads and canals, will be 

lost. Second, we cannot use Landsat for topographic 

mapping because the system is basically orthographic, 

precluding the determination of elevations. Where

suitable topographic data exist, a stereopair portraying topography can be processed from Landsat, and 

such a pair is, in fact, available to you as a handout. 

However, remember that the elevation data used to 

form the model did not come from Landsat.

UNIQUE CHARACTERISTICS

Most of you are familiar with aerial photography, 

so let's look at the unique advantages of Landsat 

imagery as compared with aerial photographs.

Continuity.—Can you imagine covering the Earth 

every 18 days with photography? I can't, but—subject 

to cloud cover, priorities, and transmission capabilities 

—Landsat does this, and moreover Landsat-1 has 

done it for more than 3 years. Just look at the published index maps showing only 2 years of Landsat 

coverage. Even so, we have a long way to go to adequately image the Earth for mapping and related 

purposes.

Near real time.—Most of the things you are looking 

for are fixed, but sooner or later you are going to 

want to see the results of a significant event. If it is 

local, an air photo is the way to go, but if it is widespread or in an isolated area, Landsat can help as 

figure 1 illustrates. This huge, seasonally dry area is 

shown here inundated, and the effects of this inundation will remain for several months. I would hate 

to have to map this changing condition with aerial 

photographs.

Geometric fidelity.—Landsat produces near-orthographic imagery of high geometric fidelity, and image 

maps with accuracy compatible with the 1:250,000 

scale can be produced. Relief displacement is minimal, and the mapping is relatively cheap and simple 

as compared with mapping from aerial photographs. 

Figure 2 shows where we have actually corrected the 

standard l:250,000-scale line map in the Phoenix area.

43
44 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

50 MILES 

I

0 80 KILOMETERS 

FIGURE 1.—Map of Cooper Creek, Australia, and ERTS imagery of the creek in flood.

Landsat is revealing many small- and medium-scale 

map errors and omissions in various parts of the 

world, and corrections and revisions based on Landsat 

are being applied by several mapping agencies. The 

Canadians, in particular, utilize Landsat for map revision—even up to the scale of 1:50,000 in provisional 

form. The World Bank is finding Landsat imagery to 

be far more accurate than available maps in many 

areas of the world where they have projects.

Multispectral compatibility.—On aerial film we record a broad waveband in black and white or at the 

most three narrower discrete wavebands in color. 

Landsat now records four discrete wavebands as 

digital radiometric values, including a band beyond 

the range of film cameras. Band 7 of the multispectral 

scanner (MSS) records 0.8 to 1.1 ^m whereas aerial

film cuts off at 0.8 /<.m. Look at the advantages of this 

near-infrared waveband (figs. 3 and 4). Landsat-C will 

also have a thermal band, which again is beyond the 

range of aerial films. The combining of waveband responses either by digital or photographic methods is, 

of course, spectacular, and Larry Rowan (USGS) will 

show how combinations can be applied to bring out 

or emphasize features of specific geologic interest.

Suitability for automation.—Landsat output is digital as well as continuous. Coupled with its geometric 

fidelity it has the potential of becoming an automated 

mapping system. The imagery is now cast on a defined 

map projection which we call the Space Oblique 

Mercator (fig. 5). As mentioned, Landsat also covers 

the same basic area every 18 days and thus forms a 

map series based on the nominal scenes covered (fig.
MAPPING AND CHARTING FROM LANDSAT 45

Original Map Corrected Map

FIGURE 2.—Map accuracy improved by Landsat imagery. Map detail (planimetry) was moved about 1 mm (0.04 in.) on this 

1:250,000-scale map of Phoenix to conform with the detail on the Landsat image. The image was found to be correct.

v •*'..* ,*'

Visible spectrum

MSS Band 5 (0.6 - 0.7 urn)

Near Infrared 

MSS Band 7 (0.8 - 1.1 /jm)

FIGURE 3.—Thin cloud penetration capability of ERTS IR sensor southeast Pennsylvania, November 16, 1972.
46 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

0.7-0.8

MSS BAND 7

iD.8-1.1 pm.

FIGURE 4.—Water boundary delineation from ERTS, Laguna Salada, northern Mexico.
MAPPING AND CHARTING FROM LANDSAT 47

SCANNER SATELLITE

FIGURE 5.—Space Oblique Mercator projection.

6). These characteristics mean that Landsat image 

maps can be made in a few days time when needed. 

Making maps from aerial photographs, as you know, 

is a matter of months or even years. Currently, total 

time involved is about 5 years per standard map in 

the Geological Survey.

CARTOGRAPHIC APPLICATIONS

Now let's look at what Landsat can do cartographically. Obviously, it can portray topography even though 

it can't define the contours. Moreover, it portrays 

topography under different conditions of seasons. 

Let's look at the Denver area (fig. 7, p. VI). Note how 

differently the topography, as well as other features, 

are recorded. Or let's look at Lac Manicouagan, 

Canada (fig. 8). Note how the lower Sun angle enhances the topography and how different the same 

features appear.

Seasonal differences are obvious, but even in the 

same season and with the same lighting we should 

look at any given area at least two or three times so 

that fixed features can be separated from temporal 

phenomena and anomalies in image processing. Under 

the existing Landsat program a minimum of 10 years 

is needed to obtain suitable coverage for the definitive 

mapping of even the Earth's fixed features. Of course, 

if long-term temporal and seasonal changes are to be 

mapped, a remote-sensing system such as Landsat 

must be extended indefinitely—and I trust that it will.

The word Landsat implies land coverage, and the

satellite was not designed to tell us much about the 

oceans. But how about coastal areas and particularly 

the shallow seas? I know two things about these 

shallow seas—they are extensive and they are very 

poorly mapped. From what I hear, they are also of 

ever increasing economic importance. Landsat's 

water-penetration capability is 10 to 20 m (33 to 66 ft) 

even under ideal conditions, but we have asked the 

National Aeronautics and Space Administration to 

adjust one MSS channel on Landsat-C which should 

increase this capability. I realize, that most of the continental shelves are covered by water deeper than 

20 m, but providing data even down to this depth 

would, I believe, be highly significant. Let's look at 

what can now be done with Landsat in the shallow 

seas (fig 9).

The published hydrographic chart obviously needs 

revision. In the Caribbean, figure 10 shows Landsat 

response related to depth over a well-charted bank, 

and nearer to home (fig. 11, p. VII).

For a variety of reasons this application is pretty 

well limited to the mid and lower latitudes. In the high 

latitudes, I suspect that the monitoring and mapping 

of sea ice may be the most important application 

(other than land area analysis) of concern to the oil 

industry. In Canada, a quick-look facility which transmits Landsat data directly to users in a matter of a 

day or so after reception has been developed and put 

to use. On Landsat-C, the thermal channel could 

double the frequency of observations as compared to 

Landsat-1 and -2 because useful observations can 

also be obtained at night. Also note that the meteorological satellites of National Oceanic and Atmospheric Administration (NOAA) and the Department 

of Defense (DOD) Defense Meteorological Satellite 

Program provides some excellent data on sea ice. 

Once we coordinate data from the three satellite systems of NASA, NOAA, and DOD, effective surveillance of sea ice can become a reality.

Landsat is not designed for atmospheric studies, 

but it will certainly record sizable smoke plumes 

from gas flares. The DOD weather satellite I previously mentioned can clearly record nighttime illumination, 

which includes the gas flares themselves (figs. 12 and 

13). Note what appear to be flares in Northwest 

Canada. If they are not gas flares, I hope one of you 

may be able to offer some other explanation. The 

bright spots certainly correlate with the oil and gas 

fields of Alberta and British Columbia. A recent 

Canadian report indicates over 2.5 billion cubic, feet 

of gas per month are being flared in Alberta alone.

According to one authority (Library of Congress) 

more petroleum products are being burned up in
48 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM 

ALABAMA

5°

APPROXIMATE SCALE 

0 50 100 MILES

50 ° 50 100 KILOMETERS

FIGURE 6.—Nominal ERTS scenes—Florida.

flares on a worldwide basis, than are being used productively. Landsat-1 and -2 cannot record flare illumination, but the thermal channel of Landsat-C should 

provide some meaningful signatures. Again, by combining the data from Landsat and the meteorological 

satellites, gas flaring can be monitored in both quantitative and positional terms on a worldwide basis.

Another application of Landsat that I wish to mention is the recording of artificially induced signals. The 

easiest signal to use is nothing more than a solar beam 

reflected to the satellite by a mirror. The mirror may

be as small as half a metre (20 inches) on a side, but 

it can saturate a Landsat picture element (pixel).

Figure 14 shows how three mirrors located in the 

vicinity of our Reston building were recorded by 

Landsat. Similar mirrors can be set up at various remote stations, including offshore drilling platforms, 

and we plan to set up such mirrors in .Antarctica during the next few months. The technique provides a 

visible position mark for an otherwise nondefined 

point. Incidentally, using this technique requires considerable expertise and close coordination with NASA,
MAPPING AND CHARTING FROM LANDSAT 

OCTOBER JANUARY

49

SUN ELEVATION 31° SUN ELEVATION 15°

FIGURE 8.—Lac Manicouagan, Canada. Landsat imagery of a huge flooded impact (meteoritic) crater.

but its practical application should be further tested. 

You may want to contact Mr. Evans (1974) of Stanford Research Institute for further information. He is 

the one who originated this novel technique.

The last application is the actual image mapping. 

Landsat maps are being made for various parts of 

the world in ever increasing numbers, and in a wide 

variety of forms as figures 15, 16, 17, and 18 indicate.

Florida and Arizona are on public sale by the 

USGS. The entire conterminous United States has 

been printed (USGS) in small-scale mosaic form (also 

on public sale) and anyone who has the need and the 

money, can now make such a map of practically any 

land area in the world. Once we justify it, this coverage can also include the shallow seas. Technical data 

relative to such map compilation are contained in 

Chapman (1974), Colvocoresses (1975), McEwen and 

Asbeck (1975), and McEwen and Schoonmaker (1974).

SUMMARY AND CONCLUSION

I've covered technical aspects of Landsat as it applies to cartography. I feel sure that such a satellite

system can in fact map the land and shallow seas of 

the Earth at scales as large as 1:250,000. However, I 

ask that you do not take the system for granted. It is 

a program that has lots of competition for the available space dollars. If you, individually or collectively, 

feel that the program is worthwhile and should continue, you must say so. My immediate concern is that 

Landsat may be converted into a specialized satellite 

to meet some particular problem of immediate concern. To me, that would be a mistake. We need basic 

information about this Earth in a continuous, uniform, 

and readily usable form. That is what Landsat is providing, and I strongly recommend that it be continued 

in the same basic form for the foreseeable future. 

Before we concentrate on a successor to Landsat,, we 

should define the satellite that will immediately follow 

Landsat-C which may expire by 1979 or 1980. I suggest we now work on Landsat-D and perhaps -E, and 

if they fly in the form established by Landsat-1, -2, 

and -C, I for one will not be disappointed. We have 

got a winner, so let's stay with it until we are sure 

we have something better.
Ln 

O

ERTS IMAGE

NAUTICAL CHART

IMERCATOR PROJECTION]

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FIGURE 9.—Comparison of nautical chart and ERTS image, Collier Bay, Australia. Scales of the originals are approximately 1:1,000,000.
MAPPING AND CHARTING FROM LANDSAT 51

Band 4 (0.5-0.6 urn) Band 5 (0.6-0.7 urn)

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KILOM 0 5 10 20 30 40 50

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FIGURE 10.—ERTS correlation to nautical chart, Banco Chinchorro, Yucatan, Mexico.
52 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

IE049-00 E0*9-30I E050-00I

E0^9-00I E049-30I E050-00I 

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FIGURE 12.—Gas flares in Saudi Arabia (Landsat).
MAPPING AND CHARTING FROM LANDSAT 53

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UNITED STATES

V Aviof/on Week A Space Techno/oay, May 13,1974 ^DMSP IMAGE)

* . . * *" 

Mop coiffe/ofed" fo DMSF image by USGS Ocfober ,1^75 »

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FIGURE 13.—DMSP image.
54 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 14.—Enlargement of a portion of ERTS image showing mirror response. Arrows point to pixels illuminated by small mirrors

on the ground.
MAPPING AND CHARTING FROM LANDSAT 55

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56 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

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MAPPING AND CHARTING FROM LANDSAT 57

FIGURE 17.—Arizona.
58 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 18.—Florida.
MAPPING AND CHARTING FROM LANDSAT 59

SELECTED REFERENCES

Chapman, W. K, 1974, Gridding of ERTS images: 

Am. Cong. Surveying and Mapping Fall Convention, Wash., D.C. 1974, Proc., p. 15-19.

Colvocoresses, A. P., 1974-1975, Marking ERTS 

images with reflecting mirrors: Memorandum 

EC-24-ERTS with addendum. (Unpub.)

———— 1975, Evaluation of the cartographic application of ERTS-1 imagery: The American Cartographer, v. 2, no. 1.

Evans, W. E., 1974, Marking ERTS images with a small 

mirror reflector: Photogrammetric Engineering, 

p. 665-672.

McEwen, R. B., and Asbeck, T. A., 1975, Analytical 

triangulation with ERTS: Am. Soc. Photogramm. 

Am. Cong. Surveying and Mapping Convention, 

Wash., D.C. 1975, Proc., p. 490-503.

McEwen, R. B., and Schoonmaker, J. W., Jr., 1974, 

ERTS color image maps (abs.): Am. Soc. Photogramm. Fall Convention, Wash., D.C. 1974, Proc, 

p. 240.

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Relationship of Mineral Resources to Linear Features 

in Mexico as Determined from Landsat Data

By Ing. Guillermo P. Salas, 

Director General, Consejo de Recursos Naturales no Renovables, Mexico, D. F.

ABSTRACT

The author presents an exercise carried out in the 

"Mexican Neovolcanic Axis Metallogenetic Province" 

to relate traces of large diastrophic movements on 

the Earth's surface to mineral deposits.

The geologic history of the Neovolcanic Axis is 

presented and related to the lineaments that may be 

observed from Landsat imagery. A number of large 

lineaments 100 km long oriented east-west are believed to be great faults. There is also evidence of 

NE-SW fracturing and north-south faulting. A predominating NW-SE lineament trend parallels the 

structural expression of the early Eocene orogeny 

(Laramide). The latter is better observed in the eastern part of the Neovolcanic Axis Metallogenetic 

Province.

Comments are made regarding the masking of extensive diastrophic evidence by recent bolson or 

valley-fill accumulation, as well as by extrusive 

igneous rock flows which have not been subjected to 

diatrophic adjustment since their empacement at the 

surface.

It was found that mineralization does have a good 

coincidence with particularly large lineaments shown 

in Landsat imagery. An incidence of mineralization is 

particularly noticeable where the structural features 

are multidirectional, perhaps caused by the emplacement of deep-seated plutons which also give rise to 

metallogenetic processes.

It is concluded that lineaments observable in Landsat imagery will enhance target area selection considerably.

INTRODUCTION

This study has attempted to relate surficial evidence 

of diastrophic movement visible on Landsat-1 imagery

along the Mexican Neovolcanic Axis (fig. 1) to metallogenetic processes.

To accomplish this objective the trends of orientation of long lineaments, generally several tens of 

kilometres in length, were observed to relate tectonics 

to the geology of the area.

An overlay map was made of the known mineral 

occurrences in the area (fig. 2). It was noticed that 

certain metallogenetic processes show incidence 

along more intensively disturbed areas.

The quality of the Landsat-1 imagery was not the 

best; this notwithstanding, most of the band 7 images 

used showed good contrast and clarity, and the features under study were clearly observed although 

cloud cover restricts interpretation in some areas.

The author was able to identify lineaments and 

faults of lengths varying from 10 to more than 100 

km, which are difficult or impossible to detect through 

the use of normal scale aerial photographs. It is expected that the results of this preliminary study may 

help to stimulate similar exercises in Mexico and elsewhere in Latin America.

It was impossible for the author to correlate observed evidence with real ground-truth evidence 

everywhere. The only correlation possible regarding 

the type of rock involved in diastrophic movements 

was taken from geologic maps along the Neovolcanic 

Axis and from previous visits of the author to the 

mining districts of El Oro and Tlalpujahua, Taxco, 

and others.

The results obtained confirm the author's contention that diastrophic movements of large dimensions 

involved a segment of the lithosphere at great depths, 

proportional to the length of the surface fracture. 

These phenomena in turn enhance the possibilities of 

mineralizing solutions reaching areas at the surface

61
62 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

MOSAICO ELABORADO CON IMAGENES DEL SATELITE ERTS 1 

MEXICO G.P. SALAS 1975

100 200 300 400 500 Km

I I I I I

FIGURE 1.—Composite of Mexico from Landsat-1 imagery showing in white line the Neovolcanic Axis Metallogenetic Province.

or near the surface and, through metallogenetic processes, becoming ore bodies.

GENERAL GEOLOGY OF THE 

NEOVOLCANIC AXIS

Unfortunately, no real effort has been made to 

study the geology of the strip of many volcanoes that 

has been called the Mexican Neovolcanic Axis 

(Mooser, 1972). Mooser, who has done much of the 

work in the region, thought that the Mexican volcanic 

strip "could be the surface evidence of a very large 

transverse fault of Continental dimensions." He claims 

that the irregular trend of zigzag fractures with large 

volcanoes at fracture intersection prove their origin 

within recent geological ages. This large transversal 

fracture represented mainly by extensive surface 

flows of andesitic lavas suffered large displacements 

in late Tertiary time and could have been originated 

by the fusion of the Cocos Plate after subduction into 

the Acapulco Trench.

This notwithstanding, oceanographic maps of the 

Pacific Ocean west of the continental part of Mexico 

do not show any structural or physiographic sea floor 

features trending into the Neovolcanic Axis as a reflection of a structural transversal fault. Rather, it 

looks as though the Clarion Fault might have been 

diverted southeast towards and into the Acapulco 

Trench (fig. 3).

Gastil (1973), agreeing with some of Mooser's proposals, considers that the structural lineaments marking the western limit of the Sierra Madre Occidental 

and the eastern end of the Basin and Range province 

of northern Mexico and southwestern United States, 

have been displaced eastwards along the same socalled transverse fault of Mooser for approximately 

160 km. He seems to have noticed a displacement of 

the axis of a regional gravity Bouguer anomaly on the 

western part of continental Mexico (fig. 4), which he 

interprets to have been displaced a similar distance 

eastward. The silver deposits map of Mexico (Salas
RELATIONSHIP OF MINERAL RESOURCES TO LINEAR FEATURES IN MEXICO 63
64 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

C» PRIETO

CRATONIC BLOCKS

I JALISCO BLOCK

II MICHOACAN BLOCK

III GUERRERO BLOCK

IV OA X A CA BLOCK

V CHIAPAS BLOCK

0 200400 600 Km

4- BIGGEST VOLCANOES OF THE QUATERNARY

FIGURE 3.—East Pacific Rise and Neovolcanic Axis structure. (After Mooser, 1972.)

and Gonzalez, 1967) provides further evidence of a 

major right lateral transverse displacement along the 

Neovolcanic Axis. Displacement of the silver provinces 

of the Sierra Madre Occidental, eastward to match 

silver provinces along the Guanajuato-Pachuca 

province agree with Mooser's 160-km right lateral 

displacement (fig. 5). The author's study of fracture 

trends and evidence from the Landsat imagery, however, does not show continuity of large fractures 

which could sustain Gastil's proposal.

Undoubtedly, Mooser's and Gastil's research are 

the best efforts to get first-hand information about 

the Mexican Neovolcanic Axis' modern geology. Unfortunately, the observations were apparently based 

on isolated visits to different Neovolcanic Axis localities with lack of continuity in time or space, so that 

they may yet require a thorough revision.

There are discrepancies in the above-mentioned 

authors' results. For instance, within the Neovolcanic 

Axis Metallogenetic Province, andesite surface flows 

predominate on its western end, and andesites and 

rhyolites predominantly appear on the eastern part 

)f the province. This is not explained by Mooser or 

Gastil. There is a large metamorphic basement complex of pre-Cretaceous age between Cabo Corrientes 

and Barra de Navidad, which extends inland almost 

to Talpa, Jalisco. The origin of this intrusive massif

has not been explained by either of the authors nor 

is its importance noted within the Neovolcanic Axis 

Metallogenetic Province. Apparently, this metamorphic 

basement complex underlies the volcanic sequence of 

andesites and outcrops between Talpa, Jalisco, and 

Bahia de Banderas, Jalisco, eastward to Ameca and 

southward to the town of Autlan, Jalisco. Thus it has 

large bearing on tectonic surface evidence.

On the other hand, the metamorphic basement complex is itself intruded by a granodiorite pluton, probably of Cretaceous age, but certainly pre-Tertiary. 

These phenomena can be observed south of Puerto 

Vallarta and west of Talpa, Jalisco. Another wide 

area of intrusive acid igneous rocks is at Purificacion 

and Armeria Rivers west of the city of Colima (fig. 6).

In studying the tectonic lineaments of the western 

part of the Neovolcanic Axis, consideration must be 

given to extensive outcrops of sedimentary rocks of 

Cretaceous age in the eastern part of the State of 

Colima and the southern part of the Neovolcanic Axis 

in the States of Jalisco and Michoacan. In this case, 

most of the Cretaceous section is made up of a thick 

limestone sequence interbedded with sandstone and 

shale formations.

From the meridian of the city of Morelia eastward 

(fig. 6), the Neovolcanic Axis is bordered on the south 

by another large area of metamorphic rocks which is
RELATIONSHIP OF MINERAL RESOURCES TO LINEAR FEATURES IN MEXICO 65

0 100 200 300 400 500 Km fc-i

FIGURE 4.—Bouguer anomalies showing coincidence of strong gradient with Sierra Madre Occidental (Gastil, 1973).

clearly visible immediately west of Valle de Bravo in 

the State of Mexico, as well as by a thick sedimentary 

section in the States of Michoacan and Guerrero west 

of Taxco. At this latter place the basement metamorphic complex underlying a thick sedimentary section 

outcrops extensively north of the city of Taxco, Eastward from the Valley of Mexico to the Gulf of Mexico, 

a sequence of volcanic rocks of late and middle 

Cenozoic age outcrop extensively. This volcanic sequence overlies the thick geosynclinal facies of the 

Sierra Madre Oriental section of thick limestone sequences and thinner shale and sandstone formations. 

This can be noticed around the town of Oriente to 

the east of the city of Puebla eastward to the city of 

Orizaba, Veracruz. The northern border of the Neovolcanic Axis is made up of the same volcanic sequence previously mentioned, to the town of Mizantla, 

Veracruz, just south of Poza Rica. This massif, the 

Teziutlan Massif, made up of the volcanic sequence 

and some intrusives, extends southward almost to the 

city and port of Veracruz on the Gulf of Mexico.

Because of the heterogeneity of the section that 

has been affected by diastrophic distortions, -it is well

to keep in mind in the interpretation of lineaments 

from Landsat imagery, that the different type of rock 

and their different ages of emplacement will of 

course behave differently to tectonic stresses. Also, 

lineaments that appear in older sections, like the 

basement complex, will not necessarily show in surrounding country which may be capped by a more 

recent volcanic sequence.

It is also well to keep in mind the way lineaments 

and evidence of distortion will appear in the imagery 

studied, if one considers that there are important 

intrusives such as those at Tamasula, Jalisco, at 

Mascota on the Rio Ameca south of Zapotlan, Jalisco, 

and along mountains of igneous rocks which lie to the 

west of Ameca and Etsatlan in the State of Jalisco. 

There are a large number of stocks at Resales and 

Tacambaro in the State of Michoacan, that can readily 

be seen in the Geologic Map of Mexico (Mejorada, 

1968). There are intrusives which may not outcrop, as 

is the case of those that underlie a volcanic andesitic 

and rhyolitic sequence at the mining district of El Oro 

and Tlalpujahua. In this case, mining activity has revealed that these intrusive stocks and dikes are post-
66 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

MEXICO

FIGURE 5.—Trend of orientation of silver deposits in Mexico showing apparent displacement of subprovinces (Gastil, 1973).

volcanic sequence in age and may have caused the 

mineralization (fig. 6).

If the lithologic heterogeneity of the stratigraphic 

column and the age of the volcanic sequence which 

covers most of the Neovolcanic Axis is studied, perhaps an explanation will be found for the variety of 

orientation of fracture and faulting which may be 

observed in the Landsat-1 imagery.

Gastil (1973) suggested that a zone of cortical weakness which extended northwestward and formed the 

Gulf of California, existed in the area that is now occupied by the Neovolcanic Axis. He advocates the 

thesis that the zone of weakness might have existed 

during the Mesozoic and that at that time the lateral 

and longitudinal displacement started to separate the 

peninsula of Baja California from the continent. He 

concludes also that the rupture movement was intensified during Oligocene and that later, during 

Miocene time, coincided with the eruption of ignimbrites and igneous extrusives which eventually formed 

the Basin and Range province to the north in the areas 

of Arizona, New Mexico, Sonora, and Chihuahua.

According to Gastil (1973), the real dislodging of 

the peninsula may have started approximately 14 million years ago. This may have originated the Neovolcanic Axis displacement of the andesite-rhyolite 

sequence which constitutes the volcanic sequence 

outcropping there.

Finally, the larger features, alineaments of fractures and faults, observed from Landsat-1 imagery 

do not result from one or two diastrophic movements 

but are the result of any number of diastrophic movements that are coincident with the emplacement of 

the volcanic sequence and the intrusive rocks.

IMAGERY INTERPRETATION

Except for a few major fractures, such as those 

mentioned at the mining district of El Oro and 

Tlalpujahua, State of Mexico, the rest of the features 

in figure 7 have not been checked extensively in the 

field. Consequently, it is obvious that a large part of 

these structural features are inferred. They are highly 

interpretational, and they should be so considered 

when studying the interpreted figures.

In spite of the quality of the photos, which were 

not the best, and the possibility of obtaining better 

band mixes with more contrast, the lineaments of
RELATIONSHIP OF MINERAL RESOURCES TO LINEAR FEATURES IN MEXICO 67

TAMPICO

PLEISTOCENO Y RECIENTE

PLEISTOCENE AND RECENT

INTRUSIVOS DEL CENOZOICO INFERIOR 

LOWER CENOZOIC INTRUSIVE

FIGURE 6.—Schematic geologic map of the Neovolcanic Axis Metallogenetic Province of Mexico.

mountains, valleys, visible fracture lines, and intrusives, are easy to detect as lineaments of diastrophic 

origin. There are mountainous areas with extensive 

valleys and other features such as straight line oriented vegetation in arid valleys which would indicate 

moisture from fractures under the alluvium. Also the 

tectonic or structural control of river courses is observed in drainage patterns in the northwestern part 

of the Neovolcanic Axis, north of Bahia de Banderas 

and in the Rio Acaponeta, Rio San Pedro, Rio Santiago, and other rivers in the State of Jalisco. The Laguna de Chapala seems to be the result of a graben. 

This is evidence of Mooser's proposed anticline along 

these features.

The imagery studied shows a number of east-west 

trending lakes in the States of Michoacan and Queretaro. These, however, are due to dammed rivers that 

may not necessarily be controlled by structural features. The east-west orientation of the river basins 

may be coincidental. For instance, the Lago Cuitzeo 

may be caused by a water table suspended by lava 

flows damming a river basin.

On the other hand, in the northeast part of the Neovolcanic Axis, lineaments are controlled by the Sierra 

Madre Oriental folds which run definitely NW-SE. In 

some areas a NE-SW displacement of these folds and 

faults may be observed on transverse faults.

It is well to emphasize that fractures and faults that 

have been observed and marked by the author 

definitely tend to show that there is no continuity of 

east-west orientation to substantiate the thesis advocated by other authors, that the origin of the Mexican 

Neovolcanic Axis could have been an old east-west 

cortical line of weakness.

It is well to emphasize also that there are fault 

lines longer than 100 km, such as the parallel faults 

immediately south of Lake Atotonilco, which run north 

and south. Notice also the north-south 100-km-long 

fault which occurs between the town of Yesca, 

Nayarit, and the Ceboruco volcano (northwestern 

area, fig. 2). The latter may be connected with the 

faulting and structural control shown by the emplacement of the igneous massif which crops out close to 

the town of Yesca. There are in connection with this
68 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM
RELATIONSHIP OF MINERAL RESOURCES TO LINEAR FEATURES IN MEXICO 69

igneous massif a cluster of quite noticeable faults, 

some 20 to 30 km long, that cross the north-south 

faults. This cluster of smaller faults shows a marked 

tendency of orientation NE-SW. This phenomenon can 

be observed to the north and east of Rio Coahuayana, 

southeast and east of the city of Colima, 70 km east 

of the city (southwestern area, fig. 2). A similar phenomenon can be observed as NE-SW faults cross 

NW-SE faults 35 km to the north and southeast of the 

city of Zimapan, State of Hidalgo (east-central area, 

fig. 2). In this case, these crossed faults are usually 

short, less than 40 km long.

In the central part of the area, in the State of 

Guerrero, and southwest of the city of Iguala, a cluster 

of faults trends NE-SW. The same NE-SW orientation 

predominates in practically all the small faults (30-40 

km long). Again, within 100 km radius of Ciudad 

Altamirano, Guerrero (south-central area, fig. 2), there 

are any number of areas in which clusters of faults 

several tens of kilometres long appear, all of them 

oriented NE-SW. Examples are the area north and 

south of Lago Cuitzeo, and between this lake and 

Laguna Yuriria, in the State of Michoacan (central 

area, fig. 2), and also east of Lake Chapala and along 

Rio Huizcata northeast of the city of Guanajuato. 

Tectonics related to intrusions are shown by a number 

of faults which appear in an area called Cerro 

Desmoronado, some 30 km east of Puerto Vallarta on 

the Pacific side of the Neovolcanic Axis. Here faults 

are multidirectional, and the author believes that these 

are caused by the later intrusives to the west of the 

town of Talpa. It looks like the stock pierced and dislocated the volcanic sequence, also giving origin to 

the mineralization. In this Cerro Desmoronado area, 

which shows extensive mineralization, are the famous 

Amaltea and Cuale mines of the Compania Minera 

Fresnillo, S. A.

A long east-west fault which appears extensively in 

the literature of the Neovolcanic Axis, is the so-called 

Falla de Acambay. The town of Acambay lies some 

20 km north of the mining district of El Oro and 

Tlalpujahua. East-west faulting appears at the mining 

district and not necessarily at the town of Acambay. 

This fault is some 100 km long, but does not connect 

with those of Chapala, and, as formerly mentioned, it 

is more likely that this faulting occurred due to the 

emplacement of intrusives which underlie the El Oro 

and Tlalpujahua mining district.

Emphasis must be made on the lack of continuity 

of many of these tectonic features as observed in 

Landsat-1 imagery. There are extensive lava flows of 

recent age, which may not reflect structural distortions 

of large magnitude and of previous geological ages.

That is, Quaternary extrusives and pyroclastics may 

disguise evidence of diastrophic or tectonic movements.

This may be the case of the mining district of 

Pachuca. Serious efforts have been made to decipher 

structural control therein. Both to the north and south 

of Pachuca City, Quaternary volcanics and pyroclastics of great thicknesses completely disguise any 

structural features that might have been observed 

otherwise. Forty or 50 km north of the Pachuca mining district, evidence of the Sierra Madre Oriental 

folding may be observed in high mountains where 

thick limestone sequences outcrop. These show a perfect lineament oriented NW-SE, but Quaternary volcanics and pyroclastics cover older rocks which might 

otherwise have shown tectonic features.

TECTONIC FEATURES AS RELATED TO 

METALLOGENETIC PROCESSES

A general study of the principal structural features 

in Mexico revealed an intimate relationship of tectonics of continental scale with metallogenetic processes which have given rise to the principal mining 

districts in the country.

The author has subdivided the country into six 

metallogenetic provinces. The Neovolcanic Axis 

Metallogenetic Province, which is the main object of 

this exercise, is one of them. It is bound on the north, 

from west to east, by the southern end of Sierra 

Madre Occidental, the Central Plateau Province, and 

the Sierra Madre Oriental. The southern boundary is 

made up, from west to east, by the Sierra Madre del 

Sur and the Sierra Madre Oriental's southern continuation.

As previously stated, it is the author's contention 

that metallogenetic processes are controlled by orogenic movements along lines of diastrophic weakness. 

There has been some previous work done along this 

line by Russian economic geologists and metallogenecists. In 1940, a group of Russian geologists, under 

the direction of Y. A. Bilikin, studied the factors that 

rule the distribution of minerals that constitute ore on 

the Earth's surface. Shatalov reported on this work 

in 1972, and the Canadian geologists, McCarthy and 

Potter (1962), studied the Soviet's results with regard 

to the origin of mineral deposits.

Bilikin's group prepared a thorough statistical 

compilation of the Soviet Union's different geologic 

districts, mineral deposits, their geologic environment, 

the country rock types, absolute age of mineralization 

of the country rock itself, and the age of tectonisms 

that gave rise to the accumulation. Bilikin (1955) reports to have found an intimate relation in time and
70 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

a recurrent relationship regarding composition of ore 

deposits between the complex specific minerals and 

the specific intrusive rocks. These in turn were all 

related to a tectonic cycle in a zone of mobile belts. 

The Canadian geologists thought this interesting 

enough to attempt such a study of the eastern part of 

Canada and the Rocky Mountains province of British 

Columbia.

There are a number of results of research on 

metallogenetic processes which relates ore deposits 

to intrusive and/or extrusive igneous rocks. Krauskopf's (1967) study, for example, is a very well documented study of orogenies with regard to the 

metallogenesis of ore deposits and the relation that 

these have to different igneous rock emplacements. 

Thus, it is reasonable to assume that ore deposit 

genetics are intimately related to the emplacement of 

those igneous rocks mentioned, and they in turn are 

related to erogenic epochs.

The origin of ore deposits is not within the scope of 

this exercise. Rather, their occurrence with respect to 

movements along mobile belts is under study. It is 

important to demonstrate that the magma which is 

originated in the upper part of the mantle, possibly 

just below the Mohorovicic Discontinuity or immediately above it, finds its way upward through the lithosphere by using large fractures and faults to rise 

toward the surface. Consequently, the author's Landsat-1 imagery study to relate large faulted areas to 

metallogenetic processes has used that concept as a 

basis for his contention.

To substantiate this thesis, the author points out the 

occurrence of large mineral deposits along the large 

fractured lines in the Neovolcanic Axis Metallogenetic 

Province such as the area in the east-central part of 

it, including the Pachuca silver deposits, the Zimapan 

lead-zinc-silver deposits, the Taxco lead-zinc-silver and 

fluorite deposits, the El Oro and Tlalpujahua gold and 

silver deposits and the Angangueo silver and gold deposits. Other somewhat smaller deposits lie along the 

extreme western part of the Neovolcanic Axis Metallogenetic Province, such as the lead-zinc-copper-silver 

deposits of Cuale and Amaltea in the Cerro Desmoronado area, immediately southeast of Puerto Vallarta 

on the Pacific seaboard (fig. 7).

All of these mineralized areas occur along very 

extensively faulted areas. Faulting may occur oriented 

east-west, as at El Oro and Tlalpujahua; or NE-SW, 

as at Zimapan; or as at Taxco where faulting occurs 

oriented mainly WNW-ESE; or multidirectional faulting and fracturing as at Cuale and Amaltea in Cerro 

Desmoronado, south of Puerto Vallarta.

From all these observations, the author surmises 

that if the tectonic feature is large enough, that is, if 

faulting occurs along more than 50 to 100 km, this 

by necessity must have also affected a large thickness 

of the lithosphere reaching into the asthenosphere, or 

the upper part of the mantle, where magmatic material exists. This magma, along with its constituent 

fluids, finds its way through the large faulted area towards the surface. The longer it has to migrate 

through the lithosphere the better opportunity it has 

to dissolve additional chemicals which eventually will 

form ore deposits useful to man at the nearest surface 

part of the lithosphere and/or outcropping.

Figure 2 shows incidence of mineral occurrences 

along and in, or about, intensively disturbed areas.

DESCRIPTION OF SOME MINERAL

DEPOSITS ALONG THE MEXICAN

NEOVOLCANIC AXIS AS RELATED TO

TECTONIC FEATURES

Specialized literature described adequately the 

geology of ore deposits of importance along the 

Neovolcanic Axis Metallogenetic Province. Consequently, and congruently with the thesis herein sustained, the author described only in general those 

tectonic features that have controlled mineralization 

in certain important mining districts.

PACHUCA Y REAL DEL MONTE MINING DISTRICT, 

STATE OF HIDALGO

This is the most important mining district in this 

province (fig. 8). Geyne and others (1963), in their 

monumental work have an excellent description of 

this district, which is located 100 km north-northeast 

of Mexico City, at the eastern edge of the Central 

Plateau Metallogenetic Province or the northeastern 

edge of the Neovolcanic Axis Metallogenetic Province. 

This mining district occurs precisely in the area where 

the folded belt of the Sierra Madre Oriental Metallogenetic Province plunges under an andesitic volcanic 

sequence. East-west faults, 20-30 km long, are vaguely 

shown in the Landsat-1 imagery, but may be mapped 

on the ground. The volcanic sequence is of PliocenePleistocene age and has not been eroded intensely 

enough to reveal more clearly structural features beneath the strata. Some NW-SE, N-S, and NE-SW faulting may be observed in the satellite photos but not as 

clearly as on the ground. Valley fill and Quaternary 

rhyolitic lava flows mask the largest structures.

The rock in this district consists of volcanoclastic 

material interstratified with low dipping andesite and 

rhyolite flows. The lowermost beds, at 1,000-m depth,
RELATIONSHIP OF MINERAL RESOURCES TO LINEAR FEATURES IN MEXICO 71

\JPffESA JARAMILLO

Tz

,TZ :

(PRESA-•",••:

%^:^t }:::'^.^y/l ,^

C]pEL..BARRIQ

TV '"'

ALLUVIAL 

PLAINS

PLEISTOCENE AND 

RECENT BASALTS

MIOCENE VIZCAINA 

FORMATION RHYOLITE

400 800 1200 1600 2000 1C MINE

FIGURE 8.—Structural map of Pachuca (Geyne and others, 1963) showing east-west and northwest-southeast faults and 

veins. Notice Quaternary rhyolite flows mask surface fault traces.

are probably of early Oligocene age and the uppermost are probably of late Pliocene and/or Pleistocene 

(Geyne and others, 1963). The whole volcanic sequence lies unconformably over the eroded, downfaulted, and intensively folded marine limestone 

sequence of the upper Mesozoic which forms the 

Sierra Madre Oriental. Immediately to the north of the 

city of Pachuca, this folded sequence of the Sierra 

Madre Oriental shows a perfect NW-SE lineament.

The Tertiary rocks have been deformed by several 

oscillating movements of varied intensities. These 

structural features have developed numerous faults 

with steep dips. The faults are usually of the normal 

tension type. However, this faulting shows well marked 

east-west strikes, but also some north-south and 

WNW-ESE orientations. It seems that the structural 

movement occurred at the end of the Oligocene and 

during the Miocene and was followed by the emplacement of dacitic-porphyry dikes and quartziferous dikes 

and sills. These dikes show a definite east-west orientation and undoubtedly were emplaced through faults 

which have the same orientation. Their age is postLaramide.

Unfortunately, most of this information has been 

obtained underground and surface evidence though 

relatively abundant is certainly not clearly observable 

from Landsat-1 imagery in this particular case.

TAXCO MINING DISTRICT, STATE OF GUERRERO

This mining district (fig. 9) lies approximately 120 

km southwest of Mexico City.

The region suffered tectonic distortion apparently 

in two different geologic epochs. The Cretaceous 

rocks outcropping show large folding in the shape of 

anticlines with axes locally oriented NE-SW. Northsouth folding is also occasionally observable. Mineralization occurs both in sedimentary and metamorphic 

rocks of the basement complex. On the other hand, 

the area suffered distortion caused by the early
72 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

-TRINIDAD

,—/S.EERNAND

MINAS VIEJAS

EXPLANATION

VEINS AND FAULTS LIMESTONES

DIORITE 

SCHIST

r~=^^E

BASIC INTRUSIVES 

VOLCANIC ROCKS 

SHALES_____

FIGURE 9.—Taxco mining district, State of Cuerrero, showing vein control by faults and fractures. (After Fowler

and others, 1948.)

Eocene orogeny (Laramide), and NW-SE trending 

large faulting predominates and may be observed in 

Landsat-1 imagery.

There was another very clear tectonic erogenic 

movement which occurred at the end of the Pliocene. 

Fries (1960), has also found evidence of intense deformation at the beginning of the Pleistocene. This 

seems to correlate well with orogenic movements in 

the mining district of Pachuca.

The Taxco mining district's main ore production is 

lead, zinc, silver, and gold. The ore occurs as vein 

filling of fractures and faults of the Taxco schists at 

Mina El Pedregal. Ore bodies also occur in fractured 

limestones of Cretaceous age at Mina El Pedregal, La 

Concha, and San Antonio. Again mineralization occurs 

in clastic beds of the Mezcala Formation at the Mina 

Jesus. Finally, a very weak mineralization process

reached the lowermost part of the overlying Tertiary 

volcanic sequence. All of this indicates that the mineralization was contemporary with the fracturing systems of the late Pliocene and early Pleistocene much 

as it happens in Pachuca. However, the main metallogenetic processes seem to have taken place in the 

late Oligocene or early Miocene and probably renewed in more recent geologic epochs.

HUAHUAXTLA MINING DISTRICT, 

STATE OF GUERRERO

This ore body is located approximately 15 km 

northwest of the city of Iguala, Guerrero. The ore 

bodies occur in faulted Morelos Formation as well 

as the Cuautla and Mezcala section of the Middle and 

Upper Cretaceous. The Huitzuco mercury district, 20
RELATIONSHIP OF MINERAL RESOURCES TO LINEAR FEATURES IN MEXICO 73

km east to Iguala, also contains mercury and antimony 

which occur principally in faulted limestone of the 

Morelos Formation of Cretaceous age as well as in 

dolomite-and anhydrite. Here again, there is indirect 

evidence of post-Cretaceous mineralization. It is thus 

possible to correlate mineralization metallogenetic 

processes to the same orogenic movements that gave 

origin to the Pachuca and Taxco ore deposits.

EL ORO AND TLALPUJAHUA MINING DISTRICT, 

STATE OF MEXICO

This is a district which has been developed since 

1521 and shut down partially until recently. It produces epithermal cavity and vein-filling gold and silver 

deposits. Siockworks are also common. The ground 

rock is made up of black slate (fig. 10).

The veins fill cavities in great and small faults which 

run nearly east and west. They are covered by andesitic rocks of the volcanic sequence of post-mineralization age. Again, in this district, it is estimated that

metallogenesis took place during early Miocene time, 

as shown in the principal veins called San Rafael, La 

Verde, and San Jose de la Borda.

The El Oro and Tlalpujahua mining district is controlled by large, parallel faults over 100 km long. Here 

NE-SW trending faults of less extension, and NW-SE 

short faulting also occur, some of which is rather recent much as it happens in Taxco and Pachuca. In the 

author's opinion this faulting may be the reason for 

the enrichment of the pre-Miocene and Miocene mineralization. The author believes that volcanic action of 

Pliocene-Pleistocene age caused the reworking of the 

original ore and gave rise to enrichment.

OTHER LESS IMPORTANT MINING DISTRICTS

There are any number of smaller mining districts 

which occur where clusters of large and small fractures show in the Landsat-1 imagery. For instance, 

the intrusive that gave rise to the Tetela gold mine in 

the northern part of the State of Puebla, approximateEJIDO , __, 

AGUA CALIENTE ^ ^ PKESA ' /^

EXPLANATION

Carbonaceous slate 

Clays _________ I 

Andesites _______ 

Ignimbrites————— 

Breccias and Tuffs — 

Basaltic Andesites_ 

Lacustrine Sediments I H~

Recent Tuffs

and Breccias ____

Alluvium 

Milonites, Talus 

Slidings

Contact _ 

Fault___ 

Syncline _ 

Anticline_ 

Volcano _ 

Mine shaft

0 1 2 5 Km

FIGURE 10.—El Oro-Tlalpujahua mining district.
74 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

ly 80 km northeast of the city of Tlaxcala, is one such 

result of the tectonic distortion.

Again, in the immediate vicinity of the town of 

Teziutlan in the northeastern part of the State of 

Puebla and at the edge of the Gulf of Mexico watershed, there are copper mines which originated at the 

contact of the intrusive rocks and limestones of postCretaceous age. In the immediate vicinity and farther 

north, the abandoned iron mines of Tatatila and the 

copper and gold deposit called Las Minas, 30 km 

northwest of the capital city of Jalapa, occur in 

intensely folded and faulted areas which show both 

the typical volcanic sequence structures of the Neovolcanic Axis Metallogenetic Province and the NW-SE 

trending controlling axis of folds and faults of the 

Sierra Madre Oriental orogeny (Laramide).

Along the western part of the area, smaller faults 

show a marked tendency of orientation NE-SW. This 

phenomenon can be observed to the north and east 

of Rio Cohaguayana 27 km southeast and east of the 

city of Colima. In the State of Hidalgo, a similar phenomenon can be observed as NE-SW faults cross 

NW-SE faults, immediately to the north and southeast 

of the city of Zimapan, Hidalgo. In this case, these 

cross faults are usually short, less than 40 km long.

In the central part of the area, in the State of 

Guerrero, immediately to the east and northeast of 

Ciudad Altamirano, a cluster of NE-SW short faults, 

less than 30 km long, intersect long NW-SE trending 

faults which show up predominantly along the Rio 

Cutzamala from the area of Ciudad Altamirano northward to the town of Tzitzio.

It seems that mineralization follows the NW-SE 

preting Landsat imagery for mineral or hydrocarbon 

NE-SW trending short faults intersect the longer ones. 

These are controlled by the early Eocene orogeny 

(Laramide).

The author wishes to stress the fact that in interpreting Landsat imagery for mineral or hydrocarbon 

exploration purposes in areas such as the Neovolcanic 

Axis of Mexico where very recent volcanic sequences 

mask older tectonic features, one must extrapolate 

into the area structural lineament from more eroded 

or uplifted areas where they can be observed clearly.

It certainly enhances the possibilities of selecting 

prospective areas by helping to pinpoint targets.

REFERENCES

Bilikin, Y. A., 1955, Metallogenetic province and 

epochs: Moscow, Gosgcoldekhizdat.

Fowler, G. M., Hernon, R. M., and Stone, E. A., 1948, 

The Taxco mining district, Guerrero, Mexico: International Geological Congress, 18th, London 

1948, Report of the Eighteenth Session, pt. 7, 

p. 2-12.

Fries, Carl, 1960, Geologia del Estado de Morelos y de 

partes adyacentes de Mexico y Guerrero, region 

central meridional de Mexico: Mexico Institute de 

Geologia, Bull. 60.

Gastil, G. R., 1973, Evidence for strike-slip displacement beneath the Trans-Mexican Volcanic Belt: 

Stanford University School of Earth Sciences, 

Conference in Tectonic Problems of the San 

Andreas Fault System, Proc.

Geyne, A. R., Fries, Carl, Segerstrom, Kenneth, Black, 

R. F., and Wilson, E. I. F., 1963, Geology and 

mineral deposits of the Pachuca-Real del Monte 

district, State of Hidalgo: Mexico, Consejo de 

Recursos Naturales no Renovables Extra-series 

publication 5E, p. 203-222, illust, 7 tables.

Krauskopf, K. B., 1967, Source rocks for metal-bearing fluids, in Barnes, H. L, ed., Geochemistry of 

hydrothermal ore deposits: New York, Holt, Rinehart and Winston, p. 1-33.

McCarthy, W. D. A. I., and Potter, R. R., 1962, Mineralization as related to structural deformation 

igneous activity and sedimentation in folded 

geosynclines: Canadian Mining Journal, v. 83 no. 

4, p. 83-87.

Mejorada, S. H. S., ed., 1968, Carta Geologica de 

la Republica Mexicana: Comite de la Carta Geologica de Mexico, 1 sh., 1:2,000,000.

Mooser, Federico, 1972, The Mexican Volcanic Belt, 

structure and tectonics: Geofisica Internacional, 

v. 12, no. 2.

Salas, G. P., and Gonzalez, R. G., 1967, Yacimientos 

de Plata en Mexico: Institute de Geologia, 

U.N.A.M., Mexico.

Shatalov, Ye. T., ed., 1972, Metallogenic analysis of 

ore-controlling factors in ore regions: Moscow, 

Izd. Nedra, 295 p., illust.
PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Landsat Contributions to Studies of Plate Tectonics

By Jan Kutina,

Laboratory of Global Tectonics and Metallogeny, 

Washington Technical Institute, Washington, D.C. 20008

and William D. Carter, 

U.S. Geological Survey, Reston, Virginia 22090

ABSTRACT

Tectolinear interpretation of satellite image mosaics 

has proven to be a powerful method for tracing the 

course of basement fracture zones which have been 

propagated upward through a platform cover and 

even through erogenic belts. The method has also 

been applied to locate fracture zones, the orientations 

of which have been changed by rotation of lithospheric plates.

A tectolinear interpretation map of the United 

States by W. D. Carter, set in context with structural 

geological knowledge of the Canadian Shield, suggests that the Hudson Bay paleolineament (HBP) of 

J. Kutina may extend into the Precambrian basement 

of the Eastern United States. Spatial correlation of significant ore districts with the HBP and associated 

structures in Canada (both in the Archean greenstone 

belt and outside) suggests that important ore concentrations may also exist along the probable extension 

of the HBP beneath the sedimentary cover of the Eastern United States, where it may intersect with an 

east-west trending fracture zone, distinguished by 

A. V. Heyl (1972), between 38° and 40°N. in the Central and Eastern United States. A number of Mississippi Valley-type ore deposits are spatially associated 

with this east-west fracture zone.

Three major northwest-trending lineaments have 

also been delineated in South America, and their extension into the Andean Region has been traced by 

statistical treatment of linears in the Landsat mosaics. 

These northwest-trending lineaments may very well 

have been E-W fracture zones in the paleogeographic 

orientation of South America before it was separated 

from Africa.

INTRODUCTION

The investigations carried out in the last decades 

by Ewing, Heezen, Hess, their coworkers, students, 

and followers have brought new insight in the knowledge of the structure of the upper parts of the Earth. 

One of the outcomes of this scientific trend was the 

concept of the "new global tectonics" as introduced 

by Isacks, Oliver, and Sykes (1968), Morgan (1968), 

Le Pichon (1968) and others. This concept, referred 

to also as "plate tectonics," has revived the old continental drift hypothesis of Alfred Wegener, giving it 

a new geophysical interpretation.

Since the time of the above papers, an enormous 

literature on plate tectonics has accumulated, with 

some papers accepting it as a proven model, and 

others expressing different degrees of agreement or 

disagreement with the new concept. The controversy 

which exists in the world literature is reflected well 

in the volume of papers "Plate Tectonics—Assessments and Reassessments," edited by Kahle (1974). 

There are a number of other critical papers that 

should be mentioned, especially that by Sheinmann 

(1973).

The basic postulate of the new theory shows that 

the upper parts of the Earth's body are composed of 

a number of rigid plates that are not in a fixed position but which move and the boundaries of which 

have changed in the course of geological time. These 

changes involved processes of different orders of 

magnitude which are mutually interrelated and are of 

basic importance for certain geochemical processes.

Metallogenic studies have shown that there exists a 

relationship between mineralization of various types 

and ages and the different types of plate boundaries

75
76 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

(Guild, 1974). One of the most important discoveries 

was recognition of the role of subduction or Benioff 

zones on metallogenic processes connected with partial melting of the subducted oceanic crust and generation of a special type of magma. The origin of 

porphyry copper deposits especially of the Andean 

erogenic belt has been explained in these terms 

(Sillitoe, 1972a, b).

Many deposits, however, are located in the interior 

of the present plates, far from their boundaries. Some 

of them may be related, as Guild (1973) and others 

have shown, to former plate boundaries, but many ore 

deposits apparently do not exhibit such a relationship.

Several authors, who studied metallogeny of broad 

regions such as the Western United States or Transbaikalia have recognized that the distribution of major 

endogenic ore deposits is controlled, beside other factors, by major fracture zones, and often by their 

intersections (Kutina, 1969; Favorskaya and others, 

1974).

As a follow up of these investigations, Kutina (1974) 

carried out a systematic study of structural control of 

ore deposition in selected regions of four continents. 

Correlating his results he concluded that large endogenic ore deposits and ore districts are usually located 

in the vicinity of, or above the intersection of, deepseated fractures, fracture zones or zones of weakness 

that belong to four sets, N-S, E-W, NW, and NE, or 

to some of these four sets, propagating upward from 

deeper levels. The upward propagation of these fractures proceeds differently in different regions depending on their geological evolution. As a consequence, 

not all of these fracture sets are developed or clearly 

expressed in the surface or subsurface portion of each 

region and the detection of some of them requires 

detailed studies by different methods. Reactivation of 

movements proceeded along these fracture zones at 

different geological times.

There exists a relationship between the intraplate 

tectonics and the course of the plate boundaries. For 

instance, one of the ore-controlling fracture sets of 

continental Central America (the NW-SE one) is 

parallel to the Middle America Arc, the boundary between the Cocos Plate and the Caribbean Plate. Ore 

deposits of a post-Laramide age lie closer to the plate 

boundary than the majority of the older ore deposits 

(Kutina, 1974).

The reconstruction of the pre-Cretaceous ("predrift") configuration of the present plates has mostly 

been done by analyzing magnetic anomalies of the 

sea floor, by applying paleomagnetic data, and by 

geometric fitting of the continental margins. Therefore, King (1970) correctly notes, when -referring to 

Bullard's reconstruction of the continents on opposite 

sides of the Atlantic, that the reconstruction has been 

done without regard for the inner constitution of the 

blocks or plates.

Correlation of the geology of the matching sides of 

continents, which are supposed to have been separated from each other, has been done in several instances. Also, the extension of metallogenic provinces 

across such boundaries has similarly been tested by 

several authors with reasonable success.

These correlations, though of principal importance, 

are usually not sufficient to estimate the angle of 

rotation of the plates and are not sufficient geological 

evidence to provide an independent check of the 

amount of rotation deduced by geophysical methods. 

Also the question of possible disappearance of a part 

of a continental mass by disintegration and subsidence 

often remains unanswered.

Detection and plotting of major, deep-seated fracture zones, especially those which are ore-controlling, 

provide a new, additional tool in fitting crustal plates 

back together. This kind of study is in initial stages 

because our knowledge of the pattern of deep-seated 

fractures within the individual plates is insufficient.

The results of Kutina's (1974) study in different 

parts of four continents and of an independent investigation by Favorskaya and others (1974) show a real 

possibility of comparing the positions and orientations 

of ore-controlling fracture zones of the individual 

plates.

The use of the above metallogenic data in testing 

the validity of plates' rotation as derived by geophysical methods presents, however, a number of problems. One of them is distinguishing whether or not 

some of the ore-controlling fracture zones represent 

new tectonic elements, superimposed on the old fracture pattern. Another question is whether zones of 

tectonic weakness may or may not exist in the substratum over which the lithospheric plates are supposed to be moving. And, if they exist, how far they 

can influence the tectonics and metallogenic processes 

in marginal parts and in the interior of the plates. 

Some of these questions are discussed separately 

(Kutina, 1976).

The introduction of Landsat (ERTS) imagery and 

the construction of image mosaics provides a new, 

common base for systematic study of linear features 

in broad territories. Swarms of lineaments extending 

sometimes for several hundreds of miles and crossing 

boundaries of different geological units are likely to 

reflect the course of major fracture zones in deeper
LANDSAT CONTRIBUTIONS TO STUDIES OF PLATE TECTONICS 77

/:-. -,v. \i // / // \ \ x\ V_3> x -r^-=^g'

(iX-HiV /^"^^^SK^^

EXPLANATION 

Missouri Lead/Zinc district

FIGURE 1.—Tectolinear interpretation of a 1:5,000,000-scale ERTS-1 mosaic of the United States by W. D. Carter, 1974.

Lineament At essentially corresponds to the 38th Parallel Lineament of Heyl (1968, 1972) and represents its independent discovery by satellite imagery.

In view of the metallogenic importance which the Ai lineament plays, the lineaments A«—A' 2 , revealed by the same 

ERTS-1 mosaic, deserve special attention.

levels of the Earth's crust which have been propagated upward due to movement of crustal blocks.

The detection of such lineaments and their correlation with the distribution of ore deposits may very 

effectively help to solve long-standing controversial 

questions and will help to map the pattern of major 

deep-seated fractures which is needed for correlation 

of the intraplate tectonics and between individual 

plates. The relationships between the location of ore 

deposits and the course and intersection of the lineaments coming from these studies may be of great 

assistance in mineral exploration.

In the present paper, two examples are presented. 

They come from a joint study of the authors, using 

some of Carter's tectolinear interpretations of Landsat mosaics.

The paper, originally presented at the Pecora Symposium at Sioux Falls, October 1975, has been updated 

by references to papers by Regan and others (1975), 

Stewart (1976), and Callahan (1976).

CONTRIBUTION TO THE INTRAPLATE

TECTONICS OF THE EASTERN

UNITED STATES

Figure 1 is the first tectolinear interpretation of a 

mosaic of satellite images of the United States as 

compiled by Carter in 1974. The illustration is based 

on the analysis of a mosaic of the conterminous 

United States consisting of 595 Landsat-1 images 

published at the scale of 1:5,000,000 (U.S. Geological 

Survey, 1974).

The illustration is presented here in its original form 

without any additional changes in order to serve as a 

base not influenced by genetic concepts.

Some of the longer lineaments have been marked 

by heavy lines by Carter, but several-others can similarly be distinguished. For instance, two broad northsouth trending swarms of linears can be recognized 

in the Western United States, one at the longitudes 

enclosing the Great Salt Lake and the other extending
78 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

through Colorado and southward. The first one essentially extends along the north-south fracture trajectory + 6 and the other along +9 of the model by 

Kutina (1969).

Two of the most prominent features of figure 1 are 

the major east-northeast-trending lineaments in the 

Eastern United States. One of them is located between latitudes 38° and 40°N. and is marked Al in 

figure 1, and the other extends between 32° and 

36°N., and is marked A.. A2 has a prominent counterpart in the Western United States, marked A'2 .

Lineament A, of figure 1 intersects the Appalachian 

orogen in the easternmost part of the country and 

apparently displaces the Precambrian of eastern Pennsylvania and New Jersey in a right-lateral sense and 

in places, as a pronounced curvature of the Appalachians. This apparent displacement has been recognized by Drake and Woodward (1963) who interpreted 

it as a right-lateral wrench fault extending seaward 

(Cornwall-Kelvin displacement). The continental part 

of this displacement has been doubted later by Root 

(1970).

The course of the lineament A, (fig. 1) as recognized 

on the l:5,000,000-scale mosaic should be understood 

as its first approximation. It is therefore not surprising 

that the east-northeast trend of this lineament as it 

appears in the easternmost part of the United States 

differs from the east-west strike of the CornwallKelvin displacement of Drake and Woodward (1963) 

who applied geological and geophysical criteria on a 

more detailed scale. The main power and contribution 

of the ERTS-1 mosaic lies in its synoptic view covering a broad territory in which the respective lineament, though less accurate in detail, could have been 

traced for a long distance.

Overlaying the pattern of linear features of figure 1 

with the distribution of the main ore deposits of endogenic and controversial origin shows (fig. 2} that most 

of the major Mississippi Valley-type deposits of lead, 

zinc, fluorite, and barite are spatially associated with 

the east-northeast-trending lineament or fracture zone 

A!. This regularity with further structural and lithological control was recognized as early as 1968 and 

1972 by Heyl, who described the respective lineament 

as the 38th Parallel Lineament.

The 38th Parallel Lineament is probably plotted 

more accurately by Heyl than in figure 2 as the geological and metallogenic interpretation by Heyl is 

based on more detailed maps. Nevertheless, the 

l:5,000,000-scale mosaic of Landsat-1 images proved 

useful in detecting the same regularity. Moreover, it is 

probable that more detailed information available 

from Landsat images at larger scales and the applicaFICURE 2.—Tectolinear interpretation of the eastern part of 

the United States, set in context with some structural and 

metallogenic features of the Canadian Shield.

Note especially the distribution of the Mississippi Valleytype deposits of lead, zinc, fluorite, and barite, many of which 

concentrate—in accordance with Heyl (1968, 1972)—in a belt 

following the 38th Parallel Lineament.

The east-northeast-trending 38th Parallel Lineament traverses the Appalachian orogen at a latitude close to 40 3 N., 

with an apparent right-lateral displacement of the Precambrian, thus giving support to the Cornwall-Kelvin wrench 

fault of Drake and Woodward (1963).

EXPLANATION

I. Precambrian of the Canadian Shield and the outcropping 

Precambrian of the eastern part of the United States (simplified from King and Beikman, 1974).

II. Younger rocks, mostly covering Precambrian basement.

III. Canada: major ore fields in the Precambrian south of 

Hudson Bay, both in the Archean greenstone belts (1-4) and 

outside (5, 6).

United States: two ore deposits in the Precambrian of the 

northeastern United States (20, 21) and the Ducktown deposit 

in Tennessee (14).

IV. Ore districts and major deposits of the Mississippi Valleytype and a few smaller lead-zinc deposits of the Eastern 

United States.

V. Deposits of other types (17, 18). 

ORE DEPOSITS AND DISTRICTS 

Canada:

1. Val d'Or district.

2. Noranda district.

3. Timmins district.

4. Chibougamau district.

5. Cobalt district and other deposits.

6. Sudbury district. 

United States:

7. Upper Mississippi Valley district.

8. Illinois-Kentucky district.

9. Tri-State district of Missouri, Kansas, and Oklahoma.

10. Central Missouri district.

11. \

12. \ Southeast Missouri lead district.

13. J

14. Ducktown district, Tennessee.

15. The Mascot-Jefferson City zinc district, Tennessee.

16. Austinville-lvanhoe district, Virginia.

17. Hamme district, North Carolina.

18. Cornwall deposit, Pennsylvania.

19. Friedensville deposit, Pennsylvania.

20. Franklin Furnace and Sterling Hill, New Jersey.

21. Balmat-Edwards, New York.

22. Central Kentucky district.

23. Cumberland River deposit.

24. Shenandoah Valley (Timberville), Virginia.

25. Northern Arkansas district.

26. Northeast Arkansas district.

27. Central Tennessee district.
LANDSAT CONTRIBUTIONS TO STUDIES OF PLATE TECTONICS 79

-;^ N» "// /'/ VxXCX ^<43fe^ J^(^ tt I'^^^Jj^h
80 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

tion of enhancement techniques would provide a more 

complete geological plot of the lineament, especially 

at places where its course was interpolated due to 

lack of structural information.

Thus, the 38th Parallel Lineament (At in fig. 1) is (1) 

spatially associated with the distribution of major deposits of the Mississippi Valley—type and (2) may 

displace the Precambrian at the intersection with the 

Appalachian orogen. Therefore, the above lineament 

appears to be a significant structural element of the 

Central and Eastern United States or its basement.

The experience from global metallogeny shows that 

the chances for economic concentration of metals 

increase along intersection of orogens by transversal 

deep-seated fracture zones, especially if ore deposits 

have been detected along them at other places. Accordingly, the area of the intersection of the Appalachians by the 38th Parallel Lineament may be 

postulated as a target area for mineral exploration. 

A number of ore deposits and occurrences have already been found in this area, among them the magnetite deposits of Cornwall and Grace connected with 

the diabase magmatism in the Triassic basin (Lapham, 

1970; Sims, 1970) and the sphalerite deposit of 

Friedensville located in the Cambrian and Ordovician 

carbonate sediments (Callahan, 1970), both in Pennsylvania (18 and 19 in fig. 2). The unique character of 

these deposits (including the deposits of Franklin 

Furnace and Ogdensburg in rocks of Precambrian 

age) within the metallogeny of the Appalachians has 

been stressed already by Guild (written comm., 1968), 

who assumed their possible relation to deep basement 

offsets along an intersecting lineament.

In view of the above significance which the 38th 

Parallel Lineament plays, special attention should also 

be given to the other east-northeast-trending lineament (A2 and A'^, fig. 1) running parallel to the former 

and located between the latitudes 32° and 36°N. in 

the Eastern United States and close to 34°N. in the 

Western United States.

The courses of lineaments A2 and A' 2 essentially 

parallel the outline of the North American craton 

(with the basement rocks as old as 1,700 to 850 m.y.) 

against the encircling marginal miogeosynclines, as 

these two units have recently been distinguished by 

Stewart (1976). According to Stewart, the miogeosynclines started to form at approximately 850 m.y. indicating the initial stages of rifting. If the above relation 

is true, these lineaments may contribute to the definition of the southern boundary of the North American 

craton.

Another very interesting correlation may exist between lineaments A, and A2 , A', of figure 1, and the

northern and southern boundaries; respectively, of a 

newly detected belt of magnetic highs in the global 

magnetic anomaly map (Regan and others, 1975). The 

belt extends in an essentially east-west direction with 

some tendencies to turn east-northeasterly to northeasterly between latitudes 30° and 40°N. through 

nearly the whole United States. Lineaments A., and 

A'o of figure 1 follow very closely the southern boundary of the belt of magnetic highs. Since lineaments AL, 

and A'o also parallel, to some degree, the southern 

boundary of the North American craton, it is possible 

that the three features are interrelated.

Figure 2 sets the tectolinear interpretation of the 

ERTS-1 mosaic of the Eastern United States in context with some structural features of the Canadian 

Shield. The illustration shows the course of the Hudson 

Bay paleolineament (HBP) as postulated by Kutina 

(1971) as well as the main ore fields south of Hudson 

Bay. The Val d'Or-Noranda-Timmins ore field (1-3 

in fig. 2), located in an Archean greenstone belt, 

contains about 1,500 occurrences of gold and about 

half that number of copper (Kutina and Fabbri, 1972).

The aim of the plot of the Canadian ore fields is to 

initiate discussion of possible presence of important 

mineral concentrations in the Precambrian basement 

of the Eastern United States. If the HBP and its 

parallel structures with which some of the ore concentrations both within the greenstone belts and outside are spatially associated, extends southward into 

the basement of the United States, it may play a role 

in structural control of ore deposition. From this viewpoint there may be special interest in the swarm of 

north-south lineaments south of Lake Ontario and 

farther south, which may possibly reflect upward 

propagation of southern extension of the HBP from 

the Precambrian basement. The respective swarm of 

north-south lineaments intersects the east-northeasttrending "38th Parallel Lineament" in the area north 

of location No. 16 in figure 2. In the area of this intersection, a coal basin has developed in western Virginia. The shape of the basin as expressed in the 

"Geological Map of the United States" (King and 

Beikman, 1974) is symmetrical along the directions of 

the two intersecting sets of lineaments.

Several areas with numerous gold occurrences and 

old small-scale mining operations for gold are known 

in the Eastern United States (Callahan, 1976). Though 

the primary source of this gold is in outcropping rocks 

which are considerably younger than the greenstone 

belts in Canada, the presence and distribution of gold 

in the Eastern United States is of special interest as 

it may represent remobilization of this metal from 

older rocks of the basement.
LANDSAT CONTRIBUTIONS TO STUDIES OF PLATE TECTONICS 81

POSSIBLE EXTENSION OF MAJOR

FRACTURE ZONES FROM THE INTERIOR

OF THE SOUTH AMERICAN PLATE INTO

THE ANDES OROGENIC BELT

A discussion of this question, preliminarily presented 

at the Sioux Falls symposium, has been further extended and included in another paper, "The Metallogenic Role of East-West Fracture Zones in South 

America with Regard to the Motion of Lithospheric 

Plates (with an Example from Brazil)," to be published 

in Djalma Guimaraes Volume, Boletim, Universidade 

de Brasilia.

ACKNOWLEDGMENTS

The senior author thanks Bethlehem Steel Corporation for the agreement to use some of his results 

from a consultant assignment.

Thanks are given Dr. Stephen J. Gawarecki and 

Mr. W. S. Kowalik for references to some papers.

SELECTED REFERENCES

Callahan, J. E., 1976, Are there Witwatersrand types 

of gold deposits in the Triassic basins of the 

Southeast ?: Geol. Soc. America, Abs., v. 8, no. 

2, p. 144-145.

Callahan, W. H., 1970, Geology of the Friedensville 

mine, Lehigh County, Pennsylvania, in Ridge, J. 

D., ed., Ore deposits in the United States 1933- 

1967: Am. Inst. Mining Engineers, v. I, p. 95-107.

Carter, W. D., 1974, Tectolinear interpretation of an 

ERTS-1 mosaic, La Paz area, southwest Bolivia, 

southeast Peru and northern Chile: Committee 

of Space Research Plenary Mtg., 17th, Sao 

Jose dos Campos, Brazil, preprint.

Drake, C. L, and Woodward, H. P., 1963, Appalachian curvature, wrench faulting, and offshore 

structure: New York Acad. Science, Trans., v. 

26, p. 48-63.

Favorskaya, M. A., Tomson, I. N., Baskina, V. A., 

Volchanskaya, I. K., and Polyakova, O. P., 1974, 

Global regularities in the distribution of big ore 

deposits (in Russian): Moscow, Nedra, 193 p.

Guild, P. W., 1973, Massive sulfide deposits as indicators of former plate boundaries: U.S. Geol. 

Survey, Open file rept, 11 p.

———— 1974, Application of global tectonics theory 

to metallogenic studies: Internat. Assoc. on the 

Genesis of Ore Deposits Symposium on Ore Deposits of the Tethys Region in the Context of 

Global Tectonics, Varna, Bulgaria, preprint.

Heyl, A. V., 1968, The 38th Parallel Lineament and 

its relationship to ore deposits (abs.): Econ. 

Geology, v. 63, p. 88.

———— 1972, The 38th Parallel Lineament and its 

relationship to ore deposits: Econ. Geology, v. 

67, p. 879^894.

Isacks, B., Oliver, J., and Sykes, L. R., 1968, Seismology and the new global tectonics: Jour. 

Geophys. Research, v. 73, p. 5855-5898.

Kahle, C. F., ed., 1974, Plate tectonics—assessments 

and reassessments: Am. Assoc. Petroleum Geologists, Memoir 23, 514 p.

King, P. B., 1970, Tectonics and geophysics of eastern 

North America, in Johnson, H., and Smith, B. L., 

The megatectonics of continents and oceans: 

New Brunswick, N.J., Rutgers Univ. Press, p. 74- 

112.

King, P. B., and Beikman, H. M., 1974, Geologic map 

of the United States: U.S. Geol. Survey, 1:2,500,- 

000.

Kutina, Jan, 1969, Hydrothermal ore deposits in the 

western United States: a new concept of structural control of distribution: Science, v. 165, p. 

1113-1119.

———— 1971, The Hudson Bay Paleolineament and 

anomalous concentration of metals along it: 

Econ. Geology, v. 66, p. 314-325.

———— 1973, Structural control of volcanic ore deposits in the context of global tectonics: Internat. 

Symposium on Volcanism and Associated Metallogenesis, Bucharest, Romania, Sept. 1973, preprint.

——— 1976, Relationship between the distribution 

of big endogenic ore deposits and the basement fracture pattern—Examples from four continents, in Internat. Conf. on the New Basement 

Tectonics, 1st, Salt Lake City, June 1974: Utah 

Geol. Assoc. Pub. 5, p. 565-593.

1976, Lithospheric plate motions—one of the

factors controlling distribution of ore deposits in 

some mineral belts: Mineralium Deposita, in 

press.

Kutina, Jan, and Fabbri, A., 1972, Relationship of 

structural lineaments and mineral occurrences in 

the Abitibi area of the Canadian Shield: Geol. 

Survey Canada Paper 71-9, 36 p.

Kutina, Jan, Carter, W. D., and Lopez, F. X., n.d., The 

metallogenic role of east-west fracture zones in 

South America with regard to the motion of 

lithospheric plates (with an example from Brazil). Submitted to the Djalma Guimaraes Volume, 

Boletim, Universidade de Brasilia.
82 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Lapham, D. M., 1970, Triassic magnetite and diabase 

of Cornwall, Pennsylvania, in Ridge, J. D., ed., 

Ore deposits of the United States 1933-1967: 

Am. Inst. Mining Engineers, v. I, p. 72-94.

Le Pichon, X., 1968, Sea floor spreading and continental drift: Jour. Geophys. Research, v. 73, 

p. 3661-3697.

Morgan, W. J., 1968, Rises, trenches, great faults 

and crustal blocks: Jour. Geophys. Research, v. 

73, p. 1959-1982.

Regan, R. D., Cain, J. C, and Davis, W. M., 1975, 

A global magnetic anomaly map: Jour. Geophys. 

Research, v. 80, p. 794-802.

Root, S. I., 1970, Structure of the northern terminus 

of the Blue Ridge in Pennsylvania: Geol. Soc. 

America Bull., v. 81, p. 815-830.

Sclater, J. G., and McKenzie, D. P., 1973, Paleobathymetry of the South Atlantic: Geol. Soc. 

America Bull., v. 84, p. 3203-3216.

Sheinmann, Yu. M., 1973, The new global tectonics 

and reality [in Russian]: Bull. Moscow Soc. 

Naturalists, Geol. Ser., v. 78, no. 5, p. 5-28.

Sillitoe, R. H, 1972a, A plate tectonic model for the 

origin of porphyry copper deposits: Econ. 

Geology, v. 67, p. 184-197.

———— 1972b, Relation of metal provinces in western 

America to subduction of oceanic lithosphere: 

Geol. Soc. America Bull., v. 83, p. 813-817.

Sims, S. J., 1970, The Grace magnetite deposit, Berks 

County, Pennsylvania, in Ridge, J. D., ed., Ore 

deposits in the United States 1933-1967: Am. 

Inst. Mining Engineers, v. I, p. 108-124.

Stewart, J. H., 1976, Late Precambrian evolution of 

North America: Plate tectonics implications: 

Geology, v. 4, no. 1, p. 11-15.

U.S. Geological Survey, 1974, Mosaic of imagery from 

Earth Resources Technology Satellite-1 of the 

conterminous United States: in cooperation with 

the U.S. Department of Agriculture, Soil Conservation Service, 1:5,000,000.
PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Landsat Data Contributions to Hydrocarbon 

Exploration in Foreign Regions

By F. P. Bentz, 

Vice President, Santa Fe Minerals, Inc., Dallas, Texas 75219

and S. I. Gutman, 

Geophysicist, Santa Fe Minerals, Inc., Orange, California 92668

ABSTRACT

Foreign exploration frequently requires that large 

areas of relatively unexplored territory be evaluated 

in the most expeditious and informative manner. The 

selection of areas with the greatest potential would 

normally start with the least expensive reconnaissance tools like photogeology, field work, and aeromagnetics before proceeding to the more costly and 

possibly more definitive techniques such as gravity, 

seismic, and, eventually, drilling. In many areas, however, this ideal sequence of evaluation can no longer 

be followed due to shortened exploration periods 

and other restrictive government regulations.

Santa Fe Minerals' past experience with Landsat 

has proved that the ready accessibility of multispectral imagery provides for quick and inexpensive reconnaissance of foreign exploration areas. Firstly, it 

allows the construction of geographic base maps 

which are often more accurate than any existing 

maps. Secondly, Landsat imagery is an invaluable 

source of geologic information; if used in conjunction with existing published data, it will, in most cases, 

improve the accuracy of geologic mapping and understanding of an area. In addition, it has been 

found that the imagery complements and aids in the 

interpretation of aeromagnetic and gravity data; this 

relationship is reciprocal.

Santa Fe Minerals has successfully experimented 

with Landsat multispectral imagery,' and, as a consequence, now routinely integrates Landsat data into 

its exploration efforts.

Exploratory work in Egypt and Yemen serves to 

illustrate how Landsat imagery is used; some results 

are presented.

INTRODUCTION

The purpose of this paper is to present some of 

the major contributions of Landsat data to Santa Fe 

Minerals' hydrocarbon exploration in foreign areas.

Explorationists find themselves today in a highly 

competitive environment, complicated by shortening 

exploration periods and increasingly restrictive governmental regulations. For these reasons it is not 

always possible to follow a normal foreign exploration sequence, which is essentially a process of isolating and identifying targets with hydrocarbon potential from a large and relatively unexplored area. 

This process usually begins with reconnaissance tools 

such as aeromagnetometry, SLAR (side-looking airborne radar), and photogeology and proceeds to the 

more costly and time consuming (but hopefully more 

definitive) methods such as seismic surveys and drilling. Landsat data, because of their ready accessibility, 

help significantly in shortening the early reconnaissance stage of operations. In addition, Landsat 

imagery is, because of its low cost per unit area, 

one of the best data buys the explorationist can 

make.

Landsat has proven itself to be a valuable source 

of geological information. It has invariably improved 

the contact and spatial relationships of outcrops in 

poorly or sparsely mapped areas. The mapping of 

linears helps to define a structural fabric or framework in the exploration area. This fabric is often indistinct or invisible at the surface but, nonetheless, 

strongly influences hydrocarbon accumulations. With 

few exceptions, the pattern of linears is highly regular 

and can often be related to stress analysis. Subtle 

color and tonal anomalies have been observed which

83
84 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

are believed to be of significant exploration importance.

Significant relationships between gravity and magnetic data and alinements or trends have been observed in Landsat imagery. Initial conclusions suggest 

that the basement and intersedimentary structures, 

which are routinely interpreted from the potential 

field data, have greater (but subtle) surface expressions than we had previously anticipated.

Because it has been successful, Landsat data are 

now routinely integrated into Santa Fe's foreign exploration programs. It aids in planning geophysical 

surveys and allows the creation of exploration base 

maps onto which the results of literature searchers and 

available data can be posted; one is now able to 

begin the data acquisition and interpretation process 

almost immediately.

Exploratory work in Egypt and Yemen will serve to 

illustrate some of the contributions that Landsat data 

have made to our foreign exploration program. The 

choice of Egypt and Yemen was made because they 

essentially represent opposite ends of the information spectrum available to the explorationist.

The permit area in Egypt has well-exposed surface 

geology, portrayed on relatively detailed geologic 

maps. In addition, there are subsurface data available from nearby wildcat tests as well as Bouguer 

gravity and residual magnetic intensity maps. In contrast, the onshore exploration area in Yemen is covered with alluvium. There are no well data available 

from the five dry holes previously drilled there in the 

early 1960's nor is there an adequate or reliable 

geological map of the area. Despite the current interest in the southern Red Sea (as a consequence of 

the new global tectonics), there is little in the published literature concerning the onshore geophysics 

of the Yemen Arab Republic.

LANDSAT DATA CONTRIBUTIONS TO 

HYDROCARBON EXPLORATION IN EGYPT

The East Cairo concession straddles the Cario to 

Suez highway and encompasses about 1 million acres 

(fig. 1). It is bounded on the east by the Great Bitter 

Lake and on the west by the Damietta Branch of the 

Nile River where it comprises a small portion of the 

highly cultivated and densely populated Nile Delta. 

The rest of the concession area consists of gently 

rolling gravel desert bounded to the south by eastwest trending limestone escarpments of Eocene age.

These physiographic provinces are an expression 

of the geology, as shown on figure 2, a geologic 

sketch map reproduced with permission from Said's 

The Geology of Egypt (Said, 1962). The 30th parallel

(crossing the map in the center) forms the southern 

boundary of Santa Fe's permit.

The bulk of the escarpment-forming Eocene limestones lie south of the 30th parallel. Most of the concession is characterized by east-west trending outcrops of Oligocene to recent age, with Eocene rocks 

showing only in a few anticlines. Exposures of Cretaceous sediments are reported from Gebel Shabrawet overlooking Great Bitter Lake. The east-west 

trending outcrop pattern is indicative of the apparent 

folding axes; the main pattern of faulting, shown on 

the map, has a northwest-southeast direction.

Figure 3 (p. VIII) is a Landsat mosaic which encompasses a much larger area than the geologic 

map. One can orient oneself by Cairo at the neck of 

the delta in the west, the Suez Canal and Great 

Bitter Lake on the east, and the Mokkattam limestone escarpment forming the southern concession 

boundary to the south.

Quite a number of geologic features shown on 

Said's map can be readily identified on the Landsat 

image mosaic; for instance, the Eocene horst of Gebel 

Oweibid. Interestingly, there are many other geologic patterns which are more visible on the Landsat 

imagery than on the surface geologic map. As an example, note the almost circular syncline southwest of 

Gebel Shabrawet which is rather inadequately represented on the geologic map.

A great number of major and minor linears can 

readily be observed on the Landsat mosaic, as shown 

in figure 4. Close scrutiny reveals that these linears

0 20 40 60

EXPLANATION 

o Abandoned well 

» Gas well 

• Producing well

80 MILES

ll I 

0 20 40 60 80 KILOMETERS

FIGURE 1. — Index map of northern Africa showing Santa Fe 

Minerals, Inc., exploration area.
LANDSAT DATA CONTRIBUTIONS TO HYDROCARBON EXPLORATION 85

31° 30 32° 30'

31* 30 32"00 32° 30

50 Km

Cenomonion 

Turonion

Kn Nubia Sandstone

Basalt

Eocene Oligocene

FIGURE 2.—Geology of Cairo-Suez District (after Said, 1962).

statistically represent a limited number of trends.

A presentation in the form of a star diagram not 

only enhances their regularity but also shows that they 

are intersecting each other at angles of approximately 

15°, 30°, and 60' (fig. 5). These are the expected 

angles for shear sets of a strain ellipse, and they can 

also be related to Moody and Hill's wrench-fault tectonic scheme (fig. 6) first published about 20 years 

ago (Moody and Hill, 1956).

This does not imply that the Cairo-Suez area is 

governed entirely by wrench faults. In an area that 

lies at the junction of several important crustal plate 

boundaries which separate the African continent from 

the Mediterranean crust to the north and from the 

Sinai and Arabian blocks to the east, one can expect 

that divergent movements of these crustal blocks 

created a forceful stress system. This was likely relieved by a complex pattern of shear zones, compressional features, and tensional rifts.

The major structural units are illustrated in a simplified manner in a regional tectonic sketch (fig. 7).

The Gulf of Suez-Red Sea system is one of the 

most outstanding features in this area. It likely consists of a combination of tensional rifting and strikeslip movements (left lateral wrench faults). Initial 

block faulting occurred toward the end of Oligocene 

time and was associated with widespread volcanism.

If sea floor spreading is indeed a factor in the later 

history of this area, it was restricted to the Red Sea 

proper and did not penetrate the Gulf of Suez.

The Gulf of Aqaba-Dead Sea shear zone is equally 

impressive in its magnitude. It is probably along this 

left lateral wrench fault that any plate movement 

caused by Red Sea spreading occurred.

A distinct N. 50° W. trend occurs at a 15° angle to 

the N. 35° W. Gulf of Suez-Red Sea trend. Said combines the two trends under the name "Erythrean or 

African faulting"; and, indeed, the shorelines of the 

Gulf of Suez and the Red Sea are controlled by segments of both of these two trends (Said, 1962, p. 33). 

The N. 50° W. direction appears to be much older 

since it is expressed in shears within the Precambrian 

shield (Abdel-Gawad, 1969). In addition, the N. 50° W. 

direction was certainly rejuvenated in more recent 

times causing some of the more prominent right lateral 

shears in our area of interest.
86 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM
LANDSAT DATA CONTRIBUTIONS TO HYDROCARBON EXPLORATION 87

N. 50° W.

Primary Folds

N. 70" E.

10 Linears 223 Linears Mapped

FIGURE 5.—Star diagram illustrating relationships between 

mapped lineaments.

Primary-Stress Direction

Primary 1st order wrench 

2nd order drag fold

2nd order wrench

=~,

3rd order Left lateral-* Jrd order Right ,atera, ^.

2nd order wrench 7 dra9 '°'d

Jfe-"1

Primary-Fold Direction ""

where a=0

Complementary 1st order wrench 

2nd order wrench

3rd order 

2nd order wrench 

2nd order drag fold

lary 1st order wrench

Primary-Stress Direction

FIGURE 6.—Wrench fault tectonics as related to lineament 

interpretation.

The north-south or "East African" trend is described 

by Said as "the old grain of Egypt" (Said, 1962, p. 32), 

yet it still seems to have played an important role in 

more recent geologic events, being responsible for 

deflections of the Gulf of Suez shorelines and of the 

Nile River.

An east-west trend related to the "Tethyan" direction is prominent in Sinai and crosses the concession 

area in several places. At Gebel Oweibid it can be 

interpreted as a right lateral wrench fault based on 

the outcrop configuration shown on the geologic map.

A major folding axis, described as the Gebel 

Maghara-Abu Roash line, crosses our area in a 

N. 70° E. direction, at right angles to the primary 

stress oriented at about N. 20° W. This primary fold 

axis is not obvious from the surface geologic map of

31°

30°

/' ,, Centers of Cretaceous and Tertiary deformation 

^- Major Anticlineal Trends 

/ Major Faults and Fault Zones 

lip- Arabo-Nubian Massif

4$y

FIGURE 7.—Regional tectonics of Northeast Africa. (Adapted 

from Said, 1962.;

our concession area; however, the magnetic intensity 

(fig. 8, p. IX) and the Bouguer gravity map (fig. 9, 

p. X) do reflect this structural orientation.

Considering the regional aspects of this main axis, 

one can discern a southwesterly plunge from the 

Jurassic outcrops at Gebel Maghara in the Sinai to 

the Middle Cretaceous outcrops at Gebel Shabrawet 

near the Great Bitter Lake and to the Lower Cretaceous and Jurassic encountered 2,000 ft below the 

surface in the Abu Roash wells.

At right angles to the primary stress lies also the 

direction of greatest tension which could, at least in 

part, be responsible for the rifting of the Gulf of Suez. 

And while a number of the mapped lineaments are 

probably related to strike-slip movements, others are 

associated with block faulting and tilting. It is believed that the major movement along the Gulf of 

Suez trend was a vertical displacement along normal 

faults resulting in tilted fault blocks. This can be 

illustrated by the uplifted Middle Cretaceous sedimentary rocks at Gebel Shabrawet west of the Great 

Bitter Lake. A similar uplift along the same direction 

of faulting probably occurred at Abu Roash west of 

the Nile Valley near Cairo. This set of block faults
88 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

would result in a steepening of the southwestward 

axial plunge across the area.

Evidence for horizontal displacements is illustrated 

by a set of drag folds that forms a distinctive pattern 

in the center of the concession area.

In the course of our work, we have observed a 

surprising correspondence between gravity and magnetic data and Landsat imagery. It usually is in the 

form of close associations of linears and lineaments 

with high gradients and magnetic accidents (fig. 8, 

p. IX). The magnetic anomalies which are essentially 

reflecting the configuration of the magnetic basement 

dramatically confirm the substance of the N. 70° E. 

regional trend that was first observed on the Landsat 

imagery. Please note the departure of the field from 

this trend in the south-central portion of the permit 

area. We have interpreted this as the reorientation of 

the basement along a major left lateral strike slip 

fault seen in Landsat data. This is an excellent example of how the potential field data and the Landsat 

imagery complement each other to arrive at a unified 

and consistent geological picture.

The correspondence of the Bouguer gravity anomalies (fig. 9, p. X) with the surface geology (fig. 2) is 

quite good. Note the roughly east-west alignments 

of gravity highs over the folded and faulted Oligocene 

sedimentary rocks in the north and observe that a 

broad, regional trend of N. 70° E. is disturbed by high 

frequency anomalies associated with contacts and 

structures, particularly in the center of the area. In 

the west, where there is a total absence of geologic 

outcrops due to the vegetative cover of the Nile Delta, 

we have a broad, elongated gravity low which trends 

north-south.

The Landsat interpretation highlights the contact 

and fault relationship inherent in the gravity data as 

well as the regional N. 70° E. trend which we feel is 

quite important to hydrocarbon accumulations east of 

the Nile Delta. Please observe that jogs in the course 

of the Nile are associated with flexures in the gravity 

anomalies and the extensions of lineaments mapped 

outside the delta. We conclude that not only is the 

present course of the Nile largely fault controlled but 

that these faults influenced the development of a 

gorge of Grand Canyon proportions which formed at 

the end of Miocene. This gigantic 10,000-ft deep erosion channel (discovered by Santa Fe's seismic reflection work) helps to explain the conspicuous northsouth gravity low mentioned above.

LANDSAT DATA CONTRIBUTIONS TO 

HYDROCARBON EXPLORATION IN YEMEN

The Yemen Arab Republic lies on the southwestern 

tip of the Arabian Peninsula (fig. 10). The area in 

which Santa Fe Minerals was interested encompasses 

more than 5.7 million acres, of which close to 4 million 

acres are located onshore. A rather restricted exploration option of 8 months required us to survey this vast 

area in the most expeditious and cost effective manner. For this purpose, an abbreviated exploration 

program was undertaken consisting of an offshore 

seismic survey combined with marine gravity and 

magnetics. An aeromagnetic survey and Landsat interpretations were conducted over the onshore portion.

The Landsat mosaic (fig. 11, p. XI) gives an indication of the nature and quality of the data as well as 

a feel for some of the interpretation problems that 

were encountered.

Saudi / 

^Arabia < f.4

FIGURE 10.—Index map showing Santa Fe Minerals, Inc., exploration area in Yemen.
LANDSAT DATA CONTRIBUTIONS TO HYDROCARBON EXPLORATION 89

The Tihama Plain extends 400 km north to south 

along the Red Sea Coast. This coastal plain gently 

dips to the west from a mountain front which dramatically rises to heights of more than 8,000 ft. Although faulting, fracturing, and jointing are clearly 

visible in the mountains, at first glance there appeared 

to be an almost total lack of these features in the 

plain due to the thick alluvial cover. On closer inspection, however, it was observed that despite the lack 

of outcrops in the Tihama Plain, there are a profusion 

of subtle color or tonal streaks as well as circular 

anomalies visible from orbit which are totally indistinct 

either on the ground or in the aerial photos (fig. 12).

Lineaments in the mountains define a structural 

fabric which is relatable to the stresses that this area 

has been subjected to as a result of regional upwarp 

or arching during the Oligocene and rifting during the 

early and middle Miocene. Linears in the coastal plain 

echo the structural fabric of the mountains lending 

support to the possibility that these color and tonal 

anomalies reflect in some way the configuration of the 

subsurface, specifically fault blocks and attendant 

structures.

Subtle circular anomalies are observed in the Landsat images and appear to be concentrated north of 

lat 14°30'N. Salt is being mined from outcrops of 

Miocene age which have surfaced along the Red Sea 

Coast, particularly around Salit (El Shazly, 1967). It is 

also understood that an oil company had drilled several of its wells on gravity lows, suggesting that salt 

domes were its exploration targets (privileged communication, 1975). The aeromagnetic survey revealed 

that no magnetic anomalies are directly associated 

with these features. As a consequence, it is confidently felt that some of the circular anomalies reflect salt 

diapirs. Their concentration north of lat 14°30'N. suggests a thickening of the section in that area, strengthening the results of the aeromagnetic interpretation.

The subtle circular anomalies (such as those targeted on fig. 13) are best seen in band 7 images and 

in stretched false-color composites. While most of the 

anomalies appear as breaks in the tonal pattern of 

the plain, some are associated with vegetation occurrences.

Of the five wells drilled by an oil operator in the 

early 1960's, three of them are located on circular 

anomalies. It is observed that all of the wells drilled 

on circular anomalies lie on the flanks rather than on 

top of structural basement highs as interpreted from 

the aeromagnetic data, further supporting the contention that these circular anomalies reflect the presence 

of numerous diapirs.

44°

16 C

vMC«S

;»K&3^

FIGURE 12.—Interpretation of lineaments, circular and tonal 

anomalies from Landsat data.

The color or tonal anomalies to which we alluded 

are highlighted in a portion of Landsat-1 scene 1117- 

06562 (fig. 14). The streaks, trending southwesterly 

appear to be related to the onshore extension of faulting as interpreted from our offshore seismic program. 

We feel that these represent a reorientation of the 

drainage patterns as a consequence of southwest tilting of the section along these faults.

The alinement of northwesterly trending streaks 

suggests that they may be the expression of faulting 

parallel to the Red Sea rift axis. Stream offsets along 

one such tonal anomaly indicate approximately 3 km 

of right lateral offset. The association with earthquake
90 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Iflrf

O 

Q_

E

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Q_

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LANDSAT DATA CONTRIBUTIONS TO HYDROCARBON EXPLORATION 91

FIGURE 14.—Detail of streaks and tonal anomalies on Yemen 

coastal plain, Landsat-1 image 1117-06562, bands 4, 5, and 

7, November 17, 1972.

epicenters (Fairhead and Girdler, 1970) further indicates that these streaks are the surface expressions 

of faulting (fig. 12).

Compagnie General de Geophysique (CGG) flew a 

4,600-km aeromagnetic survey for this exploration 

effort in April 1975. The results of this survey were 

very gratifying because they not only confirmed the 

results of the offshore work but made many of the 

features seen in the Landsat imagery understandable 

in a structural context. A few of our observations may 

serve to illustrate this point.

A north-northwest-trending fault system (interpreted by CGG) parallels the mountain front and 

some of the linears observed within and at the foot 

of the mountains.

The extensions of some lineaments from the mountains onto the Tihama Plain coincide with high magnetic gradients not initially defined as faults. This 

aids in amplifying the interpreted fault pattern.

Conversely, magnetic events interpreted as basement faults coincide with stream courses emerging 

from the mountains, suggesting structural control of 

some of the drainage patterns.

The flanks and basinal axis of a 3-km deep magnetic anomaly are reflected by surface linears.

Numerous other interrelationships between magnetic data and linears in the Tihama Plain assist in 

deciphering the structural development of the area.

It is of particular interest to note that Landsatobserved linears are not solely related to fault and 

fracture patterns but often reflect deep-seated structural trends and a variety of geologic phenomena.

Considering its demonstrated versatility, low cost, 

and ready access, Landsat imagery deserves to be 

appjied to all integrated exploration efforts, foreign 

or domestic.

ACKNOWLEDGMENTS

We wish to express our appreciation to Santa Fe 

International Corporation for encouraging us to prepare this paper. Our thanks to Dr. M. K. El Ayouty of 

EGPC for permitting us to present our findings in 

Egypt and to Elsevier Publishing Company for permission to reproduce Said's geologic map. We also thank 

Peter Coberly and Michael Wallace of Custom Color 

Labs in North Hollywood, California, who produced 

our Landsat false-color composites and Santa Fe's 

Art Department which produced the illustrations for 

this paper. Special appreciation is due to Dr. William 

A. Fischer and Donald Orr of the USGS EROS Program for inviting us to publicize our work with Landsat imagery.

REFERENCES

Abdel-Gawad, M., 1969, New evidence of transcurrent 

movements in Red Sea area and petroleum implications: Am. Assoc. Petroleum Geologists Bull., 

v. 53, no. 1, pp. 1466-1479.

El Shazly, E. M., 1967, Oil shows in Yemen and oil 

bubbles in rock salt: Arab Petroleum Congress, 

6th, Baghdad 1967, Paper no. 40 ;B-3).

Fairhead, J. D., and Girdler, R. W., 1970, The seismicity of the Red Sea, Gulf of Aden and Afar 

triangle: Royal Soc. London Philos. Trans., ser. A, 

v. 267, no. 1181, pp. 49-74.

Moody, J. D., and Hill, M. J., 1956, Wrench fault tectonics: Geol. Soc. America Bull., v. 67, pp. 1207- 

1246.
92 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Lowell, J. D., Genik, G. J., Nelson, T. H., and Tucker, S., eds., Petroleum and global tectonics: PrinceP. M., 1975, Petroleum and plate tectonics of the ton Univ. Press, pp. 129-153. 

southern Red Sea, in Fischer, A. G., and Judson, Said, R., 1962, The geology of Egypt: Amsterdam,

Elsevier Publishing Co.
PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Measurement of Luminescence of Geochemically Stressed 

Trees and Other Materials

By W. R. Hemphill, 1 R. D. Watson, 2 R. C. Bigelow, ;! and T. D. Hessen, :i 

U.S. Geological Survey

ABSTRACT

The Fraunhofer line discriminator (FLD) is an airborne electro-optical device which operates as a nonimaging radiometer and permits detection of solarstimulated luminescence several orders of magnitude 

below the intensity detectable with the human eye. 

Procedures employing a laboratory fluorescence spectrometer permit prediction of the FLD detectivity of 

a material prior to mounting an airborne test. Luminescence spectra of the material are corrected for 

wavelength variation in spectrometer source and 

detector sensitivity and solar illumination. By comparing these results with the luminescence of a rhodamine 

WT dye standard, the luminescence of the material 

may be expressed in terms of rhodamine dye equivalency at the wavelengths of several Fraunhofer lines. 

The FLD detectivity may be assessed at each Fraunhofer line, and the optimum line for field observation 

of the material may be selected.

Airborne tests of a redesigned FLD permitted 

measurement of differences in the luminescence of 

trees growing in soils containing geochemically anomalous concentrations of copper (near Denver, Colorado) and molybdenum (near Gardnerville, Nevada) 

from trees growing in background areas nearby. In 

the tests near Denver, luminescence contrast between 

background and stressed trees tended to be higher 

during periods when cloud cover was less than 10 

percent; in most cases, contrast was insignificant 

when cloud cover exceeded 10 percent. Although 

diurnal variations were also observed, these do not 

appear to be predictable or systematic. In other airborne tests, the FLD distinguished luminescing phosphate rock and gypsum from sandstone and siltstone

near Pine Mountain, California, and dispersal of oil in 

a natural seep from seawater in the Santa Barbara 

Channel.

INTRODUCTION

Laboratory and field study of the measurement and 

interpretation of luminescent materials began in 1964 

using an active 4 ultraviolet imaging system (Hemphill 

and others, 1965; Hemphill and Carnahan, 1965). This 

work led to the development of a prototype Fraunhofer line discriminator (FLD), an airborne remotesensing tool for measuring luminescence. The FLD 

was designed to operate on the Fraunhofer line depth 

principle (Kozyrev, 1956; Grainger and Ring, 1962) 

which uses the Sun as an excitation source and permits detection of luminescing materials under daylight 

conditions. Experiments with the instrument showed 

that selected materials, such as luminescing tracer 

dyes could be detected in very small quantities (Hemphill and others, 1969; Stoertz and others, 1969). For 

example, rhodamine WT dye was detected in the 

Pacific Ocean west of the Golden Gate in California 

in concentrations of less than 5.0 ppb (parts per billion). Attempts to measure the luminescence of other 

materials were not successful because (1) the prototype FLD operated at 589.0 nm (nanometres), the 

wavelength of the sodium D Fraunhofer line, and 

many materials luminesce at other wavelengths and 

(2) the sensitivity was an order of magnitude less than 

required for detection of some of these materials.

In order to predict optimum wavelength and sensitivity requirements for detection of materials other 

than rhodamine WT, luminescence of a variety of

1 Reston, Virginia; f Flagstaff, Arizona; 3 Denver, Colorado.

4 An "active" system uses an artificial source, in this case a 

cathode ray tube, to stimulate luminescence.

93
94 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

materials was measured with a laboratory fluorescence spectrometer in terms of rhodamine WT, used 

as a laboratory standard. These results, coupled with 

those obtained with the prototype FLD, were used as 

a basis for redesigning an FLD with an order of magnitude increased sensitivity. This redesigned model, 

built by the Perkin-Elmer Corporation, 7' operates at 

three discrete Fraunhofer lines, hydrogen ft at 486.1 

nm, sodium D at 589.0 nm, and hydrogen a at 656.3 

nm and has the sensitivity to detect rhodamine WT 

dye in concentrations as low as 0.1 ppb in 0.5 m of 

water at 20° C.

The objectives of this report are (1) to present the 

results of laboratory and field measurement of luminescence of geochemically stressed trees, phosphate 

rock, and crude oil and (2) to demonstrate how the 

laboratory measurement of luminescence can be used 

to predict and interpret field measurements with the 

FLD.

Since 1971, development of the redesigned FLD by 

the Perkin-Elmer Corporation, as well as associated 

laboratory and field studies, has been supported by 

the Advanced Applications Flight Experiments (AAFE) 

Program of NASA (NASA Order L-58,514), the Earth 

Resources Observation Systems (EROS) Program of 

the Department of the Interior, and the Geologic 

Division of the U.S. Geological Survey.

FRAUNHOFER LINE DEPTH METHOD

Fraunhofer lines are dark lines in the solar spectrum 

caused by selective absorption of light by gases in 

the relatively cool upper part of the solar atmosphere. 

Line widths range from less than 0.01 nm to several 

tenths of a nanometre, and the central intensity of 

some lines is less than 10 percent of the adjacent 

continuum. The lines are sharpest, deepest, and most 

numerous in the near ultraviolet, visible, and nearinfrared regions of the electromagnetic spectrum.

The Fraunhofer line-depth method of measuring 

luminescence involves observing a selected Fraunhofer line in the solar spectrum, and measuring the 

ratio of the central intensity of the line to a convenient 

point on the continuum a few tenths of a nanometre 

distant; this ratio is compared with a similar ratio of 

a conjugate spectrum reflected from a material that 

is suspected to luminesce. Both ratios normally are 

identical, but luminescence is indicated where the 

reflected ratio exceeds the solar ratio. Variation of

reflectivity with wavelengths is negligible for most 

materials over spectral ranges of only a few tenths of 

a nanometre; therefore, reflectivity differences between the central intensity of the Fraunhofer line and 

the adjacent continuum can generally be ignored. 

Equations illustrating the relation of Fraunhofer line 

depth ratios to luminescence are presented in the 

Manual of Remote Sensing (Am. Soc. Photogrammetry, 1975, p. 116-118).

LABORATORY PREDICTION OF THE

FRAUNHOFER LINE DETECTIVITY OF

LUMINESCENT MATERIALS

In order to assess the sensitivity required to detect 

luminescing materials, Hemphill and Stoertz (1971) 

and Watson and others (1973, 1974) used a laboratory 

fluorescence spectrometer (fig. 1) to measure the luminescence intensity of materials at six Fraunhofer lines 

(396.8, 422.7, 486.1, 518.4, 589.0, and 656.3 nm) in 

terms of equivalent luminescence of specific concentrations of rhodamine dye. The spectrometer was 

operated so as to produce excitation spectra; that is, 

the excitation monochromator was scanned, exciting 

the sample with monochromatic light in the near ultraviolet and visible spectrum, while the emission monochromator was stationary at the wavelength of a 

specific Fraunhofer line. This arrangement provided a 

system in the laboratory analogous to an FLD in the 

field, where the broadband excitation of the Sun produces an emission in a luminescent material, the intensity of which is monitored at one or more Fraunhofer lines. The spectrometer, equipped with a

' Use of trade name in this paper is for description purposes 

only and does not constitute an endorsement of the product by 

the U.S. Geological Survey.

FIGURE 1.—Laboratory fluorescence spectrometer. Source (A), 

excitation monochromator (B), sample compartment (C), emission monochromator (D), corrected spectra attachment (E), 

and recorder (F).
MEASUREMENT OF LUMINESCENCE 95

corrected spectra attachment, automatically adjusted 

for the wavelength dependence of the source and 

detector and produced a corrected distribution of 

excitation intensity.

To relate all luminescence spectra to one set of 

conditions, rhodamine WT was used as the reference 

"standard" prior to each measurement. When the area 

under the curve of the excitation spectra of the sample 

was compared to the area under the curve for rhodamine WT dye (at a specific dye concentration), a relative equivalent rhodamine WT concentration was 

obtained. For example, a sample having an integrated 

excitation intensity of 50 was compared to a rhodamine WT concentration of 10 ppb, which also has an 

integrated excitation intensity of 50; the sample is 

said to have had an equivalent luminescence of 10 ppb 

rhodamine WT. This standardization makes it possible 

to correct for instrument response variations during 

measurement and to assess results achieved in the 

laboratory in terms of whether or not the same material in the field would be within the sensitivity range 

of an airborne FLD.

To obtain the same wavelength and intensity dependence of luminescence in the laboratory as would 

be observed in an PIlD measurement, the sourcedetector corrected spectra must be convoluted with 

the spectral intensity of total solar radiation (direct 

sunlight plus diffuse skylight). A further correction is 

required when adjusting the standard of rhodamine 

dye as measured in a centimetre quartz cell in the 

spectrometer to that measured in the field, where 

sunlight penetrates the material and stimulates luminescence at a depth that is a function of the material's 

absorption. Descriptions of the solar and depth corrections are presented by Watson and others (1974) 

and by the Arnerican Society of Photogrammetry 

(1975, p. 118-12$).

DESCRIPTION OF THE FRAUNHOFER 

LINE DISCRIMINATOR

The FLD consists of an optical head, electronic 

console, and light collector as shown in figure 2. The 

main components in the optical head are two telescopes, one Earth-looking and one sky-looking; a rotating optical chopper wheel; three replaceable optical 

filter sets; and a photomultiplier with its power supply. 

Sunlight and skylight falling on the diffuse surface of 

the light collector are reflected by a mirror into the 

telescope of the sky-looking channel. The Earthlooking telescope observes the target whose reflectivity and luminescence are to be measured. Light 

from the two telescopes is sequentially routed through

two different paths by the rotating chopper wheel. In 

one path, light passes through a filter which is centered at a specific Fraunhofer line but whose bandpass is several hundredths nanometres wider than the 

Fraunhofer line. This signal constitutes the light 

intensity measured on the solar continuum adjacent to 

and including the Fraunhofer line and is designated 

signal "a" in the sky-looking channel and signal "d" 

in the Earth-looking channel. In the other path, a 

Fabry-Perot interference filter, with half-width of less 

than 0.07 nm, passes light coincident with the intensity 

of the central part of the Fraunhofer line; this signal 

is designated signal "b" in the sky-looking channel and 

signal "c" in the Earth-looking channel. These signals 

are fed to a mini-computer that generates luminescence and reflectance by solving the following equations: P =(d-c)/(a-b); r=(d/a)- P , where P is reflectance and r is the luminescence coefficient. Both p and 

r are displayed as four-digit numbers (from 0000 to 

9999 counts) on the front panel and are fed to a 

digital printer for permanent record; hence, 100 

counts for r implies a luminescence of 1 percent. Reflectance values are displayed and recorded as percent directional reflectance. Inasmuch as displayed 

and recorded luminescence are only proportional to 

true luminescence for each substance measured, the 

luminescence count is referenced to the count from 

a standard (such as a dye sample or a photographer's 

gray card), permitting relative luminescence measurements to be made. Reflectance and luminescence 

values are presented in this paper in terms of their 

mean, plus or minus the standard deviation of the 

mean (Hoel, 1965, p. 139).

FIGURE 2.—Perkin-Elmer FLD, showing the optical head 

electronic console (B), and light collector (C).

(A),
96 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

An automatic gain control is used to monitor and 

maintain the a-signal at a nearly constant level by 

varying the gain of the photomultiplier tube (PMT) 

detector. This permits measurements under a wide 

range of illumination and allows the PMT to operate 

at full gain under low illumination. Three sets of 

Fabry-Perot niters are available, permitting measurement at the 656.3-, 589.0-, and 486.1-nm Fraunhofer 

wavelengths. Additional niters can be made at other 

Fraunhofer wavelengths, including 396.8, 422.7, and 

518.4 nm.

Ground tests show that rhodamine WT dye can be 

detected at the 589.0-nm Fraunhofer line in 0.5 m of 

water under clear sky conditions in concentrations as 

low as 0.1 ppb; however, sensitivity under field conditions is generally considered to be 0.25 ppb. The 

relationship between dye concentration and luminescence measured by the instrument is approximately 

linear, with 1.32 ppb equating to 100 FLD counts. 

Luminescence measurements were about 25 percent 

higher under clear sky conditions than under overcast 

conditions.

Figure 3 shows the FLD optical head and light collector installed in a basket atop the landing skid and 

adjacent to the fuselage of a helicopter. The system 

also includes (1) a television camera with a remotely 

controlled focus and zoom lens for monitoring the 

target measured with the FLD, (2) a second television 

camera which monitors a bank of light emitting diodes 

displaying reflectance and luminescence data that are 

continually updated by the digital output of the FLD, 

(3) a tape recording system for recording the data 

from both cameras and additional voice description, 

and (4) a television monitor on which is displayed in 

real time the target scene upon which is superimposed 

the reflectance and luminescence counts. Boresighting of the viewing system is achieved by positioning 

a luminescence panel on the ground and marking the 

position of the panel on the television screen by the 

luminescence indicated while hovering over the panel. 

The viewing system has proven dependable and permits discrimination of small luminescence targets 

which would otherwise be lost in data reduction. It 

also permits storage of both video and digital data in 

a form which can be replayed and analyzed in the 

laboratory.

Current operational procedures for airborne measurements with the FLD are as follows:

1. Optical filter and electronic warmup—30 minutes.

2. Preflight calibration using reflectant and luminescent chips.

FIGURE 3.—FLD optical head and light collector installed in a 

basket mid-ship of a Bell Jet Ranger helicopter.

3. Inflight systems check using a ground-deployed 

luminescent panel.

4. Airborne luminescence and reflectance measurements over target area.

5. Postflight calibration using reflectant and luminescent chips.

Air temperature, extent of cloud cover, and other 

meteorological parameters, as appropriate, are recorded throughout the day.

GEOCHEMICALLY STRESSED VEGETATION

The relationship between luminescence and photosynthesis in plants is complex, but, in general, factors 

that both impede and enhance photosynthesis can 

modify luminescence (Hollaender, 1956). Several such 

factors exist in nature. Based on the air pollution work 

of O'Gara (1922), Thomas (1961, p. 236-237) ranked 

cultivated and native plants according to resistance to 

sulfur dioxide fumigation. Thomas noted substantial
MEASUREMENT OF LUMINESCENCE 97

variability in sulfur dioxide susceptibility of some 

species, including conifers, but others were relatively 

constant. Alfalfa, barley, and cotton were most sensitive. Using alfalfa as unity, elm, birch, sumac, and 

poplar were about 2.5 times more resistant, pine 7-15 

times more resistant, and live oak 12 times more resistant. Thomas (1961, p. 253) also noted that 3- to 

4-month-old ponderosa needles were sensitive to 

hydrogen fluoride fumigation but that old needles 

were resistant.

Another such factor is geochemical stress, where 

abnormally high concentrations of one or more 

metallic elements may subject plants to chemical and 

physiological changes. Copper and zinc are toxic if 

present in large quantities (Kramer and Kowlowski, 

1960, p. 225-226) and are reported to produce symptoms closely resembling iron chlorosis (Sauchelli, 

1969, p. 65). J. E. McMurtrey (in Sauchelli, 1969, p. 

156) notes that copper in excess of 0.1 ppm stunted 

tobacco plants. F. A. Gilbert (in Sauchelli, 1969, p. 

158) states that growth of tomatoes in nutrient solution was reduced by as little as 1 ppm copper. 

Sauchelli (1969, p. 112) cites zinc having a toxic effect 

in some cereal grains where levels exceed 150 ppm 

and in citrus where levels exceed 220 ppm. K. C. 

Beeson (in Sauchelli, 1969, p. 133 and 138) reports 

that concentrations of molybdenum in plants may vary 

from less than 0.1 ppm to more than 300 ppm without 

adverse effect on growth. Press (1974, p. 374-375) 

reports that bean plants grown in solutions containing 

varying concentrations of lead exhibited chlorosis and 

that spectral reflectance at 550 nm ranged from 15 

percent for 1 ppm (part per million) lead to more than 

30 percent for 500 ppm lead.

Watson, Hemphill, and Hessin (1973) grew bean 

plants hydroponically and treated the nutrient solutions with varying metal concentrations, including 

molybdenum, copper, zinc, and lead, to demonstrate 

that luminescence is an indicator of geochemical 

stress produced by metal toxicity. Measurements were 

made both in the early stage of growth and at full 

maturity. Table 1 shows luminescence differences observed for 10 plants, 5 nonstressed and 5 stressed 

with 10 ppm sodium molybdate (NaMOJ. Both groups 

were grown in a Hoagland No. 2 solution. Differences

in luminescence at 2 weeks are reversed at 5 weeks. 

The reversal not only occurs between stressed and 

nonstressed plants but also between large and small 

leaves. The difference in luminescence is reduced at 

5 weeks for the large leaves. These results illustrate 

the complexity of luminescence during various stages 

of growth and tend to support the observations of 

Thomas (1961, p. 253) in his plant fumigation experiments noted above.

To investigate the luminescence of needles of Pinus 

ponderosa, trees growing in a copper- and zinc-rich 

soil near Malachite Mine, Jefferson County, Colorado 

(fig. 4), were measured in the field using the laboratory fluorescence spectrometer and were compared 

to measurements of needles from background trees. 

Country rock where trees grow includes biotite schist 

and hornblende gneiss, and younger pegmatite dikes; 

all are of Precambrian age (Huff, 1963).

Figure 5 shows the copper anomaly in the Malachite Mine area and the location of background and 

geochemically stressed tree groups. Measurements 

were made both diurnally (every 4 hours over a 24- 

hour period) and seasonally (every 4-5 weeks, JulyNovember 1973 and April-May 1974). Data during the 

period from December 1973 through March 1974 

could not be obtained because of heavy snow. Four 

twigs were collected from each of seven background 

and seven geochemically stressed trees making a total 

of 56 samples that were measured. The needles were 

removed from the twigs, placed on a black-matte nonluminescent surface, and measured in the front-surface 

mode in the spectrometer. The 4-hour spacing between separate collection runs was determined by the 

time required for sample collection, measurements, 

and logistical considerations, but it was verified that 

the period of as much as 2 hours between time of 

collection and completion of measurement did not 

alter the luminescence of the needles beyond experimental error.

Subsequent measurement of copper and zinc in the 

ash of the needles was by standard analytical techniques, and table 2 shows the results of chemical 

analyses of samples collected during late summer and 

autumn of 1973. Mean copper content of ash from 

stressed trees on four dates exceeds the mean copper

TABLE 1.—Luminescence (source-detector, solar, and depth corrected) of 10 bean 

plants expressed in terms of rhodamine WT equivalency (ppb). The plants were grown 

hydroponically in Hoagland #2 nutrient solution; five of these plants were geochemically stressed with 70 ppm sodium molybdate (NaMOJ.

Stressed

Description

Top 

Top

surface, 

surface.

large 

small

trifoliate 

trifoliate

leaves

leaves

2 weeks

0.62

.67

5 weeks

1.05 

.64

Nonstressed

2 weeks

0.45 

.49

5 weeks

1.19 

.98
98 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 4.—Location of Malachite Mine area, Jefferson County, Colorado. Stipple pattern 

shows area of figure 5. (From Huff, 1963.)

EXPLANATION

B 

Shaft

Portal of adit

Isopleths indicating soils 

of equal copper content 

in parts per million Dashed 

where approximately located

Denver, 

C 0 L 0 R A D 0

0 IOO 200 300 400 FEET 

I I ; i i 

0 ' ' ' ' ' ' 'IOO METRES 

CONTOUR INTERVAL 50 FEET

FIGURE 5.—Distribution of copper in soil and location of sample trees growing in background and anomalous soils.

(Modified from Huff, 1963.)
MEASUREMENT OF LUMINESCENCE 99

TABLE 2.—Mean and standard deviation of copper and zinc content (ppm) of needle ash 

from 73 Pinus ponderosa growing in geochemically anomalous and background soils

Seven stressed trees Six background trees

Sample Date

July 26, 1973

Aug. 30, 1973

Oct. 18, 1 973

Nov. 12, 1973

Copper

. __ _ 175 + 16

180+8

125 + 5

140+7

Zinc

>2000

2180 + 77

2330+36

2080+35

Copper

110 + 7

115+4

100 + 7

100+4

Zinc

730 + 35

1130+30

700+84

880+30

content of the background tree ash by factors of 1.2 

to 1.6. Mean zinc content of stressed tree ash exceeds 

the background trees by factors of 1.9 to 3.3. Distribution of copper in the soil in the vicinity of the mine 

is given by Huff (1963). Additional ash analyses for 

copper content of 16 trees in the area are given by 

Howard, Watson, and Hessin (1971). These analyses 

show that copper content ranges from 280 ppm to 

660 ppm for eight stressed trees and from 120 ppm 

to 180 ppm for eight background trees.

Figure 6 shows the spectral excitation curves obMPF-3 FLUORESCENCE SPECTROMETER

100

90

80

* 70

60

50

40

30

20

10

Emission wavelength 

Emission slit 

Excitation wavelength 

Excitation slit 

Scan speed 

Sensitivity

656.3

1.0

Scan

20.0

3.0

30.0

Remarks Water cooled: Front surface mode

PINE NEEDLES • Em

• 340

E= 656.3:

RHODAMINE WT: 1200)119/1

. 'Er 

I

x = 20 nm

= 187 (Background) 

= 50 (Stressed)

r

•m

, Ax=

440 

E = 589.0 I.- =11,748

Rhodamine WT 

(x72)

Background

300 400 500 600 

EXCITATION WAVELENGTH (NANOMETRES^

FIGURE 6.—Excitation spectra of Pinus ponderosa needles 

from geochemically stressed and background trees, 

Malachite Mine, Jefferson County, Colorado, as measured with a laboratory fluorescence spectrometer 

(source-detector corrected only). Integration of the area 

under each excitation spectrum permits comparison with 

the excitation spectra of a rhodamine WT standard.

tained in March 1973 for both groups of trees and also 

for rhodamine WT dye at a concentration of 1,200 

ppb. The integrated excitation intensity is significantly 

greater for the background than for the stressed trees; 

solar-corrected rhodamine WT equivalents are 19 ppb 

and 5 ppb, respectively. Solar- and depth-corrected 

rhodamine WT equivalency is 0.4 and 0.2 ppb, respectively.

In order to test the sensitivity of the FLD to chlorophyll luminescence of stressed and nonstressed Pinus 

ponderosa, twigs were collected from seven stressed 

and seven background trees at the Malachite Mine site 

in early March 1974. Luminescence measurements 

were made within 2 hours outdoors at the Denver 

Federal Center and referenced to a nonluminescent 

gray-card standard. Mean and standard deviation of 

the mean of FLD luminescent counts was 107 ±0.5 

for background trees and 90 ±3.0 for stressed trees.

Following this initial experiment, the FLD was used 

from a helicopter to measure the luminescence of 

stressed and nonstressed Pinus ponderosa trees at the 

Malachite Mine, both on a diurnal and seasonal basis 

for the period of September 1974 through July 1975.

These results, combined with the results acquired 

with the fluorescence spectrometer during summer 

and autumn 1973 and spring 1974, indicate that luminescence contrast between background and anomalous trees was independent of air temperature, relative humidity, and wind speed, but maximum contrast, 

ranging from 1.4 to 2.2, tended to occur during parts 

of 6 days when cloud cover was less than 10 percent 

and the sun was not obscured by clouds (fig. 7). r' On 

6 days when cloud cover exceeded 10 percent, the 

diurnal luminescence trace of both groups tended to 

be similar and contrast did not exceed 1.4 (fig. 8).° 

Data collected on September 26, 1973, September 24, 

1974, and April 22, 1975, are exceptions (fig. 9). c A 

maximum contrast of 2.7 at 11:45 a.m. on September 

26, 1973, was obtained during a period of 100-percent 

cloud cover. Contrast on April 22, 1975, does not

6 Standard National Weather Service nomenclature: relative 

humidity in percent, 'wind speed in miles per hour, and cloud 

cover in percent.
100 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

JULY 26,1973 MPF-3

MAX CONTRAST I 6 AT IOOO MRS 

Stressed trees 25 ± 4 

Background trees 16 ± 3

OCTOBER I8.I973 MPF-3

MAX CONTRAST 2 I AT I300 MRS

Stressed trees 30 ± 4 

Background trees 61 * 15

900 IOOO IIOO I200 I300 1400 1500 1600 1700 900 IOOO IIOO 1200 1300 1400 1500 1600 1700

90

80

70

60

UJ

§ 50

H

| 40 

<

30

20

10

0

APRIL 30, 1974 MPF-3

MAX CONTRAST 2 2 AT 1145 HRS 

Stressed trees 35 * 8 

Background trees 17 * 6

^Relative humidity

Stressed trees 

Background trees

900 IOOO IIOO 1200 1300 1400 1500 1600 1700

FEBRUARY 25,1975 FLD

MAX CONTRAST I 5 AT 1445 HRS

Stressed trees 47 * 6 

Background trees 73 * 4

900 IOOO IIOO 1200 1300 1400 1500 1600 1700

90 p 

80-

70- 

60- 

50- 

40- 

30- 

20-

10-

0

MAY 24,1975 FLD

MAX CONTRAST1.6 AT IOOO HRS

90

Relative humidity

\______

Stressed trees 48*7 

Background trees 73*6 70

Wind speed

Cloud cover

JUNE 23, 1975 FLD

MAX CONTRAST I 4 AT 0900 HRS

Stressed trees 25*6

Background trees

900 IOOO IIOO 1200 1300 1400 1500 1600 1700 900 IOOO IIOO 1200 1300 1400 1500 1600 1700

MOUNTAIN STANDARD TIME

FIGURE 7.—Temporal luminescence of Pinus ponderosa and meteorological parameters. Maximum luminescence contrast between background and anomalous trees tends to occur during periods of minimum cloud 

cover. Standard deviation of the mean, computed for the time of maximum contrast, is at the 95-percent 

confidence level.
MEASUREMENT OF LUMINESCENCE 101

90

80

ro

60

50

40

30

20

10

AUGUST 30, 1973 MPF-3 \ 

MAX CONTRAST I 2 AT 1130 MRS \

Stressed trees 30 * 3 

Background trees 25 * 2

Relative humidity

Stressed trees

Relative humidity

0900 IOOO IIOO 1200 1300 1400 1500 1600 1700

100 ——— —-1— - 

90 r- /

Cloud cover NOVEMBER 6, 1973 MPF-3 

MAX CONTRAST I I AT 1200 MRS 

Stressed trees 38 * 3 

Background trees 42*2

900 IOOO IIOO 1200 1300 1400 1500 1600 1700

LJ 

Q

1-

a_

5

90 1-

80

70

60 

50

40

30

20

10

n

MAY 24,1974 MPF-3

MAX CONTRAST 1 2 AT 

~ Stressed trees 30

Background trees

—

—

- /

Relative humidity /

- 4 /^z^ ^*</

Background trees /

V-

\ y \ \

^

/

IIOO MRS / 

12 /

27 ±2 /

'

/^Cloud cover

/

Stressed trees

y

^ ^

Wind speed

I I I I

100

90

80

70

60

50

40

30-

20

\ DECEMBER 3, I974 FLD

X MAX CONTRAST I 2 AT I430 MRS 

jS\ Stressed trees 22±8 

Cloud cover-" ^ Background trees 27±5

Relative humidity

900 IOOO IIOO I200 I300 I400 I500 I600 I700 900 IOOO IIOO I200 I300 I400 I500 I600 I700

90

80

70

60

50

40

30 h

20

10 -

JANUARY 14, I975 FLD \ Cloud cover 

MAX CONTRAST I 2 AT I430 HRS\ /^

Stressed trees 23 * 9

Background trees 30*12

Relative humidity

h ~L~

Background trees

Stressed trees

900 IOOO IIOO 1200 1300 1400 1500 1600 1700

Temperature JULY 18,1975 FLD

MAX CONTRAST I 17 AT 1300 MRS 

Stressed trees 54 ± 3 

Background trees 46 * 4

/ Wind speed

r~—~ — — — _1_ —

900 IOOO IIOO 1200 1300 1400 1500 1600 1700

MOUNTAIN STANDARD TIME

FIGURE 8.—Temporal luminescence of Pinus ponderosa and meteorological parameters. Minimum luminescence 

contrast between background and anomalous trees tends to occur during periods of maximum-cloud cover. 

Standard deviation of the mean, computed for the time of maximum contrast, is at the 95-percent confidence level.
102 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

IOO 

90

80 

70 

60 

50 

40 - 

30

20 -__ 

10 -

SEPTEMBER, 26,1973 MPF 

MAX. CONTRAST 2.8 AT 1045 MRS

Stressed trees 15 ± 

Background trees 42*11

Relative Humidity

Background Trees 

Stressed Trees 

Wind Speed

900 1000 1100 1200 1300 1400 1500 1600 1700 

MOUNTAIN STANDARD TIME

FIGURE 9.—Temporal luminescence of Pinus ponderosa 

and meteorological parameters. Luminescence contrast 

of background and anomalous trees do not correlate 

with cloud cover conditions cited in figures 7 and 8. 

Standard deviation of the mean, computed for the time 

of maximum contrast, is at the 95-percent confidence 

level.

90

80

70

60

UJ

§50

Ij 

I 40

30

20

10

90

80

70

60

50

40

30

20

SEPTEMBER, 24,1974 FLD 

MAX. CONTRAST 1.5 AT 0930 MRS. 

Stressed trees 27 * 9 

Background trees 19 ± 5

Background Trees

\ Stressed Trees- 

__\Relative Humidity ^

Wind Speed -~-_ .——1— -—— —y

1 1 1

900 1000 1100 1200 130,0 1400 1500 1600 1700

APRIL, 22,1975 FLD 

MAX. CONTRAST 1.2 AT 1430 HRS. 

Stressed trees 66 * 5 / 

*I2 /

\

Background trees 79

\

\

Cloud Cover

Relative Humidity-^^ Humidity ^

Wind Speed

900 1000 1100 1200 1300 1400 1500 1600 1700
MEASUREMENT OF LUMINESCENCE 103

exceed 1.2 despite cloud cover of less than 20 percent 

prior to 2 P.M. Contrast of 1.3 at 3:30 on September 

24, 1974, is during a period of no cloud cover.

Standard deviation of the mean for FLD ground 

measurements of twig samples from Pinus ponderosa 

at the Denver Federal Center in March 1974 (see 

above), as well as for the fluorescence spectrometer 

measurements of trees during 1973 and 1974 at the 

Malachite Mine site ranged from less than 1 percent 

to 3 percent of the mean. However, standard deviation of the mean of airborne FLD measurements during 1974 and 1975 were frequently somewhat higher. 

This was due to the relatively sparse foliage of the 

Pinus ponderosa (which permitted bare ground to be 

observed through the foliage at relatively high frequency), whereas, pine needles completely filled the 

field of view in both the spectrometer and ground 

based FLD measurements. This experience suggests 

that a smaller standard deviation may be assured in 

airborne measurements by avoiding species or individual trees with sparse foliage.

In addition to Pinus ponderosa, airborne FLD measurements were also made July 25, 1974, and May 6, 

1975, on trees growing in soils containing background 

and anomalous concentrations of molybdenum 17 km 

southeast of Gardnerville, Nevada (fig. 10). Country 

rock includes limestone, monzonite, and volcanic 

rocks of Triassic to Jurassic age. Trees in the area are 

limited to pinon pine (Pinus monophylla) and juniper 

(Juniperus utahensis). In the 1974 measurements, the 

standard deviation of the mean of FLD luminescence 

counts for pinon pine commonly exceeded 50 percent 

of the mean; this is also attributed to viewing background soil and grass through the low-density pine 

foliage similar to the experiment at the Malachite 

Mine described above. By restricting FLD observations on both dates to denser junipers, standard deviation rarely exceeded 7 percent of the mean. 

Molybdenum content in plant ash of 32 juniper trees 

in figure 10 are shown in table 3. Figure 11 shows a 

linear regressive analysis correlating luminescence 

counts on both dates with molybdenum in concentrations of 20 to 300 ppm. Correlation coefficients of 

0.73 for the July 1974 data (17 trees) and 0.80 for the 

May 1975 data (24 trees) are significant at confidence 

levels of 99.97. Luminescence measurements were not 

performed on all 32 trees because of small size and 

low foliage density of some individuals and because 

some grew in places difficult to approach with the 

helicopter.

The 1975 data were measured at 1000 hours. Repeated measurements on 12 stressed and background 

trees at 1200 and 1500 hours showed marked diurnal

TABLE 3.—Location, molybdenum content (ppm) in ash, and 

luminescence, expressed in rhodamine WT equivalence 

(ppb), of geochemically stressed and background juniper trees 

in the Alpine Mill area. Background trees are arbitrarily 

denoted as those containing 70 ppm molybdenum or less

Tree No.

1

2

3

4

5 _ .

6 . _ _ ..

7

8

9 __ _ _ .

10

11

12

'13

14

15

16 __

17

18

19

20

21

22

23 ______________ .

24

25

26

27

28

29

30

31

32

Molybdenum

content

150

. _ 50

300

500

500

300

500

20

30

70

.. _ 50

200

500

500

70

50

100

500

150

200

500

500

100

200

70

150

200

30

70

30

._ _ 20

50

Luminescence

0.69

1.60

.73

.56

(Not measured)

.20

.74

(Not measured)

(Not measured)

1.02 .87'

.33

.53

.26

.92

(Not measured)

(Not measured)

0.18

.33

.38

.57

.58

.62

.51

(Not measured)

0.27

.88

1.09

.75

.87

(Not measured)

(Not measured)

consistency. For example, mean FLD count for background trees increased from 53 at 1000 hours to 58 

at noon, and decreased to 49 at 1500 hours. Mean 

FLD count for stressed trees showed even less variation, increasing from 37 at 1000 hours to 39 at noon 

and decreasing to 35 at 1500 hours. The 1974 data 

also appear to be diurnally consistent, although, because of high winds and helicopter power problems, 

earlier data were not acquired sequentially and the 

time of each measurement was not recorded. Both 

the 1974 and 1975 data show a decrease in luminescence of juniper with an increase in molybdenum 

content up to 300 ppm.

It is possible that luminescence may vary diurnally 

and seasonally with species; for example, although 

Pinus ponderosa repeatedly showed marked diurnal 

variability, Juniper utahensis was remarkedly consistent during the 2 days these trees were observed. A
104 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Cherokee Mine 

Area

EXPLANATION

Area of trees 

exceeding 75 ppm Mo

Sample tree

Fault

0 200 400 FEET

100 200 METRES

NEVADA 

.Gardnerville

Modified from Climax Molybdenum do to

FIGURE 10.—Location of geochemically stressed and background trees in the Alpine Mill area, about 

17 km southeast of Gardnerville, Douglas County, Nevada. Background trees are arbitrarily denoted 

as those containing 70 ppm molybdenum or less.
MEASUREMENT OF LUMINESCENCE 105

400

300

200

o 100

00

Correlation coefficientr = 0.73 (7-74) O 

= 0.80 (5-75) X

7-74

X X

5-75

0.0 0.25 0.50 0.75 1.00 1.25 1.50 1.75

LUMINESCENCE (RHODAMINE WT EQUIVALENT ppb )

FIGURE 11.—Linear regressive analysis correlating FLD luminescence counts for trees with molybdenum concentrates from

20 to 300 ppm.

TABLE 4.—Luminescence of 10 phosphate samples measured 

with the laboratory fluorescence spectrometer at 486.1 nm 

in terms of rhodamine WT equivalence (source-detector, 

solar, and depth corrected)

Sample Luminescence (ppb)

practical approach may be to restrict measurement of 

luminescence of geochemically stressed plants to 

single specie areas or to one or two species in mixed 

groups. Additional work is required to understand 

variation of diurnal and seasonal luminescence with

species. ————————————————————————————————

Blue apatite from Brazil

PHOSPHATE ROCK (low F' h ' 8h rare earths^ -—--——————— 8-0

01,,, Cunday, Colombia, Cretaceous bmall hand-carried ultraviolet lamps have been used ( 2 5% P O-,, 2% F,, 100 ppm rare earths) ___ 7.9 

to stimulate luminescing minerals and rocks, but these

methods of prospecting are limited because the lamps ^J^ ^(T^^ ph ° sphate f.

, , , rr (25% P..O-,, 2-3% F-, rare earths present) ______ 6.5 

are low powered and effective range is limited to a

metre or less. The work must be conducted at night Tennessee brown phosphate

because the low-intensity luminescence is obscured (30%+P_o.,, 3% F2 , rare earths unknown) ______ 5.4

by bright sunlight. To assess the use of the FLD in Diammonian phosphate-aqueous NH.O. + H;i PO,

prospecting for phosphate rocks, the luminescence of (N(15%), P(53%), K(0%), 0 F, ________________ 3.8

10 samples of sedimentary phosphate rocks from cook Hollow, Tennessee

several geographic locations, measured on the labora- (reprecipitable phosphate, low rare earths) ——— 2.9

tory fluorescence spectrometer, at the 486.1-nm Trjp|e super phosphate Ca,Hv POl

Fraunhofer line, are shown in table 4. All samples <N(0%), P(48%), K(0%) some F,) _________ 2.8

luminesced within the sensitivity range of the FLD

, .,_,,,, _,, /I,,,, Homeland Mine, Florida and pointed to the need for a field test. (35% p^ 3 5% ^ 200_300 ppm rare earth) ___ 1 6

Several deposits of commercial-grade phosphate 

occur in southern California (Gower and Madsen, Manatee County, Florida, red phosphate

icv:/i\ r\ r +L i • i 4. j , -4. (30% P.O.., 3% F.) _______________———— .7 1964). One of the highest grade deposits occurs near

Pine Mountain, northeast of Santa Barbara, in the North Carolina heavy fraction

upper part of the Santa Margarita Formation of ( 30% p"0- 3 - 5% ^ 20° ppm rare earths) ______ .4
106 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

EXPLANATION

II9°22'30' II9°I8'30"

Modified from Vedder, ond others (I973) 

2 Miles

3 Kilometres

Landslide deposits

Contact

Fault trace, dotted 

where concealed

Syncline, showing 

troughline

Strike and dip of beds

Anticline, showing 

crestline

FIGURE 12.—Geologic map of part of the Sespe Creek area showing location of a helicopter traverse (solid line east of Chorro 

Grande Canyon) and helicopter hovers (A through D). Numbers along traverse are FLD luminescence measurements in 

terms of rhodamine dye equivalency.

Miocene age (fig. 12) where a phosphate zone more 

than 24 m thick occurs in siltstone and siliceous shale.

Excitation spectra of gypsum and phosphate rock 

and soil samples from the Santa Margarita Formation 

measured on the laboratory fluorescence spectrometer show that luminescence at the 486.1-nm Fraunhofer line exceeds luminescence measured at 

589.0- and 656.3-nm lines. Table 5 shows that the 

luminescence of the phosphate and gypsum samples 

appear to be within the sensitivity limits of the FLD.

Two experiments were conducted to measure these 

materials in the field. Through a cooperative arrangement with the Geological Survey's Water Resources 

Remote Sensing group in Prescott, Arizona, the FLD 

was flown abroad their HU1B helicopter over the

Sespe Creek area on November 26, 1974, at a hover 

altitude of 50 m. Reflectance and luminescence of 

gypsum, phosphate rock and soil, background soil,

TABLE 5.—Luminescence of phosphate and gypsum samples, 

collected horn the Santa Margarita Formation near Pine 

Mountain, California, and measured with the MPF-3 at 

486.1 nm in terms of rhodamine WT equivalence (sourcedetector, solar, and depth corrected)

Sample Luminescence (ppb)

Phosphate pellets ____________.

Phosphate soil _______________.

Gypsum ___________________.

Gypsum soil _______________.

Assorted samples from non-phosphatic 

rocks (Tmv and Ts, fig. 12) _____.

0.37-1.05 

0.33

.65

.53

.22-0.34
MEASUREMENT OF LUMINESCENCE 107

TABLE 6.—Reflectance, FLD counts, and luminescence in terms of rhodamine WT equivalency (source-detector, solar, and depth corrected) of phosphate, gypsum, and background reference materials. Field FLD measurements were performed in November 

7974

Sample Reflectance

Gypsum 0.2253

Phosphate rock and soil .0471

Gray card

Background soil and vegetation.. _____ 

Average of 10 readings from 

Tmv and Ts (fig. 12)

FLD counts Luminescence (ppb)

68 

52 

0 

3

16

± 5 (66 

± 3 (43 

±3(0 

± 0.4

±4

±2) 

±2) 

±1)

1.16 

.95 

.26 

.30

.46

and vegetation along Chorro Grande Canyon are 

shown for the 486.1-nm Fraunhofer line in table 6. 

Although both gypsum and phosphate are luminescent, the two are significantly different in reflectance 

so that it is possible to distinguish them.

Values in parentheses in table 6 were obtained by 

placing samples of the phosphate and gypsum under 

the FLD in a static ground measurement test. Agreement between the flight and static techniques is reasonably good, with a larger standard deviation occurring in the airborne helicopter measurements 

because of the nonhomogeneity of outcrops, soil, and

vegetation in the FLD field of view. A calibration 

figure of 1.32 ppb/100 counts was used to convert 

airborne counts to rhodamine WT equivalence.

This experiment was repeated May 8, 1975, with 

a commercial rental helicopter at altitudes of 35 m 

for hover and 150 m for traverse. FLD counts for a 

single traverse are shown along the bold north-south 

line in figure 12. The counts are substantially higher 

in the Santa Margarita Formation than in the less 

phosphatic older rocks. In addition, luminescence and 

reflectance of gypsum, phosphate rock, phosphate 

soil, background sandstone, and background grass

TABLE 7.—Reflectance, FLD counts, and luminescence in terms of rhodamine WT equivalency of phosphate, gypsum, and background materials. Airborne FLD measurements were performed May 8, 1975

Run 1 Run 2

Luminescence Luminescence

Sample Reflectance FLD counts- rho. WT'(ppb) Reflectance FLD counts rho. WT (ppb)

Gypsum (hover A)

Phosphate rock and soil (hover B)

Phosphate soil (hover C)

Sandstone (hover D)

Background grass and soil

Gray card

0.111

_ _ .06

.042

.082

.041

97

77

56

41

35

0

-+- 5

-+• 7

-+- 6

•+• 4

-*- 2

-+- 5

1.54

1.28

1.0

0.80

0.72

0.26

0.0948

.051

.045

.147

.052

92 •+•

72 -*-

64 -+-

50 -*-

21 -+-

0 -+-

15

8

8

11

3

4

1.47

1.21

1.10

0.90

0.52

0.26

and soil were determined by hovering over each material along Chorro Grande Canyon (points A, B, C, 

and D, fig. 12) and collecting approximately 50 data 

points for each material. Reflectance, FLD counts, 

and rhodamine WT equivalent luminescence for two 

hover runs over Chorro Grande Canyon are shown 

in table 7.

Comparison of Tables 6 and 7 shows that relative 

values of reflectance and luminescence for gypsum 

and phosphate correlate well for both dates, although 

the 1975 data are higher; background grass and soil 

are substantially higher. These increased levels of 

luminescence could be due, in part, to greater insolation in May than in November. The differences could 

also be attributed to the fact that 1974 and 1975 

hovers were in the same area but over slightly different outcrops. Comparison between values of rhodamine WT equivalents calculated from FLD counts 

(tables 6 and 7) and those values based on measurements with a laboratory fluorescence spectrometer 

show that higher values were obtained for luminescence of phosphate from the spectrometer than with 

the FLD. This is probably caused by phosphate content of the pellet sample measured in the spectrometer in the laboratory being higher than the bulk 

phosphate rock measured with the FLD in the field. 

It is not understood why the luminescence level of 

gypsum measured with the FLD exceeds the level 

measured with the spectrometer by nearly a factor 

of 2.

In addition to the measurements noted above, phosphate rock was measured with the FLD during a
108 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

TABLE 8.—FLD counts and luminescence in terms of rhodamine WT equivalency of associated phosphate and gypsum materials in the Lakeland, Florida, area

Cray card

Phosphate venier in

Phosphate rock pile

Gypsum pile _ .

Source

dredged pit _ _.

(Royster plant) _ _.

_ _ _ 0

2 

65

._ __ 116

143 

137

189

FLD counts

-+- 2 (overcast)

it 3 (clear sky) 

-+- 12 (overcast)

-+- 4 (overcast)

± 4 (clear sky) 

-+- 11 (overcast)

it 15 (cfear sky)

Luminescence 

rho. WT (ppb)

0.26

.29

1.12

1.79

2.15 

2.04

2.75

series of airborne experiments in the Lakeland, 

Florida, area. The materials measured had been 

mined and are, therefore, not representative of 

weathered surfaces on natural outcrops as was the 

case in the California experiment. Luminescence of 

these materials is shown in table 8. Comparison of 

the gray card, phosphate rock pile, and gypsum measurements shows that the FLD performs adequately 

under overcast conditions, although rhodamine WT 

equivalency for these three materials is reduced 10, 

17, and 26 percent, respectively.

OIL SEEPS

Riecker (1962, p. 60-75) analyzed 103 crude oil 

samples from California, Colorado, Wyoming, and 

Alberta with a laboratory spectrometer; he found that 

all of them exhibited luminescence peaks in the visible region between 444 and 630 nm. Twelve percent of the samples peaked in the red at 630 nm, 

54 percent peaked in the yellow at 578 nm, and 34 

percent peaked in the blue at between 482 nm and 

442 nm. Fantasia, Hard, and Ingrao (1971) used a 

pulsed ultraviolet laser installed at dockside to discriminate several oils on seawater by measuring the 

ratio of their luminescence through narrow band 

niters centered at 433 and 533 nm.

In order to quantify the luminescence of selected 

oils in terms of rhodamine WT equivalence, the excitation spectra of 29 crude oils were measured with 

the laboratory fluorescence spectrometer by Watson 

and others (1974). The integrated excitation intensities, corrected for source-detector, solar, and depth 

effects are shown in table 9. The crude oils exhibit 

a peak rhodamine WT equivalency at Fraunhofer 

wavelengths of 518.4 nm or shorter, with 19 samples 

(65 percent) having a maximum at 518.4 nm. Luminescence of 28 of the 29 samples exceeds 0.25 ppb 

rhodamine WT equivalency and appears to be within 

the sensitivity range of the FLD.

Specific gravity of the 29 crude oils ranges from 

0.7317 to 0.9677. The dependence of bulk oil luminescence on specific gravity is shown in figure 13. A 

regressive analysis was performed on the 29 crude 

oil samples to obtain the best least-squares fit to the 

data points, with both the correlation coefficient and 

the standard error determined for six selected Fraunhofer lines throughout the visible spectrum. Correlation coefficients range from 0.34 at 656.3 nm to 0.77 

at 396.8 nm and indicate that the best correlation 

between luminescence and specific gravity occurs at 

396.8 nm.

Natural fractures in the ocean floor of the Santa 

Barbara Channel, California, permit oil of varying 

densities to seep to the surface. Throughout the 

channel, patches of oil films at various times can be 

seen with the naked eye. At times heavy crude seeps 

from narrow filaments near Coal Oil Point that extend for several miles parallel to the shoreline.

To measure the luminescence of crude oil with the 

prototype FLD, a sample of oil from the Santa 

Barbara Channel was poured into a tank of water; 

luminescence of the resulting film was not detected 

(Hemphill and others, 1969) because (1) the emission 

peak of the Santa Barbara oil is at a shorter wavelength than 589.0 nm where the prototype FLD 

operated and (2) sensitivity of the prototype FLD was 

inadequate.

Luminescence of oil seeps off Coal Oil Point were 

measured during the week of November 24, 1974, 

with the redesigned FLD operating from a helicopter 

at the 486.1-nm Fraunhofer wavelength. Data obtained 

on November 30 are shown in figure 14. Luminescence intensities of small lakes several miles inland 

from the coast average 20-40 counts less than the 

counts of so-called "clear" Santa Barbara Channel 

water, suggesting that small amounts of oil or other 

luminescing material is present in the channel.
MEASUREMENT OF LUMINESCENCE 109

TABLE 9.—Integrated excitation intensity of crude oils at specific Fraunhofer wavelengths in terms of equivalency with rhodamine WT. Samples are ordered by decreasing intensity at the 486.1-nm Fraunhofer line and corrected for source-detector, 

solar, and depth effects

Description

Sample

1C _.

2C __ .

3C __ .

4C _ _.

5C

6C _ _.

7C __ .

8C_ .

9C

10C

11C __ .

12C

13C

14C

15C

16C _ .

17C _ .

18C

19C

20C_ _ .

21C

22C _.

23C

24C_ _ .

25C

26C_ __.

27C

28C

29C

No.

. 19327

. 17394

. 31473

. 26294

. 24563

. 17636

. 29350-5 .

. 24461

. 31316

. 28212

. 31317 _ .

. 26241

. 30534-1

. 32219

__24569

. 27358

. 13786

. 27458

. 31851

. 30229-1 .

. 13588

Location

._ Michigan

._ Wyoming

._ Wyoming _ .

. Nigeria _ _ .

.--Colorado

._ Louisiana

._ Denmark

._ Mississippi _ _.

. -California - .

._ Mississippi

.-..California _ .

. Trinidad

. California

. Colorado __ .

Libya _ __ .

._ Mississippi _ .

__ Canada

Bahrain

._ Alaska _ _ _ .

. Wyoming _ .

. 25968-2 _ Wyoming _ .

. 25179

._27173 __.

. 29619

. 27360

. 14525

.17112

. 17556

. Iran

Bahrain

- California _ .

- Libya _ _ . Venezuela __ . _ Canada

_ Libya

Wavelength (nanometres)

Specific

gravity

0.8327

.7866

.8098

.8163

- _ __ .8172

.8834

.7790

.7932

-_ __ .8532

.8455

. _ _ .8377

.8318

.7317

._ _ .7713

. - .8574

.8350

. __ .8045

.7735

_ _ _ .8695

.8654

. _ _ .9110

_ _ .8430

. _ _ .8854

.8370

.8639

. _ .8481

_ _ _ .8752

_ _ _ .9677

.9312

396.8

(ppb)*

4.88

4.16

4.86

6.63

3.16

5.84

1.21

2.91

5.52

1.30

0.71

0.76

0.93

0.87

1.18

0.88

0.66

1.56

0.43

0.35

1.80

0.23

0.21

0.29

0.29

0.41

0.28

0.09

0.05

422.7

(ppb)*

12.95

11.51

13.64

12.33

8.84

11.12

3.45

6.74

8.98

3.28

1.84

2.03

2.48

2.59

3.74

2.02

1.74

2.80

1.16

0.78

2.42

0.70

0.62

0.59

0.66

0.89

0.58

0.19

0.09

486.1

(ppb)*

34.62

29.33

26.86

25.80

22.19

16.54

14.68

10.93

8.49

6.39

6.34

6.31

6.16

5.76

5.45

5.41

5.07

3.81

3.27

2.50

2.33

2.10

1.74

1.72

1.63

1.45

1.43

0.60

0.22

518.4

(ppb)*

36.36

30.46

26.36

22.17

22.63

14.84

18.16

10.58

6.91

5.93

7.77

7.22

6.89

6.48

10.64

5.66

6.40

3.78

3.95

2.91

2.29

2.52

1.97

2.25

1.90

1.60

1.06

0.78

0.26

598.0

(ppb)*

20.62

15.90

12.44

8.76

11.24

3.40

12.32

5.90

2.23

2.74

5.65

3.48

4.29

3.47

5.19

3.32

6.93

1.90

3.44

2.35

1.76

1.72

1.64

2.74

1.44

1.01

0.72

0.88

0.51

656.3

(ppb)*

5.95

6.26

3.33

3.87

4.07

2.24

5.91

2.36

0.58

1.90

2.43

1.86

1.84

2.16

2.21

1.44

2.22

0.87

2.02

0.59

1.09

1.27

0.84

1.23

0.77

0.26

0.30

0.47

0.05

* Rhodamine WT equivalency.

CONCLUSIONS

Conclusions are as follows:

1. Laboratory techniques have been developed and 

refined to permit the quantification of luminescence materials in terms of rhodamine WT dye 

equivalency and to predict reliably the detectivity of these materials with an FLD in the field.

2. The FLD has sufficient sensitivity to detect rhodamine WT dye at a concentration of 0.1 ppb 

in 0.5 m of water at 20° C; however, sensitivity 

under field conditions is generally considered to 

be 0.25 ppb.

3. Tests of the redesigned Perkin-Elmer FLD show 

luminescence measurements during clear sky

conditions are about 25 percent higher than 

under overcast conditions.

4. Airborne tests of the redesigned FLD have led to 

the development of a bore-sight television system which permits precision identification of 

ground features and correlation of these features with measured luminescence and reflectance.

5. Fluorescence spectrometer and FLD measurements of Pinus ponderosa over a 2-year period 

show significant differences in the luminescence 

of background trees and trees geochemically 

stressed by copper and zinc in the soil. Maximum luminescence contrast tends to occur dur-
110 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

10*

io3

102

io1

0.70 

10*

= -0.191201128016ex 02 

= 0.227291490025ex 02

• Sy.x = 0.780833433604ex 00

- Sm=0.293943472938ex 01 

r=-0770279558739exOO

0.80 0.90

IO4

10'

-li iu .06 o.

• m =-0.190976541393ex02

" b=0.232850504283ex 02

K Sy.x = 0.810515000180exOO

Sm = 0.305117050280ex 01

r=-0.758046381006ex 00

70 0.80 0.90 1.00

m=-0.146538157704ex 02 

b=0.197153714083ex 02 

Sy.x = 0.884004970531ex 00 

Sm=0.332782229794ex 01 

r=-0.633012244860ex 00

0.70 ioV- 0.80

IO4

IO3

10'

10'

m = -0.127042755296ex 02 

b=0.179236105438ex 02 

Sy.x=0.883699253917ex 00 

Sm = 0.332667143273ex 01 

r=0.578463406748ex 00

0.90

10*

10'

IO 1

1.00 0.70 

10 4 t0.80 0.90

JD_ 

1.00

m = -0.920318465430ex 01 

b = 0.14231£031557ex 02 

Sy.x = 0.840909979804ex 00 

Sm = 0.316559190801ex 01 

r= -0.475056124228ex 00

10°

10'

IO 1

• m = -0.6683345287491ex 01 • 

b=0 111193638171ex 02 

Sy.x = 0.909188646027ex 00 

Sm=0.342262583372ex 01 

r=-0.340892588926ex -00

0.70 0.80 0.90 1.00 0.70 

SPECIFIC GRAVITY

0.80 0.90 1.00

FIGURE 13.—Statistical plot showing correlation between relative luminescence and specific 

gravity of 29 crude oils at the following Fraunhofer lines: A, 396.8 nm; B, 422.7 nm; 

C, 486.1 nm; D, 518.4 nm; E, 589.0 nm; and F, 656.3 nm.

ing those periods when cloud cover was less 

than 10 percent.

6. FLD measurements of juniper showed significant 

correlation between molybdenum intake and 

luminescence for values up to 300 ppm molybdenum in plant ash.

7. Airborne FLD measurements in the Sespe Creek 

area, California, show that contrast between 

luminescing gypsum and phosphate rock outcrops, and older non-phosphatic sedimentary 

rocks, ranges from 1.5 X to 3 X.

8. Of 29 crude oils measured in the laboratory, 28

9.

luminesce within the sensitivity range of an airborne FLD; laboratory work also shows correlation between thickness of an oil film (such 

as would occur in a marine oil spill) and 

luminescence for oils of specific gravity of 

0.8327 or less.

Airborne FLD measurements in the Santa Barbara 

Channel show that luminescence of thicker, 

nearshore layers of oil from the marine seep 

exceeds "clear water" by a factor of 10; 

luminescence of thinner layers which have dispersed seaward are marginally detectable.
MEASUREMENT OF LUMINESCENCE 

OIL 'IN SANTA BARBARA CHANNEL, CALIFORNIA

111

NATURAL SEEP-HEAVY CRUDE 

2.02 ±0.1 ppb

THIN OIL LAYER 

0.30±0.03 ppb

"CLEAR WATER0.21 ±0.01 ppb

SANTA BARBARA

16 KM

FIGURE 14.—Map showing: (1) Dispersal of oil from natural seep off Coal Oil Point, Santa Barbara Channel, and 

(2) FLD luminescence responses from clear water, thin oil film, and heavy crude filament.

REFERENCES

American Society of Photogrammetry, 1975, Manual 

of remote sensing: Falls Church, Virginia, 2,144 

PFantasia, J. F., Hard, T. M, and Ingrao, H. C., 1971, 

An investigation of oil fluorescence as a technique for the remote sensing of oil spills: Natl. 

Tech. Inf. Service PB 203585.

Gower, H. D., and Madsen, B. M., 1964, The occurrence of phosphate rock in California: U.S. Geol. 

Survey Prof. Paper 501-D, p. 79-85.

Grainger, J. F., and Ring, J., 1962, Physics and 

astronomy of the moon, in Kopal, Zdenek, ed., 

The luminescence of the lunar surface: New 

York, Academic Press, p. 385-405.

Hemphill, W. R., Fischer, W. A., and Dornbach, John,

1965, Ultraviolet investigations for lunar missions: Advances in the Astronautical Science, v. 

20, pt. 1, p. 379-415.

Hemphill, W. R., and Carnahan, S. U., 1965, Ultraviolet absorption and luminescence investigations: U.S. Geol. Survey Tech. Letter NASA-6, 

27 p., 53 figs.

Hemphill, W. R., Stoertz, G. E., and Markle, D. A., 

1969, Remote sensing of luminescent materials, 

in Internat. Symposium on Remote Sensing of 

Environment, 6th, Ann Arbor, Michigan 1969, 

Proc., p. 565-583.

Hemphill, W. R., and Stoertz, G. E., 1971, Fraunhofer 

line discriminator progress report: Principal Investigator's Review, Advanced Applications 

Flight Experiments, NASA Langley Research 

Center, Proc., p. 171-185.
112 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Hoel, P. G., 1965, Introduction to mathematical statistics: New York, John Wiley and Sons, 427 p.

Hollaender, A., 1956, Radiation biology: New York, 

McGraw-Hill, p. 765.

Howard, J. A., Watson, R. D., and Hessin, T. D., 1971, 

Spectral reflectance properties of Pinus ponderosa in relation to copper content of the soil— 

Malachite Mine, Jefferson County, Colorado, in 

Internat. Symposium on Remote Sensing of Environment, 7th Ann Arbor, Michigan 1971, Proc., 

p. 285-297.

Huff, L. C., 1963, Comparison of geological, geophysical, and geochemical prospecting methods at the 

Malachite Mine, Jefferson County, Colorado: 

U.S. Geol. Survey Bull. 1098-C, p. 161-179.

Kozyrev, N. A., 1956, The luminescence of the lunar 

surface and intensity of the solar corpuscular 

radiation: Izvestia Krymskoi Astroizitcheskoy 

Observatorye, v. 16, p. 148-161.

Kramer, P. J., and Kowlowski, T. T., 1960, Physiology 

of trees: New York, McGraw-Hill, Botanical 

Science Series.

O'Gara, P. J., 1922, Sulfur dioxide and fume problems and their solutions: Industrial Engineering 

Chem., v. 14, p. 744.

Press, N. P., 1974, Detecting the toxic effects of 

metals in vegetation from Earth observation 

satellites: British Interplanetary Soc. Jour., v. 

27, p. 373-384.

Riecker, R. E., 1962, Hydrocarbon fluorescence and 

migration of petroleum: Am. Assoc. Petroleum 

Geologists Bull., v. 46, no. 1, p. 60-75.

Sauchelli, Vincent, 1969, Trace elements in agriculture: D. Van Nostrand Reinhold, Co., 248 p.

Stoertz, G. E., Hemphill, W. R., and Markle, D. A., 

1969, Airborne fluorometer applicable to marine 

and estuarine studies: Marine Technology Soc. 

Jour., v. 3, no. 6, p. 11-26.

Thomas, M. D., 1961, Effects of air pollution on 

plants: New York, Columbia Univ. Press, World 

Health Organization Monograph, no. 46.

Vedder, J. G., Dibblee, T. W., and Brown, R. D., 

1973, Geologic map of the upper Mono CreekPine Mountain area, California: U.S. Geol. Survey Misc. Geol. Inv. Map 1-752.

Watson, R. D., Hemphill, W. R., and Hessin, T. D., 

1973, Quantification of the luminscence intensity 

of natural materials, in Am. Soc. Photogrammetry, Symposium for the Management and 

Utilization of Remote Sensing Data, Sioux Falls, 

South Dakota, Proc., p. 364-376.

Watson, R. D., Hemphill, W. R., Hessin, T. D., and 

Bigelow, R. C., 1974, Prediction of the Fraunhofer line detectivity of luminescent materials, 

in Internat. Symposium on Remote Sensing of 

Environment, 9th, Ann Arbor, Michigan 1974, 

Proc., p. 1959-1980.
PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Use of ERTS-1 (Landsat-1) Images for 

Engineering Geologic Applications in North-Central Iran

By Daniel B. Krinsley, 

U.S. Geological Survey, Reston, Virginia 22092

INTRODUCTION

Most of the Iranian population lives adjacent to the 

margins of the interior desert basins because of the 

availability of flat land and moderate supplies of 

ground water at relatively shallow depths. The basins 

are potentially valuable sources of water and chemicals and could be utilized for the emplacement of 

roads and inexpensive airfields. The basins have not 

been fully utilized to date because of the lack of 

adequate knowledge concerning the seasonal changes 

in their surface and ground water hydrologies and in 

the physical properties of their sediments. Most desert 

basin investigations have been conducted during the 

summer when the surficial sediments are dry and have 

sufficiently high bearing strengths to support men and 

vehicles.

The repetitive coverage of ERTS-1 (all images used 

are ERTS-1 and to avoid confusion that designation 

will be used in this paper) is ideally suited to provide 

seasonal images of the Iranian basins from which 

changes in the areal extent and morphology of the 

surficial materials may be recorded in conjunction 

with contemporaneous or previous ground truth 

studies of actual surficial conditions. Data derived 

from the analyses of ERTS-1 images can provide a 

rational basis for planning the economic utilization 

(salts or water extraction and agriculture) and engineering development (roads and airfields) of these 

desert basins.

ERTS-1 images used in this study have been examined in single bands and in false-color composites 

of several band combinations.

PHYSICAL SETTING OF THE IRANIAN 

DESERT BASINS

The Elburz and Zagros Mountains (fig. 1) were compressed against the relatively older inflexible block

of the Iranian Plateau to the east during the PliocenePleistocene phase of the Alpine orogeny. Lower but 

nevertheless rugged mountains that formed along 

Iran's eastern border divide the plateau into a major 

eastern basin in Afghanistan and a major western 

basin in Iran. Within the western basin are several 

lesser mountain chains and isolated mountains as well 

as extensive desert plains. The lowest depressions in 

these deserts are occupied by smaller desert basins 

(fig. 1).

Approximately half of Iran consists of basins from 

which there are no outlets and from which the collected drainage is removed by evaporation. Moist 

winds bring considerable precipitation during the 

winter half of the year to the northern slopes of the 

Elburz Mountains which effectively bar movement of 

moisture to the south. Similarly, the Zagros Mountains 

act as a barrier to the moisture-laden westerlies. Rainfall is quickly reduced in amount southward and eastward so that the interior lies within a vast rain shadow 

and becomes increasingly arid from west to east and 

from the north to south. There is exterior drainage 

only along the north, west, and south margins of the 

country; the remainder has interior drainage.

There is a considerable water deficit in the interior 

during all seasons, and streams that do reach the 

basin sumps are generally fed by ground water. The 

upper aquifers in the alluvial fans are phreatic, but 

towards the center of the basin artesian conditions 

develop as a result of confining clay layers (Issar, 

1969, p. 94). The uppermost aquifer does remain 

phreatic to the margin of the basin sump (playa), 

where the water from the toe of the fan spills out over 

the play a surface creating a "wet zone." Evaporation 

through the capillary zone from the phreatic aquifer 

results in salinization of the water. Salinization is accentuated in the north-central basins that are underlain by Miocene evaporites.

113
114 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

T AFGHANISTAN '

Playas and associated features

0 50 100 150 200 Kilometres

FIGURE 1.—The relationship of the desert basin sumps (playas) and associated features to relief in Iran.

Although man has severely altered the natural vegetation by extensive cutting, it is doubtful that vegetation within the inner plateau seriously affected the 

amount and intensity of overland flow during the 

Pleistocene. It seems more likely that increased cold 

during the glacial periods more than counteracted any 

relative increase in humidity that might have been 

favorable to growth. Significantly, no evidence has 

been found in any of the upper Pleistocene sediments,

along the inner mountain flanks or in the playas, of 

buried trees or other vegetative debris (Krinsley, 

1972b, p. 116).

GREAT KAVIR WATERSHED

The Great Kavir watershed (fig. 2) occupies an area 

of 200,747 km2 in the northeastern quadrant of Iran. 

The northwestern divide, in the Elburz Mountains, has
USE OF ERTS-1 FOR ENGINEERING GEOLOGIC APPLICATIONS 115

GREAT KAVIR

andar-e Shahpu 

-Gach

'. Nok Kundi

. PAKISTAN

SAUDI**'—""ARABIA"'^-.

• - International boundary 

® National capital

Railroad

Road

0 50 100 150 200 Miles

0 50 100 150 200 Kilometres

FIGURE 2.—Interior watersheds of Iran: the Great Kavir and the superposed boundary of the ERTS-1 (Landsat-1) images.

summit altitudes which decrease from 4,002 m in the 

west to about 3,000 m in the east. The southwestern 

and southeastern divides have summit altitudes which 

generally range from 1,500 to 2,000 m with a few 

peaks just under 2,400 m along the southeastern divide. Within the watershed the lowest altitudes are 

found at the surface of the salt crust basins, and the 

lowest of these lies at an altitude of 650 m.

GREAT KAVIR

The central and lowest area of the Great Kavir 

watershed is occupied by the Great Kavir, a desert

area of 52,800 km - (fig. 3). In Iran, the term "kavir" 

is a generic name for playa. The Great Kavir contains 

numerous depressions occupied by true kavirs which 

have imparted their character to the entire desert.

The annual precipitation decreases from a maximum of 300 mm near the divide, but within the rain 

shadow of the Elburz Mountains, to less than 100 mm 

in the Great Kavir. Mountains along the northeast 

divide benefit from moisture-laden air skirting the 

southern shore of the Caspian and penetrating 'the 

valleys and lower passes northeast of Damghan (fig. 

1). Precipitation in this eastern area ranges from 100
116 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

36°

TEHRAN

4002 

ELBURZ ^-A_ MOUNTAINS

*•». J \ n

SURFACE TYPES 

X

34°

32 C

MIOCENE BEDROCK \

(UPPER RED FORMATION) \

U^^i PROPOSED GREAT KAVIR ROAD

0 50 100 KILOMETRES

SALT DOMES 

SAND DUNES AND

nnc\/A n IKI/^ \A/iKir-v

SAND DUNES AND A ALTITUDE IN METRES

PREVAILING WIND

__________I____________________I________

52 C 54C 56C 58C

FIGURE 3.—Elements of the Great Kavir. Map based on author's fieldwork and photointerpretation and on the Geological Map

of Iran (National Iranian Oil Company, 1959).

to 150 mm in the mountains, but there is considerably 

less in the adjacent lowlands.

In spite of the rapid decrease in precipitation southward, broad valleys with underftt and intermittent 

streams, below the mountain front, attest to the past 

erosional effectiveness of the southward flowing 

streams. Coarse alluvium including gravel beds, which 

are interbedded with clay, extends farther into the 

basin with increasing depths in the section. This stratigraphic relationship suggests previously greater 

streams. Coarse alluvium, including gravel beds, which 

materials farther from their source.

The surface of the Great Kavir ranges in altitude 

from 850 m in the northwestern part to 650 m near 

the northeastern boundary. It is underlain by Miocene 

rocks of the Upper Red Formation (Gansser, 1955, 

p. 291). These intricately folded siltstones, marls, anhydrites, and salt beds have been eroded to a peneplain where they are exposed over an area of 19,300 

km 2 .

The Great Kavir may be subdivided into eastern 

and western basins separated by the uplifted peneplain cut into the Miocene rocks. Three central areas 

of salt crust in a north-south alinement (fig. 3) approximate the peneplain divide. The location of this divide 

near the western boundary of the peneplain and the 

development of two east- to northeast-trending 

troughs (occupied by linear wet zones) in the eastern 

half of the peneplain indicate that the regional slope 

has long been toward the east. It is likely that currently 

active streams flowing westward into the western 

basin will eventually breach the divide by headward 

cutting and shift the divide eastward. The present 

stream cutting is due to increased gradients resulting
USE OF ERTS-1 FOR ENGINEERING GEOLOGIC APPLICATIONS 117

from recent tectonism. The Miocene rocks and the 

younger sediments are cut by currently active northeast-trending faults, the principal one of which is the 

Great Kavir fault (fig. 3).

SURFACE TYPES WITHIN THE GREAT KAVIR

The surface types within the Great Kavir are the 

Miocene rocks, locally pierced by salt domes, dune 

fields, fan deltas, wet zones, clay flats, and salt crusts 

(Krinsley, 1970, p. 107). The areas occupied by these 

surface types have been generalized at a scale of 

1:2,500,000 and then reduced in figure 3. Small areas 

of these types which appear in ERTS-1 images (scale 

1:1,000,000) may not be shown in figure 3.

Miocene rocks consisting of evaporites and other 

generally saliferous sediments occupy 35 percent of 

the area of the Great Kavir. At the peneplained surface of these rocks is a thin regolith of clay, silt, and 

sand with up to 47 percent halite. As a consequence 

of repeated dissolution of the salt in winter rains and 

crystallization upon the evaporation of surface moisture, or the summer evaporation of capillary water, 

the regolith has been churned into a rough surface 

resembling a plowed field. Across this vast almost 

flat surface, narrow drainageways terminate in the 

wet zones or salt crusts. Salt domes, which have 

locally pierced the Miocene rocks, are similarly cut 

by the peneplain.

The dune fields occupy 13 percent of the Great 

Kavir and are situated along its southern and southeastern borders. Fan deltas are large alluvial fans 

which transgress other surface types. The toes may 

be completely inundated during the principal runoff 

period, with the result that peripheral deposition, 

occurs in water, as at a delta. The two large fan 

deltas in the Great Kavir occupy 5 percent of its area.

The wet zone is a transitional zone which is periodically inundated and always wet. It commonly borders 

the toes of alluvial fans and fan deltas, but it also 

occupies linear basins or narrow troughs within the 

area immediately underlain by Miocene rocks. The 

linear wet zones have surface gradients of less than 

1 degree, sloping toward the salt crust areas. Wet 

zones constitute 4 percent of the kavir surface. The 

clay flat, which occupies only 2 percent of the area of 

the kavir, is a generally firm surface underlain by dry 

clay and silt, with variable amounts of salt. It is distinguished from the wet zone, with which it is pedologically identical, on the basis of its higher position 

above the dry-season water table. The salt crust occupies 41 percent of the kavir surface in basins in the 

east, center, and west. The eastern basins are generally continuous but are locally interrupted by 

Miocene outcrops in the form of northeast-trending 

ridges. The surface of the southern basin in the eastern area is 50 m higher than the northern salt surface 

adjacent to the fan delta. There is thus significant 

gradient northward toward the fan delta. Three saltcrust basins in the central area of the kavir occupy 

downwarps in the Miocene rocks. The salt crusts of 

these basins lie at different levels, and they are probably hydrologically independent. The larger middle 

basin surface is estimated to be at an altitude of approximately 850 m.

In areas of thick, white salt crusts and seasonally 

high water tables, the wet briny muds beneath the 

crusts may be more thermally expanded than the 

crusts. This process is facilitated by the transparency 

of pure salt to infrared rays and by the heat absorption of the black mud. Occasionally, the plastic muds 

are forced from beneath the salt plates outward and 

upward through the peripheral cracks. Rapid evaporation of the mud brines results in the formation of black 

salt dikes along the polygonal cracks. Grooves and 

scratches preserved in the solidified dike that were 

cut by preexisting crystallized salt during extrusion of 

the mud attest to the rapidity of the solidification.

The uneven extrusion of the briny mud frequently 

results in the tilting of the polygonal salt plates. Eventually, the area becomes a rough, jumbled mass of 

sharp and angular black salt blocks with ridges and 

pinnacles (fig. 4). Wind-driven rain and silt tend to 

modify and sharpen the rough surface features of 

these salt fields. Aeolian or alluvial silt added to the 

old salt, already darkened by the admixed black mud 

from beneath the crust, imparts a dark matte appearance to this grotesque surface. Relief among the salt 

pinnacles and ridges ranges from 30 to 50 cm.

Salt crusts and related surface features are primarily a reflection of the hydrologic regime within a 

basin. The crusts tend to buckle when they are thin, 

darkened by silt and underlain by light-colored sediments and a seasonally depressed water table. Saline 

muds are more likely to be extruded when they are 

black, and water saturated, beneath a relatively thick, 

white salt crust (Krinsley, 1972a, p. 173).

POTENTIAL FOR ENGINEERING DEVELOPMENT

Almost all materials produced in northern and central Iran are exchanged by means of trucks moving 

along the east-west and northwest-southeast road that 

passes through Tehran (fig. 5). Goods from the north 

destined for the region immediately south of the Great 

Kavir must travel more than 900 km rather than the
118 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 4.—Rough black salt ridges and pinnacles adjacent to the dry-season road across the Great Kavir, 40 km south of Moalleman. Local relief ranges from about 30 to 50 cm, view northwest, date September 2, 1966.

200 km that would be required if an all-weather road 

existed across the desert. Less dramatic but nevertheless significant savings in time and in transportation 

costs could be achieved with such an all-weather road 

terminating at Nain farther to the southeast (fig. 5). 

Trucks traveling from Damghan to Nain cover the 750 

km in 9 hours; the route across the Great Kavir would 

be 450 km and require 6 hours.

Rough dry-season roads of gravel and dirt exist for 

caravans or 4-wheel drive vehicles along the route 

indicated in figure 5, between Damghan and Nain. 

Engineering procedures associated with the construction of an all-weather road across the Great Kavir

would be concerned with stabilizing, strengthening, or 

constructing a subgrade over the saliferous surficial 

materials and installing culverts and bridges to permit 

normal drainage across the route of the eventual road 

alinement. This section of the report is concerned with 

the use of ERTS-1 scenes in the selection of a preliminary road alinement through the Great Kavir.

ANALYSIS OF THE ERTS-1 IMAGES OF THE 

GREAT KAVIR

The basis for the analyses of the ERTS-1 images 

of the Great Kavir is familiarity with its actual ground
USE OF ERTS-1 FOR ENGINEERING GEOLOGIC APPLICATIONS 119

-• International boundary 

® National capital

0 50 100 150 200 Miles

o 50 100 150 20C Kilometres

FIGURE 5.—Existing Iranian road net and the proposed Great Kavir road, which is shown by a bold dashed line. The north and

south extensions of the proposed road are shown by solid bold lines.

conditions and sediments during the summer and 

autumn of 1965, 1966, and 1974. In addition to ground 

control, this area was viewed from low-flying aircraft, 

and many of its details were compiled from aerial 

photos at scales of 1:30,000 and 1:60,000.

Initially, false-color diazo transparencies were prepared from positives of ERTS-1 images. Yellow, red, 

and blue were used for MSS bands 4, 5, and 7 respectively. These three colors were then composited 

to form a false-color transparency. The composite

was then compared to actual ground and aerial photos 

and interpreted in the light of the investigator's experience. The false-color illustrations used in this 

report are products of a subtractive color system. The 

dyes used in this system are magenta, yellow, and 

cyan, but the resultant pure colors are red, green, and 

blue.

In the false-color composites, water is blue, salt is 

white and the saliferous silt and clay regolith of the 

Miocene sediments is buff to light brown. The purity
120 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

or intensity of these colors reflect differences in the 

composition, hydrology, or morphology of the surface 

materials. With increasing depth, water ranges in color 

from aquamarine to dark blue to black. With increasing saturation, the salt crust ranges in color from pure 

white to aquamarine. With increasing roughness or 

microrelief, the salt crust ranges in color from pure 

white (smooth crust) to black (rough salt ridges; figs. 

4 and 6, p. XII). Combinations of wet, silty and rough 

salt crust result in mixed false colors which require 

special considerations in their correct interpretation. 

In the ERTS-1 scene of September 20, 1972 (fig. 6, 

p. XII), white areas are smooth salt crust and black 

areas, adjacent to the dry-season road, are rough 

black salt ridges and pinnacles (fig. 4). There is no 

standing water, in that area, at that time of year. In 

the ERTS-1 scene of May 12, 1973 (fig. 7, p. XIII), the 

black areas adjacent to kilometres 75 and 90 are 

white salt crusts covered by water (compare figs. 6, 

p. XII, and 7, p. XIII).

SELECTION OF A PRELIMINARY ROAD 

ALINEMENT THROUGH THE GREAT KAVIR

The area of the Great Kavir most suitable for the 

construction of an all-weather road lies entirely within 

one ERTS-1 scene (figs. 2 and 6, p. XII). The center 

point of the September 20, 1972, image of that scene 

is 34°35'N.; 55°12'E. False-color diazo composites 

were prepared from positives of ERTS-1 images 

.taken of the Great Kavir on September 2 and 20, 

1972, December 19, 1972, February 11, 1973, March 

1, 1973, and May 12, 1973. The route of the existing 

dry-season road was overlain on each diazo composite, and the seasonal hydrologic conditions along 

four critical segments of that route south of Moalleman were recorded (table 1).

The four critical road segments represent areas that 

are subject to soil saturation by water or even local 

flooding and thus require special engineering considerations. The road segment from kilometres 25 to 50

TABLE 1.—Hydrologic conditions along critical segments of the dry-season road across the Great Kavir as inferred from ERTS-1

images

Identification of 

ERTS-1 image*

Distances in kilometres south from MoaMeman

25-50 60-63 90-100 110-116

Sept. 2, 1972, 

34°35'N., 55°09'E., 

8104106265.

Sept. 20, 1972, 

34°35'N., 55°12'E., 

8105906265 

Figure 6.

Dec. 19, 1972, 

34°35'N., 55°09'E., 

8114906273.

Feb. 11, 1973, 

34°35'N., 55°05'E., 

8120306274.

Mar. 1, 1973, 

34°36'N., 55°01'E., 

8122106275.

Moist surface at km 40 _ Moist surface at km 62 _ Dry salt crusts

Moist surface at km 40 _

Wet surface at km 40; 

dissolution of salt 

crusts.

Wet surface at km 40; 

dissolution of salt 

crusts.

Wet surfaces at km 32 

and km 40; dissolution of salt crusts at 

km 40.

.do _ ________ Dry salt crusts

Obscured by cloud _ —

Partly obscured by 

cloud, probably wet.

Moist to wet salt crusts; 

dissolution of salt 

crusts.

Wet soil and salt crusts; 

dissolution of salt 

crusts.

Wet soil and salt crusts; 

dissolution of salt 

crusts; standing 

water.

Moist surface at km 

113.

Do.

Moister surface at km 

113.

Obscured by cloud. 

Wet surface at km 113.

May 12, 1973, 

34°43'N., 54°56'E., 

8129306274 

Figure 7.

Wet surfaces at km 32 

and km 40; dissolution of salt crusts at 

km 40.

Wet surface at km 62 _ Wet soil and salt crusts; 

dissolution of salt 

crusts; standing 

water.

Wet surface at km 113.

Summary

Alinement to west with Bridge or raised road- Raised roadbed and 

culverts probably re- bed required. bridge required, 

quired over wet areas.

Alinement to west 

around wet area.

*Date, location, identifier (EROS Data Center identification number), and figure number in this report.
USE OF ERTS-1 FOR ENGINEERING GEOLOGIC APPLICATIONS 121

lies in the area underlain by Miocene bedrock (fig. 3). 

It is always moist along a narrow drainageway at 

kilometre 40 during the dry season, but this area becomes wet by mid-December. Dissolution of the local 

salt crust parallel to the drainageway suggests saturation of the surficial materials. By March, the surface 

in a slight depression is also wet at kilometre 32. The 

road from kilometres 25 to 50 can be alined inexpensively to the west on good natural subgrade to avoid 

the two wet areas (fig. 7, p. XIII); culverts will be required along drainageways.

The segment from kilometre 60 to 63 lies in a depression within the area underlain by Miocene bedrock (fig. 3). It is always moist at kilometre 62 during 

the dry season and becomes moister by midDecember. This segment is wet by mid-May and a 

bridge or raised roadbed would be required at kilometre 62 (fig. 7, p. XIII).

The segment from kilometres 90 to 100 lies in an 

area that is occupied principally by salt crusts (fig. 3) 

which undergo significant changes in their surface 

conditions during the seasons. Salt crusts are dry during September but become moist by mid-December 

with some dissolution. By early February, both soil 

and salt crusts are wet with continuing dissolution of 

the salt. Standing water is present by March 1, and 

its areal extent has increased by mid-May. This segment is the most difficult and would require both a 

raised roadbed and a bridge. Although an alinement 

to the east would avoid the wettest areas, the costs 

of engineering for the poor subgrade over the increased length of the road (up to 30 km) would be 

prohibitive (fig. 7, p. XIII).

The segment from kilometres 110 to 116, which 

lies within the area underlain by Miocene bedrock, is 

always moist at kilometre 113 during the dry season, 

and becomes moister by mid-December. By March 1, 

the surface is wet at kilometre 113, and this condition 

continues into May. This area can be avoided by a 

short alinement to the west (fig. 7, p. XIII).

The use of ERTS-1 images provides a method for 

examining areas that are seasonally inaccessible in 

order to determine hydrologic changes that affect soil 

conditions and thus their engineering properties. There 

must be some knowledge of actual ground conditions 

in order to correctly interpret the ERTS-1 images, 

and the eventual determination of the location of any 

engineering project such as a road alinement should 

be based on a longer record of observation and onsite investigation.

POSTSCRIPT

The author met with His Excellency Javad Shahrestani, Minister of Roads and Transport of Iran, on 

September 24, 1974, at the latter's invitation for the 

purpose of discussing the construction of an allweather road across the Great Kavir. Further information was provided to Minister Shahrestani by the 

author in November 1974 and during January and 

March 1975.

In August 1975, the Ministry of Roads and Transport of Iran awarded a contract to a joint venture 

company, Peyma-Harland (Harland Bartholomew and 

Associates International, Inc., of Washington, D.C., 

and Peyma Consulting Engineers of Tehran, Iran) to 

provide consulting engineering services for a feasibility and location study for a highway that will begin 

in the vicinity of Damghan (fig. 5) and terminate in the 

vicinity of Nain. The first phase of this project will be 

to delineate the exact route of the highway. This 

phase will be completed in approximately 7 months, 

at the end of February 1976. The second phase, which 

will require 18 to 24 months, will involve the final 

design and contract documents for the highway construction. The final construction phase will require 

approximately 2Vi to 3 years and should be completed no later than February 1981.

REFERENCES

Gansser, A., 1955, New aspects of the geology in 

central Iran, in World Petroleum Congress, 4th, 

Rome 1955, Proc., sec. I, Geology Geophysics, 

p. 279-300.

Issar, A., 1969, The ground water provinces of Iran: 

Internat. Assoc. Sci. Hydrol. Bull., v. 14, no. 1, 

p. 87-99.

Krinsley, D. B., 1970, A geomorphological and paleoclimatological study of the playas of Iran: U.S. 

Geol. Survey Interagency Rept. Military-1, 329 p., 

4 plates, 155 figs., 17 tables.

————1972a, Dynamic processes in the morphogenesis of salt crusts within the Great Kavir; 

north-central Iran, in Internat. Geol. Cong., 24th, 

Montreal, Proc., sec. 12, p. 167-174. 

-1972b, The paleoclimatic significance of the

Iranian Playas, in Zinderen Bakker, E. M. Van, 

ed., Palaeoecology of Africa: Cape Town, A. A. 

Balkema, v. 6, p. 114-120.

National Iranian Oil Company, 1959, Geological map 

of Iran (1:2,500,000) with explanatory notes: 

Zurich, Orell Fussli.

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Applications of Remote-Sensing Technology 

for Powerplant Siting

By Leo Eichen and Richard F. Pascucci, 

Dames & Moore, Cranford, New Jersey 07016

INTRODUCTION

Remote sensing as a practical service consists of 

acquisition of various data acquired remotely, e.g., 

satellite observations and aerial overflights: the interpretation of the source data in the context of the 

problems involved, e.g., geotechnical evaluations and 

environmental assessment; and the presentation of 

the results in suitable format to facilitate later phases 

of an investigation, e.g., planning detailed field surveys and the layout of bore-hole drilling programs.

It should be noted that remote sensing is never a 

solution in itself but rather a significant tool to assist 

the investigator in his basic skills. For example, the 

analysis of imagery acquired from satellites or aircraft 

from which specific information is sought (geologic 

mapping or environmental assessment) is best performed by scientists trained in these disciplines. 

Assistance, where required, in the techniques of image 

enhancement or computer-assisted analysis can be 

provided by remote-sensing specialists.

DATA ACQUISITION

Remote sensors generally provide the following 

advantages:

• When carried aboard aircraft or spacecraft, they 

offer a synoptic overview not achieved by ground 

survey methods. Observations of the total scene 

recorded as an image present a visual set of data 

patterns not merely a group of data points as 

would have been provided by ground methods.

• The sampling technique is an unobstrusive way of 

gathering data. The mere presence of a ground 

survey team, for example, investigating potential 

sites for development may result in the spread of 

unfounded rumors and cause unwarranted adverse reactions that may hinder further evaluation of the site.

• Images have a very high information density compared with graphic, textual, or electronic storage 

media.

• Remote-sensor observations provide a more comprehensive picture of the terrain than do field 

methods. Although the level of detail recorded 

by a sensor may not be so detailed for a small 

area as ground observations, the sensor record 

affords a valuable overview in a manageable 

form. The cost/benefit ratio between overhead 

coverage and ground traverses for a given area 

greatly favor the remote sensing approach except in cases where investigation of only a very 

small area is required.

TYPES OF REMOTE-SENSING DATA

Satellite-Acquired Data—Landsat and S/cy/ab

For broad, regional coverage requirements (e.g., 

site selection and regional tectonics) the use of satellite imagery from NASA's Landsat and Sky lab programs has proven to be an invaluable aid.

In July 1972, NASA launched the first unmanned 

satellite specifically designed to acquire Earth resources information. Since then a second vehicle was 

launched in January 1975, with a third scheduled for 

1977. A fourth vehicle is planned for 1978-79 with 

insertion into Earth orbit from NASA's Space Shuttle. 

The capabilities of the Landsat systems currently 

in operation provide for imaging the entire globe in 

100 X 100-nautical-mile increments from an orbital 

altitude of approximately 500 nautical miles (fig. 1). 

This orbit was designed so that sensing is always conducted at a constant sun angle (approximately 9:30

123
124 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 1.—Landsat satellite.

a.m. local time). The only deviation in illumination 

occurs as a result of the seasonal variations in sun 

elevation.

Each satellite repeats coverage of any given swath 

of the United States every 18 days, and, with both 

satellites operating, each swath is covered every 9 

days. This allows changes on the surface to be monitored regularly. Overseas coverage is obtained on a 

selected area basis. The sensor system aboard the 

satellites consists of a multispectral line-scanner. This 

system generates individual scenes, with each scene 

scanned in four different wavelengths to produce four 

similar images simultaneously, as follows:

Green Band . . . records in the 0.5 to 0.6 /.<.m range 

Red Band ..... records in the 0.6 to 0.7 ^m range

IR Band ...... records in the 0.7 to 0.8 ^m range

IR Band ...... records in the 0.8 to 1.1 /j.m range

As the vehicle travels along its orbit, each frame 

overlaps the previous one by about 10 percent so as 

to provide continuous coverage. Adjacent parallel 

orbits are spaced so that side-lap coverage is about 

10 percent at the Equator with greater side-lap nearer 

the poles.

The observations of the Earth are transmitted to 

ground receiver antennae as electrical signals and are 

subsequently converted to facsimile images in the

laboratory. Figure 2 is an example of such imagery.

The three Skylab missions were provisioned with 

two film camera systems. The astronauts photographed swaths of the Earth's surface with different 

film-filter combinations (black and white, color, colorinfrared photography) in two photo scales. Exposure 

intervals were cycled to accomplish stereoscopic coverage. Under good photographic conditions, it has 

been reported that ground resolutions approximating 

30 ft (10 m) have been obtained.

Airborne-Acquired Data

A vast amount of remotely sensed data is acquired 

by aircraft, including inexpensive light aircraft, using 

hand-held, 35-mm cameras or mapping cameras over 

open ports in the floor of the plane. For broader regional coverage, more sophisticated imaging systems 

are carried aboard multiengined prop and jet aircraft 

(including the RE-57 and the U-2) for moderate- and 

high-altitude missions.

Aerial cameras with different capabilities are designed for different photographic missions utilizing a 

wide range of film and filter combinations. The most 

common cameras are those employed by aerial survey 

firms where metric data are required for high precision applications such as in contour mapping or
APPLICATIONS OF TECHNOLOGY FOR POWERPLANT SITING

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FIGURE 2. — Landsat image of New York City and vicinity.
126 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 3.—Thermal infrared image recording of surface heat emissions. (Daedalus Enterprises, Inc.)

compiling volumetric quantities, etc. These cartographic cameras are designed to provide low image 

distortion with high illumination tolerances to maintain photometric quality. The most common cartographic cameras provide 9 X 9-inch image frames on 

rolls of aerial film. Image scale factors can be altered 

by varying (1) the flight altitude or (2) the camera's 

focus through the use of interchangeable lens cones 

of varying focal lengths. Stereoscopic photography is 

accomplished by selecting exposure intervals so that 

successive frames overlap each other by 50 to 60 

percent.

Thermal Infrared Scanners

An improved remote-sensing device which detects 

heat emissions from the surface of terrain or water 

bodies employs an optical scanning technique to record observations beyond the visual range (thermal 

infrared, see fig. 3). These observations are accomplished by virtue of surface phenomena which illustrate a "thermal contrast" with respect to its background, e.g., warmer outfall effluent into a colder 

stream.

Scanners are configured with single or arrayed detectors which sense the incoming signal from a collector optic (scanning mirror). Scanners look at a 

single "spot" of ground at any given instant in time. 

The "spot" is scanned laterally to produce a line of 

imagery. The forward motion of the aircraft "collects" 

successive lines to produce a swath of the scene. The 

incoming optical signal image is converted to a modulated electrical signal which can be either recorded 

on tape for later reproduction or used inflight to vary 

a point source of illumination to photographically record the image on film.

Side-Looking Airborne Radar (SLAR)

SLAR is an active sensor which can obtain images 

either during the day or at night and through most 

cloud cover. The system carries its own "illumination" 

source that transmits a radar beam off to the side of 

the aircraft, normal to the flight path (hence the term 

"side-looking") and detects the back-scattered radar 

from ground objects. These signals modulate a light 

source (cathode ray tube sweep), through focusing
APPLICATIONS OF TECHNOLOGY FOR POWERPLANT SITING 127

FIGURE 4.—Sketch diagram, typical side-looking airborne radar system. (Modified from Westinghouse Electric Corp., 1967, Side Look Radar.)

optics, and onto a film recorder (fig. 4). Imagery obtained from this system depicts the terrain in a way 

unlike conventional photographic records. Gray shades 

in SLAR images are a function of several terrain 

characteristics, such as object roughness and the basic 

electrical properties of the materials. The moisture 

content of soils also affects the film record. Due to 

the low gazing angles of the system's "illumination" 

sources, especially toward the horizon, SLAR images 

highlight terrain relief features so as to create the 

impression of a "three-dimensional" display. This 

rendition often emphasizes subtle relief features, as 

in a scene illuminated by the sun at a low angle. These 

enhancement characteristics are often most useful in 

detecting fractures, faults, stream patterns, and other 

terrain relief features of significance in geologic 

studies (fig. 5).

Aeromagnetics

Airborne aerial magnetic surveys measure the differences in magnetic susceptibilities of rock types

over a study area. A series of parallel and perpendicular flights is designed to provide a complete set 

of "gamma" profiles recorded by the magnetometer 

and referenced to a common magnetic datum. The 

data are processed to produce magnetic contour plots 

from which geophysicists interpret anomalous zones 

associated with geologic structures (fig. 6).

The interpreted magnetic map is often used in conjunction with overlays generated by image analysis 

showing lineaments. These overlays are superimposed 

over the aeromagnetic map and provide corroborative 

evidence of significant geologic structures, such as 

fault and fracture zones.

Ground-Acquired Data

To supplement information derived from overhead 

coverage, geological and geophysical ground surveys 

are performed to provide details over specific site 

locations (e.g., suspect areas which may impact in the 

location and design of nuclear power generating 

facilities).
128 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

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FIGURE 5.—Side-looking airborne radar image by International Aeroservices Corp. and Goodyear Aerospace Corp.

For these purposes, portable ground magnetometer, 

gravity meter, and seismic surveys are conducted.

DATA ANALYSIS AND SYNTHESIS

In most site investigations, the analysis of remotely 

sensed data is limited to Landsat imagery and off-theshelf aerial photos for reasons of cost effectiveness. 

The cost of these data sources, where purchased from 

the Federal or State government, ranges from a few 

tens to a few hundreds of dollars. Interpretation and 

analysis costs rarely exceed $10,000 to $15,000, and 

a considerable quantity of structural information 

usually results. Other sources of remotely sensed data 

are not often used if they have not previously been 

acquired. However, in order to illustrate the methods 

and procedure of remote-sensor data analysis, it will 

be assumed that data from all of the previously described sensors exist (i.e., Landsat, Skylab, SLAR, 

aeromagnetics, gravimetrics, aerial photos, and 

thermal infrared).

In general, the procedure of analysis begins with 

small-scale formats and progresses to larger scales. 

The Landsat imagery, typically at a scale of 1:500,000,

is usually analyzed first; followed by SLAR, typically 

at a scale of about 1:250,000; and proceeding on to 

aerial photos at about 1:25,000 and a thermal infrared 

scan at a scale of 1:10,000 or larger. The aeromagnetic and gravimetric data are interpreted separately 

at about the same time as Landsat and SLAR. The 

following describes the methods and criteria employed in the analysis and interpretation of each 

remote-sensor data product:

• Satellite Analysis—The interpretation of Landsat 

imagery is usually performed on spectral bands 

5, 7, and the color-infrared composite. Supplementary coverage from Skylab where available 

is included. The principal effort is directed toward 

the detection and delineation of linear features 

that are neither manmade nor caused by bedding 

or foliation (fig. 7). It is evident, by the process 

of elimination, that such features are very likely 

to be either faults or fractures at the surface of 

the Earth or surface expressions of deep-seated 

dislocation. Each lineament is interpreted as being either a "probable fault" or a "possible fault."
APPLICATIONS OF TECHNOLOGY FOR POWERPLANT SITING 129

78°00'00" 77°52'30" 77°45'00"

38°07'30'

38°00'00'

37°52'30'

NEUSCHEL'S 

LINEATION

TOTAL INTENSITY IN GAMMAS 

CONTOUR INTERVAL 25 GAMMAS

BASED ON HALF Ml LE SPACED, EAST-WEST 

FLIGHT LINES 500 FEET ABOVE GROUND

FIGURE 6.—Typical aeromagnetic map, Mineral, Virginia. (Modified from Neuschel, S. K., 1970, Correlation 

of aeromagnetics and aeroradioactivity with lithology in the Spotsylvania area, Virginia: Ceol. Soc. America

Bull., v. 81, p. 3575-3582, fig. 2.)

An example of a "probable fault" is offset 

bedding or an offset ridgeline. An example of 

a "possible fault" is a very straight stream segment, which may have developed by headward 

erosion along a fault or which may simply be a 

consequent stream following the original slope 

of the surface upon which it developed.

All of the lineaments are selected on the basis 

of satisfying one or more of the following criteria:

1. Alignment of drainage. This refers to a rectilinear segment of a stream, river or lake. 

If a valley is observed, but not the stream

itself, criterion number 3—alignment of 

geomorphic features—is used.

2. Alignment of lithology. A rectilinear interface between two lithologic types assumed to be evidence of a "possible 

fault."

3. Alignment of geomorphic features. This includes straight ridgelines and valleys that 

do not appear to be caused by bedding.

4. Alignment of vegetation. This criterion includes rectilinear interfaces between vegetation types as well as long, straight
130 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 7.—Lineament analysis of Landsat image (1072-15190). 

(From Withington, C.F., 1973, Lineaments in coastal plain 

sediments as seen in ERTS imagery, in Natl. Aeronautics and 

Space Admin. Coddard Space Flight Center, Symposium on 

Significant Results obtained from Earth Resources Technology Satellite-1, 2d, New Carrollton, Md., March 1973, 

Tech. Presentations, v. 1, p. 517-521.)

narrow bands of vegetation, such as those 

bordering a watercourse.

5. Alignment of optical density (tone). This 

criterion is employed when the cause of 

an observed alignment could not be identified further; that is, when only a rectilinear tonal difference could be seen.

6. Offset of drainage. This refers to a rectilinear, lateral displacement of a stream.

7. Offset of lithology. A rectilinear discontinuity in the strike of a contact is regarded 

as evidence of a "probable fault." In most 

instances, lineaments that are probably 

caused by an offset in lithology were 

identified as offset or geomorphic features. 

This is due to the fact that the interpretation of geomorphic features is virtually 

certain while the interpretation of lithologic types is conjectural.

8. Offset of geomorphic features.

9. Offset of vegetation. (When interpreted as 

not being the work of man.)

10. Offset of optical density (tone).

In general, but by no means always, criteria 6 

through 10—offset—are regarded as "probable

faults," while criteria 1 through 5—alignments— 

are regarded as "possible faults" unless the alignment is very rectilinear and well-defined. The 

suspected faults are delineated on a transparent 

overlay registered to the Landsat image.

• Analysis and Interpretation of SLAR—The same 

procedure is followed, and the same criteria are 

employed as in the analysis and interpretation of 

Landsat imagery; that is, the analyst searches for 

evidence of alignment and offset. The SLAR is 

first examined for evidence corroborating the 

lineaments found in the Landsat imagery and is 

then searched for evidence of additional lineaments. As with the results of the Landsat analysis, the suspected faults found in the SLAR 

imagery are delineated on a transparent overlay 

registered to the SLAR. Figure 8 is an example 

of SLAR analysis.

• Analysis and Interpretation of Aeromagnetic Data 

—The aeromagnetic contour maps are interpreted without consulting the Landsat or SLAR 

data. The criteria used for recognizing aeromagnetic "lineaments" include:

1. Termination of highs.

2. Termination of lows.

3. Changes in gradient.

4. Linear contour patterns.

5. Alignments of highs and lows.

6. Long, linear "alteration" lows.

7. A combination of the above criteria.

Lineaments that conform to these criteria are 

delineated on a transparent overlay registered to 

the aeromagnetic contour map.

• Analysis and Interpretation of Gravimetric Data— 

The gravity contour map is interpreted in conjunction with the magnetic map. Differences in 

map construction introduce small errors in the 

alignment of the interpreted gravity lineaments 

and magnetic lineaments, but these displacements 

do not invalidate the existence of anomalies.

Gravity lineaments are interpreted according 

to the same criteria used in interpreting the magnetic lineaments described above. The results are 

delineated on an overlay registered to the gravity 

contour map.

• Analysis and Interpretation of Aerial Photos—The 

principal difference between analyzing aerial 

photos and satellite (or SLAR) images is that the 

synoptic overview of the latter is exchanged for 

the stereoscopic view of the former. In other 

words, the integrating effect of the large-area, 

small-scale data set is supplemented by the great
APPLICATIONS OF TECHNOLOGY FOR POWERPLANT SITING 131

FIGURE 8.—Lineament analysis of SLAR imagery.

density of detail provided by the large-scale, 

three-dimensional format of the photo. The analytical criteria remain the same, however, in that 

the analyst is searching for evidence of alignment 

and offset. The principal function of the photointerpretation phase is to detect corroborative 

evidence of lineaments found on Landsat and 

SLAR and to locate smaller lineaments that 

Landsat and SLAR failed to detect.

• Analysis and Interpretation of Thermal Infrared 

Imagery—Thermal infrared imagery is seldom 

used in site investigations unless it has been previously acquired for some other purpose. This is 

because it is generally believed to be noncost 

effective in investigations of this kind, where it 

is unlikely to detect structures that have not 

already been detected less expensively through 

the use of Landsat and aerial photos. However, 

if thermal imagery exists and can be purchased 

at low cost, or, if the site is underlain by a limestone terrain in which near-surface cavities can 

be expected, it is well worth the additional cost.

Unlike thermal pollution studies, site investigations do not require that the thermal imagery be 

calibrated so as to give accurate temperature 

readings. The only requirement is that temperature differences and anomalies be observable

and caused, for the most part, by differences and 

anomalies in soil moisture or vegetation, which 

in turn may be caused by faults and near-surface 

cavities.

Figure 9 (p. XIV) shows a machine-aided analysis of thermal imagery in which the colors represent preselected temperature ranges. For 

example, faults serving as ground-water conduits 

may cause the superjacent soil to be wetter 

(cooler) than the surrounding soil, and cavities 

may drain the overlying soil causing it to be 

dryer (warmer).

Synthesis of Remotely Sensed Data—When the interpretation and analysis of all of the remote 

sensor records have been completed, a transfer 

scope is used to plot all of the delineated features of structure and lithology at a common 

scale and format on separate transparent overlays. These are registered to a common base 

map on which known faults have been delineated. 

Superimposition of the several transparent overlays results in an effective synthesis of the 

separate data sets contributed by each of the 

remote sensors that were employed. A synthesized overlay is then prepared which combines 

all of the geological features from the separate 

overlays. The separate structural features are
132 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

indicated by different line weights and patterns— 

one weight or pattern indicating that the feature 

was observed on all sensors and on the "ground 

truth" map, another weight indicating that the 

feature was seen on all of the sensors but one, 

and so on down to those features that were observed on one sensor only. Figure 10 (p. XIV) 

shows a synthesis of Landsat, aeromagnetic and 

and gravimetric data.

APPLICATIONS

Nuclear Powerplant Siting Studies

Dames & Moore routinely utilizes satellite and 

aerial imagery to support investigations for the location of potential plant sites and as an integral part of 

studies for the safety analysis of selected sites.

The interpretation of these images is performed to 

extract information relating to the regional geology 

and tectonics.

Utilizing imagery from the Landsat and Skylab 

Programs, analyses are conducted to delineate regional lineaments from which indications of faulting and major fracture patterns can be assessed. 

This information is presented on overlays to standard 

1:250,000 maps of the project area. Correlations are 

made between the linears interpreted from the overhead coverage arid known faults as shown on existing 

geologic maps. Linears which may have been erroneously compiled as manmade features (i.e., roads or 

railroads) are corrected (eliminated); existing fault 

traces which appears on geologic maps may be extended. By virtue of the broad (synoptic) view afforded from satellite altitudes, new lineations, heretofore 

undetected, add to the store of geologic information 

about the region.

In addition to the linear compilation, annotations 

showing geologic contacts in greater detail can be 

compiled and correlated to formational units from 

existing geologic mapping. By this means the final 

overlays will have provided investigators with lithologic and soils maps of significantly more comprehensive information.

As a complement to the satellite data, Dames & 

Moore has acquired available SLAR coverage for a 

number of projects. SLAR imagery has been used as 

correlative information and has been found to be 

extremely useful in that subtle surface linears are enhanced by SLAR, thereby facilitating detection.

Another data input applied to the geologic analysis 

is aeromagnetic mapping. Often these data are not 

available; however, where costs are justified, new 

surveys have been executed and the results indicative

of subsurface structure are applied to those lineament 

features obtained by visual analysis. Regional magnetic anomalies, where found, can be matched to the 

scale of the linear compilation and often highlight 

zones for priority field checking at later stages of a 

siting program.

The procedures described above constitute an 

initial reconnaissance phase from which a "first-cut" 

evaluation of desirable sites can be made. Once this 

decision is made, a followup analysis utilizing highland low-altitude aerial coverage is conducted. The 

higher resolution aerial photography provides the 

greater ground resolution from which detailed geologic mapping of localized areas can be performed.

The resulting products (annotated maps, photographs) are useful in orientating field crews and directing them to outcrop locations, suspected faulting, 

et cetera. These are supplied to the project field offices and utilized in the field for planning detailed 

surveys.

In addition to remote-sensing analysis for geologic/ 

tectonic information, Dames & Moore has performed 

visual image interpretation and computer processing 

for land use mapping and ecological assessment.

Digital magnetic tape data have been used to create 

land-use maps for several siting studies using computer-interactive techniques. Figure 11 shows such a 

map, in which four categories of use have been identified. Parcels of land down to about 1 acre in size 

are shown. Where secondary or tertiary levels of detail or higher ground resolution are required, aerial 

photography and visual interpretation methods are 

employed along with ground truth surveys to delineate 

these subgroup requirements.

The land use thematic maps output, from the multispectral processing, may be compiled in a variety of 

formats. Different themes or categories may be displayed as alphanumeric characters, colors, or shades 

of gray.

Projects where similar requirements are applicable 

include: environmental impact reports, wetlands 

mapping, agricultural and forest stand inventories.

The same techniques employing electronic processing for land use data are also extremely useful in surface water mapping. Using color-infrared data, 

accurate delineation of land/water interfaces can be 

made down to the highest resolution of the data. In 

some cases, physical and chemical pollutants can be 

identified and traced back to their sources both in 

estuarine and marine environments. Using thermal 

infrared data, surface temperature differences of less 

than 1°F can be mapped, providing an excellent tool 

for mapping differential thermal effluents, spotting
APPLICATIONS OF TECHNOLOGY FOR POWERPLANT SITING 133

FIGURE 11.—Digitally processed land use data from Landsat observation.

water seepage, or freshwater sources on the terrain 

surface.

EXAMPLES

A brief description and illustrations of three nuclear 

powerplant studies involving typical tasks performed 

by Dames & Moore employing remotely sensed data 

and techniques are as follows:

Site Selection, South Carolina—A preliminary investigation utilizing Landsat imagery (bands 5 

and 7) was conducted to ascertain major regional 

lineaments over the State of South Carolina. This 

"front-end" survey was performed to delineate 

indicators of subsurface structure which provided 

initial information as to:

1. Areas that might be eliminated on the basis 

of potential fault-related zones.

2. Where other suitability factors favored plant 

siting near these zones, further studies 

could be planned to direct subsequent 

ground investigations to these areas.

Site Assessment/Regional Tectonics, Ameri and 

Bandar Bushehr, Iran—The area circumscribed 

by a 200-mile radius which originates at each of 

these two sites was evaluated and supported by 

Landsat image analysis. The analysis provided 

overlays upon which observed lineaments and 

existing fault traces were compiled. These products were correlated with a plot of epicenter 

locations to determine subsequent requirements 

for geologic field investigations. At a later stage, 

critical areas were analyzed in detail using 

l:50,000-scale aerial photos, in stereo, and utilized in field surveys to verify faulting.

Site Specific Investigation, Fulton, Pa.—The result 

of a regional tectonic study via Landsat visual 

interpretation detected a number of lineaments 

within a 10- to 20-mile radius of the site area. 

Corroborative information was achieved from 

SLAR, high-altitude U-2 overflights and detailed 

aerial photos at a relatively large scale. In addition, an aeromagnetic survey was performed so 

that the synthesis of all source outputs provided
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FIGURE 13.—Multispectral computer processed classification map of an area west of Koh-i-Dalil, Pakistan, showing five areas classed as "mineralized." 

Reconnaissance field checks showed that some hydrothermal alteration and sulfide mineralization is present in each area. (Adapted from Schmidt, 

R. G., Clark, B., and Bernstein, Ralph, 1975, Search for sulfide-bearing areas using Landsat-1 data and digital image-processing techniques, 

in Natl. Aeronautics and Space Admin. Earth Resources Survey Symposium, Houston, Tex., June 1975, Proc., v. 1 B, p. 1013-1028.)

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APPLICATIONS OF TECHNOLOGY FOR POWERPLANT SITING 135

isolated areas to be used in planning ground magnetic surveys, seismic investigations and ultimate 

verifications by bore-hole drilling. Figure 12 (p. 

XV) shows lineament data from three sources: 

Landsat, SLAR, and U-2 photos. 

Uranium Exploration—We are witnessing a new 

surge in exploration activities for increased 

sources of uranium to support the projected 

needs of the nuclear power industry. Remotesensing techniques have been developed which 

now afford cost-effective means for surveying 

vast areas and mapping zones which may contain 

potential new deposits.

Two methods which are employed utilize satellite and aerial photography along with geophysical survey data, as follows: 

1. Visual interpretation for lineaments coupled 

with aeromagnetic and gravity data reductions and correlated with geologic maps 

and known deposits provide an overview to 

delineate areas of potential mineralization

which may be associated with faults and 

fractures. Figure 10 (p. XIV) shows areas 

in which lineaments derived from Landsat 

data, aeromagnetic data, and gravimetric 

data are coincident (dark swaths), and areas 

in which Landsat lineaments are coincident 

with either aeromagnetic or gravimetric 

lineaments (light swaths). Areas of known 

mines (shown as light dots) show a high degree of correlation with these areas of 

coincident lineaments.

2. Multispectral computer processing to delineate potential mineralized zones which 

may be associated with surficial features 

(such as halos) and which show a unique 

spectral response (signatures) on Landsat 

multichannel scanner data (fig. 13). 

By these procedures an area survey may be accomplished to delineate potential mineralized zones whose 

occurrences may be related to deposition in faults/ 

fractures or in sedimentary structures.

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Landsat-1 Image Studies as Applied 

to Petroleum Exploration in Kenya

By John B. Miller, 

Chevron Overseas Petroleum, Inc., San Francisco, California 94105

ABSTRACT

The Chevron-Kenya oil license, acquired in 1972, 

covers an area at the north end of the Lamu embayment. Immediately after acquisition, a photogeologic 

study of the area was made followed by a short field 

inspection. As geophysical work got underway, an 

interpretation of Landsat-1 (ERTS-1) images was 

completed as a separate attempt to improve geological knowledge. This paper describes the method 

used in the image studies, the multispectral characteristics of rock units and terrain, and the observed 

anomalous features seen in the Landsat imagery.

The observed lineaments seem to be part of the 

regional fracture system associated with East Africa 

rifting and crustal expansion. A trend intersection at 

the north end of the Lamu embayment might be interpreted as a failed, immature triple junction, with one 

postulated arm opening into the Rudolf trough and 

a second arm into the Ogaden basin. The Lamu embayment is viewed as a possible aulacogen.

A feature of some significance to the geologic interpretation is an early Quaternary depositional summit 

surface formed from merging alluvial fans. The surface 

is slightly cut by shallow modern valleys eroded into 

the top part of Pliocene sedimentary deposits just 

beneath. Absence of a fan near the northwest license 

corner and a swampy area along the Ewaso N'Giro 

drainage suggest subsidence along what may be a 

structural trough or downwarp.

The postulated local trough along the Ewaso N'Giro 

is confirmed by the results of magnetometer and 

gravity surveys over the area and some early results 

of reflection seismic studies. The geophysical results 

also support certain predictions made from the photogeology and image studies relative to the basin 

boundaries and larger lineaments. For example, anomalies are found along the Lagh Choichuff, Lagh Bogal, 

Ewaso N'Giro, and Hagadera-Liboi lineaments.

However, convincing geophysical evidence of the 

Habaswein-Wajir Bor lineament has failed to materialize. Postulated fault relief along the trend, downdropped to the south, seems to be present relative to 

a structural block of basement rock at and west of 

Wajir but is not apparent relative to the sedimentary 

units and underlying basement farther east, toward 

the Somali border. Something of a puzzle in interpreting the geology of this northeast corner of the 

license area is the fact that the sedimentary section 

north of the lineament as indicated from the preliminary geophysics is very much thicker than the 

section measured in surface exposures.

Anomaly A, a large circular feature seen in the 

Landsat imagery, partly coincides with the apparent 

"basinal" (thick sedimentary) area east of Wajir. The 

real nature of this anomaly is not yet apparent.

The Landsat imagery yielded a surprising amount 

of information in this flat, relatively featureless area. 

The success obtained strongly supports Landsat 

studies as a valid exploration tool. Such image studies 

and photogeologic work nicely complement one another.

The study has helped to define the relationship of 

the Lamu embayment and its internal structure with 

surrounding regional features, such as the East Africa 

rifting, the Rudolf trough, the Bur-Acaba structural 

ridge, and the Ogaden basin.

INTRODUCTION

When Landsat-1 (ERTS-1) was launched by the National Aeronautics and Space Administration in July 

1972, a door was opened toward a new type of information, quick and inexpensive to use. Among many

137
138 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

uses, the information can assist in exploring for oil, 

gas, and minerals.

The task of Landsat-1, also Landsat-2 and future 

units, is to provide an orderly array of pictorial images 

over what eventually may be most of the Earth's surface. Already the coverage is large and in many instances repetitive through time and changing seasons, 

snow, flood, and drought.

Many geologists who have made serious and wellinformed efforts to use Landsat imagery have obtained good results. Also, they have recognized some 

of the limitations of such work. These things have 

been reported principally through the NASA ERTS-1 

symposia, especially those of March and December 

1973.

Several things contribute to a rather unique value 

of the Landsat imagery as it applies to exploration. 

One is the coverage that is already great and promises 

to be all but worldwide. Also, the multispectral capability, supplementing what can be seen on conventional 

airphotos, helps the geologist to distinguish different 

types and combinations of rock, soil, and vegetation 

and to find anomalies. The orthographic exactness 

and scale uniformity of Landsat imagery is of special 

value. An important application of the data is to provide quickly useful planimetric and geologic maps in 

areas where information is sparse. Inaccuracies in existing maps can be corrected while posting the maps 

with additional new information visible on Landsat 

images.

The Landsat-1 imagery is of two types: MSS (Multispectral Scanner) data and RBV (Return Beam Vidicon) data. However, the bulk of Landsat-1 data and 

all the Kenya imagery is MSS.

The Landsat imagery of Kenya was not obtained 

in time to be helpful in selecting the initial Chevron 

acreage. It was obtained soon afterward, however, 

and was used in making an early appraisal of the area 

and in planning a work program. Also, it was part of 

the basis for filing later on a smaller additional optional block which adjoins the initial block at its 

northwest boundary and corner.

At each stage after its original presentation in Cairo, 

Egypt, additions have been made to this paper x to 

keep abreast of the progress in acquisition and exploration. This revision adds geophysical information 

not previously given.

GEOLOGIC BACKGROUND

The Chevron oil exploration license covers the 

northern part of the basinal feature df the Kenya 

coast known as the Lamu embayment (fig. 1). That 

much was known in 1972 when the exploration right 

was acquired. But not much was known about the 

exact basin shape, its limits, and structural nature.

1 Updated and slightly edited from a paper which was presented November 1974 at the Fourth Exploration Seminar, 

Egyptian General Petroleum Corporation, Cairo; in February 

1975 at the Research Conference on Remote Sensing, University of Kansas, Lawrence; and in June 1975 at the NASA Earth 

Resources Symposium, Houston.

FIGURE 1.—Index map showing regional features and areas of 

the Chevron exploration license and option (shaded line). 

Lineaments are numbered: (1) Lagh Bisika, (2) Lagh Bogal, (3) 

Lagh Katulo, (4) Habaswein-Wajir Bor, and (5) HagaderaLiboi. Area of Landsat image mosaics, figures 2 and 3, shown 

as dashed line.

Previously, British Petroleum-Shell had held an oil 

lease over a large part of the Lamu embayment, including some of the ground taken by Chevron. Most 

of the BP-Shell rights had been relinquished, leaving 

only a relatively small area along the Kenya coast.

BP-Shell had explored extensively and drilled 16 

"dry" wildcat wells in the Lamu embayment. Only 

three of these—Meri-1, Waligero-1 and Wal Merer-1 

—are on the Chevron tract. These were enough to 

demonstrate the presence of more than 12,000 ft 

(3,660 m, approximately) of sedimentary rocks within 

the land acquired by Chevron. Several other wells of 

substantial depth were known to exist some distance 

to the east, in neighboring Somalia.

But while information on the embayment itself was 

sketchy, certain information on surrounding areas was 

well documented by the Geological Survey of Kenya. 

In the area west and north of Mombasa, Caswell
LANDSAT-1 STUDIES APPLIED TO PETROLEUM EXPLORATION IN KENYA 139

(1953, 1956), Sanders (1959), Thompson (1956), and 

Williams (1962) reported a thick section of sedimentary rocks. This includes Karroo-type red beds 

(mainly continental sandstones, Carboniferous and 

Permian through Triassic), a section of marine shales 

and local shelf-type limestone (Jurassic and Cretaceous), and locally along the coast onlapping marine 

deposits of Tertiary age. The aggregate section of 

Karroo-type beds totals about 22,000 ft (6,700 m, approximately). The Jurassic section totals 6,600 ft 

(2,010 m). The Cretaceous is incompletely represented 

in exposures by only about 300 ft (90 m) of section.

In the area north of the license area, extending to 

the Ethiopia border, the stratigraphic column begins 

with Triassic strata and ranges through the Lower 

Cretaceous. These rocks have also been described 

by geologists of the Kenya Geological Survey, particularly in reports by Thompson and Dodson (1958), 

Baker and Saggerson (1958), Saggerson and Miller 

(1957), and Matheson (1971). As compared with sedimentary rocks at Mombasa, the thickness is much 

less and the lithology is somewhat changed. The 

Triassic again is a Karroo-type facies, but the exposed 

thickness is only 2,000 ft (610 m). The Jurassic strata, 

roughly 5,500 ft (1,680 m) thick, are mainly dense, 

gray shelf-type limestones. About 2,500 ft (760 m) of 

Cretaceous section consists mostly of shallow-water 

sandstone and some interbedded marine shale.

Contrasts both in thickness and lithology are found 

when the stratigraphic units north of the license area 

are compared with those observed near Mombasa. 

However, it is not clear where and why the changes 

occur nor what may be their significance to the possible presence of commercial hydrocarbons.

Available maps show most of the surface in the 

license area as Quaternary alluvium. Jurassic limestones abut and enter the area east of Wajir, some 

late Tertiary volcanic rocks occur in the northwest 

corner, and Precambrian metamorphic rocks crop out 

in the southwest. Several small Jurassic exposures 

are reported just outside the area, north of Mado 

Gashi. Preliminary investigations have shown that, 

over much of the area, erosion has cut very shallow 

valleys into underlying clays considered of Pliocene 

age. While the exact age of these is subject to question, the clays are mainly older than sands and soils 

found on the undissected summits, and older by yet 

another stage than the alluvium in the modern streamflats. They appear to be the top part of a fairly thick 

Miocene-Pliocene section known in much of the Lamu 

embayment.

A complex, sloping plateau rises from an altitude 

of about 1,200 ft (370 m) above the sea at the west

margin of the Lamu embayment north of Garissa to 

a structural swell reaching a height of more than 6,000 

ft (1,830 m) along the Kenya (Gregory) Rift Valley. 

This is mainly an area of Precambrian rocks, including a variety of metamorphic and intrusive rocks, but 

there are also great areas of volcanic rocks and 

several large volcanic peaks. The more resistant 

crystalline masses stand as prominent inselbergs. 

Many belts of hills representing old topography occur 

within and between the valleys. In this terrain are 

well-preserved parts of three planation surfaces, produced by denudation after principal stages of structural uplift associated with the African rift system. 

The plateau area was tilted seaward in Late Cretaceous, middle Tertiary, and late Tertiary episodes of 

domal uplift (Saggerson and Baker, 1965; Matheson, 

1971; Baker and Wohlenberg, 1971).

Two geologic papers containing new, important information relative to the Lamu embayment were 

published in 1973. One of these, by Walters and Linton of BP-Shell (1973) provides subsurface information on the Lamu embayment. The other, by Gulf Oil 

geologists Beltrandi and Pyre (1973), described the 

geology of adjoining basinal areas in Somalia. Although these add substantially to available knowledge, 

they provide incomplete answers about basinal structure, bounding limits, and stratigraphy.

GEOLOGICAL INTERPRETATION

METHODS

To conduct this study, Chevron purchased 70-mm 

positive transparencies of all four spectral bands of 

the required Landsat-1 imagery. These were composited into color, using an early model International 

Imaging System (I2 S) additive-color viewer then available at the Chevron Oilfield Research Laboratories 

at La Habra, California. Several color arrays were 

recorded as 35-mm color slides on Ektachrome highspeed film. For interpretation of the imagery, the 

35-mm slides and also the 70-mm black and white 

images were projected on the wall of a darkened 

room. A sheet of white drafting paper fastened to the 

wall served as a projection screen and as a base for 

annotating the geology and other photographic detail.

Since completion of this work, Chevron Overseas 

has obtained, at its home office, an improved PS 

viewer. This eliminates dependence on color slides, 

and makes it possible to annotate on a transparent 

medium directly over the screen of the compositor. 

This is done at a favorable scale of 1:500,000. During 

annotation, the image is examined with a binocular
140 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

headpiece which provides li/2 X and 2!/2 magnification.

Just prior to the Landsat study, even predating the 

availability of the Landsat imagery, I conducted a 

photogeologic study of our area (airphoto scales 

partly 1:40,000; partly 1:80,000) and made a 6-day 

trip into the field. This work extended from September into early November 1972. This experience in 

Kenya was most fortunate as a prelude to the work 

on the Landsat images. Of course, such experience is 

never amiss. As background toward evaluating a new 

and unfamiliar type of imagery, it proves to be especially helpful. It is a framework for judging the physiographic and geologic phenomena as registered by the 

Landsat sensors and for evaluating the usefulness of 

the data.

Two Landsat image mosaics are used to illustrate 

this paper. These copy fourth-generation products 

from the 70-mm positive transparencies acquired from 

the EROS Data Center at Sioux Falls, South Dakota. 

The first step was to photographically enlarge the 

images into a set of negatives at 1:1,000,000 scale, 

produced on 9 X 9-inch film. Contact prints from these 

formed the original mosaic, which then was reproduced into a single mosaic negative and into photographic prints.

The remainder of this paper is an appraisal of information recovered from the interpretation of the 

Landsat images. Comparisons are made, from time to 

time, with detail as seen on airphotos and occasionally 

as seen on the ground. A comparison is made also 

with geophysical data obtained since the Landsat 

analysis was completed.

PHYSIOGRAPHY

Much of the drainage pattern is seen on the Landsat 

images with remarkable clarity, even into the headwaters of relatively minor drainage courses. In viewing the Landsat images, this is almost the only 

evidence of relief. An impression of relief is better 

when there are ground shadows, but very few slopes 

in the area are steep enough to produce shadows. 

The exceptions are the cuestas of Triassic sandstones 

roughly 80 km north of Wajir, several lava features 

west of Wajir, the Bur Wein anticline south of El Wak, 

and inselbergs of basement. All of these hills are 

small, even at the scale used during the interpretation. 

At the reduced size of the present mosaics and maps 

(figs. 2-5) they become all but invisible.

The drainages are gullies and wide, flood-washed 

channels in a semi-arid terrain. These are seen clearly 

in Landsat images and can be drawn accurately. The 

drainages that originate on the plateau and enter the

region from the west have relatively wide streamflats. 

The Tana River carries a good flow of water. Through 

the use of the infrared image particularly, the dark 

meandering line of this can be followed readily (fig. 2). 

The other streams are seasonal. The Ewaso N'Giro 

spreads and much of its flow is arrested at the Malka 

Galla swampy area north of Mado Gashi. Lush vegetation at the "swamp" produces high response in the 

infrared as compared to the green and red band response, so that a false-color image registers flaming 

hues of red. Below this spot, the Ewaso N'Giro drainage channels become narrow and dispersed, and, 

while borders of the streamflat are sharply defined, 

the channels within it are indistinct. The same is true 

for other similar streams. For example, a 15-km segment of Lagh Katulo as sketched differs from the 

main stream course marked from airphotos, but the 

difference is inconsequential in small-scale mapping 

amid shifting channels.

The relief, indeed, is low. Except for an escarpment 

along the Yamicha area lava bench, the only hills with 

substantial sloping profiles are either west or well to 

the north of the Chevron license. Although there is 

about 180 m of slope in 220 km from the west edge of 

the license to the southeast corner, the horizon, as 

seen on the ground, is commonly flat. The most 

rugged ground generally consists of a gentle, faintly 

rilled slope into a shallow valley, a low-cut bank, and 

then an equally gentle rise to a low, broad summit. In 

perhaps half of the license, these slopes are so slight 

as to be imperceptible during ordinary stereoscopic 

study of airphotos. They are defined mainly by directions of rainwash and drainage rather than visible 

relief. Remarkably, much of the drainage of these insubstantial slopes is seen almost as clearly on Landsat 

images as on the airphotos.

ROCK SIGNATURES

Quite a number of boundaries between rock types 

can be traced on the Landsat images even though the 

nature of the lithology is not clear. To some degree, 

even the approximate nature of the lithology can be 

surmised. In this text, the visible characteristics of 

units will be reviewed in successive order of decreasing age. Many of the characteristics are not seen in 

figures 2 and 3 because these are much smaller than 

the images employed for interpretation.

The migmatitic character of the basement rocks 

seems to be subtly evident. A peculiarity of folia is 

that they show on many scales, which range from 

microscopic size into the outcrop and then to a 

textural grain seen on airphotos. In the Kenya
LANDSAT-1 STUDIES APPLIED TO PETROLEUM EXPLORATION IN KENYA 141

FIGURE 2.—Landsat image mosaic Carissa-Wajir-El Wak area, Kenya, band 7 scenes. The lines where the images are 

matched show as sharp, straight boundaries parallel and normal with the slant margins. The dark Jurassic limestones northeast of Wajir, transected by the Lagh Katulo alluviated valley and fault line, are clearly visible. The 

Hagadera Liboi lineament is also prominent. The white flecks in the lower right hand scene and at extreme lower 

left are clouds. Landsat images 1190-07052 (upper left), 1189-06593 (upper right), 1190-07054, 1189-07000, 

1190-07061, and 1153-07003.

migmatites, some of the foliated grain is reproduced 

even in the Landsat images. It appears as faint, 

shadowy bands, probably representing rock and 

topography and interwoven layers of differing lithology. In places, there are inselbergs indicating resistant rock. A wide color range, from eggshell and flesh 

tones into green and gray very likely represent composition ranges from light-reflective bands of quartzose 

rocks and feldspar through rocks of intermediate

composition, mantling residual material rich in iron 

oxides, into belts of relatively fresh rock containing 

unoxidized femic minerals, gray slate, and, locally, 

marble.

The Triassic conglomerate and sandstones north of 

Wajir stand out from the metamorphic complex mainly 

because of their sharp, arcuate- and irregular-shaped 

cuestas. The well-stratified and resistant character of 

the rocks is revealed by the erosional form of the
142 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 3.—Landsat image mosaic, Carissa-Wajir-EI Wak area, Kenya, band 5. The Lagh Bisika, Lagh Bogal, 

Lagh Bor, and at least part of the Wajir Bor lineaments are quite apparent. The Pliocene-Pleistocene depositional surface is better defined by band 5 than band 7 (fig. 2). The expanding wedge of "upper" 

Merti can be found by comparing band 5 with band 7 imagery; it is seen in mainly the Tana River valley 

wall north of Carissa. With apex near the metamorphic rocks and expanding as a narrow wedge eastward, 

the unit contrasts sharply with the rim of darker duricrust, just north. Its base, seen as a contrast with 

the lighter colored "lower" Merti, shows better on the band 7 imagery of figure 2.

ridges. The low dip present in the strata can be construed from down-dip expanse of the dip slopes.

A basal boundary of the Jurassic limestone can be 

followed only inexactly. The limestones appear quite 

dark in bands 6 and 7, somewhat less dark in bands 

4 and 5, and show as dark gray partly flushed with 

red in the composite image. The red is a response 

from a combination of thin soils and sparse vegetation.

Cretaceous sedimentary units show in the extreme 

northeast as sharply denned ridges and cuestas. The 

direction of dip is generally discernible.

Pliocene and Quaternary volcanic rocks, mainly 

basalts, are present in the northwest part of the area. 

In fresh outcrop, these register darkest in all color 

bands, and, in the color composites, they show as 

nearly black. There is a weathered surface and some 

soil across the basaltic mass at Yamicha, but, in its
LANDSAT-1 STUDIES APPLIED TO PETROLEUM EXPLORATION IN KENYA 143

ROCK UNIT BOUNDARIES 

LINEAMENTS

""'"

/////// LINEAR UNITS 8 

STRATIFICATION

ARCUATE ANOMALIES, 

INTERPRETED AS 

POSSIBLE BEDFORMS.

CHEVRON

LEASE BOUNDARY

FIGURE 4.—Lineaments, rock unit boundaries, and other features as interpreted from the Landsat imagery. The Qs 

symbol designates part of the Pliocene-Pleistocene summit depositional surface, regarded primarily as Quaternary material. Centered at A and near its margins by a circular pattern of drainage is Anomaly A. Scale 

1:2,500,000.

southern escarpment, which probably marks an Of somewhat the same age are the Plioceneoriginal flow edge, the volcanic rocks are very fresh. Pleistocene clastic deposits. These show the most 

Farther north, a virtually unweathered volcanic flow varied color signatures of all—a greater range than 

is defined both by its lobate form and nearly black are accounted for by known differences in lithology. 

color The Pliocene part can be locally divided into two
144 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

SEDIMENTARY 

I——I RECENT

ALLUVIUM 8 OUTWASH

PUO- PLEISTOCENE 

DEPOSITIONS SURFACE

CALCRETE 

PLIOCENE 

CRETACEOUS

mm JURASSIC (j)

H TRIASSIC 

METAMORPHIC a IGNEOUS

FTTTTI TERTIARY 8 QUATERNARY VOLCANICS.

PRE-CAMBRIAN 

METAMORPHIC (B) 

ft IGNEOUS

FIGURE 5.—Rock unit distribution, broadly defined from Landsat imagery and other sources.
LANDSAT-1 STUDIES APPLIED TO PETROLEUM EXPLORATION IN KENYA 145

parts. At the top and probably Quaternary in age is a 

depositional surface and calcrete (fig. 5).

The main unit, the Merti sands and clays named in 

Kenya geological literature, is regarded as late Pliocene. These sediments fill a late structural sag along 

the Lamu embayment. The observed relationships 

strongly suggest faulting along the western basin 

margin, because the "End Tertiary" erosion surface 

extends across basement rocks at elevations of 600 ft 

(182 m) or more west of Mado Gashi but drops beneath the Merti in the basin. As shown by the thickness of Merti beds in the Dera borehole, near the 

basement rock boundary—240 ft (73 m) to top of 

basalt; 408 ft (124 m) to base of volcanic debris: 

Matheson, 1971, p. 19—the "End Tertiary" surface 

seems to drop structurally at least 250 ft (76 m) in 

crossing the basement boundary.

The boundary of the Merti deposits with basement 

rocks is plainly seen on Landsat-1 imagery at the Tana 

River. The basement appears banded. The adjoining 

Merti is finely rilled and, especially in band 7, has a 

lighter tone (fig. 2). Extrapolating from topographic 

maps, the thickness of Merti beds exposed in the 

valley slope near the basement boundary is about 

600 ft (180 m).

Above this, and within my knowledge recognized 

only on the Landsat-1 imagery, is a second unit. It 

begins at the basement boundary and thickens wedgelike into the basin. It is slightly darker in bands 5, 6, 

and 7 than the sediments beneath. I distinguish this 

wedge-shaped unit tentatively with the name "upper 

Merti," but suppose it may not be readily separated 

from the underlying part of the Merti except in the 

Tana Valley. Saggerson and Baker (1965, p. 57) mention 300 ft (90 m) of Merti sediments at Garissa. On 

the basis of the Landsat-1 image, at least 200 ft (61 

m) of these seem to belong to the "upper Merti." 

Seemingly they will entirely overlie the estimated 600 

ft (183 m) of Merti beds exposed near the basement 

boundary.

The distinguishing tonal difference of the "upper" 

Merti from underlying beds is clearly seen in the color 

image and in the longer wavelengths of bands 5, 6, 

and 7. It is seen hardly at all in band 4. The smaller 

sensitivity of shorter wavelengths to these lithic divisions may explain why the divisions were not recorded 

during work on conventional airphotos. Coupled with 

this is another reason: The sediments are unconsolidated. They are intricately scored by rilled drainage, and small masses of the material have moved 

downslope through the action of crumbling and mudflow. The boundary, as seen on the airphoto, has 

probably been softened and blurred by this action. On

the other hand, as seen in the overview of the Landsat 

image, the boundary is relatively sharp and conspicuous.

Above the Merti is a thin unit of sand, marl, and 

calcrete deposits or "caliche." This tends to form a 

duricrust with thickness commonly ranging from 1 ft 

to perhaps 8 ft (about 2 or 3 m). The top surface, 

probably Pleistocene, is a thin layer of soil thinly 

mantled with sand. Near the town of Wajir, the 

Quaternary deposits—about half sand and shale, and 

the top half mainly calcrete—thicken to as much as 

100 ft (30 m) and contain a substantial amount of 

ground water. Calcrete outcroppings in this area 

appear on the Landsat images as white patches.

The depositional surface of the Quaternary duricrust (mapped Qs) has been cut and partly destroyed 

by the modern system of streams. Nevertheless, there 

are numerous remaining patches. The distribution of 

these bears on several aspects of the geology, including the reconstruction of previous drainage and a 

definition of lineaments.

Remnants of the surface, as seen on airphotos, have 

a relatively dark gray cast and slight, benchland-type 

rims. Commonly there is a pattern of widely spaced 

"pits" that appear to be subtle, periodically wet depressions. Where the surface has been destroyed, 

there are rilled slopes or an expansive surface of clay 

which is broken, probably along jointing, into polygons 

or prisms. Each polygon has an almost imperceptible 

hummock and central cluster of brush (as confirmed 

on the surface) surrounded by bare clay and a wash 

of white sand.

The depositional surface stands out quite well on 

the Landsat imagery, although a color composite is 

needed for most effective mapping. It supports grass 

and significantly more trees than are found over most 

adjoining rock units. Consequently, in addition to a 

darker cast than most surrounding rock units except 

limestone and basalts, the false-color images rendered 

by the surface are distinctly reddish. A response that 

comes from grass and trees, the reddish tint is probably somewhat seasonal, dependent on rains.

Examination of the surface suggests two main parts, 

a sloping plain from the north-northwest, and what 

may be called the Tana fan from the southwest. 

Judged from valley entrenchment and airphoto stereoscopy, there is a definite easterly slope to the Tana 

fan. Also, the plain beyond the Ewaso N'Giro tends to 

undulate slightly across axes parallel to the present 

drainage. As judged from the distribution, destruction 

of some of the surface, e.g., the northwesterly part 

and a belt along the Ewaso N'Giro, seems to have
146 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

started before development of the southern part of 

the surface was complete.

Examination of the Landsat images reveals several 

elements within the plain that were not noticed on 

airphotos. Located between the Ewaso N'Giro and 

Lagh Bogal (fig. 4), these can be effectively defined 

only on the color image (fig. 6, p. XVI). They show 

as four or possibly five differing arcuate bands of 

color. Their shapes suggest giant bedding structures. 

Preserved parts of the Quaternary depositional summit coincide with the associated arcuate forms, indicating these might be anchored by resistant layers 

among somewhat complex stratigraphic forms just 

beneath the surface. For example, they could mark 

the upper edges of several shallow, trough-shaped 

features related to erosion and depositional patterns. 

Although probably not sensitive to structural trends, 

these might be significant to the distribution of possible shallow ground water.

LINEAMENTS

As used in this paper, the term lineament refers to 

apparently natural lines, bands, and anomalous zones 

generally more than 10 km (6 mi) long. These lines and 

linear bands are associated variously with straight or 

slightly arcuate drainage courses, tonal lines, aligned 

erosional breaks in the Quaternary depositional surface, and occasionally other phenomena.

A set of linears aligned about N. 50°-60° E. probably is paired with another set aligned N. 45°-60° W. 

Representatives of the northeasterly set are the 

Habaswein-Wajir Bor and Hagadera-Liboi lineaments. 

Trends in the northwesterly set are along the Lagh 

Katulo, Lagh Bogal and a segment of the Ewaso 

N'Giro. Considered as conjugate directions, the intersection angles generally fall between 60° and 80°.

Another set of lineaments (e.g., Lagh Choichuff, 

Lagh Bor) commonly bears about N. 10° W.-N. 20° W. 

Probably conjugate with this is the Lagh Bisika and 

several smaller trends bearing N. 70° W. The intersection angle ranges between 50° and 65°.

A number of lineaments, accentuated in figure 4, 

are discussed below. Among the many linear features 

present, these seem to relate, as seen in figure 1, to 

geologic phenomena well beyond the figure 4 map 

boundary.

HABASWEIN-WAJIR BOR TREND

This wide, subtly defined linear anomaly (lineament) 

crosses the license area at its middle west boundary 

and, east of Wajir, continues into Somalia. The anomaly forms a band distinguished in part by sparsity (a 

result of erosion) of the Quaternary duricrust.

The trend is defined by two bounding' linear features comprised of separate, aligned, but not quite 

continuous, lineaments. Parts of these are formed by 

straight stream courses and other parts by tonal 

changes occurring, for example, along straight edges 

of remaining areas of the duricrust where fractures 

are probably a controlling factor in the erosion.

The ending of ridges where Jurassic limestone is 

exposed northeast of Wajir seems to be part of the 

tonal change along part of the lineament. This suggests that the trend, in this sector, may be an expression of a fault that steps the limestones downward 

into the basin where they may then be overlain by 

younger sediments.

An easterly extension of the Habaswein-Wajir Bor 

trend may play a part in an offset in basement rocks 

along the north flank of the Bur-Acaba structural 

ridge in Somalia. This is mentioned further in later 

paragraphs.

In the southwesterly direction, the HabasweinWajir trend extends toward distant Mt. Kenya, a 

major volcano.

Some 60 km south of the Wajir Bor trend is a 

parallel Landsat lineament, mainly tonal. It is not 

named, but on the map passes nearly through the 

center of the feature called Anomaly A (fig. 4). The 

lineament may play a part in the tectonic scheme and 

therefore will be mentioned again.

HACADERA-LIBOI LINEAMENT

About parallel to the Habaswein-Wajir Bor feature, the Hagadera-Liboi lineament crosses the southern part of the license and then extends into Somalia. 

Much of it is defined by drainage along a southerly 

leg of the Ewaso N'Giro (locally called Lagh Dera) 

past the Liboi military post. Toward the west, it runs 

along lesser drainage courses and finally extends 

along the south margin of the Tana River valley. In 

this segment, it partly outlines the edge of the preserved Quaternary surface.

As it is traced eastward on Landsat-1 imagery, the 

Hagadera-Liboi lineament aligns directly along the 

southerly edge of the Bur-Acaba structural ridge. 

This ridge, in Somalia, is a major uplift exposing an 

area of granite and metamorphic basement. The local 

geology indicates that at least its southern flank is 

faulted. The Habaswein-Wajir Bor and HagaderaLiboi linear features were first defined through the 

Kenya photogeology. Their exact coincidence, when 

projected by means of Landsat imagery into Somalia, 

with the boundaries of the Bur-Acaba structural ridge 

is considered geologically significant.
LANDSAT-1 STUDIES APPLIED TO PETROLEUM EXPLORATION IN KENYA 147

CHOICHUFF, BOR, AND EWASO N'GIRO LINEAMENTS

The Lagh Choichuff and its companion trend, Lagh 

Bor, trend southward across the license boundary 

along drainage courses bearing these names.

Just within the license, each is crossed by southeastward features—the Lagh Bogal and Lagh Bisika 

lineaments. The Lagh Bor feature is not seen southward of its juncture with these features. The Choichuff 

trend meets the valley of the Ewaso N'Giro and—if 

structural aspects are continuous—changes in trend 

from S. 20° E. to a new direction of S. 25°-30° E.

The apparent bend along the Ewaso N'Giro apparently is caused by an interaction between trends and 

by structural slivering. When viewed with the aid of 

a regional map, the Choichuff lineament is found to 

align with a segment of seacoast north of Malindi and 

the lower stream course of the Tana River. This suggests a deeply rooted fracture nearly parallel to the 

fault which bounds the west margin of the basin.

LACH BOCAL AND LACH BISIKA LINEAMENTS

These two trends cross the northern part of the 

license area and intersect at a narrow angle. Some 

structural interference may occur where the two 

trends meet. There is a hint of left-lateral displacement of the Lagh Bogal feature, but exact placement 

of the lineaments and definition of offset are uncertain.

The Lagh Bogal lineament is about axial relative to 

a structural-morphologic feature called the Rudolf 

trough by Brock (1965, p. 101-102). From a regional 

standpoint, it might be appropriate to name the lineament from North Island in Lake Rudolf because it can 

be traced this far to the northwest (fig. 1) and probably is responsible for the North Island volcanic center. 

It is also associated with a concentration of volcanic 

craters northeast of Mount Marsabit. The Lagh Bisika 

feature also passes northwestward, but lies slightly 

askew to the trough. This trend flanks the south side 

of Mount Marsabit and merges with a bounding linear 

of the trough about at the south end of Lake Rudolf. 

Along the Kenya-Ethiopia border, linears flanking the 

north side of the Rudolf trough are seen on the 

Landsat imagery.

LAGH KATULO FAULT

A fault displacement of Jurassic sediment along the 

Lagh Katulo can be detected both on Landsat imagery 

and on the Kenya airphotos. The displacement can be 

seen in the structural attitudes, also in the distribution 

and expanse of Mesozoic rock units. The faulted 

lineament can be traced northwestward into Ethiopia, 

also southeastward into Somalia.

OTHER ANOMALIES

ANOMALY A

This anomaly is partly within the license area. It 

centers east of the international border, in Somalia, 

and is a large anomaly of relatively pale tone and 

color, outlined by a circular drainage pattern. Its 

eastern edge is marked by a prominent deviation of 

the Lagh Katulo stream course. A northern boundary 

is the Wajir Bor lineament; a southern boundary is the 

Liboi lineament. The feature therefore may be related 

structurally to the Bur-Acaba structural ridge which 

apparently develops astride this same trend and 

structural block, farther east.

In a fold regime, such an anomaly is suggestive of 

a domal uplift. Within this extension regime amid a 

strongly developed fracture system the domal implication becomes much less forceful. The stream systems 

seemingly are deflected across major fracture lines, 

then follow along polygons of fracturing. The anomaly 

as a whole is outlined by a rimlike margin of the 

preserved Quaternary duricrust, reduced by sapping 

action to a circular outline.

Whatever the difficulties in exact interpretation, the 

anomaly probably is related in one way or another to 

the conditions of subsurface structure.

MALKA GALLA AREA

The periodic collection of water over the Ewaso 

N'Giro streamflat is not strinkingly abnormal at sites 

such as this where extensive drainage from highlands 

empty into arid plains. Yet it does suggest a break in 

the stream gradient and a possible structural sag.

Possibly more significant than the "swamps" is the 

apparent absence, in this sector, of any large alluvial 

fan coincident with the Ewaso N'Giro. The Quaternary 

duricrust developed mainly over fans entering from 

the southwest (Tana River sector) and north (Lagh 

Choichuff and Lagh Bor, and similar drainage).

The absence of a substantial fan on the Ewaso 

N'Giro may be construed as evidence of structural 

subsidence. Acting as a sediment trap, substantial 

subsidence would arrest the movement of sediment 

and minimize the growth of fans.

Construed in this way as a discrete structural sag 

filled with young clastic sediments, the area may be 

ideal for large, relatively shallow supplies of ground 

water.

BUR WEIN

The Bur Wein anticline (Baker and Saggerson, 1958) 

lies within Cretaceous outcrops about 40 km south 

of El Wak. This feature, a sharply defined domal up-
148 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

lift, shows in the Landsat image as a unique feature. 

Its steep flanks, clearly visible, set it apart from all 

other recognized features. The characteristics of the 

Bur Wein anticline, as contrasted with the surrounding 

geology, suggest it as a diapiric feature possibly developed over an igneous plug.

ANALYTICAL REVIEW

Four basic directions have been described in the 

pattern of lineaments. Three of the directions are 

coincident with major rift directions mapped in East 

Africa. The examples, classified roughly in terms of 

regional direction groups, are northward, parallel to 

the Gregory Rift Valley (Choichuff), northwestward 

(Lagh Bogal-Rudolf), and northeastward (HabasweinWajir Bor)—the northwestward and northeastward 

systems parallel regionally to the Rukoban and Ruaha 

fracture sets in Tanzania. Except for local minor 

deviations, the directions are remarkably consistent. 

Not only the younger Cretaceous and post-Cretaceous 

rifts but also the older basins filled with Karroo-phase 

sandstones as old as Permian conform with this pattern. The rift and fracture system tends to divide the 

continental block into entire and partial hexagonal 

prisms.

The regional tectonics apparently are dominated by 

vertical movements and tensional stress. The Lamu 

embayment, which contains a succession of sedimentary rocks beginning with Karroo sandstones, is 

postulated as an extension basin of possible failedarm type. Any compression-type structures within the 

embayment are probably of secondary importance.

Evidence of downfaulting of Pliocene sediments at 

the basement boundary west of Garissa is construed 

from the geometry of bedding and sedimentary fill 

(observed in the Landsat image) as these combine 

with known relief. The faulting suggests this line as 

a main, if not necessarily a unique western boundary 

to the basin, rather than as a less important line of 

sedimentary onlap and tilting.

The anticipated northern limit of the Lamu embayment, east of Wajir, is the line of postulated fault 

relief across the Habaswein-Wajir Bor lineament. 

North of this, Triassic sandstones and Jurassic carbonates are found in outcrop, resting on metamorphic 

basement. South of it, one might expect a much 

thicker section, ranging to Tertiary age.

Westward from Wajir, the situation changes. It is 

possible to relate three separate phenomena and 

conclude from them that an apex of the basin may 

extend into the northwest corner of the license area— 

its margin staggered, perhaps, between several intersecting faults: (1) the semi-swamps of the Ewaso

N'Giro, (2) an absence of a clearly defined "Quaternary surface" fan, as previously discussed, combine 

to indicate an active structural sag, and (3) Jurassic 

outcrops reported in this area, stepped far to the west 

of the Jurassic boundary northeast of Wajir. These 

outcrops must be preserved in a downwarped or 

down-dropped block and suggest a major offset or 

displacement of the basin margin.

Construed from this evidence is the idea that a 

somewhat discrete trough or graben may extend to 

the northwest corner of the Chevron holding.

A number of lineaments converge within the northern part of the tract. These may relate partly to the 

termination of the Lamu embayment if the embayment is, in fact, an aulacogen or failed arm. The 

northerly trend of the Lamu embayment combined 

with two lesser branches may form a triple junction. 

One of these, behaving as a carbonate shelf northwest 

and landward from the Bur-Acaba ridge, goes into 

the Ogaden basin of Ethiopia and Somalia.

The other, the narrow grabenlike trough toward 

Lake Rudolf, seemingly could have been a Mesozoic 

valley which directed Mesozoic river drainage into 

the Lamu embayment. This could bring about major 

changes in sedimentary thickness and facies—changes 

not yet known, but possibly important to oil occurrence—within the Chevron holding. Possibly, also, the 

trough could have held a short-term arm of the sea.

GEOPHYSICAL PROGRAM

During 1973, an airborne magnetometer survey and 

helicopter-mounted gravity survey were made. These 

surveys were planned with the benefit of photogeologic knowledge. The work was already in progress 

during the Landsat study. A seismic program, which 

benefits from all previous work, is going forward in 

1974 and 1975.

There is a limited correlation between the geophysical results and the analysis made from Landsat 

images and the airphotos (fig. 6, p. XVI; figs. 7, 8). At 

this preliminary stage, neither the coincidence of 

anomalies where coincidence occurs, nor a lack of 

coincidence is very well understood. The best correlations are these:

1. A good magnetic definition, and a modest gravity 

definition closely matching the construed fault 

along the western basin boundary. The data do 

not suggest a single profound structural drop-off, 

but instead one that is stepped or, most likely, 

involves an element of tilt as well as faulting.

2. Defined in all geophysical results is a troughlike 

feature in the northwest part of the license area
LANDSAT-1 STUDIES APPLIED TO PETROLEUM EXPLORATION IN KENYA 149

LEGEND

LINEAMENTS ANOMALIES AND AXES

LOW OR BASIN (MAGNETIC) (GRAVITY) (SEISMIC)

INTRUSIVE HIGH O + + HIGH

FAULT (GRAVITY OR MAGNETIC) )AS INTERPRETED 

LOW |_STRUCTURALLY

CHEVRON LEASE 

BOUNDARY

FIGURE 7.—Comparison of Landsat imagery structural features with crudely represented geophysical data.
150 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

EXPLANATION

FAULTS - Barb* are on 

Interpreted downthrow side 

MAJOR STRUCTURAL HIGHS 

(Magnetic features, supported by 

other data)

FIGURE 8.—Structural pattern derived from geophysical data over the northern part of the initial Chevron license. In Somalia, 

a less detailed pattern is located as well as possible from the small-scale published maps of Beltrandi and Pyre (1973). The 

shaded outlines define the position of the colored Landsat images reproduced in figure 6. These permit a comparison 

with imagery, maps, and descriptions given in this paper. The position of Anomaly A, in right part of map, is indicated.

Magnetometer and gravity data spread rather uniformly over the area of the Chevron license. There is also a grid of 

seismic lines over the whole area, but the principal density of seismic data is in the west. Very apparent is the triangular 

anomaly formed around the magnetic high in the eastern half of the Chevron holdings, caused evidently by a relatively shallow body of igneous rock, probably mainly intrusive. This anomaly appears as a central point within a distinct 

three-way branching of structure. The details shown within Chevron holdings are adapted from interpretations of geophysical data by Chevron geophysicists R. F. Flege and R. M. Wright.

There is insufficient information on structural control in Somalia to properly evaluate this part of the map. The differences 

in geology from the Kenya to the Somalia side of the border may well be caused by the relative spacing and position of 

data points. For example, inspection of the Landsat imagery, not all shown here, suggests the southeastward-trending fault 

which passes the Bur Amber-Bur Acaba ridge in Somalia as a probable extension of the Lagh Katulo fault. It is simply a 

little askew, as shown, and poorly located in the sector near the Kenya border.

more or less coincident with the inferred structural sag along the Ewaso N'Giro. A northeast 

and east boundary of this feature is evidently 

a fault. For a considerable distance, the fault 

lies along the Lagh Bogal lineament. About at 

the juncture of the Lagh Bor lineament it turns 

south through an area where there is no distinct, matching linear. It tends to die away near 

the center of the Chevron holding.

3. Rocks having high seismic velocities and the magnetic properties of basement project slightly into 

the license area in the Giriftu structural block, 

just east of the Lagh Bor lineament.

4. Shallow magnetic basement, probably igneous, 

lies along the Lagh Bogal and Lagh Bisika lineaments southeast of their juncture and about 80 

km southeast of Wajir. A tonal Landsat lineament parallel to the Wajir Bor lineament extends

northeastward from this point and bisects the 

feature called Anomaly A. As noted by geophysicist R. F. Flege, the magnetic and gravity 

anomalies which signify the presence of the 

igneous body are roughly triangular. Their 

shapes correspond with magnetic linearity in 

three directions about parallel to the Wajir Bor, 

Rudolf trough and Lamu embayment directions 

of structure. Conceivably, the magnetic anomaly 

may represent an igneous mass related to triple 

junction spreading.

5. The area north of this basement high, over part 

of Anomaly A and the entire northeast corner 

of the license area, has a thick section of sediments. This relatively basinal feature is confirmed by early results of seismic work.

6. A general gravity high trend crosses the area 

along a line just north of the Hagadera-Liboi
LANDSAT-1 STUDIES APPLIED TO PETROLEUM EXPLORATION IN KENYA 151

lineament. A magnetic high trend follows this 

in a general way. Basement along the crest of 

this feature, as compared to the flanks of the 

feature, appears relatively shallow.

Some differences and things yet unexplained are 

apparent also:

1. There appears to be no distinct downstepping of 

the basin from the carbonate shelf northeast of 

Wajir toward Anomaly A. Also, the apparent 

depth to basement within and immediately adjacent to the Jurassic outcrops is at least twice 

what it should be as judged from the stratigraphic measurements of the surface sections 

reported by Thompson and Dodson (1958), 

Joubert (1963), and others. Why this is so is not 

yet clear.

2. No substantial geophysical anomaly has been 

found along the Habaswein-Wajir Bor lineament. 

The Giriftu basement block seems to end near 

the lineament probably through downfaulting. 

West of the Lagh Bor lineament, no geophysical 

anomaly at all seems to be associated with the 

Habaswein-Wajir lineament. East of the town 

of Wajir, gravity data fail to detect the lineament. Magnetic and seismic data show a local, 

minor feature which seems to have neither great 

displacement nor continuity.

3. The transverse basement high aligned parallel to 

the Hagadera-Liboi lineament seems to terminate the structural trough which extends along 

a part of the Ewaso N'Giro. This trough, which 

lies in the northwest part of the license area, 

tends to end against the northwest flank of the 

high.

4. From geophysical evidence (fig. 8), the central 

structural depression along the Ewaso N'Giro is 

not directly along the valley of this stream as 

my foregoing analysis implies. Instead, it lies 

farther to the north and east, about at the Ewaso 

N'Giro-Lagh Bogal drainage divide. Possibly the 

present stream valley is eroded in softer ground 

where the duricrust was thin or along a line 

where faulting has weakened it.

5. Low velocity beds that seemingly would be Tertiary do not commence just southward of the 

Wajir Bor lineament, as predicted. Their first 

appearance is approximately at Lagh Bisika, 

some 70 or 80 km farther south.

6. Although phenomena coinciding with many of the 

major imagery lineaments are seen in the geophysical data, the features generated along a 

single lineament are often highly varied. A substantial number of the individual elements among 

these are elongated in direction of the lineament identified on airphotos. Yet from the geophysical evidence alone, one generally would 

not integrate them as a structural trend.

The idea that the Lamu embayment may have 

originated as an aulacogen, even though unproven, is 

partly supported by gravity data. Readings over the 

embayment are consistently higher than strongly negative readings generally obtained over the outcropping 

Precambrian rocks to the west. The readings are not 

anomalous to what is commonly regarded as a normal 

crustal thickness for continents.

Significant, however, is a three-way alignment 

seen among the structural components of the basin. 

This is quite apparent in figure 7 as well as in detail 

added by figure 8.

CONCLUSIONS

The results of the Landsat image study are analyzed 

here as they fit within an evolving program of exploring for oil in Kenya. They start with a review of 

geological knowledge initially available, progress 

through a comparison of Landsat image analysis with 

photogeology, and finally compare the results with 

what has been learned during the beginning and intermediate stages of geophysical exploration.

The Landsat information assists the geological program in two ways:

1. By helping to define an oil license area and the 

end of the Lamu embayment relative to a regional geological setting, and

2. By improving the definition of anomalies and 

lineaments significant to interpreting structure 

and stratigraphy. The area provides a severe 

test of the use of Landsat data, because surface 

geological differences within the license area 

are few and the relief very low. Almost all the 

important basin geology is concealed by young, 

flat-lying Pliocene and Quaternary fill. Useful 

ideas have sprung from the information extracted, and this is counted as progress. 

In addition, the Landsat studies contributed evidence for suspecting subsidence along the Ewaso 

N'Giro near Malka Galla and suggested a branching 

arm of the basin toward the Rudolf trough. When 

supported by geophysical evidence, this led to filing 

on an option area adjoining the original Chevron 

license, thus extending the Chevron holdings.

Several of the anomalies are defined better on the 

Landsat images than on the airphotos. The Lagh 

Bisika lineament, as a distinct fracture direction, was
152 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

defined only from Landsat data. On the airphotos it 

might be thought of simply as a sub-fracture parallel 

to the Lagh Bogal lineament. The Hagadera-Liboi 

lineament and the Lagh Katulo fault are defined more 

completely on Landsat images than on airphotos. 

Anomaly A was not covered completely in airphoto 

work and did not become apparent until the Landsat 

images were examined.

On the other hand, substantial evidence in support 

of the Habaswein-Wajir Bor trends comes from the 

pattern of smaller fractures observed only on airphotos. In the Landsat imagery, this lineament— 

mainly seen as a tonal band—has its best expression 

northeast of Wajir extending into Somalia. Its coincidence with the north flank of the Bur-Acaba structural 

ridge appears more than coincidental. I believe the 

lineament is an important, valid structural feature and 

do not understand why the geophysical data in Kenya 

do not show it clearly.

The similarities of trends mapped by means of geophysics with many features of the Landsat and airphoto interpretation suggests that a great number of 

the chosen anomalies and lineaments are structurally 

valid. The directions are generally alike, even when 

the positions differ. Many Landsat lineaments are 

wide bands—10 km and more—where the position of 

the annotation or drawn line is rather arbitrary. There 

is also the chance of fault-line anomalies: surface 

traces shifted laterally from the phenomena that cause 

them.

The complex overall associations point to complex" 

rather than simple geology. They are not conducive 

to an early and complete understanding.

During the Landsat image study, evidence was 

found of a previously unrecognized lithologic division 

within Pliocene deposits west of Garissa and also an 

internal depositional structure within Pliocene-Pleistocene deposits along a summit east of the Ewaso 

N'Giro. These proved helpful in understanding structural and basinal depositional patterns and in reconstructing basin history. And significantly, they show 

how Landsat images can function as a separate source 

of information.

In the Landsat interpretation, I have used a modified 

form of the usual techniques and skills of photogeology. The Landsat studies give an overview predisposed to finding regional anomalies, while airphotos 

more effectively look at local detail. The Landsat and 

airphoto work logically should go hand-in-hand, neither 

of them separately and alone, because each of them 

may lose the things most easily seen by the other. 

Landsat imagery adds multispectral data that are geologically useful. Most significant of all, Landsat studies

have the advantage of very quick interpretation over 

new areas and regions. Such work saves time and 

money and gives a substantial basis for new ideas.

REFERENCES

Baker, B. H, and Saggerson, E. P., 1958, Geology of 

the El Wak-Aus Mandula area: Nairobi, Geol. Survey of Kenya, Report no. 44, 48 p.

Baker, B. H., and Wohlenberg, J., 1971, Structure and 

evolution of the Kenya Rift Valley: Nature, v. 229, 

p. 538-542.

Beltrandi, M. D., and Pyre, A., 1973, Geological evolution of Southwest Somali, in Blant, G., ed., Sedimentary basins of the African coasts: Paris, 

Assoc. of African Geol. Surveys, p. 159-178.

Brock, B. B., 1965, The Rift Valley Craton, in The 

World Rift System, International Upper Mantle 

Project: Geol. Survey of Canada Paper 6614, p. 

99-123.

Caswell, P. V., 1953, Geology of the Mombasa-Kwale 

area: Nairobi, Geol. Survey of Kenya, Report 

no. 24, 69 p.

Caswell, P. V., 1956, Geology of the Kilifi-Mazeras 

area: Nairobi, Geol. Survey of Kenya, Report 

no. 34, 54 p.

Joubert, P., 1963, Geology of the Wajir-Bor area: 

Nairobi, Geol. Survey of Kenya, Report no. 57, 

34 p.

Matheson, F. J., 1971, Geology of the Garba Tula 

area: Nairobi, Geol. Survey of Kenya, Report no. 

88, 30 p.

National Aeronautics and Space Administration, Goddard Space Flight Center Earth Resources Technology Satellite Symposium, 2d, New Carrollton, 

Md, 1973, Abs.

———— Earth Resources Technology Satellite Symposium, 3d, Washington, D.C., 1973, Summary of 

Results.

Saggerson, E. P., and Baker, B. H., 1965, Post-Jurassic erosion surfaces in Eastern Kenya and their 

deformation in relation to rift structure: Geol. 

Soc. London Quart. Jour., v. 121, p. 51-72.

Saggerson, E. P., and Miller, J. M., 1957, Geology of 

the Takabba-Wergudud area: Nairobi, Geol. Survey of Kenya, Report no. 40, 42 p.

Sanders, D. L., 1959, Geology of the Mid-Galana area: 

Nairobi, Geol. Survey of Kenya, Report no. 46, 

50 p.

Thompson, A. O., 1956, Geology of the Malindi area: 

Nairobi, Geol. Survey of Kenya, Report no. 36, 

63 p.
LANDSAT-1 STUDIES APPLIED TO PETROLEUM EXPLORATION IN KENYA 153

Thompson, A. O., and Dodson, R. G., 1958, Geology mentary basins of the African coasts: Paris,

of the Kerkali-Melka Murri area: Nairobi, Geol. Assoc. of African Geol. Surveys, p. 133-158.

Survey of Kenya, Report no. 43, 35 p. Williams, L. A. J., 1962, Geology of the Hadu FundiWalters, R., and Linton, R. E., 1973, The sedimentary Isa area: Nairobi, Geol. Survey of Kenya, Report

basin of coastal Kenya, in Blant, G., ed., Sedi- no. 52, 62 p.

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Regional Linear Analysis as a Guide

to Mineral Resource Exploration

Using Landsat (ERTS) Data

By R. A. Hodgson, 

Gulf Research and Development Company, Pittsburgh, Pennsylvania

ABSTRACT

The direct association of commercial mineral deposits with geologic features having a linear surface 

expression, such as faults and fracture zones, has long 

been known. Landsat data, displayed in appropriate 

formats, comprise a remarkably effective tool for 

recognizing and mapping several orders of such features in considerable detail. The data also allowed the 

definition of complex fracture-lineament systems over 

significantly large regions.

Regional fracture-lineament systems mapped to 

date show patterns that appear to be reasonably consistent with those predicted by theories which postulate such fracture patterns result from stresses generated by systematic and nonsystematic changes in 

the Earth's shape and/or shifts of the lithosphere with 

respect to the geographic pole.

As sufficient detailed data become available for 

large regions with respect to the areal distribution 

and nature of the various orders of linear features, it 

will become possible to evaluate better present fracture-tectonic theories as well as to establish empirically significant spatial relations between various types 

of mineral deposits and elements of the fracture network. Perhaps at that point it may become possible 

to develop a valid genetic theory for predicting in 

advance the location of environments specifically 

favorable for mineral deposits.

INTRODUCTION

The direct association of commercial mineral deposits with several orders and types of linear structural features such as faults, fracture zones, and joint 

systems has long been established. The fact that such

structures commonly have a systematic spatial disposition has been well documented for over a century. 

Many mineral deposits occur along or at the intersection of linear structures where geologic conditions are 

favorable. Thus, any new technique should be investigated which promises to aid in the delineation of the 

spatial relations and structural characteristics of the 

various orders of linear features. The Landsat spacecraft provides a new platform for observation of such 

features and a very effective digital-analog system for 

the recording, display, and analysis of data.

The use of Landsat data to delineate and analyze 

regional linear features is, of course, quite recent. The 

Landsat system was not designed specifically for such 

a job but, as it turns out, has several features which 

make it particularly well suited for the purpose. The 

most important of these features from the standpoint 

of analysis are:

1. Synoptic nature of the imagery.

2. Temporal character (capability of recording the 

same scene every 18 days or every 9 days 

where both Landsat-1 and -2 are operational).

3. Very extensive areal coverage.

4. Capability for both digital and analog enhancement 

of images.

5. Unrestricted availability and low cost of raw data.

6. Variety of useful formats for analysis and display 

of data.

The Landsat system operates within a well-defined 

digital-analog framework and, therefore, imposes a 

specific approach in the analysis of the data by the 

investigator. Figure 1 is a flow chart showing the 

various steps and options in the use of Landsat data 

for minerals exploration.

155
156 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

PROGRAMMING

OF

DATA

ACQUISITION

DATA

ACQUISITION

(SATELLITE)

DATA

TRANSMISSION

(SATELLITE)

BLACK & WHITE/ 

>AND FALSE 

fcOLOR 

^MOSAICS 

'/////////////A

% IMAGE 

^GENERATION/^

//ON FILM % 

XXOR PAPER %

N

^ANALOG \

^ENHANCEMENTS 

^PROCEDURES

Vxiolor additive \v 

\\viewe rs-mosaic^v

s. x \x\xx\xxxx x \N

OBJECTIVE 

DETERMINE

DIRECT SIGHT '"• 

IMAGE ANALYSIS 

AND •: 

^INTERPRETATION; 

{Level 1) •:

DIRECT SIGHT 

ilvlAGE ANALYSIS 

AND ;

.INTERPRETATION::

(Level 1) ...... ......;•

SYSTEMATIC AND 

NONSYSTEMATIC 

ANALYSIS AND 

INTERPRETATION 

OF LEVEL 1 DATA 

(OPTIONAL)

APPLICATION

DATA

RECEPTION 

TRANSLATION 

OF SIGNALS

GENERATION 

OF

COMPUTER 

COMPATIBLE 

TAPE (CCT)

IMAGE 

GENERATION

OBJECTIVE 

DETERMINE

FILM PAPER

w\xx\\

DIRECT SIGHT 

IMAGE ANALYSIS 

AND : 

JNTER.PRE.TATION.;

FIGURE 1.—Chart showing sequence of Landsat data flow from acquisition to application in minerals exploration.

PRIMARY FACTORS IN ANALYSIS

Before undertaking the analysis and interpretation 

of linear geologic features from Landsat images a 

number of factors should be considered which individually and together determine the effectiveness

and validity of the results. These factors are outlined 

in figure 2.

The hardware and software characteristics of the 

Landsat system are most important in that they determine the ultimate resolution of any data acquired
REGIONAL LINEAR ANALYSIS, GUIDE TO MINERAL EXPLORATION 157

1. CHARACTERISTICS OF DATA ACQUISITION SYSTEM

2. FORMATS OF DATA PRESENTATION

3. METHODS OF DATA ANALYSIS

(METHODS MUST BE APPROPRIATE TO DATA)

4. METHODS OF DATA INTERPRETATION

LEVEL I—DIRECT SIGHT DELINEATION FROM

PHOTOGRAPH

LEVEL II—APPLICATION OF THEORETICAL 

CONCEPTS

5. APPLICATION (EXPLORATION OBJECTIVES) 

EXPERIENCE 

THEORY

FIGURE 2.—Primary factors considered in use of Landsat data 

for analysis and interpretation of regional linear geologic 

features.

as well as the various data formats available for 

analysis and interpretation.

Analytic data handling procedures differ with digital 

and analog formats even though the objectives may 

be entirely similar. More detailed information resides 

in the computer compatible tape (CCT), for example, 

than in the photographic images for the same scene. 

With respect to regional linear analysis more information often can be gained from mosaics composed of 

the images of several scenes than from a single scene 

even though the scale and definition of the two photographic representations are the same.

It is important that the methods used to analyze 

Landsat data be appropriate to the nature of the data. 

This implies a working knowledge of the data systems 

as well as a knowledge of the geological parameters 

involved. For example, because of the synoptic nature 

of the imagery, the areal pattern of linear features can 

be established more effectively by direct inspection 

of the image than by a statistical treatment of data 

from a series of observations at points over the image.

The various options on digital enhancement operations should be considered carefully as some are more 

useful than others for enhancement of linear features. 

Inspection of images shows that the linear features 

are represented by a series of tonal or morphological 

events which can be visually integrated into a single 

large-order feature. Mathematical analytic procedures 

such as linear stretching and edge enhancing of the 

data tend to magnify or emphasize the changes in 

reflectance which identify linear features. Procedures 

such as clustering may help establish significant but 

not obvious areal differences in reflectance across a 

linear feature suggesting it may mark a fault zone or 

a geologic boundary, etc.

There are two distinct levels of interpretation involved in using the imagery to investigate regional

linear features. The first level involves the identification and delineation of the various orders of linear 

features from the raw data. This may be accomplished 

by direct sight interpretation of photographic images 

or may involve a complex technology of data enhancement and viewing techniques. The end result is usually 

a map showing directly the structural character and 

spatial relations of the features sought.

At the second level of interpretation, theoretical 

concepts can be applied to the "observed" data and 

various established analytic techniques used to study 

some portion of the data content of specific interest. 

For example, one might consider that areal changes 

in angles of intersection of a certain class of linears 

is important or that a certain spacing or azimuth is 

critical. The results of such systematic analyses can 

be presented using contour maps, graphs, etc.

Where analysis and interpretation are being done 

for a specific exploration purpose, the exploration objectives must be kept in mind and the methods of 

investigation designed to abstract as much as possible 

of the desired information from the imagery. How the 

results are applied to the problem at hand depends, 

of course, on the experience and theoretical views of 

the user.

LANDSAT DATA ACQUISITION SYSTEM

Of particular interest to the interpreter are the 

main elements of the Landsat data acquisition system, 

inasmuch as the primary limitations on the use of 

Landsat data for regional linear analysis appear to 

reside primarily in the Landsat system itself and have 

to do with parameters such as spatial resolution, spectral bands recorded, the Earth's atmosphere, and data 

handling formats.

Landsat is a remote-sensing system that operates 

in limited and specific wavebands. It has a lower limit 

of spatial resolution which is significant from the 

standpoint of the interpretation of linear features. The 

manner in which the system records and transmits 

data determines to a great extent the digital and 

analog formats in which the data can be presented 

for analysis. The basis for these formats should be 

understood at least in outline so that unwanted bias 

is not introduced into the interpretation of linear features from the imagery.

The Landsat-1 spacecraft, from which the imagery 

discussed in this paper was derived, has two image 

acquisition subsystems. These are the Return Beam 

Vidicon, or RBV, and the Multispectral Scanner, or 

MSS. All the data used here for analysis are from the 

MSS. Figure 3 shows the main features of the MSS 

subsystem.
158 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

SCANNER Optics6 Detectors 

per band: 

24 Total

Scan mirror

(Oscillates

nommally±2.89°)

Field of View = 11.56 c

185km

(6 Line/Scan/ Band

W

s / /

FIGURE 3.—Main features of the Landsat-1 MSS subsystem.

The MSS is a four-band scanner which operates in 

the solar-reflected spectral region from 0.5 to 1.1 /on. 

The four spectral bands are 0.5 to 0.6 /dm, 0.6 to

0.7 /xm, 0.7 to 0.8 fim, and 0.8 to 1.1 /urn. There are 

six detectors for each of the four bands, and the 

spectral bands do not overlap. Scanning is accomplished by means of an oscillating flat mirror placed 

between the ground scene and a double reflector 

telescopic optical chain.

The video outputs from each of the detectors are 

sampled, commutated, and multiplexed into a modulated stream so that the data can be encoded and 

transmitted to a ground receiving station. At the receiving station, the raw data are compiled on video 

tapes which are transmitted to the NASA Data Processing Facility at the Goddard Space Flight Center.

At this point the data are converted into computer 

compatible tapes and 70-mm film images through the 

Initial Image Generating Subsystem, shown schematically in figure 4. These two products are the basic 

material which is used in one form or another for the 

mapping, analysis, and interpretation of geologic features.

A single Landsat scene comprises about 34,000 

km - on the ground and the ground resolution of the 

system is about 80 m from the operational altitude of 

918 km. As shown schematically in figure 5, any given

DATA 

SYSTEMS

DIGITAL 

SUBSYSTEM

DATA 

SYSTEMS

INITIAL IMAGE 

GENERATING SUBSYSTEM

70mm 

IMAGE

t

FIGURE 4.—Diagram showing configuration of the Initial Image Generating Subsystem.
REGIONAL LINEAR ANALYSIS, GUIDE TO MINERAL EXPLORATION 159

image is composed of parallel scan lines each containing a large number of video data points. A film image 

of a scene can be generated from the MSS video data 

where the radiance levels recorded on the tape can 

be projected on 70-mm film at successive points along 

a scan line to produce pixels, or picture elements, in 

specified intensities or levels of gray. The resulting 

image looks very much like an aerial photograph from 

which, however, it differs significantly in several obvious respects.

DIRECTION

OF 

SPACECRAFT

•3000 to 3450 Bytes

SCAN LINES

2340 

SCAN 

LINES

FIGURE 5.—Diagram showing the main elements comprising a 

Landsat image.

DEFINITIONS

The term "linear" as used by photogeologic interpreters has acquired some specific connotations with 

respect to length which are not implied where the 

term is used in this discussion. The term is used here 

in the general descriptive sense as defined by Webster; 

that is, the term pertains to a line or lines, consisting 

of lines, in a straight direction, resembling a line, 

narrow, long, and uniform in width.

In general, the regional linear features of t he 

Earth's surface as seen on Landsat imagery can best 

be described by the technical term "lineament" as 

originally defined by William Herbert Hobbs (1904, 

1911). Lineaments are generally found to be composite 

geomorphic and structural features when examined 

in detail and as shown schematically in figure 6.

The term "fracture zone" is used here to describe 

linear structural features (other than known faults) 

which have a direct expression on the Landsat imagery 

and can be reasonably inferred to be a direct expression of fracturing.

The term "planetary" is used to describe those regional or super-regional lineaments which are of a 

length, width, and linearity which would indicate they 

extend to great depths in the lithosphere. They are 

azimuthally distributed in systems that reasonably can 

be inferred to reflect their generation by the body 

forces of the Earth. In addition, they show morphologic similarities to equavalent features on the other

WwX'awSJSt

SCHEMATIC DIAGRAM INDICATING THE

COMPOSITE EXPRESSION OF A LINEAMENT

after HOBBS (1911)

SCHEMATIC DIAGRAM INDICATING THE 

COMPOSITE NATURE OF DISLOCATION LINES 

after HOBBS (1904)

FIGURE 6.—Schematic diagrams showing the composite structural and physiographic aspects of lineaments.
160 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

terrestrial planets and so may be features which are 

common to all such planets and which are generated 

initially by similar forces.

BASIC TYPES OF GEOLOGIC STRUCTURES

The study of the nature of geologic structures suggests that there are two basic types which can be 

classed as continuous or discontinuous and distinguished on the basis of their distribution in time and space. 

The types of structures and the main characteristics 

which distinguish them are outlined in figure 7. The

major linear features viewed on Landsat imagery 

clearly fall into the category of continuous structures. 

This is of great importance to minerals exploration 

as the universal and remarkably uniform distribution 

of these features as well as their persistence across 

all other structures of whatever age suggests some 

level of constant or intermittent structural activity 

along their length and at their intersections. As a result we may expect to find structures favorable for 

mineralization distributed more or less uniformly 

around the Earth in rocks of all types and ages.

BASIC TYPES OF STRUCTURES

CONTINUOUS DISCONTINUOUS

SYSTEMATIC JOINTS

MASTER JOINTS

JOINT ZONES

LINEAMENTS

BELTS OF LINEAMENTS

FAULTS

FOLDS

CLEAVAGE

VOLCANIC

CRYPTOVOLCANIC IMPACT

MAIN CHARACTERISTICS MAIN CHARACTERISTICS

1. UBIQUITOUS OCCURRENCE IN ROCKS 

OF ALL TYPES AND AGES—NONREVERSIBLE

2. MAINTAIN UNIFORM AREAL PATTERNS 

OVER VAST AREAS

3. UNIFORM SPACING MAINTAINED BETWEEN ELEMENTS OF EACH ORDER

4. REGIONAL AND PLANETARY ORDERS 

CROSS ALL OTHER STRUCTURAL 

FEATURES WITHOUT DEVIATION OR 

OFFSET

5. ALL SYSTEMATIC LINEAR FEATURES 

CROSS EACH OTHER WITHOUT DISCERNIBLE OFFSET

6. LARGER ORDERS—COMPLEX STRUCTURES

1. ISOLATED STRUCTURAL EVENTS IN

TIME AND SPACE

2. NONUNIFORM AREAL DISTRIBUTION

3. CLEAVAGE AND FLEXURES— NONREVERSIBLE— EPISODIC

4. FAULTS— REVERSIBLE (?)— EPISODIC

5. VOLCANIC— EPISODIC

6. CRYPTOVOLCANIC AND IMPACTUNIQUE— NON REPEATED

FIGURE 7.—Basic types of geologic structures.

ORDERS OF SYSTEMATIC LINEAR 

FEATURES

Linear features seen at the Earth's surface occur in 

several distinct orders and, individually, range from 

a few metres to hundreds of kilometres in length. 

Within each order, they tend to occur in well-defined 

sets or systems which extend quite uniformly over 

very large areas. The main orders of systematic linear 

features are listed in figure 8.

The two largest classes of linear features are the 

subject of discussion here, but it is useful to consider 

that they may be end members in a continuous or 

intermittent series of genetically related structures at 

the other end of which is the systematic joint.

A field example of regional linear feature is the 

Florence Pass lineament (Hodgson, 1965). This feature is some 100 km in length and crosses the center 

of the Big Horn Mountain Range in Wyoming. The 

lineament is marked along its length by a series of 

deep valleys in Precambrian terrane where it crosses 

the highest part of the mountain. It is expressed as a 

monoclinal flexure in the sedimentary rocks on the 

gentle west flank of the range. These characteristics 

are shown in figure 9. Some normal faulting is present 

along the line of the lineament at the very crest of the 

range. A lineament of this magnitude is usually a complex structure of some width as was recognized long 

ago by Hobbs. Field examples of smaller orders of 

linear structures are shown in figure 10.
REGIONAL LINEAR ANALYSIS, GUIDE TO MINERAL EXPLORATION 161

ORDERS OF SYSTEMATIC LINEAR 

FEATURES

1. PLANETARY

2. REGIONAL

3. LOCAL

FRACTURE ZONES 

MASTER JOINTS 

SYSTEMATIC JOINTS

DISTINCTION MAY BE BASED ON LINEAR 

EXTENT AS WELL AS CHARACTER

FIGURE 8.—Orders of systematic linear features.

FIGURE 9a.—Aerial view west along Florence Pass lineament 

showing physiographic expression of the structure. (Sketch 

after photo by R. A. Heimlich in Hodgson, 1965). See figure 

9b, p. 162.

Figure 11 shows graphically the order of linear 

features which we are likely to see on Landsat images 

considering the ground resolution of the system as 

80 m. As indicated in the figures, we can see only the 

widest of fracture zones directly, and then only under 

favorable lighting and environmental conditions. It is 

possible, however, to infer the presence and even the 

spatial relations of smaller orders of linear features 

indirectly. This is because of the distinctive reflectance 

signatures of vegetation and soils above fractures

where the environmental conditions are slightly different from those in the immediately adjacent areas. 

Topographic features which develop preferentially 

along such linear fractures also reveal their presence. 

Obviously, there is no difficulty in seeing regional 

linear structures in Landsat imagery.

INTERPRETATION

Regional lineaments are not identified by a unique 

spectral signature but rather by a series of signatures. 

It is the difference in spectral signatures between any 

point or area along or within the lineament and that 

of areas immediately adjacent that makes the lineament visible.

The prominence of a given lineament may vary 

according to the spectral band in which it is viewed, 

but the larger lineaments are usually visible in all 

bands primarily because they are identified by differences rather than uniformity of spectral signatures 

and so may be marked by a wide spectral band of 

reflectances.

Digital data enhancement procedures, where used, 

should be designed to emphasize local spectral differences. This can be done by a number of mathematical 

operations such as linear stretching, edge enhancing, 

or by developing signatures and themes for areas 

along a lineament which, by inspection, appear favorable for defining the total extent of the feature. Analog enhancement procedures involve the use of color 

additive viewers, changing of scales and total area 

viewed, and the selective use of printing screens in 

making black and white photographic copy. The 

screen technique is particularly useful in that detail of 

the image is eliminated or de-emphasized without significant loss in distinction among gray levels. The end 

result is the enhancement of the larger linear features 

by increasing the apparent contrast between them 

and their surroundings.

The order, or size, of linear features recognized in 

direct viewing of images and mosaics is a function of 

the maximum ground resolution of the imagery which, 

of course, is the limiting factor in the ultimate amount 

of detail which can be seen and so determines the 

smallest order of linear structure which can be 

mapped. The two parameters of the imagery which 

can be varied within wide limits are scale and total 

area of the Earth's surface presented in a single view. 

Features not at all apparent, or seemingly poorly defined in a single scene, may show clearly on a mosaic 

at the same scale and in the same spectral band but 

depicting a much larger area. Decreasing scale tends 

to enhance the appearance of increasingly larger 

linear features as scale is reduced.
162 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

108°00' 

45°00' ———

NORTHERN BIGHORN MOUNTAINS 

WYOMING

Structure contours drawn at 500' 

interval on top of Cleverly form.

44°00

Boundary

Precambrian

Outcrop

44 00

108°00' 107°00'

FIGURE 9b.—Structure contour map of the northern Big Horn Mountains, Wyoming, showing location and structural geometries

of the Tensleep and Florence Pass lineaments. (After Hodgson, 1965.)

These observations and principles can be illustrated 

by showing examples of regional and planetary lineaments.

Figure 12 (p. XVII) shows a color composite image 

of a Landsat scene in the Great Basin and includes the 

area around Twin Falls, Idaho, and the region to the 

south. Looking at the image itself one can see a narrow but very distinct linear feature extending diagonally across the top of the image from left to right just 

to the south of the predominantly red area. From the 

changes in the colors of the surncial material and the 

fabric of the topography, it is evident that the lineament crosses a variety of physiographic and geologic 

features. It extends unbroken for a distance of nearly
REGIONAL LINEAR ANALYSIS, GUIDE TO MINERAL EXPLORATION 163

SYSTEMATIC JOINTS

15m

MASTER JOINTS

Joint zone deforming graywakes of the o 

Lower Carboniferous strata dips about 25 

a quarry NE of Olomouc, Czechoslovakia. 

C Photo by Miroslav Plicka)

FRACTURE ZONES

FIGURE 10.—Smaller orders of linear geologic structures.
164 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

RESOLUTION OFLANDSAT IMAGERY & INDIRECT IDENTIFICATION 

OF LINEAR FEATURES (INFERENCE)

80 M

I

LANDSAT LANDSAT 

SCENES MOSAICS

SYSTE 

JOI

iMATIC ' 

NTS

i

V///////A

FRACTURE 

ZONES

REGKDNAL PLAN ETARY

MASTER 

JOINTS

RESOLUTION OF LANDSAT IMAGERY & DIRECT IDENTIFICATION 

OF LINEAR FEATURES (OBSERVATION)

1M 3M

SYSTEMATIC 

JOINTS

80 M 

|lOOM

LANDSAT 

SCENES

LANDSAT 

MOSAICS

FRACTURE 

ZONES

REGIONAL PLANETARY

MASTER 

JOINTS

FIGURE 11.—Smallest order of linear geologic structure seen on Landsat imagery by direct observation or by inference.

a hundred miles in this scene. To determine how much 

farther it may extend in either direction would require 

enlarging the area viewed. The feature itself appears 

to be a wide fracture zone and may well include a 

number of normal faults. It maintains its remarkably 

straight course through mountainous terrain as well 

as flat lowlands and so must be essentially vertical in 

nature and extend to great depth.

Figure 13 (p. XVIII) shows the same lineament 

mapped to scale on the "Tectonic Map of the United 

States" (USGS and AAPG, 1961). The feature follows 

the trend direction of mapped faults and, in places, is 

coincident with them. It appears from the lineament 

that the structural trend of the west limb of the Snake 

River downwarp continues far to the southeast of 

Twin Falls. The fact that the Landsat feature shows 

so plainly is a good indication of recent tectonic movements along it. This also is information which can be 

readily checked in the field.

By increasing the size of the area viewed without 

losing essential detail, it becomes possible to map 

similar features to their full extent and to delineate 

larger features which cannot be denned initially on a 

single image. Figure 14 shows the western United 

States as depicted by the band 7 U.S. Department of 

Agriculture Landsat mosaic at the scale of 1:5,000,000. 

Less than half the visible lineaments have been 

mapped here, but enough are marked to illustrate the 

remarkable parallelism among sets of lineaments over 

very great distances. The light lines show individual 

linear features which appear to belong to a given set 

but are generally more irregular in their course than 

their neighbors. Note also the remarkable uniformity 

of spacing in places between members of the same
REGIONAL LINEAR ANALYSIS, GUIDE TO MINERAL EXPLORATION 165

FIGURE 14.—Sets of major lineaments identified on the 1974 band 7 USDA Landsat mosaic of the United States at scale 1:5,000,000.
166 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 15.—First-order lineaments of the United States taken from the band 5 Mosaic of the United States as published in

the July 1974 issue of Ceotimes.

set and the orthogonal spatial relations between at 

least two of the sets. Of great tectonic significance is 

the apparent lack of offset of one great lineament by 

another where they cross each other and the lack of 

significant deviation where they cross major fold 

belts.

The broad band delineates a wide zone of several 

closely spaced parallel lineaments which, taken together, may comprise the largest order of lineaments.

One can continue to reduce scale and increase the 

area viewed to define larger and larger linear features, if they exist. As noted previously, the printing 

screen can be used to enhance the contrast of the 

larger features. Figure 15 shows the results of mapping 

lineaments which have a transcontinental extent (or 

at least a transmosaic extent) on the band 5 mosaic 

of the United States published as the center fold in 

July 1974 issue of Geotimes. (This is an example 

where the dot screen used in making the plate for 

printing the mosaic resulted in an enhancement of the 

largest linear features.) Several of the east-west 

lineaments show an excellent correspondence in geographic position with the great east-west fracture

zones of the Pacific such as the Murray, Pioneer, and 

Mendocino suggesting they are in fact single continuous structures of global significance.

In detail, most of the major features recognized are 

composed of a connected series of structural phenomena along their length such as fault zones, fracture zones, linear folds and fold belts, and edges of 

regional features such as downwarps and upwarps, 

all constituting narrow, linear zones of deformation 

when considered at the viewing scale. A few lineaments are marked by what appears to be a single 

well-defined suture along their length. There is a generally systematic distribution for all orders of linear 

features. As a generalization, one can say they are 

distributed azimuthally in sets following approximately 

NE, NW, E-W, and N-S directions over very large 

regions.

At this point one can take the data derived from 

this first level interpretation of the imagery and use 

it directly to pinpoint areas which, on the basis of 

previous experience, promise to be prospective. One 

may, however, wish to proceed to the second level 

of interpretation in which the observed data are con-
REGIONAL LINEAR ANALYSIS, GUIDE TO MINERAL EXPLORATION 167

sidered, not only in the context of previous experience, but also within the context of one or more 

hypotheses concerning the origin and significance of 

linear structural features and the manner in which 

they may exert control on the location and genesis of 

ore deposits. Thus, at the first level, the interpreter 

must decide on the nature and extent of the features 

which he has detected in the imagery and present the 

data in some form of direct use such as a map. At the 

second level, he may apply systematic analysis to the 

data and interpret this within the context of some 

hypothesis. As a result, the theoretical views and experience of the interpreter have a strong influence on 

the nature of the second level interpretation.

The observed systematic areal pattern of the major 

lineaments is reasonably compatible with that predicted by theories which postulate large-scale systematic fracturing in the lithosphere as a result of 

global deformation caused by systematic and nonsystematic changes in the rotation of the Earth or the 

position of its axis of rotation relative to the lithosphere.

The several theories that postulate crustal fracture 

patterns similar to those we observe on the Landsat 

imagery have been reviewed in detail in the literature 

by Sender (1947), Vening-Meinesz (1947), and

Belousov (1962). As a result of the investigations outlined here, it can be concluded that the tectonic forces 

which first produced the great Earth lineaments are 

global in nature and have to do with tidal forces and 

changes in the Earth's shape caused by changes in 

the rate of rotation of the Earth. These forces can be 

considered to act today at essentially the same level 

they did in the beginning, and the major lineaments 

have existed since then and have maintained a continuous low level of tectonic activity.

This hypothesis, if true, is significant in that it states 

that linear features have always existed in the Earth's 

crust as we see them today and, therefore, could have 

acted as channelways for mineralization at any time 

in geologic history.

If such uniform structural conditions for mineralization persisted through geologic time, has there been 

a uniform distribution of mineralization, or has there 

been any preferential mineralization along lineaments 

having certain azimuths? Are there ore belts along 

which we might expect certain types of minerals to be 

more plentiful than others? These possibilities have 

been considered, of course, and figure 16 shows a 

map by Nikolai Thamm in which he has marked the 

Silver Line of Spurr, noting incidentally that it follows closely a great circle. Thamm has also noted that

FIGURE 16.—Spurr's Silver Line and the platinum-nickel line of Thamm. (After Thamm, 1976.)
168 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 17.—Zonal distribution of platinum-nickel deposits along a Great Circle in eastern Africa. Note correspondence in 

azimuth with fracture zones and ridges of the Indian Ocean. (After Thamm, 1976.)

there appears to be a preference for the occurrence 

of platinum and nickel along a similar line or belt 

through Africa and the Middle East, Middle Europe 

and Siberia. This too follows a great circle. Figure 17 

shows the southern portion of this zone in Africa 

where Thamm has noted a remarkable coincidence in 

trend and extent between the ore belt and the great 

fractures traversing the Indian Ocean. Thus, it seems 

that great ore channels may exist and follow the 

azimuths of great lineament belts. Within these belts 

we may find that actual mineral deposits are preferentially associated with a particular class or order of 

linear feature as suggested diagrammatically in figure

18. They may occur preferentially along a given set of 

lineaments within an ore belt, at or near lineament 

intersections, et cetera.

As a working hypothesis, we might start with 

Thamm's statement in his last paper (1976) that "All 

such zones, lines or belts seem to originate at considerable depths and more often than not, bear no 

relation to any surface structures. Just as with jointing, the existence of mineral-bearing zones is a 

permanent phenomenon, i.e., it re-appears with its 

identical mineralization after long periods of time and 

and after structural disturbances in an independent 

manner."
REGIONAL LINEAR ANALYSIS, GUIDE TO MINERAL EXPLORATION 169

GENETICALLY RELATED 

SECONDARY FRACTURES

PLANETARY FRACTURE

REGIONAL FRACTURE

FRACTURE ZONES

FIGURE 18.—Sectional diagram showing various orders of fractures which may be genetically related and which may control the

location of mineral deposits.

CONCLUSIONS

In conclusion one can say that Landsat imagery 

offers a new and powerful tool for the delineation in 

detail of regional linear structures. It serves as a guide 

to pinpoint areas of direct interest to minerals exploration which can then be further investigated with 

conventional means.

The synoptic aspect of Landsat imagery, coupled 

with the amount of detail shown, largely eliminates 

the need for the statistical approach in mapping regional linear features. Their identification is direct 

and, in many examples, unequivocal. Systematic 

analytic methods should be directed primarily toward 

enhancing or abstracting some particular aspect of 

interest from the total observed data content.

The remarkably straight course of regional lineaments over tens to hundreds of kilometres shows they 

are vertical and must extend far into the lithosphere 

if not entirely through it in some cases. They may 

serve as channelways for mineral producing solutions 

from the greatest depths.

Persistence of regional linear structures across all 

other structures suggests some level of continuous 

structural activity along the lineaments. The possibility 

of periodic increases in the level of such activity must 

be considered.

It may be, however, that such activity, while promoting the upward movement of mineralizing solutions from great depths, may inhibit the formation of 

mineral deposits along the lineament itself near the 

surface. More favorable environments might be found 

along associated secondary orders of linear structures 

as suggested by Wertz (1976) and as diagrammed in 

figure 18.

We must consider that geologic features occurring 

along the same lineament, although separated by tens 

or hundreds of kilometres may, in fact, be genetically 

related and time equivalent.

Mineralization could occur in connection with the 

lineaments at any time in geologic history, at successive intervals along the same lines or belt and, involve 

the same mineral suites each time.

Detailed information on the location and nature of 

existing mineral deposits over large regions is needed 

to test the various existing hypotheses of the regional 

associations of mineral deposits and regional lineaments. Once such associations are established, it will 

increase our ability to extrapolate favorable conditions for mineralization into new areas and so decrease the costs of regional exploration by making 

the exploration programs more efficient.

SELECTED REFERENCES

Belousov, V. V., 1962, Basic problems in geotectonics 

(Eng. ed., J. C. Maxwell, ed): New York, 

McGraw-Hill, 816 p.
170 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Blanchet, P. M., 1957, Development of fracture analysis as exploration method: Assoc. Am. Petroleum 

Geologists Bull., v. 41, p. 1748-1759.

Gay, S. P., Jr., 1973, Pervasive orthogonal fracturing 

in Earth's continental crust: Am. Stereo Map Co. 

Tech. Pub. no. 2, 121 p.

Haman, P. J., 1961, Lineament analysis on aerial 

photographs exemplified in the North Sturgeon 

Lake area, Alberta: West Canadian Research 

Pub., sec. 2, no. 1, 20 p.

————1975, A lineament analysis of the United States: 

West Canadian Research Pub. Geology and Related Sciences, Series 4, no. 1, 27 p.

Hobbs, W. H., 1904, Lineaments of the Atlantic border 

regions: Geol. Soc. America Bull., v. 15, p. 483- 

506.

————1905, The correlation of fracture systems and 

the evidence of planetary dislocations within the 

Earth's crust: Wis. Acad. Sci., Arts and Letters 

Trans., v. 15, p. 15-29. 

-1911, Repeating patterns in the relief and in

the structure of the land: Geol. Soc. America 

Bull., v. 22, p. 123-176.

Hodgson, R. A., 1961a, Regional study of jointing in 

Comb Ridge-Navajo Mountain area, Arizona and 

Utah: Assoc. Am. Petroleum Geologists Bull., v. 

45, p. 1-38.

————196Ib, Reconnaissance of jointing in Bright 

Angel area, Grand Canyon, Arizona: Assoc. Am. 

Petroleum Geologists Bull., v. 45, p. 95-97.

————1965, Genetic and geometric relations between

structures in basement and overlying sedimentary 

rocks, with examples from Colorado Plateau and 

Wyoming: Assoc. Am. Petroleum Geologists Bull., 

v. 49, p. 935-949.

Isachsen, Y. W., Fakundiny, R. H., and Forster, S. W., 

1973, Evaluation of ERTS-1 imagery for geological sensing over the diverse geological terranes of New York State, in NASA Goddard 

Space Flight Center Symposium on Significant 

Results Obtained from Earth Resources Technology Satellite-1, 2d, New Carrollton, Md., Mar. 

1973, Tech. Presentations, v. 1, sec. A, p. 223- 

230.

Kjerulf, Theodor, 1880, Die Geologie des sudlichen 

and mittleren Norwegen: Bonn, Gurlt, 350 p.

Krebs, Wolfgang, 1975, Formation of southwest Pacific Island arc-trench and mountain systems: 

Assoc. Am. Petroleum Geologists Bull., v. 59, 

p. 1639-1666.

Kutina, Jan, 1975, Tectonic development and metallogeny of Madagascar with reference to the

fracture patterns of the Indian Ocean: Geol. Soc. 

America Bull., v. 86, p. 582-592.

Lillestrand, R. L, and Hoyt, R. P., 1974, The design of 

advanced digital image processing systems: 

Photogrammetric Eng., v. 40, p. 1201-1218.

Mollard, J. D., 1957, Aerial mosaics reveal fracture 

patterns on surface materials in southern Saskatchewan and Manitoba: Oil in Canada, v. 9, p. 

26-50.

Pariiskii, N. N., 1960, Earth tides and the Earth's inner 

structure: Akad. Nauk SSSR Vestnik, no. 6, p. 

61-69.

Pilger, A., 1976, The importance of lineaments in the 

tectonic evolution of the Earth's crust and in the 

occurrence of ore deposits in Middle Europe, in 

Internat. Conf. on the New Basement Tectonics, 

1st, Salt Lake City 1975, Proc.: Utah Geol. Assoc. 

Pub. no. 5.

Polyakov, M. M., and Trukhalev, A. L, 1975, The 

Popigay volcanotectonic ring structure (Eng. ed.): 

Internat. Geology Rev., v. 17, p. 1027-1034.

Prucha, J. J., Graham, J. A., and Nickelsen, R. P., 

1965, Basement controlled deformation in 

Wyoming province of Rocky Mountains foreland: 

Assoc. Am. Petroleum Geologists Bull., v. 49, 

p. 966-992.

Sender, R. A., 1947, Discussion of shear patterns of 

the Earth's crust by F. A. Vening-Meinesz: Am. 

Geophys. Union Trans., v. 28, p. 939-945.

Spencer, E. W., 1959, Geologic evolution of the Beartooth Mountains, Montana and Wyoming, pt. 2, 

Fracture patterns: Geol. Soc. America Bull., v. 70, 

p. 467-508.

Stovas, M. V., 1957, The irregularity of the Earth's 

rotation as a planetary geomorphological and 

geotectonic factor: Geol. Jour, of the Ukrainian 

S.S.R., v. 3, p. 58-69.

Thamm, Nikolai, 1969, Great circles—The leading 

lines for jointing and mineralization in the upper 

Earth's crust: Geol. Rundschau, v. 58, p. 667-696.

————1976, The distribution of oil and natural gas 

deposits in the Earth's crust in relation to the 

mineralization with Ni, Pt, and Cr along Great 

Circles (abs.): Internat. Conf. on the New Basement Tectonics, 1st, Salt Lake City 1975, Proc.: 

Utah Geol. Assoc. Pub. no. 5, p. 617.

U.S. Geological Survey and American Association of 

Petroleum Geologists, 1961, Tectonic map of the 

United States, exclusive of Alaska and Hawaii: 

U.S. Geol. Survey, 2 sheets, scale 1:2,500,000 

(1962).
REGIONAL LINEAR ANALYSIS, GUIDE TO MINERAL EXPLORATION 171

Vening-Meinesz, F. A., 1947, Shear patterns of the 

Earth's crust: Am. Geophys. Union Trans., v. 28, 

p. 1-61.

Wertz, J. B., 1976, Detection and significance of lineaments and lineament intersections in parts of the 

North Cordillera, in Internat. Conf. on the New 

Basement Tectonics, 1st, Salt Lake City 1975, 

Proc.: Utah Geol. Assoc. Pub. no. 5, p. 42-53.

Wise, D. U., 1958, The relationship of Precambrian 

and Laramide structures in the southern Beartooth Mountains, Wyoming: Billings Geol. Soc., 

9th Am. Field Conf., Guidebook, p. 24-30.

—1964, Microjointing in basement, middle Rocky 

Mountains of Montana and Wyoming: Geol. Soc. 

America Bull., v. 75, p. 287-306.

—1976, Sub-continental sized fracture systems 

etched into the topography of New England, in 

Internat. Conf. on the New Basement Tectonics, 

1st, Salt Lake City 1975, Proc.: Utah Geol. Assoc. 

Pub. no. 5.

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

The Application of Remote Sensing Technology

to Assess the Effects of and Monitor Changes in

Coal Mining in Eastern Tennessee

By A. E. Coker, A. L. Higer, and R. L. Rogers,

U.S. Geological Survey, Tampa, Florida; Miami, Florida;

Roswell, New Mexico

ABSTRACT

In response to significant increases in coal mining 

activity expected in the Appalachians, an area with 

limited available data and rugged terrain, remotesensing techniques are used to monitor and assess 

coal mining changes for investigating the effect of 

mining on water quality, sedimentation, and stream 

flow in this region. Digitally rectified and rescanned 

Landsat data were integrated with existing maps at 

a scale of 1:24,000. The images, acquired between 

February 1973 and March 1975, were used to analyze 

mining activities during this period. The processed

data are also used to delineate land-water cover type 

including vegetation species and agriculture and water 

areas. These data are useful for updating maps of 

strip mining activity, updating assessments of coal 

reserves, and surface mine detection and monitoring. 

The mapping techniques utilized the Bendix MDAS 

(Multispectral Data Analysis System) system. Thermal 

imagery data are used to delineate ground-water outflow, acid mine drainage, ponding on strip-mining 

benches, storm runoff, and surface-water flow. These 

remote-sensing data provide information to aid development of a digital and pictorial data base.

173

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Exploration by Petroleum Independents Using Imagery 

and Photos from EROS and Manned Space Surveys

By R. W. Worthing, Consulting Geologist, 

The Reserve Petroleum Company, Oklahoma City, Oklahoma

My early evaluation of the Landsat program was 

that it would be a high-cost through-put for the independent. I was wrong. The U.S. Geological Survey and 

Goddard Space Flight Center have made it available 

for the "poor-boy" oil company.

Nevertheless, problems exist. For example, the lack 

of ability to extract information from this wonderful 

aid to exploration results in a "hit and miss" approach, 

due to lack of training of independent geologists and 

engineers. This will soon disappear as user education 

increases. I hope soon that small company management or funders quit saying that "this erudite program 

is not for us."

This paper is concerned largely with lineaments as 

they relate to brecciation and improved carbonate 

petroliferous reservoirs, such as chalk, oolitic lime, 

dolomite, and clay-silica limes. The existence of these 

lineaments, containing hairline fractures, joints, or 

megashears, increases the rate of oil production from 

reservoirs of these types that account for more oil, 

over the world, than the sandstones.

The Landsat program and related underflights have 

been directly responsible for renewed interest in shear 

patterns on the Earth's surface because they have 

revealed anomalies that had been forgotten or perhaps had not been previously revealed. The extent of 

such shear patterns as seen on Landsat data has been 

noted frequently. In many areas, matching sets or 

pairs of shears are present at approximately right 

angles. These sets of shears at right angles are often 

recognized although one set may be more obscure 

than the other. What is less well known in areas, such 

as Oklahoma and the Illinois and Michigan basins, is 

that there are sometimes secondary and tertiary

rectilinear joint sets, which are only clear locally and 

which are not widely recognized or accepted, although 

they are sometimes described as joint patterns. What 

is far more important to this presentation is the fact 

that new spectral bands of surveying have picked up 

secondary and otherwise very obscure joint sets, even 

sets that have been missed in previous geological data 

gathering.

Let us examine the newly recorded evidence of 

these phenomena which may be discerned at least 

faintly across the major portion of Oklahoma's 

Anadarko basin (Landsat image 1347-16462). x To me, 

these are indications of previously undetected regional tectonic directions. The well-known primary 

fracture sets in Oklahoma are N. 70°W. and N. 14° E.

It is also significant that the newly detected lineaments reveal a graben 5 miles wide and approximately 

35 miles long not previously known and possibly of 

considerable importance in western Oklahoma. Only 

the previously known Seneca graben in northeastern 

Oklahoma approaches this in size. Needless to say, 

I intend to pay close attention to "Landsat" lineaments 

in the future and I believe their study will become a 

major chapter in the basic structural geology texts of 

the future.

In a different application, impressive work has been 

coming recently from West Coast studies of faulting 

and (or) earthquakes. The Landsat color print of San 

Francisco Bay (image 1075-18173) shows parts of the 

Calaveras, Hayward, and San Andreas (the Granddaddy) faults. On an image produced by combining 

bands 5 and 7 in black and white and enlarging the

1 Copies of referenced images may be obtained from the 

EROS Data Center, Sioux Falls, South Dakota 57198.

175
176 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

image to approximately 1:125,000 scale, shear features are shown. I am told that Landsat has recorded 

many lineaments along which strain and (or) faulting 

has occurred in the California mobile belts. These are 

of considerable importance as a contribution to new 

earthquake knowledge. Incidentally, the association of 

this tectonic belt to second order anticlines containing 

very valuable oilfields has been pointed out in the 

literature by Moody and Hill (1956) and others.

Studies applying this type of tectonic analysis to the 

Michigan basin suggest that the Scipio-Albion field is 

a "baby" San Andreas structure. Scipio was discovered with the help of a crystal ball gazer. If this 

embarrasses the geologists, think of the evaluation 

engineers who said the wells would not pay—only to 

watch 140,000,000 bbl flow out between 1959 and 

1968. The decline curve is still straight and very flat.

Some geologists agree that the Scipio-Albion field 

lies over a basement shear zone and more agree that 

the Trenton Limestone reservoir is not broken by 

faulting. A possibility of rock flow associated with 

strain or a strain lineament has been noted. The possibility of post-glacial movement of perhaps 1 mile 

does coincide with a lineament detected on Landsat 

imagery. The economic importance attached to lineament tectonics in the Michigan basin is impressive. 

Every oilfield in the Michigan basin with an accumulation of 10,000,000 bbl of crude oil (actually $100,000,- 

000 of products at present prices) can be closely 

associated with such tectonic patterns.

Landsat images of the Saginaw Bay area (image 

1320-15525) show three important geologic controls 

which mark the Michigan Thumb fault running from 

the Bay City area and controlling the southeast side 

of this fresh-water basin. On these images, the Arenac 

shelf can be seen protruding into Saginaw Bay as a 

result of movement along the Bay Rifle River lineament. The Arenac shelf lineaments come to the surface and are known to cause fracturing in the Bayport 

Limestone of Mississippian age; far more importantly, 

these lineaments have been associated with productivity in Arenac County amounting to as much as 

1,600,000 bbl per 40-acre well and recoveries in the 

Deep River Pool are at least 40,000 bbl per acre. 

These are extremely high productivities for the U.S. 

oil industry.

Cores from reservoirs developed in fractured shear 

zones are typical of secondary dolomitization. The 

sharp black areas are high-permeability through-put 

channels that make these reservoirs excellent, and 

there is a coincidence of these zones with linear features expressed on Landsat data.

The Nisson anticline in the Williston basin is similar to the Scipio feature and has a string of pools 

with an expected production of 500,000,000 bbl. I 

think it is very important that there are two or three 

features that appear to be of similar mechanical origin 

in the Illinois and Michigan basins, and they are untested.

In an entirely different mineralized situation, let's 

look at the southern Illinois and Kentucky fluorspar 

districts which produce approximately 150,000 tons 

of fluorspar per year. The economic importance of 

this mineral may be measured by prices of $109 per 

ton and up for calcium fluoride (wet cake) and indications that prices may rise in a tight market. It now 

appears that a half dozen mining companies are active 

in the area and producing fluoride valued at up to 

$15,000,000 per year from an area with most unusual 

lineaments. These producers and possibly some of 

those prospecting, in the west, might take stock of 

these patterns and look for similar structures elsewhere.

There are at least six different directions of shear 

disturbances visible on Landsat data of the Illinois 

basin. One set, at least, appears to be important to 

the accumulation of highly productive oil pools found 

in the pre-Pennsylvanian carbonate rocks and seems 

to be closely allied with a similar pattern of major 

shear zones throughout the mid-continent area as well 

as the southern, middle, and northern Rocky Mountains. Oil and gas fields, in this area, are spatially 

coincident with these shear zones, and trie same type 

of shear lineaments appear to be significant in the 

State of California where second order anticlines associated with these shear patterns are, quite obviously, controlled by the regional pattern. The major shear 

belts of the Rockies also seemingly control second 

order tectonic features which in turn may partly control the orebodies of the Colorado mineral belt.

The gross continental orientation of lineations, such 

as those shown in an analysis of major lineations of 

the United States, undertaken by W. D. Carter (in 

Fischer and others, 1976), may have far reaching scientific implications. In Carter's analysis, the orientation of the primary pair of shears appears to rotate 

clockwise as they approach the western edge of the 

continent; is this a reflection of continental mobility?

I would like to emphasize that the science of exploration may have experienced a new dawning in 

July 1972 and that as yet the new sun has not come up 

over the horizon. This is only a personal opinion, but 

I would like to restate that early skepticism on the 

part of individuals in the oil industry as to the value 

of the new imagery was premature, often resulting
EXPLORATION BY INDEPENDENTS USING PHOTOS AND SPACE SURVEYS 177

from (1) poor images or mosaics, (2) lack of understanding, and (3) incorrect experimentation. Further, 

the independent exploration geologist lacks experience in putting the computer to work to realize the 

full value of the data. There is perhaps much disillusionment based upon not seeing that "particularly 

favorite crustal structure or geomorphic anomaly." 

Take heart; there can be a reason for this!

REFERENCES

Fischer, W. A., Angsuwathana, Prayong, Carter, W. D., 

Hoshino, Kazuo, Lathram, E. H., and Rich, E. I., 

1976, Surveying the Earth and its environment

from space: Am. Assoc. Petroleum Geologists 

Mem. (in press).

Moody, J. D., and Hill, M. J., 1956, Wrench-fault tectonics: Geol. Soc. America Bull, v. 67, p. 1227.

POSTSCRIPT

The ABC's of Discovery

A for Alluvial Deposition, Areal Geology, etc. 

B for Below Surface Mining & Drilling Data, etc. 

C for Color Photos—Computer Printouts, etc. 

We can now say: ABCD's of Discovery—ADD "D" 

D for Determinations and Discovery from Space

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Tectonic Deductions from Alaskan Space Imagery

By Ernest H. Lathram and Robert G. H. Reynolds, 

U.S. Geological Survey, Menlo Park, California

ABSTRACT

Inductive analyses (reasoning from specific data to 

general conclusions) based on compilations of detailed mapping postulate numerous tectonic and 

metallogenic lineaments. Landsat, NOAA, and Nimbus 

images provide successively more regional and general views, which permit direct observation of 

significant lineament patterns. Deductions based on 

these patterns are in accord with many inductively 

derived patterns and solutions and provide new insights into tectonics and metallogenesis.

Most major space image lineaments reflect zones 

of weakness, many of which have persisted since Precambrian time, and most of which reflect major 

tectonic discontinuities. These lineaments display coherent patterns throughout the North American 

Cordillera suggesting a consistent regional stress field. 

Subparallel sets of lineaments 1,000 km or more in 

length trend dominantly northwest, northeast, east 

and north. The pattern of these lineaments is considered to represent the surface trace of the boundaries of a mosaic of crustal blocks.

In Alaska, some lineaments (e.g., northwest-trending 

Yentna lineament) reflect differential movement of 

crustal blocks in response to contemporary forces of 

plate convergence. Others coincide with portions of 

sutures that reflect earlier plate interactions, and still 

others traverse successively accreted belts of continental crust, suggesting that continental masses and 

materials accreted to them react to the stresses of 

plate convergence by accommodation along lines of 

weakness preexisting in the continents.

Many inductively derived metal "province" outlines 

reflect lineament trends, and some areas of metal 

fecundity occur at lineament intersections. The use 

of space image lineament to define crustal block

boundaries and the analysis of the metallogenic character within the area of single blocks may be a fruitful exploration tool.

INTRODUCTION

Lineament studies of continental masses have a 

common foundation in the work of Sender (1947) proposing a "global regmatic shear" pattern for Earth, 

and of Katterfel'd and Charushin (1970) for Earth and 

other planets as well; a pattern resulting from stresses 

induced by the rotation of a planet on its axis. Moody 

and Hill (1956) modified this thesis and developed 

"wrench fault tectonics," later applied by Moody 

(1973) to petroleum exploration. Alinements of 

mineral deposits led Heyl (1972) and Snyder (1970) to 

postulate lineaments along the 36th, 38th, and 41st 

parallels in the United States and Kutina (1969) to 

formulate an empirical "shear stress net" of mineralizing lineaments in the western United States. Many 

others, among them Thomas (1974), Roberts (1964), 

Sikabonyi and Rodgers (1959), Tweto and Sims (1963), 

Maughan (1966), Haites (1960), and Ozoray (1972) 

point to more local systems of fractures, believed to 

be crustal in origin and to have controlled the site or 

origin of oil or mineral deposits.

The most fascinating lineament studies in the past 

have been those dealing with features of the ocean 

floor. The combined work of many authors, summarized in the maps of Pitman, Larson, and Herron (1974), 

display a lineament system of oceanic ridges and 

nearly orthogonal fractures or transform faults. These 

have become a cornerstone of the new' global tectonics. The discovery of concentrations of metal-rich 

brines and sediments along spreading plate boundaries 

has led to metallogenic concepts in these areas sim179
180 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

ilar to the concepts basic to lineament studies on the 

continents.

All of the above studies have one element in common—the derivation of general hypotheses through 

the synthesis of specific details, i.e., inductive reasoning. Even the quantum-jump from the hypothesis of 

sea-floor spreading to the theory of plate tectonics is 

inductive, resting as it does on the synthesis of scattered data developed through oceanographic study.

The advent of polar-orbitting satellite imagery, particularly that of Landsat, has for the first time permitted application of deductive methods through 

lineament study. For the first time, lineaments can be 

observed directly over large areas of the Earth, their 

pattern defined, and their geologic and metallogenic 

significance examined and amplified by specific study. 

Lineament studies from Landsat imagery have been 

pursued by many researchers and are reported 

primarily in Proceedings of various Landsat symposia 

(Freden and others, 1973, 1974; Smistad, 1975), the 

First International Symposium on the New Basement 

Tectonics (Hodgson, Gay, and Benjamins, 1976) and 

the First William T. Pecora Memorial Symposium (this 

volume). Most of these Landsat studies have concentrated on areas the size of several states or smaller, 

and many have been concerned with analyses of the 

number and concentration of linears, i.e., "linear populations." To our knowledge, only three studies (Carter, 

1974; Haman, 1975; and Hodgson, oral commun., 

1975) have treated the distribution of Landsat lineaments throughout the conterminous United States.

Metallogenic modeling has occupied the attention 

of many earth scientists. Earlier models based on the 

classical geosynclinal theory generally related exogenic deposits to crustal downwarping, plutonism, and 

associated hydrothermal activity, primarily in mobile 

zones. Most recent models (see Guild, 1972), based 

on contemporary plate tectonic theory, associate 

exogenic deposits with subduction or mantle upwelling along plate margins. Repeated tectonism or plutonism, changes in the rate of subduction, or the 

development of new plate margins are believed to 

generate differing epochs of mineralization. As Kutina 

(oral commun., 1975) and others point out, however, 

many deposits occur in continental interiors distant 

from mobile zones or plate boundaries, under conditions difficult to reconcile with either tectonic theory, 

despite application of "intracratonic," "platform," 

"intraplate," "small-plate," and "migrating plume" 

theories.

Lineament studies of continental masses have generally presumed exogenic deposits to be related to 

crustal fractures, or zones of weakness, which have

provided pathways for mineralizing agents to rise 

from a general source in the lower crust or upper 

mantle and form deposits wherever host conditions 

were propitious.

Our approach to metallogenic modeling combines 

the new dimension of space image lineament study 

with tectonic knowledge and theory to develop new 

insights into continental tectonics. Through these additional parameters, we attempt to identify viable new 

rationales for mechanisms of mineral concentration 

and favorable locales for mineral exploration.

We have chosen to concentrate our attention, not 

on linear populations, but on the location and pattern 

of continental-sized lineaments—those 1,000 km or 

more in length—and their geologic, tectonic, and 

ultimately metallogenic significance. We have also 

chosen not to limit our study to Landsat imagery. If 

our conclusions (Lathram and Albert, 1976) are correct, that abundant, short, sharp linear features reflect 

the youngest deformation of the upper lithosphere 

and tend to mask less abundant, longer, and more 

diffuse lineaments marking deeper crustal structures, 

and the conclusions of Shapiro (1971) that all imagery 

contains comparable quantities of data and only the 

level of generalization changes with altitude and scale 

of viewing, imagery from other satellites will assist 

in regional lineament study. This is analogous to the 

practice in airborne magnetometry in which the flight 

altitude is increased to observe deeper magnetic 

fields. Accordingly, we have analyzed imagery taken 

by Nimbus (1,100-km altitude, ~3.7-km resolution) 

and NOAA (1,500-km altitude, 1-km resolution) as well 

as Landsat (900-km altitude, 80-m resolution) satellites. 

All analyses have been by visual examination of photographic prints and mosaics, primarily the Landsat 

mosaics of the U.S. Department of Agriculture and 

of the Canadian Department of Energy, Mines and 

Resources. We have examined geologic, tectonic, 

magnetic, and gravity maps and reports, and all the 

lineaments represented can be shown to coincide with 

known alinements or discontinuities in the character 

of lithospheric materials.

We have concentrated on space image lineaments 

in Alaska. However, because data on Precambrian 

and Paleozoic geologic history is sparse in Alaska, we 

have made a general examination of imagery of the 

western parts of Canada and the conterminous United 

States, where such data exist. We believe that conclusions as to the antiquity and recurrent nature of 

structures whose trace is marked by lineaments in 

these areas can be extrapolated directly to similar 

lineaments in Alaska along whose trace geologic, tec-
TECTONIC DEDUCTIONS FROM ALASKAN SPACE IMAGERY 181

tonic, and geophysical anomalies or discontinuities 

indicate significant changes at depth.

Our studies suggest that a pattern of continentalsized lineaments, recognized in Alaska, extends over 

the entire North American Cordillera and probably 

over the entire continent. These lineaments reflect 

major crustal boundaries, and higher or more synoptic 

satellite views seem to reveal deeper and more fundamental structures. We believe that knowledge of the 

nature and history of these lineaments is not only 

important in unraveling the tectonic history of a region but is critical to understanding how continental 

masses react internally to the stresses of plate movement. This knowledge can lead to the development of 

even more fundamental tectonic theories than those 

of today, theories that reconcile both mobilistic and 

stabilistic evidence of lithospheric deformation. To us 

a lineament network as a guide to a "plumbing system" is too simplistic; we view the lineament pattern 

as a plan of a mosaic of crustal blocks (similar to that 

of Garson and Krs, 1976) whose horizontal and vertical jostling through geologic time has guided tectonic 

relief to Earth stresses and, concomitantly, has guided 

the emplacement of orebodies.

LINEAMENT PATTERN

Study of a 1971 Nimbus IV image resulted in identification of a number of previously unknown very 

long lineaments in Alaska (Lathram, 1972). Subsequent 

study of Landsat images and mosaics (Lathram and 

Albert, 1976; Lathram and Reynolds, 1975) revealed 

not only most of these lineaments and others as well, 

but also a possible geometric pattern. Further examination of the Nimbus and Landsat images and 

mosaics, and of images from NOAA 3 satellite has 

disclosed even more lineaments (fig. 1).

The lineaments identified occur as alinements of 

surface geologic structures, linear valleys or ridges, 

and linear changes in tonal contrast marking differences in soil type, soil moisture, or vegetation. Most of 

the major lineaments are composed of combinations 

of some or all of these. Most are broad and diffuse, 

some being poorly identifiable for short stretches 

along their length. Parts of the trace of many of the 

lineaments coincide with the trace of known major 

faults in Alaska of Cretaceous or younger age (Grantz, 

1966), which are primarily strike-slip in character.

The number of large lineaments identifiable on 

space imagery of Alaska (fig. 1) increases from 

Nimbus (fig. 1A) to NOAA (fig. IB) to Landsat (fig. 1C) 

views, i.e., from smaller scale, low-resolution images 

to larger scale, higher resolution images. Most lineaments visible on Nimbus and NOAA images can be

identified on Landsat images, but on the smaller scale 

images they tend to be more diffuse and can be less 

accurately located. The more synoptic view of the 

smaller scale images, however, permits recognition 

of a greater length for some of the lineaments than 

that shown on the Landsat mosaics and also shows 

that some shorter, individual, alined lineaments are 

probably segments of a longer lineament that is only 

intermittently discernible. On the other hand, the 

sharpness of features in the higher resolution images 

may lead to selection of unrelated younger tectonic 

elements as representatives of the lineament, and 

cause its mislocation. Some lineaments visible on the 

low-resolution images are less easily recognized on 

Landsat mosaics. Examples are the curvilinear and 

circular features shown on the NOAA image (fig. IB). 

They are recognizable on the Landsat mosaic but 

were identified only after they were recognized on 

the NOAA image.

It is also apparent that, at the scale and resolution 

of the Landsat imagery, the number of lineaments 

discernible, and their varied trends, tend to obscure 

a regular pattern (fig. 1C). This suggests that for the 

purpose of broad, regional tectonic study, the optimum scale and resolution may lie between that of 

the NOAA and Landsat imagery. This observation is 

supported by our increased ability to discern broad 

lineament systems in the conterminous United States 

by examining a lithograph print of the Department of 

Agriculture l:5,000,000-scale Landsat mosaic (U.S. 

Geological Survey, 1974) and comparing it to the 

original 1:1,000,000-scale mosaic. Carter (1974) also 

had good success in identifying many of these lineaments by direct study of the l:5,000,000-scale mosaic.

Identification of a systematic pattern of lineaments 

in Alaska (fig. ID) required the elimination of a large 

number that constitute a concealing background. The 

lineaments shown on the Nimbus and NOAA images 

display a pattern, and we have found that they are 

marked by significant geological or geophysical anomalies or discontinuities along much of their length. 

These lineaments were used as guides in identifying 

the lineament pattern.

We are aware of the degree of subjectivity involved 

in the selection of individual lineaments forming the 

resulting pattern. Many other lineaments are parallel, 

or nearly so, to those selected, and through future 

study may be shown to be of greater tectonic significance. The number selected was determined by 

the scale of this study, to illustrate the pattern clearly 

and its existence elsewhere as well. A broadly comparable spacing is apparent (fig. ID); Albert (oral 

commun., 1975) has noted in more detailed studies in
170° 160° 150° 140°

130° 120° 170° 160° 150° 140°

1

180° 150° 140°

130° 160° 150° 

FIGURE 1.—Space image lineaments in Alaska. A, Nimbus satellite. B, NOAA satellite. C, Landsat satellite. D, Landsat lineament pattern

tion of symbols on figure 1DJ
TECTONIC DEDUCTIONS FROM ALASKAN SPACE IMAGERY 183

Alaska that major lineaments parallel to those shown 

occur with a general spacing of multiples of about 

30 km.

It is tempting to assign firm compass measurements 

to the trends of these lineaments; however, the trend 

of most is not sufficiently consistent, and the orientation of the overall pattern seems to change slightly 

from area to area. This may be partly due to problems 

of map projection, but, if these lineaments do reflect 

crustal block boundaries and the blocks have moved 

differentially, one would not expect sharp, straight 

boundaries. Further, no persuasive model has yet been 

proposed to explain the mechanism of propagation of 

crustal features through overlying younger material. 

Hence, we are unsure how later tectonic movements 

would affect the trends of lineaments marking deep 

crustal features. For example, a number of the lineaments are transected by faults known to have significant lateral displacements, i.e., the Denali fault 

system, but are not themselves offset, suggests that 

later tectonic movements either had little effect or 

some mechanism exists whereby the lineament readjusts its trace. In order to permit some comparison 

of these lineaments with those in other distant areas, 

their trends in central Alaska are approximated to be 

roughly N. 40°E., N. 60°E., N. 50°W., N. 80°W., 

and N.

Previous study (Lathram and Albert, 1976) showed 

that lineaments having trends parallel to those of the 

pattern in Alaska also characterized the western 

United States. Examination of Nimbus and NOAA 

imagery, the new Landsat mosaics of western Canada 

and the Landsat mosaic of the western United States 

substantiates this conclusion and shows that the pattern recognized in Alaska extends throughout the 

North American Cordillera (fig. 2).

GEOLOGICAL AND GEOPHYSICAL 

EVIDENCE

It is impractical to discuss in this paper all of the 

geological and geophysical features that characterize 

the lineaments identified in the pattern (figs. ID, 2). 

Consequently, we shall discuss briefly some selected 

lineaments in Alaska, mention some others elsewhere 

in the North American Cordillera for which evidence 

of antiquity and persistent movement is known, and 

compare the space image lineament pattern to lineaments or linear crustal fractures recognized in some 

previous inductive studies.

It is also impractical to include adequate geographic, geologic, or geophysical detail in the figures. 

Most of our data appear on the Tectonic Map of North 

America (King, 1969) and the Bouguer Gravity Map

of Alaska (Barnes, 1976), which should be used in 

conjunction with this paper. Data that do not appear 

on these maps are referenced to the appropriate 

paper.

Examination of the supporting data will show that, 

whereas most lineaments are discernible throughout 

their length, many do not coincide with linear changes 

or disruptions in surface geology and/or subsurface 

geophysical data throughout their length. Portions of 

lineaments marking significant tectonic or geophysical 

changes are adjacent to portions that show none. We 

have no explanation for this, other than that the sensible adjustment on the boundary occurred prior to 

emplacement of the earth materials yielding the geologic or geophysical data. Therefore some mechanism 

must exist for the propagation of these lineaments 

through overlying strata.

Lineament A, the Tanana lineament of this paper 

(fig. ID), trends along the Tanana River and northwest 

to Cape Lisburne in northern Alaska. At the Canadian 

Border, it separates the dominantly polymetamorphosed Precambrian(?) and Paleozoic Yukon-Tanana 

terrane from the Permian and younger arc-trench representatives to the southwest. In the Fairbanks area, 

it transects the southern margin of the metamorphic 

terrane but coincides with a marked change in structural trends within the terrane, a series of saddles in 

otherwise north-trending magnetic anomalies (Brosge 

and others, 1970), and a zone of shallow microseisms 

(Gedney and others, 1972). Throughout this area the 

lineament separates two regimes of significantly disparate gravity anomalies. Through the Ray Mountains, 

between Fairbanks and the Koyukuk River area, 

structural trends are nearly orthogonal to the lineament, and no disruption in them or change in Permian 

and younger tectonic elements is evident, but the 

lineament follows a line marking a regional change in 

gravity measurements. In the Koyukuk area, it 

coincides with, and may have governed the location 

of, an anomalously northwest-trending Cretaceous 

basin in the Yukon-Koyukuk Volcanic Province of 

Patton (1973). Between the Koyukuk area and Cape 

Lisburne, the lineament marks a structural warp in 

mid-Paleozoic Brooks Range strata, a line dividing 

distinctive gravity anomalies under the Brooks Range 

from disparate anomalies to the south and southwest, 

and a line of change in structural style in Jurassic and 

Cretaceous formations northwest of the Delong 

Mountains (Lathram, 1974). If extended to the northwest under the Chukchi Sea, the lineament would 

coincide with the fault boundary between the extension of the thrust-faulted Paleozoic strata of the
184 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 2.—Space image lineament pattern in North American Cordillera. (See text for explanation of symbols.
TECTONIC DEDUCTIONS FROM ALASKAN SPACE IMAGERY 185

Brooks Range orogen and the Mesozoic basin to the 

northeast (Grantz and others, 1975).

Lineament B (fig. ID) coincides with the Tintina 

fault in Yukon Territory and extends northwest to Icy 

Cape. In the southeast, the lineament separates the 

unmetamorphosed Yukon stable block (Lathram, 

1973) and MacKenzie Mountain thrust belt from the 

Yukon-Tanana metamorphic complex, and is followed 

by a series of magnetic lows (Brosge and others, 

1970) and an alinement of excursions in gravity contours. To the northwest, it marks the eastern termination of the Kobuk trench, the point of inflection of 

the Paleozoic schist and ophiolite rim of the YukonKoyukuk Volcanic Province, and a pronounced offset 

in the low gravity anomaly underlying the Brooks 

Range. Between the Range and the coast, the lineament parallels Mesozoic facies lines (Detterman, 1973) 

and bisects a broad gravity low.

Lineament C (fig. ID), described by Lathram (1972) 

and Lathram and Albert (1976), may represent an 

early Paleozoic continental margin throughout much 

of its length, and is characterized by a series of gravity 

highs and alined gravity gradients.

Geologic and tectonic features along lineament D 

(fig. ID) were detailed by Lathram and Raynolds 

(1975). Briefly, in the east, the lineament coincides 

with a fundamental fault separating Paleozoic and 

Mesozoic strata. In the Cook Inlet area, it marks 

significant changes in physiographic and magnetic 

features, is the northern terminus of the Aleutian 

Volcanic Arc and the northern boundary of the 

Jurassic intrusive core of the Alaska Peninsula. In the 

west, a young pluton is anomalously foliated parallel 

to the lineament on the Bering Sea coast. A pronounced line along which gravity contours change 

trend and strong linear anomalies terminate or seem 

to be offset follows the lineament through much of 

its length.

Elsewhere in the North American Cordillera, the 

lineaments are characterized by features whose nature and history are better known. Lineament E (fig. 

2) is marked by the MacDonald or East Arm fault 

system and coextensive Hay River fault and Skeena 

Arch believed to have exhibited persistent movement 

since Precambrian time (Haites, 1960; Sikabonyi and 

Rodgers, 1959; Sutherland-Brown and others, 1971). 

Lineament F (fig. 2) coincides with the AthabascaPeace River lineament, active since the Precambrian 

and particularly in the late Paleozoic (Sikabonyi, 

1967). Lineament G (fig. 2) lies along and is a continuation of the Lewis and Clark line which, in the 

eastern Washington and Idaho area, has been persistent since the Precambrian (Sales, 1968). Lineaments H and I (fig. 2) correspond to postulated 

basement structures Eaton and others (1975) believe 

controlled the emplacement of the basalts of the 

Snake River Group. Lineament J (fig. 2) marks the 

line described by Yates and others (1966) and Taubeneck and Armstrong (1974) as the western boundary 

of Precambrian basement.

A compilation was made of the lineaments and 

crustal fractures proposed by a number of other 

authors through inductive analysis (fig. 3). The pattern 

of space image lineaments correlates well with many 

of these features, in general orientation, if not in specific compass trend, and many individual space image 

lineaments correspond to mineralizing crustal fractures. Although many of the long lineaments of the 

compilation (fig. 3) are based on physiographic expression, some of the long and most of the short 

linear elements are based on geological, geophysical, 

or tectonic evidence.

TECTONIC CONSIDERATIONS

The existence of a systematic pattern of space 

image lineaments 1,000 km or more in length and 

evidence that many (1) coincide with faults known to 

have been persistent since Precambrian time, (2) correspond to systems of mineralizing crustal fractures 

recognized locally, (3) mark significant changes in 

gravity and magnetic fields, and (4) bound fundamental tectonic elements suggest to us that these 

lineaments reflect boundaries between crustal blocks. 

Vertical and horizontal adjustments along these 

boundaries in response to Earth stresses have resulted in each block possessing different properties 

and a different history. This accords with the principal 

conclusions reached by Garson and Krs (1976) who 

recognized crustal block tectonics in the Red Sea 

area, reasoning primarily from geophysical data but 

also noting the coincidence of some Landsat lineaments with geophysical lineaments.

Recognition of the possible existence of a mosaic 

of crustal blocks in Alaska, each with a varied history 

of vertical or horizontal adjustment, helps to explain 

the known varied character and disjunctive distribution of basement rocks in the State.

A number of the lineaments evident in the North 

American Cordillera transect boundaries that have 

been considered to coincide with former ocean/ 

continent interfaces without notable deviation in 

trend. Garson and Krs (1976) discussed the rifting 

of a continent to generate a spreading ridge (e.g., the 

Red Sea and Atlantic Ocean) and concluded that 

ancient crustal fractures determine the form and posi-
186 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 3.—Lineaments and crustal fractures suggested in selected inductive analyses. Compiled from: Moody (1966) and 

Ozoray (1972), (most long lineaments, fine line); and (a) Grant (1969), (b) Zietz and others (1969, 1971), (c) Thomas 

(1974), (d) Roberts (1964), (e) Shoemaker and others (1974), (f) Muehlberger (1965), (g) Cook (1957), (h) Heyl (1972), 

(i) Stewart and others (1975), (j) Yates (1968), (k) Maughan (1966), (I) Landwehr (1967), (m) Eaton and others (1975), (in 

western Canada) Haites (1960).
TECTONIC DEDUCTIONS FROM ALASKAN SPACE IMAGERY 187

tion of the ridge and of the transform faults that 

transect it. In consequence, continental crustal fractures are traceable across passive continent/ocean 

boundaries into major transform faults. This conclusion does not hold for active continent/ocean margins, 

in which the two are decoupled, and for members of 

different plates. Indeed, in the Pacific Ocean, ringed 

by active margins, few transform faults have been 

demonstrated to be coextensive with either continental fractures or space image lineaments.

Our studies suggest that oceanic crust with active 

margins, whose spreading is not directly associated 

with continental rifting and whose structures may 

trend at angles to continental structures, will react 

with continental crust in a manner such that failure 

will occur along or parallel to lines of weakness preexistent in the continental crust. Accordingly, the 

preexisting lines of weakness in the continents will be 

reactivated, and extensions of these lines of weakness 

will develop in the products of the interaction as they 

are accreted to the continents. Sympathetic parallel 

lines of weakness will also develop in the accreted 

materials. This mechanism helps to explain the propagation of lineaments near active plate margins but 

does not explain their vertical propagation along 

passive margins nor within continental interiors.

From the foregoing, it is evident that the study of 

space image lineaments can provide insight into the 

nature of ocean/continent interactions and their 

effects within continental interiors. The Yentna lineament is an instructive example.

The Yentna (Y, fig. ID) and parallel Tanana lineaments (A, fig. ID) played a significant role in the 

interaction between the Pacific (oceanic) plate and 

continental Alaska in late Cenozoic time. The Yentna 

lineament forms the northeast boundary of a zone of 

pronounced change in trend of structures in the continental shelf (Von Huene and Shor, 1969), the northeast boundary of the segment of ocean floor warped 

in the 1964 Alaska earthquake (Plafker, 1969), the 

northeast boundary of the major interarc basin of 

Cook Inlet (Grantz and Kirschner, 1975), and the 

northeastern termination of the late Cenozoic volcanic 

arc of the Aleutian Islands and Alaska Peninsula. The 

lineament parallels the direction maintained by the 

oceanic plate vector in the Gulf of Alaska over the 

last 40 million years (Grow and Atwater, 1970). In 

the Alaska Range, the lineament coincides with the 

Yentna lineament of Van Wormer and others (1974) 

along which a warp occurs in the northwest-dipping 

Benioff zone, or zone of inclined earthquake foci. 

According to these authors, northeast of the Yentna 

lineament the Benioff zone is more steeply inclined

and dips more northerly. The Benioff zone continues 

northeast beyond Mt. McKinley and terminates near 

the Tanana lineament.

These data suggest that movement of the Aleutian 

Arc-Trench system in the last 40 million years has 

been essentially translatory northwestward past the 

more resistant main continental mass of Alaska. The 

stress of plate interaction has been successively accommodated along crustal block boundaries parallel 

to and southwest of the Tanana lineament. The change 

in the Benioff zone at the Yenta lineament is suggestive of drag resulting from dextral shear. Southwestward of the Yentna, the volcanic chain of the Alaska 

Peninsula is segmented in plan, segment boundaries 

coinciding with lineaments at Lake Iliamna and at 

Controller Bay which trend northwest parallel to the 

Yentna and Tanana lineaments. To the west, a similar 

segmentation of the Aleutian Volcanic Arc has been 

noted (Jordan and others, 1965). The Tanana lineament also coincides in part with an earlier suture of 

Permian-Triassic age (Richter and Jones, 1973).

From the above phenomena, we conclude that adjustments in continental crust as a result of oceanic 

plate convergence have occurred along zones of weakness already existing in the continental crust. Continued adjustments have occurred successively along 

other zones of weakness parallel to these preexisting 

zones of weakness. We believe that the tectonized 

remnants of the Permian to early Cenozoic arcs and 

basins owe their present shape to accretion against 

a northern buttress formed of a northeast-trending 

early and middle Paleozoic continental shelf on the 

northwest and a remnant northwest-trending Precambrian and Paleozoic remnant volcanic arc complex in the northeast (Yukon-Tanana Upland). 

Northward compressive stresses which successively 

collapsed these arcs and basins against the continental 

mass (Richter and Jones, 1973; Jones and others, 

1970) were relieved by decoupling along northeastand northwest-trending fractures already existing in 

the continental crust, parallel to the trends of the 

buttress. Two of these fractures are now visible as 

northeast- and northwest-trending lineaments which 

mark the trace of parts of the Denali fault system in 

eastern and western Alaska.

Short, convex-east curvilinear features were noted 

in the area south of the Denali fault system on examination of the NOAA images (fig. IB). They are 

less apparent, but present, on Landsat images and apparently are enhanced by the distortion of the NOAA 

images. These curvilinears do not accord with any of 

the lithologic or tectonic trends in the area, except 

the slightly convex-east arcuate pattern of volcanoes
188 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

from Lake Iliamna to the Yentna lineament. The 

Denali fault system exhibits a history of dextral movement since Cretaceous time, but there is also evidence 

of vertical movement in the segment west of the 

Nenana River (Grantz, 1966). The vertical movement 

in this area would accord with the presumed northwest shortening in response to crowding from the 

Tertiary arc complex, but the dextral movement is 

less easily understood. Clague and others (1975), 

studying the age of volcanic rocks dredged from the 

Hawaiian Ridge and Emperor Seamounts, recapitulated the case for the Hawaiian-Emperor bend forming as a result of a change from north to northwest in 

the movement of the Pacific plate over a melting spot 

in the mantle and added supporting evidence of progressive changes in age of volcanism that would ensue 

were this hypothesis valid. They conclude the age of 

the bend is 41 to 43 m.y. If such a vector change occurred, it would have impressed a counterclockwise 

rotation on the area south of the Denali fault system, 

engendering a dextral stress release along it. The 

curvilinear features may reflect this distortion and, 

therefore, be young and temporary.

METALLOGENIC SIGNIFICANCE

In an earlier study, Lathram and Gryc (1973) related some of the space image lineaments to the 

distribution of mineralized areas, and compared, this 

with the conclusions of Sutherland-Brown and others 

(1971) that areas of mineral concentration in British 

Columbia were related to the intersection of major 

through-going orthogonal structures. Preliminary comparison of the full pattern of lineaments developed in 

this paper to the distribution of mineral deposits in 

Alaska has as yet revealed no significant additional 

relationships. However, comparison of this pattern 

of lineaments to the empirical "shear-stress network" 

developed by Kutina (1969) in the western United 

States reveals that a large number of lineaments 

cross a number of highly mineralized areas, a large 

number of lineament intersections coincide with 

metal-rich areas (as do Kutina's "shear-stress" lines), 

and there is a striking correlation between the two 

patterns in orientation and spacing of individual elements. Further, the trends and spacing of lineaments 

of the space image pattern correspond closely to the 

trends and spacing of "deep-seated tectonic zones" 

recognized by Garson and Krs (1976) in the Red Sea 

area. Garson and Krs showed these zones to be related not only to mineral deposits in the continental 

crust but also to brine pools in the Red Sea. Further

study of the pattern in Alaska, or modifications to it, 

should be fruitful for mineral exploration.

Many metallogenic experts, especially Clark and 

others (1974) in Alaska and Sutherland-Brown (1974) 

in British Columbia have also pointed to broad areas 

or zones of like mineralization which seem uncontrolled by major structures. Sutherland-Brown (1974, 

p. 54) in particular studied the regional distribution 

of metals as shown by geochemical sampling and 

concluded that the similarity between the pattern of 

mineral deposits and metal background means that 

the deposits owe their origin to the level of background in the terrane they inhabit—"the rocks have 

the ore deposits they deserve." On the other hand, 

Sillitoe (1974) has examined the known linear zonation of mineral deposits in the Andes and, using 

geologic discontinuities transverse to the length of the 

zones, has subdivided the Andes into tectonic segments, each with a metallogenic character different 

from that of its neighbors.

From the foregoing, we suggest that mineral concentrations may be expected along or at the intersection of space image lineaments that mark significant crustal block boundaries. We also suggest that 

the identification of major crustal block boundaries 

through the study of space image lineaments and the 

analysis of the tectonic history, geochemistry, and 

mineralization within each block (as opposed to 

broader regions or zones) may also be fruitful in 

mineral exploration. In fact, the differing history experienced by individual blocks as the result of relief 

of internal as well as external plate stresses may be 

a more significant determinant of the mineral fecundity of an area. A possible example is the lower Kuskokwim area, rich in mercury deposits as compared 

to the rest of Alaska. Although individual deposits 

seem controlled by local faults, the area of mineralization is not related to a single lineament but is 

largely confined between two northeast-trending 

lineaments (Lathram and Gryc, 1973) and two northwest-trending ones, the Yentna and one parallel to it 

south of Lake Iliamna.

CONCLUSIONS

We conclude that:

1. Most space image lineaments 1,000 km or more 

in length are the surface expression of major 

changes in the character of the lithosphere resulting from persistent movement, vertically 

and/or horizontally along zones of weakness in 

the crust.
TECTONIC DEDUCTIONS FROM ALASKAN SPACE IMAGERY 189

2. A systematic pattern exists in these lineaments 

and represents a systematic pattern of boundaries of a mosaic of crustal blocks.

3. Differing vertical and/or horizontal adjustments 

from block to block in response to plate 

stresses result in differing tectonic histories and, 

hence, differing geological and geophysical 

characteristics in the lithosphere of each block.

4. The response of continental crust to forces of 

plate convergence or divergence and of oceanic 

crustal materials accreted to the continents during plate convergence is guided by accommodation along these preexisting crustal block 

boundaries.

5. Metal concentrations may not only be controlled 

by these crustal block boundaries and their 

intersections, as felicitous channels for the migration of mineralizing agents but may also be 

governed by greater or lesser mineral fecundity 

within individual blocks, as determined by differences in tectonic history.

6. The study of very long space image lineaments 

and their geologic significance provides a 

powerful new tool for tectonic and metallogenic 

analysis.

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PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Computer-Enhanced Landsat Imagery as 

a Tool for Mineral Exploration in Alaska

By Nairn R. D. Albert, 

U.S. Geological Survey, Menlo Park, California,

and Pat S. Chavez, Jr., 

U.S. Geological Survey, Flagstaff, Arizona

ABSTRACT

Recent work in the Nabesna and McCarthy quadrangles, Alaska, indicates that computer-enhanced 

Landsat imagery shows many of the known mineral 

deposits and can help in the prediction of potential 

mineral occurrences. False color, "simulated natural 

color," and color ratio techniques, were used successfully in conjunction with a black and white, single 

band image mosaic of Alaska. Computer techniques 

involved two stages of digital image processing (1) 

atmospheric anch Sun-elevation corrections, noise removal, computer mosaicking, and change of the data 

format and (2) image enhancement, involving data 

manipulation for maximum discrimination of surface 

materials and structure. Application of a new technique called a "sinusoidal" stretch gave information 

not available in other products having standard contrast stretches. We identified several orthogonal sets 

of linears and found parallel linears to be regularly 

spaced at approximately 30 to 35-km intervals. The 

locations of known mineral occurrences correlate 

well with the linears. Extensions of known faults and 

possible locations of hidden intrusive bodies were 

identified. Analysis of numerous areas of anomalous 

light reflectance showed that whereas most are associated with known mineral occurrences, altered 

zones, or geochemical anomalies, some are not and 

may represent unexplored altered zones or mineralized areas worthy of future exploration.

INTRODUCTION

Recent work carried out in the Nabesna and McCarthy quadrangles, Alaska, under the Alaskan Mineral Resource Assessment Program (AMRAP) indicates that Landsat data can significantly help detect 

and predict mineral occurrences, when used in conjunction with geologic mapping, geochemical sampling, and aeromagnetic and gravimetric data. Landsat 

data can provide additional information on geology 

and structure relevant to mineral exploration that 

cannot be or may not have been acquired by other 

methods.

This report presents the results of Landsat data 

interpretation in the Nabesna quadrangle, Alaska 

(Albert, 1975), and the preliminary results of similar 

interpretations in the McCarthy quadrangle, Alaska, 

and their significance for mineral exploration.

LOCATION

The Nabesna and McCarthy quadrangles are in 

south-central Alaska (fig. 1) bounded on the north 

and south by the 63°N. and 61 °N. latitudes and on 

the west by 144°W. longitude. The eastern boundary 

is the Alaska-Canada border (141°W. longitude).

PHYSIOGRAPHY

Topographic extremes in the area studied range 

from a low of about 305 m (1,000 ft) in the western 

part of the McCarthy quadrangle to a high of more 

than 5,000 m (16,400 ft) in the southeastern part. 

The area can be divided into three types of terrain: 

(1) Plains and lowlands from about 305 m (1,000 ft) 

to 1,220 m (4,000 ft) with heavy to moderate vegetation and few outcrops; (2) low mountains from about 

915 m (3,000 ft) to 1,830 m (6,000 ft), with heavy to 

light vegetation and numerous outcrops in the higher

193
194 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

500 1000 KM

FIGURE 1.—Map of Alaska showing location of the Nabesna 

and McCarthy quadrangles.

elevations; and (3) high rugged mountains from about 

915 m (3,000 ft) to peaks of 5,000 m (16,400 ft), with 

moderate to no vegetation, numerous glaciers, heavy 

snow cover and extensive outcrops.

Temperatures in these quadrangles range from 

highs above 38°C (100°F) during the summer to lows 

below -57°C (-70°F) during the winter. Much of the 

area is underlain by discontinuous permafrost.

BRIEF GEOLOGIC DESCRIPTION

The Nabesna and McCarthy quadrangles are underlain by three general geologic terranes that are separated by the Denali and Border Ranges faults (fig. 2). 

North of the Denali fault are mainly regionally metamorphosed lower Paleozoic sedimentary and subordinate igneous rocks. South of the Denali fault and 

north of the Border Ranges fault, there are three assemblages of extensive andesitic volcanic and associated sedimentary and intrusive rocks: Upper Paleozoic, Upper Mesozoic, and Upper Cenozoic. South of 

the Border Ranges fault are extensive Mesozoic 

flysch-type sedimentary deposits.

Most mineral production in the Nabesna and McCarthy quadrangles, chiefly copper, gold, and silver 

(Richter and others, 1975; MacKevett and Cobb,

63°N

62°N

61 "N

144°W EXPLANATION 141°W

Ksm Lower Paleozoic Metasedimentary Rocks

HI and Subordinate Igneous Rocks

pn Upper Paleozoic, Mesozoic, and Cenozoic

[ \ Andesitic Volcanic and Associated Sedimentary

|H and Intrusive Rocks

mi Mesozoic Flysch-Type Deposits

100 KM

FIGURE 2.—Map of the Nabesna and McCarthy quadrangles 

showing generalized geologic terranes.

1972), has been in the area between the Denali and 

Border Ranges faults.

INTERPRETATION OF IMAGERY

The study of three kinds of computer-enhanced 

Landsat imagery in conjunction with a single-band, 

black and white Landsat image mosaic of Alaska, resulted in (1) the identification of linear and circular 

features and their correlation with known geology, 

mineral occurrences, and geophysical data and (2) the 

identification of mineral occurrences and numerous 

potential targets for future exploration.

LINEAR FEATURES

One of the types of imagery used in this study was 

the Alaskan Landsat mosaic constructed in 1973 by
COMPUTER-ENHANCED TOOL FOR MINERAL EXPLORATION IN ALASKA 195

the Soil Conservation Service, U.S. Department of 

Agriculture, using band 7 images generated without 

computer enhancement. Because of the synoptic perspective and low Sun-angle of the non-summer images 

used, the mosaic was most useful for identifying linear and circular features. Additional linear and circular features were identified on the computerfiltered imagery discussed below.

Three nearly orthogonal sets of linears were identified in the Nabesna and McCarthy quadrangles (fig. 

3). The predominant set trends approximately N. 43° 

W. and N. 48° E., the subordinate sets approximately 

N. 72° W. and N. 20° E. and N. 87° E. and north. 

Parallel linears trending N. 43° W., N. 48° E. or N. 

87° E. are spaced approximately 30-35 km apart.

East-trending linear features seen clearly on Landsat imagery (figs. 3 and 4) suggest the existence of 

major east-trending concealed structures in the 

Nabesna quadrangle south of the Denali fault. Aeromagnetic (Griscom, 1975) and gravimetric (Barnes

63*N

144°W EXPLANATION 141 °W

Linear feature (dotted where uncertain) 

Known mines

100 KM

FIGURE 3.—Map of the Nabesna and McCarthy quadrangles 

showing linear features and mine locations.

and Morin, 1975) data support the Landsat interpretations. These east-trending structures can also be 

seen in the McCarthy quadrangle (figs. 3 and 5) on 

Landsat imagery and should be substantiated by 

future aeromagnetic and gravimetric studies.

The correspondence of known mineral occurrences 

to linear features in the Nabesna and McCarthy quadrangles is very good. Of 257 known mineral occurrences (Richter and others, 1975; MacKevett and 

Cobb, 1972; MacKevett, written communication), 141 

(55%)' occur within 1 km of linear features. One 

hundred twenty-four occurrences are prospects or 

mines, 78 (63%) of which occur within 1 km of linear 

features. Of the 17 mines, 14 (82%) occur within 1 

km of linear features (fig. 3). These correlations suggest a strong relation between linear features and 

the more significant mineral occurrences.

Statistically, the different mineral commodities in 

the McCarthy quadrangle appear to be related to the 

trend of specific orthogonal linear feature directions 

(table 1). For example, 34 of 85 copper prospect and 

mine deposits occurring within 1 km of a linear feature are associated with northwest-trending linears. 

Subordinately, 18 copper deposits are associated with 

northeast-trending linears. This orthogonal relation 

appears to apply for silver, molybdenum, and, possibly, antimony. Gold, on the other hand, occurs primarily near linears with north-northeast and northeast directions and subordinately near linears with 

northwest trends. Chromium, iron, zinc, and nickel, 

not shown, also appear to have preferred orthogonal 

linear direction associations.

Evaluation of significant mineral occurrences in 

each linear direction reveals three groupings: (1) 

northwest and northeast-trending linears to which 

most mineral occurrences are related, (2) northnorthwest, north-northeast, and east-trending linears, 

and (3) west-northwest, east-northeast, and northtrending linears to which the fewest mineral occurrences are related. Although the information is preliminary and incomplete, these trends are suggestive 

of the relations resulting from the Moody and Hill 

(1956) model for primary, secondary, and tertiary 

fault and fold development in regions of wrench-fault 

tectonics.

CIRCULAR FEATURES

Numerous circular features were identified in the 

Nabesna and McCarthy quadrangles (figs. 4 and 5). 

North of the Denali fault, these circular features can 

be correlated with aeromagnetic and geologic data 

suggesting that they may be related to concealed in-
196 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

63°N

62°N

144°W EXPLANATION 

Linear and circular features (dotted where uncertain)

Color anomaly 

50

141°W

100 KM

I

FIGURE 4.—Map of the Nabesna quadrangle showing linear and circular features and color anomalies observed on computerenhanced Landsat imagery. (From Albert, 1975.)

TABLE 1.—Number of significant mineral occurrences (mines and prospects) in the 

various linear directions in the McCarthy quadrangle, Alaska

Linear direction

Copper

Cold __ _

Molybdenum

Silver

Total

E WNW NW

3

11 5 34

3

2

9

11 5 51

NNW N

5 2

1

1

3

10 2

NNE

6

6

12

NE

18

5

3

26

ENE

4

2

1

7

trusive bodies. Those circular features observed be- COMPUTER-ENHANCED IMAGERY 

tween the Denali and Border Ranges faults, some

nearly 200 km in diameter, appear to be related to Three types of computer-enhanced Landsat imvolcanic activity. The relation of circular features to agery were used successfully to locate mineral ocmineralization is not yet clear. currences in the Nabesna quadrangle: (1) color ratio,
COMPUTER-ENHANCED TOOL FOR MINERAL EXPLORATION IN ALASKA 197

2°N

61 °N

144°W EXPLANATION 

Linear and circular features (dotted where uncertain)

50 100KM

141°W

FIGURE 5.—Map of the McCarthy quadrangle showing linear and circular features.

(2) standard false color, and (3) simulated natural 

color. An additional enhancement technique called a 

"sinusoidal" stretch is being used on imagery of the 

McCarthy quadrangle. Analysis of these "sinusoidally" stretched images is still in progress, but preliminary observations indicate that they can supply 

information not available on other types of images.

Digital image processing can be separated into 

two stages, the preprocessing or "clean-up" stage and 

the actual image enhancement stage. The output of the 

clean-up stage is called a data base and is used as 

input to the different image-enhancement techniques.

The preprocessing stage includes noise (striping) 

removal, haze and Sun-elevation corrections, and a 

geometric correction (Chavez, 1975). The final step 

in the preprocessing stage is to mosaic by computer 

the different images needed to cover the area of interest. For the 3-degree quadrangles in Alaska, it

usually means mosaicking parts of three or four 

images. Four data-base tapes are then generated, each 

containing one of the four Landsat bands that cover 

the entire area of interest.

The several enhancement techniques used in this 

study can be separated into the following types: contrast stretches, color ratios, structural and linear enhancements, simulated natural color, and a "sinusoidal" stretch that maximizes the color variations within 

an image.

The first type of enhancement, contrast stretch, is 

a standard false color composite made by using three 

of the four Landsat bands to which linear stretches 

have been applied. For this study, band 4 was filtered 

with blue light, band 5 with green, and band 7 with 

red. The second type of enhancement, color ratios, 

involves the division of spectral values of one band by 

those of another band and the application of linear
198 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

stretches to the subsequent ratios. In the Nabesna 

quadrangle, the color-ratio image was generated by 

filtering bands 5/4 with red light, 6/4 with green, and 

4/5 with blue.

Structural and linear enhancement is generated by 

the use of a high-frequency filter that removes most 

of the albedo information in order to bring out structural and linear information. In this study, the structural and linear information obtained by this method 

was added to that observed on the Alaskan image 

mosaic.

Another type of enhancement is the simulation of 

natural color (Eliason and others, 1974). In this technique, a pixel (picture element) is classified into one 

of three general categories, vegetation, rocks and 

soils, and water, using the ratio of band 5 to band 6 

after haze removal. Once the pixel has been classified, 

a different algorithm is used for each category to 

extrapolate a theoretical value for the blue region of 

the spectrum. This new band is then used to generate 

a color composite with colors approximating those 

that might be seen without atmospheric effects from 

satellite altitude (fig. 6, p. XIX).

A recently developed enhancement technique, the 

"sinusoidal" stretch, is applied to any three bands 

used to generate a color composite having maximum 

color variation (fig. 7, p. XX). Most dissimilar materials 

show up as dissimilar colors in the composite except 

where materials have the same spectral response in 

all three bands selected. The sinusoidal stretch extends multiple-input spectral reflectivity values over 

the entire output spectral range such that the color 

changes are gradual for small differences of gray 

levels. This new stretch enhances not only large 

spectral differences within the image but also very 

subtle differences not usually enhanced by other 

methods.

Color anomalies identified on Landsat imagery were 

found to correspond well with known mineral deposits 

and geochemical anomalies. A color anomaly is considered to be a variation in tone or color observed 

on the images that differs significantly from the local 

background color, indicating a reflectivity difference 

on the ground.

In the Nabesna quadrangle, 120 color anomalies 

were identified on the standard false color and simulated natural color images. Of these, 72 and 69 were 

identified respectively on the standard false color and 

simulated natural color images. Twenty-one were 

identified on both. No color anomalies were identified 

on the color-ratio image.

Of the 120 color anomalies, 39 correspond to known 

mineral occurrences. Of the 81 that do not, 17 correspond to geochemical anomalies (fig. 8). Of the 64 

color anomalies that correspond to neither known 

mineral occurrences nor geochemical anomalies, 27 

were in areas that were not geochemically sampled. 

Thus, at least 56 (47 ?o) of the color anomalies observed on Landsat imagery of the Nabesna quadrangle 

appear to be related to mineralization. (Many others 

are thought by Richter | oral comm., 1975J to correspond to unmapped altered zones). In addition, 27 

color anomalies may be related to unknown mineral 

occurrences and should certainly be targets for future 

exploration.

Studies of computer-enhanced Landsat imagery in 

the McCarthy quadrangle are still in progress. Three 

types of imagery are being used: (1) simulated natural 

color, (2) color ratio with bands 5/4 in blue, 6/7 in 

green, and 7/4 in red, and (3) false color using sinusoidal stretches, with the various bands expressed in 

different color combinations.

One of the advantages of the sinusodal stretch is 

that snow, a major ground cover in Alaska, does not 

have to be displayed in white, as it does in standard

Color anomalies

Mineralized zones

No mineralized 

zones

No geochemical 

anomalies

Not related to 

geochemical 

anomalies or 

mineralized 

zones

Geochemical 

anomalies

No geochemical 

samples

(TARGETS FOR EXPLORATION) 

4 4 

RELATED TO 

MINERALIZATION 

OR GEOCHEMICAL 

ANOMALIES

FIGURE 8.—Breakdown of color anomalies seen on computerenhanced Landsat imagery and their association with mineralized areas and geochemical anomalies in the Nabesna quadrangle.
COMPUTER-ENHANCED TOOL FOR MINERAL EXPLORATION IN ALASKA 199

false-color and simulated natural-color images (fig. 7, 

p. XX). Photographically, the white, snow-covered 

areas tend to "bleed" over into adjacent non-snow 

areas, reducing reflectivity discrimination of rock, soil, 

or vegetation differences.

By superimposing mapped faults in the McCarthy 

quadrangle over a sinusoidally stretched image with 

bands 5 in green, 6 in blue, and 7 in red, it was possible to draw numerous extensions of these faults based 

on linear and curvilinear features visible in the image 

(fig. 9). The true nature of these extensions and their 

relation to mapped faults is uncertain. Their actual 

surficial expressions have not been observed by field 

geologists (MacKevett, oral comm., 1975) and may 

be detectable only by high-altitude imaging systems. 

Additional data on the existence and nature of these

extensions may soon be available 'upon completion of 

an aeromagnetic map of the McCarthy quadrangle.

Further studies of the Landsat imagery of the McCarthy and other Alaskan quadrangles now in progress will make possible a more thorough evaluation 

of sinusoidally stretched imagery and its usefulness in 

mineral exploration.

CONCLUSIONS

Landsat data have furnished significant geologic 

and structural information to mineral resource appraisal studies of the Nabesna and McCarthy quadrangles, Alaska. Information of this type, when used 

in conjunction with geologic, geophysical, and geochemical data, is -a modern tool that should be con2°N

••••f'Vx.

. \ K

\ '

^ EXPLANATION 61°N

144°W 141°W

__ __ __ ....... Mapped faults (dotted where uncertain)

^^ _^_ _^_ ...... Mapped low-angle faults (dotted where uncertain)

Possible extensions of faults

50 100 KM

I———————————————————————————I

FIGURE 9.—Map of the McCarthy quadrangle showing known faults and their possible extensions as determined by linear 

and curvilinear features visible in the sinusoidally stretched fa!se-co!or Landsat image of the McCarthy quadrangle.
200 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

sidered essential to effective regional mineral exploration.

REFERENCES CITED

Albert, N. R. D., 1975, Interpretation of Earth Resources Technology Satellite imagery of the 

Nabesna quadrangle, Alaska: U.S. Geological 

Survey Misc. Field Studies Map MF-655J, 2 

sheets, scale 1:250,000.

Barnes, D. F., and Morin, R. L., 1975, Gravity map of 

the Nabesna quadrangle, Alaska: U.S. Geological 

Survey Misc. Field Studies Map MF-655I, 1 sheet, 

scale 1:250,000.

Chavez, P. S., Jr., 1975, Atmosphere, solar, and MTF 

corrections for ERTS digital image (abs.): 

American Society of Photogrammetry, Fall Convention, Phoenix, Ariz. Oct. 1975, Proc., pp. 69- 

69a.

Eliason, E. M., Chavez, P. S., Jr., and Soderblom, L. A., 

1974, Simulated true color from ERTS: Geology, 

v. 2, no. 5, pp. 231-234.

Griscom, Andrew, 1975, Aeromagnetic map and interpretation of the Nabesna quadrangle, Alaska: 

U.S. Geological Survey Misc. Field Studies Map 

MF-655H, 2 sheets, scale 1:250,000.

MacKevett, E. M., Jr., and Cobb, E. H, 1972, Metallic 

mineral resources map of the McCarthy quadrangle, Alaska: U.S. Geological Survey Misc. 

Field Studies Map MF-395, scale 1:250,000.

Moody, J. D., and Hill, M. J., 1956, Wrench-fault tectonics: Geol. Soc. America Bull., v. 67, pp. 1207- 

46.

Richter, D. H., Singer, D. A., and Cox, D. P., 1975, 

Mineral resources map of the Nabesna quadrangle. Alaska: U. S. Geological Survey Misc. 

Field Studies Map MF-655K, 1 sheet, scale 

1:250,000.
PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Evaluation of Improved Digital-Processing Techniques of 

Landsat Data for Sulfide Mineral Prospecting

By R. G. Schmidt, 

U.S. Geological Survey, Reston, Virginia

and Ralph Bernstein, 

International Business Machines Corporation, Gaithersburg, Maryland

ABSTRACT

A relatively simple method of digital computer 

classification of multispectral scanner data was tested 

at an ideal porphyry copper deposit in a very arid 

part of Pakistan and was then successfully applied to 

mineral exploration in an adjacent region. The surface 

expressions of the already known porphyry copper 

deposit and the five new prospects discovered in this 

experiment are all characterized by abundant lighttoned sulfate minerals and do not seem to contain 

much pigmentation by iron oxides.

Digital multispectral classification was performed 

at the IBM Digital Image Processing Facility by using 

reformatted computer-compatible tapes of one scene. 

A test area of 55 km'- was selected in the Saindak, 

Pakistan, area, which included a well-mapped porphyry copper deposit. A "supervised" classification 

table was prepared of high and low limits of acceptable reflectance in each of the four spectral bands for 

each surface type by using control areas selected 

from a geologic map. The first classification table was 

revised several times until it was deemed capable of 

giving information useful in mineral exploration, even 

though we expected that many of the rock identifications would be incorrect. This revised table was applied to evaluation of 2,100 km 2 in the Chagai District, 

Pakistan. Of 50 sites classified as "mineralized" by 

the digital-processing program, 23 were selected as 

possibly similar to the control area and therefore 

deserving of inspection in the field. Nineteen of these 

were visited in October 1974; five of the sites, constituting a total area of 4.7 km ~, contain sulfide-bearing 

hydrothermally altered rock that is mostly quartzfeldspar porphyry. Parts of all five sites are believed 

to represent parts of porphyry copper systems. The 

presence of copper beyond trace amounts has been 

established at two points, and the prospects are under 

investigation by the Government of Pakistan.

It may be important when using remote-sensing 

methods in some geologic environments to seek 

altered parts of porphyry copper deposits that are not 

specifically enriched or pigmented by iron oxides.

Our experiment indicates that simple methods of 

digital classification of Landsat data can aid in the 

location of mineral deposits in desert terrain. These 

methods can complement conventional methods of 

mineral exploration.

A major problem in identifying the sulfide-bearing 

areas is the overlap of reflectance values of mineralized areas with the reflectance values from other 

high-albedo areas, such as parts of drywashes and, 

most commonly, areas of windblown sand. In an effort 

to solve this problem, new classification tables using 

several classes for each rock type have been prepared. Each class has relatively close high/low limits; 

several classes are therefore needed to cover the full 

range of albedo that can be expected from each 

major surface type, as for example, from similar rock 

occurring on slopes of different orientation to the Sun. 

The narrowed reflectance limits increase the possibility of discrimination between materials of generally 

similar reflectance values. Recent tests of these more 

sophisticated classification tables suggest that we can 

now achieve better discrimination of mineralized areas 

than we did in the evaluation study in 1974. Future 

satellite-borne sensors having higher sensitivity, wider

201
202 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

spectral range, narrower spectral bands, and greater 

resolution should help to alleviate the reflectanceoverlap problem.

Our experiment used high-albedo areas associated 

with intense quartz-sericite alteration as guides to 

sulfide mineralization although some of the control 

areas do contain some hematitic and some jarositic 

pigmentation. Attempts to use strongly red stained 

areas in the outer pyrite zone as control areas resulted 

in no satisfactory delineation of the area of mineralization. All prophyry copper deposits may not include 

areas of light-toned sulfate and/or clay alteration; 

also, not all known deposits have "red-thumbs" or 

areas of strong red iron oxide pigmentation derived 

from decomposition of pyrite.

INTRODUCTION

The concept of using remote-sensing methods at 

the Saindak porphyry copper deposit predated Landsat-1 by almost 10 years, for it was discussed by the 

geologists during field mapping from 1961 to 1966, 

and some simple spectral tests were made at that 

time using ordinary color photography and colored 

filters (Schmidt, 1968, p. 59). Two investigations that 

have sought a simple method of identifying sulfide 

deposits using Landsat multispectral scanner data 

have used the Saindak deposit as a test site because 

the deposit is large, has well-developed alteration 

zones, and scant vegetation and is well exposed and 

undisturbed (fig. 1). The deposit has been mapped in 

detail at a scale of 1:6,000 (Khan, 1972), and the 

senior author was familiar with the deposit and region. Both investigations used image 1125-05545 

(Nov. 25, 1972) and the first experiment also used 

image 1090-05595 (Oct. 21, 1972) and 1124-05491 

(Nov. 24, 1972). In the first experiment, false-color 

composites were visually examined to locate possible 

favorable areas; in the second, favorable areas were

FIGURE 1.—Index map showing the Chagai District and Saindak, Pakistan.
IMPROVED DIGITAL-PROCESSING DATA FOR SULFIDE PROSPECTING 203

selected by digital computer classification. The nearwinter solstice date of these images and the resultant 

low Sun illumination angle was probably an advantage 

in the first experiment and a disadvantage in the second.

Both experiments were designed to test relatively 

simple methods of utilizing Landsat multispectral 

scanner (MSS) data in mineral exploration. Simplicity 

is considered important because we are looking for 

a method that may find wide usage in both government and private sector mineral exploration applications.

For the first experiment, false-color composites were 

made using NASA system corrected MSS images of 

three scenes over a very arid and vegetation-free part 

of the western Chagai District, Pakistan. Later, a color 

composite was also prepared from MSS bands 4, 5, 

and 7 by computer processing of the taped data to 

produce an image that was geometrically corrected 

for systematic errors and radiometrically adjusted 

(fig. 2, p. XXI). These composites were visually examined for tonal features resembling the known 

porphyry copper deposit at Saindak (Schmidt, 1974). 

Seven areas were selected for prospecting, and three 

of these were field checked. None of the three contained significant mineralization. Later analysis of the 

results indicated that too few areas were selected by 

visual examination and that this method must be considerably modified for greatest effectiveness in mineral exploration. Some further testing in which more 

light-toned areas are selected should be made before 

the results of this experiment can be considered final.

In the second experiment, machine processing was 

used. Digital multispectral classification was experimentally performed on the reformatted computercompatible tapes of one scene. The IBM Digital Image 

Processing Facility was used for image correction, 

image enhancement, and multispectral classification 

(fig. 3). A 55-km 2 area in the Saindak vicinity was 

extracted and displayed in photographic form using 

the imagery printer, and a test area was selected 

which included known porphyry deposits. Areas representing specific rock types were identified, and their 

reflectance values were extracted for MSS bands 4, 5, 

6, and 7. Provisional classification tables were prepared for given geological units; each table was used 

to classify the test area, and the tables were modified 

upon comparison of these results with the known geology. The cycle was repeated five times until a classification table was developed that could, it was hoped, 

provide information useful in mineral evaluation. High 

accuracy of identification was not considered to be

necessary for success of the method, and was not 

expected.

Then the multispectral classification program, using 

the classification table already prepared, was used to 

evaluate 2,100 km 2 east of the test area, and a partial 

field check of the results was conducted. By evaluating 

the resultant digital classification map, 23 prospecting 

targets were selected as being similar to the Saindak 

altered rock area, and 19 of these were visited in the 

field. Of these 19, 5 localities constituting a total area 

of 4.7 km 2 contain hydrothermally altered rock, 

mostly quartz feldspar porphyry. A program for evaluation of these new prospects has been prepared by 

the Government of Pakistan.

Despite the apparent success of the 1974 application experiment, it used classification tables that were 

relatively simple. While the number of sites falsely 

classified as mineralized was not unreasonable when 

compared to other standard field methods of mineral 

prospecting, we had reason to believe that our method 

could be refined. This would result in more distinct 

delineation of mineralized areas, fewer areas falsely 

classified as mineralized, and perhaps improvement 

of quality of mapping of other surficial materials. This 

refinement has been the goal of our continuing 

experimentation.

Acknowledgments.—The original color composite 

experiment conducted by the U.S. Geological Survey 

was partly supported by the National Aeronautics and 

Space Administration. Financial support for part of 

the digital processing experiment and for the travel 

expenses of the field checking was provided by the 

EROS Program, and logistical support in the field was 

furnished by the Resource Development Corporation, 

a Pakistan Government corporation. The extraction of 

reflectance data for several sites in the experiment 

area by Jon D. Dykstra of Dartmouth College, using 

computer facilities and algorithm of the NASA Goddard Institute of Space Studies, New York, is gratefully acknowledged.

GEOLOGY OF THE EXPERIMENT AREA

The general geology of the western Chagai District 

is portrayed on 1:253,440 photogeologic maps (Hunting Survey Corporation, Ltd., 1960). The rocks of the 

region consist of marine and terrestrial sedimentary 

and volcanic rocks of Cretaceous to Holocene age, 

and a few shallow intrusive bodies. The influence of 

widespread volcanism is continuous in the geologic 

record from Cretaceous time to the present. The highest mountains in the area are the dormant volcanoes 

Koh-i-Sultan in Pakistan and Kuh-e-Taftan in nearby 

Iran.
SOURCE DATA 

PRODUCT GENERATION AND ANALYSIS DIGITAL PROCESSING OF CCTs

FIGURE 3.—Graphic summary of digital processing and data analysis performed in the experiment.
IMPROVED DIGITAL-PROCESSING DATA FOR SULFIDE PROSPECTING 205

The Mirjawa range area, where the known porphyry copper deposit, Saindak, is located, has mostly 

folded and much faulted (along northwest trends) sedimentary and volcanic sedimentary strata. Except for 

a group of large and extensive pre-Tertiary sills, intrusive and extrusive volcanic rocks make up but little 

of the total outcrop area, but volcanic material is 

common in sedimentary strata. Cretaceous rocks 

represent a wide variety of marine and continental 

depositional environments; lower Tertiary rocks are 

mostly shallow marine deposits, and upper Tertiary 

and Quaternary strata are largely of continental origin.

The Mashki Chah region can be considered geologically as a western extension of the Chagai Hills, 

west of the volcano, Koh-i-Sultan. In this extension, 

gently folded Cretaceous and undeformed Tertiary 

volcanic rocks with low dips (probably initial) are 

common and widespread, and intrusive rocks, especially stocks, are more abundant than in the Mirjawa 

ranges. Faults are widespread. The folding lacks the 

strong linear pattern characteristic of the Mirjawa 

ranges, and the two areas are dissimilar structurally. 

Recently dried or still weakly flowing sinter-depositing 

saline springs, plus small weak fumaroles on Koh-iSultan, indicate that there is still a little hydrothermal 

activity.

ECONOMIC GEOLOGY

Several large areas of the Chagai District contain 

volcanic rocks of intermediate and felsic composition, 

within which small bodies of hypabyssal intrusive 

rocks may be considered to have a good potential for 

large sulfide deposits of the porphyry copper type. 

Mineral reconnaissance in the Chagai District has been 

spotty and mostly for high-grade deposits. Small 

copper occurrences are widespread in the region, but 

none had been known within several miles of the new 

prospects identified in this experiment.

At Saindak, a group of small copper-bearing porphyritic quartz diorite stocks cut northward across the 

folded lower Tertiary stratigraphic section (Ahmed, 

Khan, and Schmidt, 1972). The stocks may be cupolas 

on a single barely exposed granitic body 8 km (5 mi) 

long and as much as 1.5 km (1 mi) wide or separate 

but related intrusive bodies. The group of stocks is 

surrounded by zones of intense hydrothermal alteration very similar to those of the ideal model described 

by Lowell and Guilbert (1970). At Saindak, the innermost area seen at the surface is a zone of potassic 

alteration containing hydrothermal biotite (Shahid 

Noor Khan, oral communication). This is surrounded 

successively by zones of quartz-sericite alteration and 

finally a 1- to 3-km zone of propylitic alteration in

which pyroclastic rocks in particular are altered to a 

hard, dark epidote-rich hornfelsic rock.

Copper mineralization is probably restricted to the 

potassic alteration zone and the inner part of the 

quartz-sericite zone, both mostly but not entirely 

located in the intrusive quartz diorite porphyry. The 

copper-bearing zone is in turn enclosed in a sulfiderich zone that contains as much as 15 percent by volume pyrite (locally pyrrhotite), probably limited to 

the outer part of the quartz-sericite alteration zone. 

Mineralization in the propylitic zone is limited to lean 

lead-copper-silver veins (Ahmed, Kahn, and Schmidt, 

1972, p. A19-A20) and local hematite and pyrrhotite 

skarns formed by replacement of limestone beds 

(Ahmed, Khan, and Schmidt, 1972, p. A19).

The pyrite-rich peripheral zone and the innermost 

quartz-sericite and potassic zones have been eroded 

to form a cross-structural valley in which the surficial 

materials are light toned and highly reflective. Soils 

related to certain parts of many porphyry copper deposits the world over have distinct red and orange 

anomalies, and this is true at part of the Saindak deposit as well, especially over the pyrite-rich zone in 

the valley north of the main areas of mineralization. 

The amount of red and yellow coloration in the most 

central part of the alteration zone at Saindak seems 

less than in some peripheral areas but, unfortunately, 

this has not been measured quantitatively. Alluvial 

and windblown materials cover part of the light-toned 

soil, and it is necessary to use much care in selecting 

specific control areas for any remote-sensing experiment.

COMPUTER-AIDED INFORMATIONEXTRACTION EXPERIMENTS

Computer-aided information-extraction experiments 

were conducted to identify potential sulfide-orebearing localities. The experimental approach is summarized in figure 3. Shown here are the source data 

used, the digital processing applied to the source data, 

the products generated, the analysis conducted, and 

the final products. By a combination of digital image 

processing and information extraction, and visual 

analysis and evaluation, three processing operations 

were performed: digital image generation, support 

data generation and analysis, and multispectral classification and analysis.

Digital image generation.—The uncorrected Landsat multispectral scanner (MSS) data were reformatted into band separated 185 km x 185 km areas, 

and each band was radiometrically (intensity) adjusted 

and systematically geometrically corrected (Bernstein,
206 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

1974). The resulting computer-compatible tape (CCT) 

data were then converted to an image on film from 

which black and white and color composite prints 

were made. These prints were used as aids in the 

selection of the field prospecting sites during the 

evaluation of the classification results and also during 

the field checking.

Support data generation and analysis.—The formatted but uncorrected CCT's were used for analysis, 

especially preparation of classification tables, prior to 

the multispectral classification operation. Shade prints 

(computer printouts providing the reflectance values 

in each spectral band) for selected areas were prepared and used as a geographic reference for precise 

location of individual data samples or picture elements 

(pixels) relative to known ground features and rock 

types. Numeric data for the four MSS bands were 

extracted for each pixel in the known areas, and 

maximum and minimum sensed-reflectance limits were 

chosen for each rock type. A known highly altered 

and copper sulfide-bearing part of the deposit at 

Saindak was the source of data used to prepare the 

classification tables. Five revisions were made and 

tested, and one alternate classification table was tried, 

resulting finally in classification table "B" shown on 

table 1. Table 1 shows three general types of materials: (1) Mineralized rock, including intensely hydrothermally altered (quartz-sericite zone) quartz diorite, 

and pyritic rock, (2) Alluvial and eolian materials, recently moved dry-wash alluvium and eolian sand being 

the materials most likely to be confused with the first 

group, and (3) A loose category of dark surfaces that 

includes both hornfels-type bedrock and many areas 

of desert-varnished lag gravels (especially in class 10). 

These tables of reflectance limits were then used on

an interactive basis to classify a nearby region within 

the same Landsat scene in which copper sulfide-bearing areas were suspected but in which no deposits 

were known (application area).

Multispectral classification and analysis.—A spectral-intensity discrimination program was used for 

multispectral classification on the application area 

using the tables prepared for the Saindak deposit. The 

program tested the reflectance of each pixel within 

the application area against the maximum and minimum reflectance limits in the table and determined 

into which surface class (rock type) the pixel belonged. 

The symbol for that class was printed as part of a 

classification map. When the observed values fit more 

than one class (when classes were set up with overlapping limiting values), a pixel was placed in the class 

that was considered first in the search sequence.

The digital classification method using table "B" 

was used to evaluate an area of 2,100 km - near Saindak considered to have good potential for porphyry 

copper deposits (fig. 4). The results were printed out 

in 13 computer-generated vertical strip maps. These 

maps were examined for groups of pixels classified 

as one of the four mineralized classes (two classes 

each of mineralized quartz diorite and pyritic rock), 

and about 50 groups or concentrations were identified. 

Each was then evaluated for probability of correct 

classification, relationship to concentrations of other 

classes, and comparison with known rock types and 

known occurrences of hydrothermal mineralization. 

From this examination, 30 localities most deserving 

reconnaissance checking in the field were chosen. The 

locations of these targets were marked on an enlarged 

(1:253,440 scale) digitally enhanced image of MSS 

band 5 in order to simplify location on aerial photoTABLE 1.—Digital classification table "B" used in 7974 mineral evaluation in the Chagai District, Pakistan

Class 

number

1 

2 

3

4

5 

6

7

8 

9

10 

11 

12

Reflectance limits of 

multispectral scanner bands

Mineralized 

rock

Dry-wash alluvium

Boulder fan

Eolian sand

Rock type

Quartz (High reliability 

diorite [low reliability

Pyritic (High reliability 

rock (Low reliability

(High reliability 

[low reliability

(High reliability 

(Low reliability

Various dark surfaces including hornfelsic rock outcrops, 

desert-varnished lag gravels, and detrital black sand

Symbol

0 

8 

X 

X

-

+

>

I

n

H

4

46-50

44-45

41-45

41-45

39-46

41-45

33-40

38-44

45

33-36

24-35

29-36

5

52-60

52-60

47-54

47-54

39-46

46-51

39-46

46-54

46-127

28-38

19-27

28-38

6

50-60

45-49

39-44

39-44

35-44

42-49

30-35

42-51

42-127

29-35

20-32

20-28

7

18-22

18-19

16-17

16-19

14-17

18-19

9-16

18-22

18-63

11-15

8-12

9-14
IMPROVED DIGITAL-PROCESSING DATA FOR SULFIDE PROSPECTING 207

TABLE 2.—Revised classification table "SSD" prepared in April 1975

Class 

Number

1 

2

3

4

5 

6 

7 

8

9 

10 

11 

12 

13 

14

15 

16

17

Reflectance limits of 

multispectral scanner bands

Rock type

Detrital black sand

Dry wash alluvium

Eolian sand

Mineralized rock

Dark surfaces, except detrital black sand

TABLE 3. — Revised classification

Class 

number Rock type

1 

Detrital black sand 

2

3 Dark pebble desert

4 

5 Dry-wash alluvium 

6

7 

8 

9 Eolian sand 

10 

11

12 

,., Unmineralized felsic intrusive

rock 

14

15 

16 Mineralized rock, pyritic 

17

18 

19 Mineralized rock, sericitic 

20

21 

22 Dark surface, except detrital 

black sand

Symbol

f

_

•

0 

0 

@

(D

0

I 

H

table "S" prepared in

4

27-30

28-32

38-44

43-48

49-54

43-48

37-43

33-38

39-42

41-44

43-46

44-46

46-49

49-52

33-36

24-35

29-36

September

5

26-28

27-31

39-44

44-48

59-66

50-58

41-50

35-42

41-45

44-48

47-51

50-53

53-56

56-59

28-38

19-27

28-38

7975

6

23-26

25-27

35-38

38-43

54-62

46-55

38-47

32-39

33-38

37-41

41-45

45-48

48-51

51-54

29-35

20-32

20-28

7

9

10

13-16

15-18

23-27

19-24

15-20

12-16

14-16

16-18

17-20

18-20

19-21

20-22

11-15

8-12

9-14

Reflectance limits of 

multispectral scanner bands

Symbol 4

27-30

28-32

» 35-36

35-39

= 39-43

43-47

37-43

43-48

49-55

54-60

60-66

F 48-52

F 44-48

F 40-44

P 39-42

P 41-44

P 43-46

Q 46-49

Q 48-51

Q 50-53

I 33-36

K 24-35

H 29-36

5

26-28

27-31

34-38

37-42

41-46

46-50

41-50

50-58

59-68

67-76

76-85

55-60

51-56

46-51

41-45

44-48

47-51

51-55

54-58

57-62

28-38

19-27

28-38

6 7

23-26 9

25-27 10

31-34 12-13

31-36 13-15

35-41 1 5-1 7

41-46 17-19

38-47 15-20

46-55 1 9-24

54-63 23-27

62-70 27-30

70-78 30-33

50-54 21-24

47-51 19-21

43-47 17-19

33-38 14-16

37-41 16-18

41-45 18-19

45-49 19-21

49-53 21-22

52-57 22-24

29-35 11-15

20-32 8-12

20-28 9-14
208 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

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IMPROVED DIGITAL-PROCESSING DATA FOR SULFIDE PROSPECTING 209

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210 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

graphs and in the field. As part of the field check all 

anomalous areas were first examined on stereoscopic 

pairs of l:40,000-scale aerial photographs. At this 

point, it was possible to reject seven more areas as 

probably related to windblown sand.

Nineteen sites were examined in the field, and four 

desirable sites were not reached in the field checks. 

Five sites were found to be extensive outcrops of 

hydrothermally altered sulfide-rich rock (figs. 4 and 

5). Two additional sites contain altered rock with 

some sulfide but seem less attractive for prospecting 

at this time.

EVALUATION OF RESULTS

Classification using table "B".—In the evaluation 

using table "B," mineralized rock is believed to have 

been generally identified correctly, but much other 

light-toned surface was also classified as mineralized. 

Alluvium was mostly classified accurately, but some 

gravel fans derived from light-toned rocks were not. 

Perhaps only 25 percent of dune sand was correctly 

identified by means of table "B," most sand having 

been classified as mineralized rock. Classification of 

areas of dark rock outcrops and several types of lag 

gravels yielded different combinations of classes 10, 

11, and 12 and made it possible to differentiate among 

some of these materials, and some of these differentiations were made among surfaces having surprisingly 

subtle differences.

In classification table "B," four of the main surface 

types are each represented by a high and low reliability class. The high reliability or more restrictive 

class has reflectance limits in at least one band that 

made it exclusive from all other high reliability classes; 

the secondary class has reflectance limits that overlap 

the limits of at least one other class. The classes of 

two reliability levels have not been used in later tables. 

The classification map made by using table "B" is 

compared with a geologic map (fig. 6).

In building table "B," as the acceptable reflectance 

limits of a class were narrowed, fewer matches were 

found. In classes 1 and 2 (mineralized quartz diorite, 

table 1), for example, if we chose limits that included 

most pixels in the training areas and also many pixels 

in all the areas of known mineralization, we also got 

false classifications in dry-wash material. The limits 

were subjectively adjusted wider or narrower so that 

enough points were classified correctly in the areas of 

known mineralization to call attention to those areas 

and the false classifications were reduced to an acceptable level. Because revisions to the tables are 

time-consuming and successive revisions generally

achieve diminishing improvement, table "B" as used 

in this experiment was revised only a few times.

The three dark-surface classes were established on 

the basis of small samples of particular rock formations in training areas, but the classes were very unsatisfactory in discriminating among the three 

formations. The classes would have been abandoned 

except that various combinations of the three classes 

delineate areas of dark rock outcrops and lag gravels. 

The printout of class 11 (symbol #) in particular resulted in abundant pixel groups just inside the perimeter of the propylitic zone at Saindak (no similar 

propylitic zone in volcanic sedimentary rocks, as at 

Saindak, was found near the new prospects).

Classification using table "S".—The data collected 

in the field check made it possible to evaluate the 

accuracy of identification of all of the surface types, 

not the mineralized rock alone, and to revise the 

tables to improve accuracy. A new style of table 

evolved, having several relatively narrow classes 

spanning the expected albedo range for each rock 

type but no high and low reliability classes, resulting 

in classification table "SSD" (table 2) and finally 

classification table "S" (table 3). The limiting values 

for each class span relatively narrower ranges than 

those in table "B" and more classes are required. The 

use of several classes for a range in albedo from 

similar surface types is designed as a simple way to 

compensate for variations in reflectance angles, especially those caused by southeast- and northwest-facing 

slopes, and also albedo-related systematic changes in 

color balance of similar surfaces, regardless of their 

cause. Classification using table "SSD" was performed 

to reevaluate part of the application area. An area of 

170 km- was tested that includes four of the new 

prospects. The results are very encouraging.

The area tested using table "SSD," included 13 of 

the groups of "mineralized"-class pixels originally 

evaluated using table "B." Of the 13 pixel groups, 7 

had been selected as possibly mineralized rock and 

worth field checking, 5 were subsequently visited 

during the field check, and 4 were found to contain 

some mineralization. Evaluation of the same area 

using table "SSD" resulted in the delineation of only 

5 areas as "mineralized;" 4 of these were known 

from earlier field checking of table "B" targets to 

have mineralization, 1 was identified in the earlier 

evaluation but not chosen as deserving a field check, 

and one was not delineated by the table "B" evaluation. (The latter two sites, not chosen for checking in 

the earlier study, have not had field examinations). 

One mineralized site identified using table "B" was 

omitted by the table "SSD" evaluation. Table "SSD"
IMPROVED DIGITAL-PROCESSING DATA FOR SULFIDE PROSPECTING 211

DIGITAL CLASSIFICATION MAP

==XXXX = XB XXX== XXX= = = = X=

======= =xx=xx=========== =

==== xxxxxxxx=====xx======== ===

===========x=== x xxx==

===x x===- = =x == x====

x xx*=xx=x= xxx==xxxxxxx=xxx=== 

gxxx x======xxx xxxx xx x xxxxx=

=== ====== x=== —

xx= xx «x xxxxxx= 

===x===x xx 

= x x xx= == =

= ==•= == = = = = =: ===*.======x

==== x -=

= = XX -= === =x ax= 

===x x = ==

====xxx= =x=== 

== x =====xxx== 

== x=xxxxxxxxxxxxxxxx

=== ========== x=X = X === X = =

==== ====== ===== == x X = ====

GEOLOGY MAPPED IN FIELD

X X =XX = =XX

=== ==xi===== •••••x-xx= 

xx= x="TMx«x ixx xx

========+ = ====X I ==XX 8=

============= x= = - XX===X X=

xx=====xx= x==xxxx*=====xx= ==

==X-= XXII XXX X== =XXX=X

==-xx =x =• ix= ix==== =x==

= X X X XX XX=== =

=XiiiR == == XXX XXX====

= =xx XXXXi =X X=ii XX=======

==XXXX I XXXX HXX====== XX=

=XX8 XX= =XX== ====== X=

=X====- =Xi ====XX====

XX

=XXX X »i

=XXXX XXXX='

==x== = ===

= ==x xx==x=

DIGITAL CLASS IFI CATION 

MAP

EXPLANATION

A I I u v i urn

Mineralized 

quartz diorite

Pyrite-rich rock

Geology adapted from S. N. Kahn, 1972

5000 FEET

2 KM 

__I

Unpatterned areas are 

other rock types

FIGURE 6.—Comparison of digital-classification map made by using table "B" and geology mapped in field, Saindak porphyry

copper deposit, Pakistan.

does a much more effective job of separating mineralized areas from other light-toned materials, largely 

eliminating the need for human evaluation of a large 

number of "false" tonal anomalies. Omission of one 

of the best areas of mineralization points to the need 

for slight revision of the mineralized rock classes.

Revisions to table "SSD" have yielded table "S" 

which includes classes to cover sands of higher albedo 

and dry-wash material of lower albedo than were included in table "SSD," classes for dark pebble desert 

and unmineralized felsic rock (rock types not included 

in earlier tables), and modified reflectance limits for 

part of the mineralized rock classes. Only a few preliminary tests have been made of this new table.

SUMMARY

Visual evaluation of false color composites and a 

relatively simple method of digital classification were 

tested as aids to mineral exploration by using areas 

of known hydrothermal alteration and mineralized 

and altered intrusive stock as control areas. Both 

methods seem to be useful exploration tools, and 

greatest advantage is probably gained by using them 

together. The simple classification method was applied 

to evaluate 2,100 km - of area regarded as having a 

high potential for deposits of the porphyry copper 

type, leading to the discovery of five sizable areas of 

hydrothermally altered rock containing abundant 

sulfide, disseminated or in stockwork veins. Although
212 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

the classification method used was relatively simple 

and unrefined, and 14 prospecting targets proved to 

be false leads, the number of sulfide-bearing areas 

identified was outstanding, and the falsely classified 

areas were not so many as to require an unreasonable 

amount of field checking. Further experimentation indicates that better discrimination of mineralized areas 

than we used in the field test can be achieved. Our 

study indicates that simple methods of digital classification of Landsat data can aid in exploration for 

mineral deposits in desert regions, and these methods 

can complement conventional exploration techniques.

REFERENCES CITED

Ahmed, Waheeduddin, Khan, S. N., and Schmidt, R. G., 

1972, Geology and copper mineralization of the 

Saindak quadrangle, Chagai District, West Pakistan: U.S. Geol. Survey Prof. Paper 716-A, 21 p.

Bernstein, Ralph, 1974, Scene correction (precision 

processing) of ERTS sensor data using digital 

image processing techniques: Third Earth Resources Technology Satellite-1 Symposium, v. 1:

Technical Presentations Section B, NASA SP351, Dec. 10-14, 1973, p. 1909-1928.

Hunting Survey Corporation, Ltd., 1960, Reconnaissance geology of part of West Pakistan; a Colombo Plan Cooperative Project: Toronto, 550 p. 

(Report published by Government of Canada for 

the Government of Pakistan).

Khan, S. N., 1972, Interim report on copper deposit 

of Saindak, Chagai District (Baluchistan), Pakistan: Pakistan Geol. Survey, Saindak copper 

report no. 1.

Lowell, J. D., and Guilbert, J. M., 1970, Lateral and 

vertical alteration-mineralization zoning in porphyry ore deposits: Econ. Geology, v. 65, no. 4, 

p. 373-408.

Schmidt, R. G., 1968, Exploration possibilities in the 

western Chagai District, West Pakistan: Econ. 

Geology, v. 63, p. 51-60.

————1974, The use of ERTS-1 images in the search 

for large sulfide deposits in the Chagai District, 

Pakistan: U.S. Dept. of Commerce, Natl. Tech. 

Inf. Service, E74-10726, 38 p.
PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

A Deeper Look at Landsat-1 Images of Umiat, Alaska

By Andre F. Maurin 

Compaignie Franchise des Petroles, Paris, France,

and Ernest H. Lathram, 

U.S. Geological Survey, Menlo Park, California

ABSTRACT

Discussion of subjective evidence for visual identification of previously unrecognized lake lineations 

shown on Landsat-1 (formerly ERTS-1) image 1004- 

21395 (Fischer and Lathram, Oil and Gas Journal, May 

28, 1973) led the senior author to undertake more 

precise geomorphic mapping. The use of a new 

statistical tool, the Texture Analyser, has provided a 

mathematical control for lake lineations as they were 

first sketched by Fischer and Lathram. The structural 

pattern has been developed into a full map of the 

area covered by thaw lakes. Enlarged pictures of an 

almost similar image taken by Landsat-1 earlier in 

the spring confirm the meteorological origin, but with 

an underlying tectonic influence for the most conspicuous (north) trend in lake shores. A second trend, 

east-northeast, is demonstrated to result from a complex elliptical pattern caused by numerous closed 

structures. Further details are given on the potential 

of the Texture Analyser for cuesta mapping and fault 

enhancement through discrimination of certain values 

of grays, although this last method is not as accurate 

as other computerized programs such as gray stretching. Its instant reading makes it very valuable for 

geomorphic applications in numerous domains.

INTRODUCTION

The Arctic Coastal Plain of Alaska is characterized 

by thousands of thaw lakes. Many are oriented; 

elongated rectilinear shorelines trend approximately 

N. 9° W., nearly perpendicular ( — 85°) to the prevailing wind direction. Most authors ascribe the orientation of these lakes to elongation of shorelines 

through wind-induced erosion (Black and Barksdale,

1949; Carson and Hussey, 1962; Price, 1968; Black, 

1969).

In many of the elongated lakes, short shorelines 

are straight and orthogonal to long ones, suggesting 

to Rosenfeld and Hussey (1958) a possible structural 

control. In addition, in the Umiat area, individual lakes 

are aligned in a direction perpendicular to the elongation, as are linear areas betweeen lakes, and some 

groups of lakes, lines of lakes and lines of interlake 

areas form oval or circular cluster-shapes. These observations led Fischer and Lathram (1973) to suspect 

that the lake orientation results from control by concealed structural patterns.

The features noted above are consistent with patterns noted in other areas and ascribed to blockfaulting (Bostock, 1948; Price, 1968). In particular, the 

alignment of individual lakes and the linear pattern 

of interlake areas seem more logically to be the result 

of structural control, as wind influence generally initiates a random distribution pattern, acting only on 

individual shapes. With respect to oval or circular 

cluster shapes, it is interesting to note Bostock's illustration of an "oval basin shape developing" within an 

area of oriented lakes strongly affected by block 

faulting (Price, 1968, p. 794).

The purpose of this paper is to present the method 

and preliminary results of a mathematical analysis of 

lake distribution and orientation in northern Alaska 

(fig. 1) designed to provide an objective and rigorous 

basis for geomorphic interpretations and for inferences of structural control. The method combines the 

regional (34,000 km -) view and orthoplan representation of Landsat images with the statistical analysis 

capability of the Texture Analyser (Leitz-Ecole des 

Mines de Fontainebleau, France), originally developed

213
214 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Brooks Range 50 Km

FIGURE 1.—Index map of northern Alaska showing physiographic provinces, the area covered by Landsat image 1004- 

21395, and the area of oriented lakes previously studied by 

Carson and Hussey (1962).

for analysis of microscopic textural fabrics. Landsat-1 

image 1004-21395 (fig. 2), the basis for Fischer and 

Lathram's interpretations, is admirably suited for the 

purpose. All of the geomorphic features described 

above are included on a single scene. Further, the 

band 7 image (0.8-1.1 //m) presents a high contrast 

between land and water and a sharp definition of the 

form and distribution of lakes, because this part of 

the light spectrum is absorbed by water.

The method assists in geomorphic analysis by assessing the statistical value of each character and 

provides a more firm basis for naturalistic interpretations but, like other such computer-like systems, 

should not be substituted for human interpretations.

Computer enhancement of the quantitative values 

produced by Landsat multispectral sensors has previously been employed for several purposes. Values 

of light reflectance, grouped by computer as to type 

of natural or manmade feature having a characteristic, reflectance or group of reflectances, have been 

used to determine land cover by class, and type and 

species of vegetation (Ellefsen and others, in press; 

Hall and others, 1974). Ratios, or augmentations, of 

reflectances in different wavelength bands have been 

utilized to identify rock types, alteration products, and 

soil types (Rowan and others, 1974; Albert, 1975). In 

addition, gratings, with parallel or concentric ruling,

have been used to augment the appearance of linear 

or curvilinear features and to determine qualitatively 

the trends and patterns of Earth features. The method 

here employed permits the objective measurement of 

the trend of linear or curvilinear features and of the 

form and shape of Earth features and of their quantification by ADP methods. In short, it provides a statistical basis for geometrical description of Earth 

features, a fundamental step in the study of structures 

and their significance in the exploration for mineral 

and mineral fuel resources.

MATHEMATICAL APPROACH

The mathematical basis for and geometric rationale 

of the use of structural elements in texture analysis 

is given in Serra (1972). The description of a prototype 

Texture Analyser and its use is given by Klein and 

Serra (1972). Since their paper, an operational model 

has been built from the prototype. Most applications 

for the Texture Analyser and previous quantifying 

instruments have been directed toward study at microscopic scales (grain distribution in cement and in 

ground ore, ore mineralogy and metallurgic study in 

polished section, porosity distribution, cytology, etc). 

The application reported here represents a quantum 

jump in the scale of study.

For clarity some mathematical terms employed 

herein require a simplified definition:

1. Eros/on.—an elementary geometrical operation for 

filtering, resulting in the "smoothing" of boundaries (grain contours, patches, etc.) such as suppression of peaks. (Presumably high band-pass 

spatial filtering, ed.—)

2. Dilatation.—complementary process to erosion, 

addressing intergrain geometry (e.g., porosity). 

(Presumably low band-pass spatial filtering, 

ed.—)

3. Opening.—the result of both erosion and dilatation 

processes designed to improve, through simplification, the structural meaning of a geometrical 

pattern. Because of the possibility of varying the 

size of the hexagonal element (the geometric 

figure employed to analyse patterns), such a 

pattern provides great flexibility in observation.

4. Closing.—the reverse function of opening; e.g., a 

closing to simplify grain pattern is an opening 

with respect to the porosity pattern.

GRAY DISCRIMINATION

This is the basic step in use of the Texture Analyser. As the analyser makes statistical counts of white
A DEEPER LOOK AT LANDSAT-1 IMAGES OF UMIAT, ALASKA 215

•SKSafeJWh

FIGURE 2.—Landsat image 1004-21395, band 7, of the Umiat area. Lakes are in black.

or black dots, contrast in the image must be high, ever, increased contrast was obtained by making a

and intermediate gray levels suppressed. The un- simple ozalid print of the positive transparency (fig. 3)

enhanced positive transparency from Landsat band 7 and by making a high-speed Ektachrome slide for

provides sufficient contrast for a direct read-out. How- microscopic use.
216 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

TREND "A 

ON Fig.4

FIGURE 3.—Ozalid print of positive transparency of Landsat image 1004-21395, band 7, showing contrast enhancement and 

location of detailed figures. Two dashed circles represent the areas in which average lake lengths were measured automatically. Three small heavy circles are the three zones studied to produce the direction diagram in figure 4.

AVERAGE LENGTH OF LAKES puting the average length of linear groups of uninterrupted black dots recognized by the analyser along

An automatic survey of the length of lakes was selected diameters of circular fields of observation, 

made on the analyser. This was accomplished by com- Two large circular areas were surveyed providing a
A DEEPER LOOK AT LANDSAT-1 IMAGES OF UMIAT, ALASKA 217

count of more than 100 lakes. Trend A (fig. 3) was 

chosen arbitrarily parallel to the major trend in lake 

shores and dry paths (linear interlake areas) with a 

similar direction. The average length of lakes along 

Trend A is 1.426 km. A measurement perpendicular 

to Trend A yields 1.406 km, while counts at 20°, 40°, 

and 60° from Trend A give 1.102, 1.147, and 1.246 

km, respectively.

(Because this computation involves a complicated 

statistical function, requiring nearly 2 hours for hand 

calculation of these five measurements, a hardware 

connection is under development to permit instant 

computation.)

TRENDS OF PREFERENTIAL ALIGNMENTS

A reduced photographic slide of the lake area was 

observed through the microscopic apparatus using 

programmed rotations of the "electronic rotating 

stage." Six circles were analysed at high speed. Each 

circle was studied by "Hit or Miss Transformation" 

(Serra, 1972) of black versus white lengths, every 2°. 

The computation for one circle required about 60 

seconds. The direction diagram (fig. 4) shows these 

measurements integrated in 4° segments.

Out of the six circles, three give apparently random 

diagrams (not represented in fig. 4), but three seem 

to give rather significant results. Figure 4 is a diagram 

composed from mixing the three last results. This

diagram is qualitative and provides two families of 

trends.

The first family is composed of two clear trends 

which form a narrow angle bisected by Trend A (figs. 

3 and 4). The second family is composed of a number 

of lesser trends, subtending a greater angle (40°), 

bracketed by two major trends; the bisectrix of the 

second family we designate as Trend B. It should be 

stressed that in no way is this rose diagram influenced 

by the length of lakes. Following Serra's (1972, p. 

95-96) consideration, these trends represent the proportion of black (lake) versus white (land) segments 

in a given direction. By the same token, this measurement provides an indication of preferential rectilinear 

alignments either of lakes or of paths.

At this point in the investigation, it is clear that it is 

not possible to apply to the Umiat area the conclusions of Carson and Hussey (1962) resulting from 

their field study near Point Barrow, north of the 

Umiat area. Normal winds could initiate a narrow 

forked pattern such as that of Trend A by interference 

in wind directions (Carson and Hussey, 1962, figs. 3, 

4, and 5), but Trend B and the anomalous length computed in average length counting must originate 

through another process. It is logical to expect a 

greater influence of tectonics in the Umiat area as 

compared to the Point Barrow vicinity, as it is common for structures to decrease in intensity from the

I

FIGURE 4.—Direction diagram computed from the three heavy small circles of figure 3. A and B are significant trends discussed in the text.
N3

_ioo

H 

>

C 

>m 

O O

O

73

O

FIGURE 5.—Steps in erosion and opening process. A, circular area investigated with gray discrimination; note that the outer zone of the control screen is not 

discriminated. B, hexagonal erosion of blacks (black spots); shape of hexagons is apparent. C and D, hexagonal opening of blacks with two standard sizes 

of hexagons. A rectilinear pattern is indicated by arrows, the nested curvilinear trends arc shown by dashed lines, and an offset is apparent. Analysis of 

unenhanced positive transparency of Landsat band 7 image.
A DEEPER LOOK AT LANDSAT-1 IMAGES OF UMIAT, ALASKA 219

inner to outer zones of foothills and toward the plains, 

as in northeast British Columbia.

Observing trends along the Ikpikpuk River extending some 15 miles southward from the Point Barrow 

area, Rosenfeld and Hussey (1958) inferred a structural influence, and suggested an additional eastnortheast lineation (i.e., Trend B). It is obvious that 

the smaller scale and wider observation offered by 

Landsat images allow instant perception of a greater 

span of anomalous trends.

HEXAGONAL TRANSFORMATIONS

Klein and Serra (1972) describe the Texture Analyser as an apparatus able to "measure forms, sizes, and 

patterns." Sizes and forms have been partly investigated in the two preceding sections. Hexagonal logic 

allows the analysis of the structural pattern (this logic 

may also be introduced into the first two steps).

The circular areas shown on figure 3 were analysed 

through hexagonal transformation (figs. 5 and 6). Each 

figure exhibits the control image, after gray discrimination (electronic suppression of intermediate levels of 

gray) of the exact area of survey. Then, this image is 

transformed into a set of patches made of individual 

hexagons (fig. 5B). These patches are the result of a 

mathematical erosion (Serra, 1972) determined by the 

size of individual hexagons (notice that the hexagon 

is the most complex polygon which allows a complete 

coverage of a bidimensional surface without overlap; 

such an overlap would be embarrassing for statistical 

purposes). The next processing is opening of black 

patterns. Klein and Serra (1972), and Serra (1972) 

demonstrate the structural value of such a mathematical process, and complete references to earlier works 

are contained in their papers.

Figures 5C and D exhibit an ENE-WSW trending 

linear set and a near-circular feature made of two 

crescentic anomalies of possible morphological value. 

Such circular or elliptical lineations of lakes deserve 

a lot of attention. Coupled with crescentic lineations, 

they are believed to be the subtle expression of a 

mini-cuesta system, e.g., erosional breaks formed on 

very gently sloping beds within the Pleistocene Gubik 

Formation.

Figure 6, converted into the hexagonal pattern and 

opened (comparable to 5D), shows a crescentic imbrication of prime significance in geomorphic mapping. 

It is located close to the most northerly Foothills anticline axis (Lathram, 1965; Fischer and Lathram, 1973, 

fig. 3) and provides a basis for geomorphic mapping.

-v.

FIGURE 6.—Another area studied using the erosion and opening 

process. A, control screen without gray discrimination. B, 

eroded and opened cluster zone. Analysis of unenhanced 

positive transparency of Landsat band 7 image.

GEOMORPHIC MAPPING

We believe the foregoing mathematical data indicate a structural origin for both Trends A and B (figs. 

3 and 4). With respect to B, the angular array of high 

values, broader than the array for Trend A and with 

many intermediate trends, may originate from a different tectonic cause than that of A. The Trend A array 

may be caused by intercepts with narrowly diverging 

rectilinear paths or lines of lakes, whereas the B array 

may reflect numerous broadly divergent intercepts 

controlled by the curved outline of the ellipses. Logically, intercepts with a rectilinear zone would be narrow, but intercepts tangent to the outline of an ellipse 

would be broadly divergent. By the same reasoning,
220 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

the more narrow angular display of Trend A may 

represent both a wind-induced preferential shore 

direction and a structural element. This element may 

have lesser impact on morphology than the ENEWSW trending ellipses.

Unfortunately, the Texture Analyser is not designed 

at present to analyze and compare curved elements, 

but only to compare and measure straight ones. A program to analyze and compare the radii of curved 

image features is being developed and will be operational in late 1975.

Accordingly, conventional methods of geomorphic 

interpretation, guided by the foregoing data and reasoning, were used to develop a structural map of the 

area (fig. 7). Using the surface anticline (Lathram, 

1965) closest to the Coastal Plain as a standard, deflections and bends of the north-flowing Ikpikpuk 

River are considered to be produced by anticlinal 

plunges, with apexes located east of the river. West 

of the most southerly bend in the river on the Coastal 

Plain, three sets of lakes arranged in three crescentic 

patterns appear to be the remnants of the bend as 

the river was displaced erosionally to the east.

ENE-WSW lineations between lakes (paths) are 

clearly bent and follow lines of elliptical anomalies. 

These lines are considered to be anticlinal axes; the 

chaplets of apexes create elliptical patterns. The

Syncline 

Contour and axis

Crescent

. *

Fault'*

FIGURE 7.—Structural interpretation by conventional geomorphologic study using outcropping anticline as a standard and 

the elliptical "path" concept.

three more northerly axes are drawn on less sure 

grounds but are suggested by the lines of ellipses.

The long clear lineament along the east bank of the 

river (fig. 7) is one of several linear anomalies lying 

parallel to Trend A. However, its special bearing on 

tectonic interpretation deserves some discussion. 

Axes on the west, aligned along the centers of crescents, are displaced from those on the other side of 

this lineament. The lesser number of lakes and elliptical anomalies on the west side may indicate that this 

is a down-thrown block. However, this feature is interpreted herein as a transverse fault. Other lineaments parallel to this fault or Trend A could also 

represent minor fracturing. We note that the lineament shown on figure 7 is an extension of the transverse trend of the Maybe Creek "low" recognized by 

Brosge and Whittington (1966, p. 583).

ADDITIONAL OBSERVATIONS FROM THE 

LANDSAT IMAGERY

Additional observations have been made which 

substantiate our interpretations and provide additional support for the mathematical approach. At the 

same time, the incredible amount of information displayed on Landsat imagery is demonstrated.

OBSERVATIONS ON METEOROLOGIC EFFECTS 

ON THAW-LAKES

About 20 percent of the lakes investigated in this 

study are oriented according to the definition of Carson and Hussey (1962) and Black (1969). This permits 

a thorough test of their concepts. On Landsat-1 image 

1004-21395, the east-west banding of clouds provides 

an instant meteorological indicator of the wind direction they derived from many historical records. Further, an almost similarly located image (1345-21344, 

band 7) taken by Landsat-1 on July 3, 1973, (almost 

1 month earlier than the previous one) exhibits partially frozen lakes (fig. 8). Some of the elongated lakes 

contain mushroom-shaped ice cakes which substantiate the observations of Carson and Hussey (1962) as 

shown on their figures lOa, b, and c (Ikroavik Lake) 

and support their meteorological interpretation. The 

symmetrical pattern of the ice cakes and the bulbous 

shape of the distal wings. indicate a dominant wind 

blowing westwardly and counter-rotational lake currents as they suggest. The repetitive views of Landsat 

provided a time dimension they were not afforded in 

the field, i.e., Landsat observations every 18 days and 

their field work once per summer.
A DEEPER LOOK AT LANDSAT-1 IMAGES OF UMIAT, ALASKA 221

FIGURE 8.—Two selected areas of Landsat image 1345-21344,

band 7, with common orientation showing mushroom ice

cakes (arrows) in black lakes.

APPLICATION OF THE TEXTURE ANALYSER 

TO STRUCTURE IN THE FOOTHILLS

Although the topic of this paper is centered around 

the thaw-lakes area, some observations in the Foothills south of the Coastal Plain will "help understand 

the anticline-transverse faulting pattern in the Coastal 

Plain. Once again, information is derived from Landsat-1 image 1004-21395, proving the wealth of information provided by such small-scale imagery. Near 

the big bend of the Ikpikpuk River, the map of Lathram (1965) indicates a number of anticlines within the 

area of figure 9 (location on fig. 3).

After gray discrimination, a further process eliminates, through thresholding, some specific grays from 

the control scale (right of fig. 9B). This helps in delineating dip slopes and displacements by enhancing 

shadows and triangular facets. Hexagonal transformation with minimal erosion strongly enhances such 

displacements. Cross faults appear very sharply (fig. 

9C). It is interesting to note that most of these faults 

are parallel to Trend A.

Analysis of the Foothills zone on image 1004- 

21395 exhibits two groups of faults (with dextral and 

sinistral offsets) belonging certainly to a transverse 

fault system. These observations support the structural map (fig. 7) of the thaw-lake area.

FIGURE 9.—Experimental processing of part of the Northern 

Foothills shown on Landsat image 1004-21395. 

A, Control image. See figure 3 for location of surface 

anticlinal axes. B, Same image after thresholding of penultimate gray level of the analyser, scale shown on right 

margin without level 1 (white). C, Hexagonal transformation of the black and white information of figure B, with 

minimal erosion. Note that in C shadows which may be 

cuestas are more strongly enhanced. Faults are enhanced 

and clearly shown by linear disruptions (see arrows); in 

some cases offsets along the faults can be quantified by 

the analyser.
222 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

CONCLUSION

The morphologic value of both Landsat imagery 

and the use of the Texture Analyser have been demonstrated.

In such an area as the Arctic Coastal Plain, where 

technical problems of resource exploration (ecology, 

costs, etc.) are very stringent, the method can provide a maximum of information without environmental stress, can be evaluated with a minimal amount of 

conventional checks, and provide guides to the optimum location of such checks. The structural map may 

be greatly improved and become an actual operational tool.

These results are sufficiently encouraging to pursue 

the same approach west and eastward. To the east 

the Prudhoe Bay area will provide the type of checking and control required. Precise angular measurements are needed in order to separate tectonic effects from those of dominant winds in those areas 

where both directions are not parallel or perpendicular, and work on these is proceeding.

The use of only two sequential Landsat images of 

the same scene has permitted observations to be 

made in three domains, the conciliation of the two 

main genetic theories for the origin of thaw-lakes, 

and a suggestion of even.more fundamental ideas:

1. The Foothills domain in which faulting is normal 

to anticlinal axes.

2. The thaw-lake area in which nearly perpendicular 

linear trends point toward a structural pattern, 

and ice cakes in many of the lakes conform to 

meteorological theories of the formation of 

oriented lakes.

3. The cloudy zone in which banding is parallel to 

the general direction of the mountains.

From these observations we believe that meteorological conditions, mainly dominant winds over the 

Coastal Plain, are a topographic consequence of the 

Range and Foothills system. Further, the structural 

pattern within the Plain is a weak but subsequent 

image of the tectonic style in the Foothills. If these 

conclusions are valid, then a perfect similarity should 

exist between wind-induced shore patterns and cross 

faulting through an anticlinal area of great petroleum 

potential.

ACKNOWLEDGMENTS

Publication of this paper has been authorized by 

Compagnie Frangaise des Petroles (Paris and Calgary). We thank Messrs. Klein and Serra for kindly 

providing mathematical precision and Centre de Morphologic Mathemotique of Ecole des Mines, in Fontainebleau, France (Co-owner with IRSID, of the 

patent on the Texture Analyser, manufactured by 

Leitz, Germany), for experimental access to the Texture Analyser. J. M. Fonck and M. Riguidel, CFP, 

Paris, provided much information on previous and 

future use of the machine.

REFERENCES

Albert, N. R. D., 1975, Interpretation of Earth Resources Technology Satellite imagery of the 

Nabesna quadrangle, Alaska: U.S. Geol. Survey 

Misc. Field Studies Map MF-655J, 2 sheets, scale 

1:250,000.

Black, R. F., 1969, Thaw depressions and thaw lakes, 

a review: Biul. Peryglacjalny, no. 19, pp. 131- 

150.

Black, R. F.,- and Barksdale, W. L, 1949, Oriented 

lakes of Northern Alaska; J. Geol., v. 57, pp. 

105-118.

Bostock, H. S., 1948, Physiography of the Canadian 

Cordillera, with special reference to the area 

north of the fifty-fifth parallel: Geol. Survey Can. 

Memoir 247, 106 p.

Brosge, W. P., and Whittington, C. L, 1966, Geology 

of the Umiat—Maybe Creek region, Alaska: 

U.S. Geol. Survey Prof. Paper 303-H, 638 p.

Carson, C. E., and Hussey, K. M., 1962, The oriented 

lakes of Arctic Alaska: J. Geol., v. 70, pp. 417- 

439.

Ellefsen, R., Gaydos, L, Swain, P., and Wray, J., New 

techniques in mapping urban land use and monitoring change for selected U.S. Metropolitan 

areas: an experiment employing computer-assisted analysis of ERTS-1 MSS data, in Internat. 

Soc. of Photogrammetry, Commission VII Symposium, Banff, Alberta, Oct. 1974, Proc. (in 

press).

Fischer, W. A., and Lathram, E. H., 1973, Concealed 

structures in Arctic Alaska identified on ERTS-1 

imagery: Oil and Gas J., v. 71, no. 22, pp. 97- 

102.

Hall, F. G., Bauer, M. E., and Malila, W. A., 1974, 

First results from the crop identification technology assessment for remote sensing: West 

Lafayette, Indiana, Purdue University, Laboratory 

for Application of Remote Sensing, LARS Information Note 041874.

Klein, J. D., and Serra, J., 1972, The Texture Analyser: 

J. Microsc., v. 95, pp. 349-356.
A DEEPER LOOK AT LANDSAT-1 IMAGES OF UMIAT, ALASKA 223

Lathram, E. H., 1965, Preliminary geologic map of 

Northern Alaska: U.S. Geol. Survey open-file 

map, scale 1:1,000,000.

Price, W. A, 1968, Oriented lakes, in Fairbridge, R. 

W., ed., The encyclopedia of geomorphology: 

Reinhold Book Corp., pp. 784-796.

Rosenfeld, G. A., and Hussey, K. M, 1958, A consideration of the problem of oriented lakes: Iowa 

Acad. Sci. Proc., v. 65, pp. 279-287.

Rowan, L C., Wetlaufer, P. R, Goetz, A. F. H., Billingsley, F. C., and Stewart, J. H., 1974, Discrimination of rock types and detection of hydrothermally altered areas in South-central Nevada by 

the use of computer-enhanced ERTS images: 

U.S. Geol. Survey Prof. Paper 883, 35 p.

Serra, J., 1972, Stereology and structuring elements: 

J. Microsc., v. 95, p. 93-103.

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Why Landsat? 

A Management View

By J. Robert Porter, Jr., President, 

Earth Satellite Corporation, Washington, D.C.

Earth Satellite Corporation has provided substantive geological consulting services to over 100 projects in which Landsat imagery has been utilized. To 

the best of my knowledge, this is considerably more 

exploration experience with Landsat than any other 

commercial or governmental group has had to date. 

Today, I thought you would be interested in some of 

the conclusions we have made, considering these 

projects as "case studies" from which one can generalize about the learning curve corporations and individuals experience in working with Landsat data. 

For the purpose of this presentation, I am only going 

to address the oil and gas applications of EarthSat 

and exclude our hydrological and geothermal activities.

Two years ago, the initial decision to utilize Landsat (then ERTS) imagery was generally made either 

at the top or the bottom of the corporation. The reason for this was quite simple, and can be related to 

the time frame in which a person's job is evaluated. 

A corporate president or vice president of exploration in a medium to large company is primarily focusing his attention on attaining his corporate goals over 

a 2- to 10-year period. He was interested in understanding, first and foremost, how Landsat and/or 

other remote-sensing techniques may affect his corporate strategy. Further, he was interested in introducing new technology to his exploration groups from 

the standpoint of developing a "training" familiarity 

which may pay off in a few years. In brief, he expected very little in the short term but felt a "little 

money ought to be put into this to see what's there."

At the bottom of the organization are the geologists and engineers who are basically interested in 

preparing themselves and their company for the future, even if the new technology is not of proven 

worth initially.

In the middle sits the exploration manager for a 

district or a region, who has a very tight, well-defined 

exploration budget and who must obtain results within 

a short period of time or be considered a failure. 

Understandably, he was initially not interested in 

Landsat because there was no one in his organization, 

or elsewhere, who could convince him 2 years ago 

that this would save him time or money and help him 

meet his corporate objectives with more certainty. 

During the last 2 years a significant change has taken 

place and Landsat is becoming an exploration tool 

which will soon be routinely a part of the budget controlled by this exploration manager. The use of Landsat imagery has moved from research to operations.

The reason for this is simple. The technology works! 

There is no question but that a new "quality" of information is available. I say "quality" because its 

contribution to the investment decision is quite different, for example, than aerial photography.

The way a corporation utilizes Landsat imagery 

varies considerably with its familiarity and experience. 

Almost every group I know went through an initial 

"gee whiz" phase in which they bought or were 

shown a few photographs from Sioux Falls and noted 

with interest that several features they were familiar 

with could be seen in the imagery. Alternatively, they 

may have been impressed by a false-color rendition 

of some salient or subtle feature exhibited by a commercial vendor.

The second phase is characteristically much more 

professional but not yet commercial. At this point, 

geologists and engineers are looking at Landsat 

imagery as' though it were a low resolution aerial

225
226 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

photo. Naturally they became more interested in 

technique development which, in a sense, from their 

view at this time, is a means of compensating for the 

"limited resolution" inherent in Landsat. During this 

phase, several important mental limitations still exist. 

Primarily, they do not really understand what is different in the scene they view which wouldn't be better 

perceived by an aerial photograph if they had it. The 

principal attraction is low cost and newness. Nonetheless, at this point, Landsat imagery starts to be a 

tool in which features are identified and related to one 

another so that it becomes incorporated, somewhat 

traditionally, into ongoing operational programs.

In the third phase, by combining a model of resource occurrence (based on theory and previous 

work) with the large area relationships visible in 

orbital imagery, data from satellite platforms become 

a powerful exploration tool.

The unique ability of satellite systems to acquire 

imagery that portray large portions of the Earth's 

surface enables geologists to characterize large, widely separated regions (such as shield areas or extensive 

sedimentary sequences) and compare known mineralized areas with as yet unexplored areas as an important first step in the search for mineral deposits. 

Moreover, once having located an area of general 

interest (a proper geologic environment), investigators 

have mapped the tectonic style of the area and delineated those subareas which generally favor economic accumulations of minerals—for example, 

sedimentary basins, greenstone belts, and fold mountain belts. In several instances, the Landsat imagery 

enabled the geologists to proceed a step further and 

identify and map structural features as lithologic 

associations within the subareas which might serve 

as keys to economic accumulations of minerals, 

petroleum, ground water, or geothermal resources— 

for example, salt domes, anticlines, intrusions, ultramafic rocks, and fracture intersections. At this level 

of detail, the geologist is able to correlate known 

economic deposits with lithologic and structural features perceived in the imagery and draw additional 

inferences about factors controlling and localizing 

economic deposits, thus refining his initial exploration 

model.

There is some evidence that space imagery can 

lead to the direct detection of certain geologic resources by virtue of recognizing such features as 

gossans, peculiar tonal-textural features that are 

strongly correlated with oil and gas production, depressions under the icecaps that mark possible geothermal heat sources, or terraces along streams known 

to carry gold. However, most often the contribution

of space-acquired data is based on inferences drawn 

from experiences or from a particular exploration 

model. In these circumstances, the strength of space 

data as an exploration tool is greatly increased by the 

inclusion of ground data in combination with data 

from other exploration devices such as airborne magnetometry. Several exploration groups are now doing 

just this. The space imagery is used to locate the 

favorable structural setting, and then airborne electromagnetic and gravity data are used to refine the details of the model. Targets thus identified are followed 

up on the ground using geochemistry, resistivity, conventional mapping techniques, and, finally, drilling.

Several geologists have used Landsat and Skylab 

imagery to tentatively locate structural features of 

interest to petroleum exploration. In Alaska, near the 

Umiat oilfield, Fischer and Lathram (1973) spotted a 

peculiar arrangement of lakes that geophysical data 

corroborated as an attractive structural feature for 

petroleum exploration. Further, Saunders and others 

(1973), related lineaments seen in Landsat imagery to 

oil and gas occurrences in west Texas. Based on the 

relationships they saw in the imagery, they have identified several prospective areas.

In the Anadarko basin, we found that many of the 

known oil and gas producing structural features could 

be identified on Landsat and Skylab imagery. In addition, we reported that, as yet unexplained, tonaltextural features, called "hazy anomalies," are 

strongly correlated with oil and gas production. Upon 

examining the pervasive pattern of lineaments seen 

in the space imagery and correlating these with geophysical and well data, we concluded that faulting 

has played a much larger role in the origin and development of the basin than was previously suspected. 

Based on the study of Landsat imagery in the Basin 

and Range province of the western United States, we 

noted a complex interrelationship between faulting, 

intrusion, and mineralization. Interrelationships noted 

can be used to guide further exploration even in this 

relatively well explored area. We also noted that there 

seems to be a regular spacing of lineaments (fractures) 

that control mineralization and that the highest potential for mineralization is at the intersection of two 

such regularly spaced sets.

The savings in time and money realized from these 

applications is already substantial and will increase 

as they are used more widely and as these tools are 

more completely integrated into exploration programs.

Phase three could be called the "commercial phase" 

in which the technology is better understood and 

the product is both incorporated into ongoing commercial strategy and becomes a stimulus to the change
WHY LANDSAT? A MANAGEMENT VIEW 227

in corporate strategy. In my opinion, to equate Landsat 

imagery with aerial photography is to miss the point 

almost completely and to lose much of the enormous 

commercial edge Landsat can provide. Landsat sees 

geological features in a way aerial photography 

doesn't.

First, its perspective is different. It is not a substitute. It is different. Not always better. But always 

different. It avoids the distortion of wide-angle viewing and permits the application of computerized techniques to areas of meaningful geological size where 

the illumination levels and Sun angle are uniform. The 

net effect of this is that in Landsat imagery features 

can be detected and often identified which are totally 

unrecognizable in conventional aerial photography. 

Further, it has been our experience, and the experience of our clients, that in virtually every case, even 

those in which extensive ground work and aerial 

photography had been previously done, significant 

new geological features were revealed through the 

utilization of Landsat imagery.

Second, its spectral coverage is different from any 

existing film system and its output format on digital 

tape provides analysts with many more levels of spectral intensity variation to evaluate and manipulate.

Third, traditionally companies have been restricted 

as a practical matter strategically to areas in which 

they already had a substantial base of geological information. The use of Landsat as a means to evaluate 

rapidly new areas changes the cost equation dramatically and makes it possible for a company to 

consider an entirely new exploration strategy. For 

example, in a number of projects in which we have 

been associated, prospective concession areas were 

rapidly and effectively evaluated so that the exploration costs of alternative prospects could be evaluated 

for less money and with greater certainty than was 

ever possible previously. Consequently, the companies 

were not dependent on limited photography or secondhand geological interpretations based on limited 

information. Further, a consistency was added to the 

evaluation not previously possible, and new options 

have been made available at very modest cost in 

dollars and in time.

So what is next? There is no question in my mind 

that within 5 years Landsat will be a standard medium 

used by the oil and mining industries. Unquestionably 

coincident with this would be greatly improved enhancement techniques taking advantage of digital 

tapes and repetitive looks during different seasons 

to identify different features. (One of the great misconceptions during the second phase of development 

mentioned above is the approach that one picture does

it. This is just not so and repetitive coverage under 

different seasonal and weather conditions makes a 

significant difference.)

Further, one must consider the context of the times. 

The advent of Landsat technology is certainly timely: 

First, because the demand factor for new oil, gas, and 

mineral reserves is inordinately high and great pressure is being put both from the economic and a 

nationalistic standpoint on finding new reserves. Second, associated with this, companies are very much 

of a mind to spread their bets and diminish their risk, 

in part because they recognize that the political 

climate of the world is such that it is not possible to 

predict which situations will be stable from an economic standpoint over the period required to attain 

a reasonable return on investment. Further, this economic unpredictability does not correlate simply with 

traditional indicators of political stability as is shown 

by the fact that even well-established and "stable" 

governments have become increasingly aggressive in 

regulation and taxation under the pressures of the 

energy crisis. Finally, of great consequence, is the 

fact that new exploration models must be developed. 

The ability of satellite systems to provide an uninterrupted view of the regional geology of large areas, 

coupled with the new concepts of plate tectonics, 

provide many opportunities for perceiving interrelationships that previously had gone unrecognized. 

These types of perceptions have far-reaching consequences, both for geologic exploration and the 

development of geologic hypotheses on the origin and 

evolution of major portions of the Earth's crust. For 

example, in some of our work using Landsat imagery, 

we have observed that a constant spacing in major 

fractures in the Earth's crust appears to be characteristic of specific crust blocks. Geologic theory has long 

held that the emplacement of intrusive bodies of 

igneous rocks, some of which may carry economically 

valuable minerals, is controlled largely by pre-existing 

fractures. Thus once the fracture spacing pattern is 

determined and a few economic deposits are found 

in a particular area, one has a powerful tool for 

searching for other deposits in the same region.

Another promising area of research and one which 

will undoubtedly receive increasing attention as mineral exploration increases over the next few years, is 

the field of geobotany. While this work certainly 

pushes the state-of-the-art of Landsat resolution, 

nevertheless Landsat affords a needed opportunity to 

obtain repetitive coverage at low cost so that correlation can be established and new geobotanical exploration models developed.
228 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Finally, a significant edge will be gained by those 

organizations which are able to restructure their exploration strategy to take advantage of this technology 

over the next 3 years. All pictures and all people are 

not equal, and the merging of high-quality enhancement techniques coupled with high-quality geological 

minds will be a telling combination. On the other hand, 

I would like to close with a note of caution. We are 

just now at the beginning of a commercial phase 

where we are starting to understand critical subtleties 

of the technology with which we work. Oil and mineral exploration is a damn tough business. Answers 

are not spewed out of black boxes run by aerospace 

"whiz kids." Rather, valuable information is provided 

which must be evaluated within the context of a sound 

exploration model. As was the case with all other new 

exploration techniques, the state-of-the-art will always 

be stretched and challenged beyond its reasonable 

limits, and the ability of black boxes to provide answers, as always, will be oversold. Nonetheless, this

is an exciting time because what we are seeing is a 

revolution in access and perception which will tax us 

all over the next 5 years in just applying the current 

state-of-the-art. On the other hand, there is a lot of 

profit to be made, and a lot of losses which could be 

avoided, if we get on with it aggressively.

REFERENCES CITED

Fischer, W. A., and Lathram, E. H., 1973, Concealed 

structures in Arctic Alaska identified on ERTS-1 

imagery: Oil and Gas Jour., May 28, 1973.

Saunders, D. F., Thomas, G. E., Kinsman, F. E., and 

Beatty, D. F., 1973, ERTS-1 imagery use in 

reconnaissance prospecting—Evaluation of the 

commercial utility of ERTS-1 imagery in structural reconnaissance for minerals and petroleum: 

Type III Final Report to Natl. Aeronautics and 

Space Admin. Available from U.S. Dept. of Commerce Natl. Tech. Inf. Service as E74-10345.
PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Regional and Global Geological Studies 

Using Satellite Magnetometer Data

By Robert D. Regan, 

U.S. Geological Survey, Reston, Va.

ABSTRACT

A global magnetic anomaly map derived from satellite measurements offers a new perspective in regional 

and global geologic studies. Preliminary correlation 

with tectonic and geologic maps indicates that in addition to reflecting obvious large-scale features such as 

continental shields, the map also reveals many unexplained structures. Particularly striking are the lack of 

anomalies in the Pacific Ocean, with the exception 

of a pair ( + 6 gammas and — 6 gammas) near the 180° 

meridian in the area where the Emperor Seamount 

and the Hawaiian Island chain intersect, a broad magnetic low over the Gulf of Mexico, and several highs 

in the central United States.

Also evident is a major magnetic anomaly in central 

Africa that does not directly correlate with any known

tectonic feature. This anomaly, termed the Bangui 

anomaly, was discovered in the satellite data and 

confirmed by aeromagnetic measurements. The anomaly is over an area of thick continental crust and has 

been interpreted as a massive crustal intrusion that 

may be related to crustal thickening. Many major 

mineral deposits are associated with this body.

Although much more work is needed to completely 

interpret the map and to determine the causes of all 

the anomalies, the initial results show the utility of a 

satellite magnetometer as a geological/geophysical 

tool.

The global magnetic anomaly map and a complete 

discussion of its derivation are published in the 

Journal of Geophysical Research, v. 80, no. 5, p. 794.

229

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

AIRTRACETM-An Airborne Geochemical Exploration Technique

By A. R. Barringer,

Barringer Research Limited,

Rexdale, Ontario, Canada, M9W 5G2

ABSTRACT

The AIRTRACETM system is a new airborne geochemical technique for collecting and analysing atmospheric particulate material and relating this to the 

underlying geology and geochemistry. The technique 

depends upon the existence in the atmosphere of a 

dispersion of particulate material which covers a broad 

range of particle sizes. The coarser material above 10 

p. in diameter tends to be localized to such an extent 

that if this size fraction is used the effects of manmade 

pollution are not a problem in most exploration areas. 

In temperate and tropical regions vegetation is a 

prime source of the particulates utilized in the system 

and laboratory research with radioactive traces as 

well as field surveys has demonstrated the important 

role played by vegetation in releasing particulates. 

carrying heavy metals and other trace elements.

Special techniques have been developed for separating particulates of local derivation from the general ambient background by specifically isolating the 

material in rising thermal plumes. Good results have 

been obtained in test surveys over orebodies covered 

by glacial overburden and heavy vegetation. Elements 

detected include Cu, Zn, Ni, Mn, Fe, Cr, Cd, Al, Mg, 

Ca, Ti, Si, and C. Techniques for measuring uranium 

are under development. Tests have also been carried 

out over an oil and gas field, and it has been demonstrated that airborne anomalies correspond with the 

location of the field as well as surface rock and soil 

anomalies in carbon isotopes and manganese. The 

equipment is being flown in helicopters and fixed 

winged aircraft.

INTRODUCTION

In the conventional approach to geochemical exploration samples of soil, stream sediment, rocks, or

plant material are gathered on a reconnaissance basis 

or on a close grid in order to determine the regional 

or detailed distribution patterns of mineralization. The 

methods of sampling and analysis have been studied 

over a period of more than 25 years and have led to 

the establishment of geochemical exploration as a 

prime mineral exploration method (Hawkes and Webb, 

1962; Levenson, 1974). Considerable research has 

also been carried out in hydrocarbon geochemistry; 

however, the techniques of geochemical exploration 

for oil and gas appear to have found widespread 

application only in Russia (Kartsev and others, 1954).

In the work reported in this paper investigations 

have been made of the use of atmospheric particulate 

geochemistry as an exploration tool for both minerals 

and hydrocarbons, with the aim of supplementing 

ground geochemical methods and providing techniques 

for low-cost, large-scale airborne reconnaissance.

An early proponent of the use of atmospheric particulates for airborne geochemical applications was 

Weiss (1967). Weiss initially employed a filter method 

for sucking in air and an X-ray analytical technique 

for analysing particles on the filters. Subsequently, he 

has used a system of towed filaments that are dragged 

through the air in order to collect particles on their 

surfaces. These filaments are periodically wiped, and 

the material subsequently analysed. Weiss has referred 

to the atmospheric aerosols as containing mineral 

particles and has stated that the method is not applicable where the terrain is covered by heavy vegetation 

(Weiss, 1971).

In the present investigations, attempts have been 

made to develop new particle collection techniques 

that are capable of separating and collecting particles 

that have risen from underlying terrain and rejecting 

particles that have travelled substantial distances

231
232 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

laterally. Investigations have also been carried out on 

the contribution of vegetation to the generation of 

meaningful geochemical responses in the atmosphere, 

and, in addition, there has been substantial analytical 

chemical research to develop appropriate methods 

for use in atmospheric geochemistry.

SOURCES OF ATMOSPHERIC 

PARTICULATES AND AEROSOLS

The sources of atmospheric particulates and aerosols are both manmade (anthropogenic) and natural, 

the former being a source of interference in airborne 

geochemical studies. Anthropogenic pollutant sources 

associated with urban and industrial areas generate 

very high loadings of atmospheric particulates, the 

effects of which tend to be localized in the giant 

particle sizes (plus 10 /<) but carry great distances 

under some meteorological conditions in the small 

particle size range. In urban environments the mean 

residence time in the atmosphere of submicron particles in the absence of precipitation is in the order of 

100 to 1,000 h (Esmen and Corn, 1971). Pollutant 

particles of greater than 10 /L in diameter will, therefore, have mean residence times of less than 10 h and 

will be generally localized to the vicinity of urban 

and industrial areas. Studies of easily recognized carbon and flyash spherules over the North Atlantic 

confirm that these pollutant particles do not exceed 

6 /it in diameter over open ocean and reach larger 

sizes in only a very small percentage of the total mass 

of particulates in ocean areas close to pollutant 

sources such as the Bay of Maine (Parkin and others, 

1970). It has been estimated that the mean residence 

time of particles in the lower troposphere is about 4 

days (Poet and others, 1972), and it is, therefore, clear 

that in the absence of precipitation there can be widespread migration of the mean particulate burden over 

distances that can on occasion amount to hundreds 

of miles or more. The fine particle component is the 

fraction that migrates, and it is this fraction which 

contains the highest concentration of trace metals 

(Lee and others, 1967). Approximately 45 percent of 

the mass of particles in nonurban air close to the 

ground lies in the size range above 10 p. in diameter 

(Noll and Pilat, 1971), and it is essential to consider 

only this size range if the effects of urban and industrial pollution are to be minimized when studying the 

atmospheric geochemistry of nonurban areas.

The existence of high concentrations of heavy 

metals in atmospheric particulates is observed even 

in regions remote from civilization (Rahn and Winchester, 1971); this is frequently cited as evidence of

an all-pervading influence of anthropogenic pollution. 

However, the presence of high concentrations of 

heavy metals in atmospheric particulates is by no 

means a proven indicator of the influence of pollution, since it has been found that particulates rich in 

heavy metals can be released from vegetation by a 

phenomenon that parallels the release of water by 

transpiration (Beauford and others, 1975). Once again 

the effects of large-scale migration of particulates 

from vegetation sources can be minimized by considering on'y particles of greater than 10 p in diameter. The release of heavy metals from vegetation 

and particle localization will be dealt with in greater 

detail later.

Additional natural terrestrial sources of particulates 

and aerosols include the weathering of geological 

materials to produce soil particulates at the surface, 

the effects of wind erosion (Hilst and Nickola, 1959), 

the formation of aerosol particles derived from 

naturally occurring hydrocarbons produced by plants 

(Went, 1964, 1967), the generation of condensation 

aerosols by homogeneous gas reactions (Walter, 

1973), the formation of condensation nuclei by 

evaporation processes in semiarid terrains (Twomey, 

1960); and the production of organic particulate material by the decay, biodegradation, and weathering 

of plant material.

The oceans also provide a significant source of particulates in the atmosphere. Ocean derived particulates are generated by dehydration of windblown 

spray and the bursting of air bubbles entrained by 

wave action or rain (Woodcock and Gifford, 1949; 

Blanchard and Woodcock, 1957; Junge, 1972). Particulates of marine origin can contain up to 20 percent 

of organic carbon (Hoffman and Duce, 1974) and in 

some areas can contain even higher percentages of 

organic material. This anomalously high concentration 

of organic substances in marine particles is derived 

from the organic layer on the ocean surface (Garrett, 

1967; Barger and Garrett, 1970). Aerosols generated 

by bursting bubbles are coated with the organic 

material (Blanchard, 1963, 1964, 1968; Garrett, 1967; 

Williams, 1967). Microorganisms can also be injected 

into the atmosphere from the ocean surface by the 

bubble-bursting mechanism (Carlucci and Williams, 

1965; Blanchard and Syzdek, 1972), and airborne 

marine microorganisms have been observed by the 

author and his colleagues as well as other researchers 

(ZoBell and Mathews, 1939; Stevenson and Collier, 

1962).
AIRTRACETM—AN AIRBORNE GEOCHEMICAL EXPLORATION TECHNIQUE 233

RELEASE OF HEAVY METALS IN

PARTICIPATE FORM FROM NATURAL

SURFACES

The transfer of elements into the atmosphere from 

vegetation is of special interest in relation to the 

application of atmosphere geochemical methods in 

vegetated terrain. Movement of elements into the 

atmosphere from coniferous trees has been studied 

(Curtin and others, 1974), and it has been suggested 

that volatile exudates are the carrier. It has also been 

suggested that aerosols may be formed subsequently 

by agglomeration processes from the volatiles and 

that they could be used for geochemical sampling 

purposes. Recent work, however, with laboratory 

plants using radioactive zinc 65 and lead 210 as 

tracers in the plant nutrients has indicated that the 

initial release takes place in particulate form (Beauford and others, 1975). Some of this work, as yet unpublished, has shown that particulates in small 

laboratory plants are released dominantly in the submicron range. However, in the natural environment 

particles labelled with radioactive tracers can be 

released through a size range that is collected through 

all stages of a multistage particles impactor. It is of 

particular significance to the present study to note that 

radioactively labelled particles in size ranges up to 

at least as large as 10 /A in diameter can be released 

under free convection even in the absence of any 

wind.

The release of radioactive materials from vegetation that has been sprayed with a solution containing 

strontium 89 has been reported; it has been shown 

that there is a steady loss of radioactivity to the 

atmosphere (Moorby and Squire, 1963). It was suggested that the release might be taking place during 

the shedding of cuticular waxes, but the work was 

not continued by Moorby and Squire to verify this 

concept. Cuticular waxes abound on the leaves of 

most plants in the form of small wax platelets which 

provide the leaves with a water shedding surface. 

These platelets are continuously released by abrasion 

and the rubbing of leaves against each other and, in 

many instances, are able to renew themselves (Eglinton and Hamilton, 1967; Martin and Juniper, 1970). 

The use of various solvents on particulates that have 

been released from vegetation, clearly indicates that 

they carry only a small wax content and an analysis 

of the solvent extracts also shows that the waxes do 

not appear to be the major carrier of metals.

In considering the mechanisms of elemental release from plant surfaces it is important to note that 

such surfaces contain salts that can be readily leached 

out by rain or dew (LeClerc and Breazeale, 1908;

Long and others, 1956; Clement and others, 1971). 

Whereas most studies are concerned with the leaching of major elements such as K, Na, and CI, the 

writer and his colleagues have confirmed (to be published) that the heavy metal trace elements such as 

copper, lead, and zinc may also be leached from the 

surface of leaves with simulated dew or rain. It seems 

highly probable that the deposition of elements at the 

surface of leaves is related to the transpiration process in which soil solutions carrying dissolved salts 

are taken up by the plaht roots, but the evaporation 

from the leaf surfaces is confined to the release of 

essentially pure water. Some of the salts in upward 

migration through the plant are utilized in the normal 

metabolic processes of the plant; however, certain 

elements may be enriched in the vicinity of the leaf 

surfaces.

A preliminary study is being carried out using newly 

available equipment on the distributions of 19 elements in soils, plants, and vegetative particulates on 

two sites in the Bancroft area of Ontario, Canada. 

The region is one of Pre-Cambrian geology, and one 

of the sites carries pegmatitic uranium mineralization 

while the other has only background values in 

uranium. Analyses of the A and B soils, bark, needles, 

and branches of conifers and deciduous trees were 

studied as well as the particulates generated by this 

vegetation. Particulates were sampled by filling large 

plastic bags with vegetation material and collecting 

the particulate material released by agitating the bags. 

High-volume suction sampling methods were used 

employing a small cyclone thereby providing sufficient 

material for precision multielement analysis.

Results are shown in table 1 and indicate certain 

interesting features. For example, the concentration 

of many elements in the particulates released from 

branches and needles is comparable with the concentration of these elements in soil. However, in the case 

of Fe, Al, Ti, and U, these elements are substantially 

depleted in the plants with respect to the soil concentrations, but the particulates released by the plants 

in general are enriched in comparison with the plant 

concentrations. It seems as if the vegetation minimizes 

the uptake of these elements and at the same time 

tends to further eliminate them by shedding enriched 

particulates. These elements belong to the nonbiogenic class that occupies a certain restricted area in 

an ionic radius/ionic charge diagram (Hutchinson, 

1943; Brook, 1972).

It will also be observed that uranium mineralization 

is more readily detected in the particulate material 

than in the vegetation from which it is derived.
TABLE 1.—Analyses of soils, plants, and vegetative particulates 

(Figures quoted are parts per million dry weight)

Cd Zn Ni Cr Co Cu Ag Mo

SAMPLE SITE

Conifer Needle Particulates ___

Deciduous Bark Particulates _ _

Deciduous Branch Particulates _ 

Forest Litter

Forest Litter Particulates

9.4 84.2 

12.5 52.5 

0.9 45.9 

2.9 35.9 

1.5 74.1 

8.0 66.1

4.1 122.4 

0.4 126.8 

1.8 58.9 

14.4 105.1 

2.5 79.8 

2.0 70.5

13.7 

5.9 

6.0 

7.3 

24.2 

18.4

5.6

ND 

37.1 

ND 

8.8 

ND

64.1 

74.3 

6.6 

ND 

56.1 

13.6

7.3 

9.2 

71.2 

19.5 

7.3 

21.8

5.5

7.6 

ND 

3.9 

1.3

4.4

1.1 

9.6 

6.2 

8.7 

2.1 

6.6

9.7 

7.9 

5.0 

3.2 

3.2 

22.6

11.1 

4.1 

2.3 

25.8 

7.0 

11.1

1.6 19.7 

1.6 27.5 

ND ND 

1.6 3.0 

0.8 3.3 

4.6 4.3

1.1 3.9 

3.2 7.7 

2.1 4.7 

3.4 5.9 

1.0 2.8 

1.9 6.3

SAMPLE SITE

Soil A Zone

Soil B Zone

Conifer Bark Particulates _ _ _ _ 

Conifer Needles

Conifer Needle Particulates ___

Deciduous Bark Particulates _ _ 

Deciduous Branches

Deciduous Branch Particulates _ 

Forest Litter

Forest Litter Particulates _ _____

Cd Zn

3.5 35.2 

4.3 35.2 

1.6 48.8 

2.6 56.0 

0.9 33.8 

13.7 65.4

4.0 51.0 

0.6 40.2 

1.6 15.1 

15.6 46.7 

3.2 82.0 

4.2 61.8

Ni

8.5 

16.2

ND 

5.4 

ND 

12.7

10.5 

ND 

10.9 

3.9 

7.6 

12.4

Cr

29.6 

51.4 

ND 

3.3

ND 

12.6

7.3 

9.2 

ND 

22.5 

ND 

49.3

Co

3.9 

4.6 

ND 

1.8 

3.2 

0.5

3.4 

7.1 

7.8 

9.8 

3.2 

7.9

Cu

4.1 

3.8

4.7 

5.0 

2.9 

43.5

12.0 

4.7 

4.1 

15.2 

5.9 

12.0

Ag Mo

1.0 7.3 

0.8 8.9 

ND 2.4 

0.4 2.2 

1.6 10.1 

2.7 2.8

2.6 5.5 

2.1 7.7 

2.6 6.7 

3.8 8.3 

1.6 4.5 

2.7 8.3

Mn

Fe*

7— URANIUM

250 

134 

288 

176 

716 

61

173 

112 

92 

117

737 

433

32290 

43552 

102 

119 

314 

1643

476 

297 

204 

929 

195 

723

Sr Ca Mg K Na

Al* 

ANOMALY

11.1 

5.5 

17.4 

8.7 

30.2 

5.0

47.5 

34.3 

12.0 

23.3 

29.1 

27.7

2— BACKGROUND

Mn

134 

190 

190 

223 

261 

59

81 

98 

17 

60 

653 

226

Fe*

12445 

13944 

136 

187 

76 

1687

451 

221 

ND 

937 

102 

4154

Sr

8.5 

7.6 

25.5 

27.9 

18.1 

6.6

72.4 

97.4 

6.2 

24.2 

30.5 

23.0

1695 

727 

5437 

2746 

10159 

532

10865 

8169 

2983 

6340 

8804 

7595

SITE

Ca

1403 

1158 

5938 

6600 

4507 

702

15707 

18027 

800 

4784 

9543 

4878

1689 

1434 

396 

25,4 

768 

328

435 

474 

184 

392 

1157 

940

Mg

1685 

1596 

442 

464 

525 

460

314 

367 

69 

342 

1059 

1212

2000 

2800 

1200 

1200 

2800 

800

3200 

3600 

1200 

2400 

2400 

2800

K

1600 

2000 

1600 

1600 

2400 

ND

4000 

5600 

1200 

2400 

2800 

2800

353.7 

375.0 

ND 

122.2 

149.1 

108.0

207.4 

11.4 

130.7 

137.8 

81.0 

44.0

Na

348.0 

240.1 

ND 

76.7 

39.8 

144.9

71.0 

2.8 

161.9 

62.5 

275.6 

133.5

1089

1357

10

7

19

60

30

9

N

46

13

40

Al*

705

843

17

18

1

90

30

16

N

41

197

"Elements depleted in plants with respect to soils and enriched in particulates compared to plants.
AIRTRACETM—AN AIRBORNE GEOCHEMICAL EXPLORATION TECHNIQUE 235

A further example of this phenomenon was noted in 

some tests over a small deposit of massive sulfides 

carrying copper and zinc in the Pre-Cambrian shield 

of Manitoba. There was a moderate geochemical 

anomaly in the soils, but conventional biogeochemistry 

for copper and zinc in the vegetation gave no indication of the anomaly while there was positive indication 

in particulates released from vegetation collected in 

large plastic bags. Further studies are continuing to 

gather more case histories on the relationship between 

element concentrations in soil and vegetation and the 

particulates released by that vegetation.

The role of vegetation is likely to be a very significant factor in any approach to airborne geochemistry, since plant surfaces cover an area many times 

their area as seen on an aerial photograph. Even in 

sparsely vegetated terrain, the total plant surface area 

can represent a sizable proportion of the land/air 

interface and in temperate regions having moderate 

to heavy vegetation cover, the interface is dominated 

by plants. Since this plant cover projects into the 

boundary layer and is exposed to the microclimate 

of circulating convective currents and surface winds, 

it provides a major contribution to the total particulate 

burden in vegetated temperate and tropical regions. 

Furthermore, although some of the organic content 

of atmospheric particulates in the small size range is 

derived from the condensation and exudation of plant 

volatiles such as terpenes (Went, 1967), 20 percent or 

more of the atmospheric particulate burden is normally composed of nonvolatile organic material (Neumann 

and others, 1959). It is the plus 10 p. fraction of this 

nonvolatile organic material that is the main information carrier for the AIRTRACETM system in vegetated 

regions.

With regard to the sources of inorganic particulate 

material in the atmosphere in relation to metals and 

mineralization, it is obvious that weathered and dusty 

soil surfaces are a prolific source. The geochemistry 

of some of these surface particulates has been studied, 

and figure 1 shows analyses for metal and copper in 

the top few millimetres of surface dust sampled in a 

traverse across the nickel orebody at Agnew in Western Australia.

A number of case histories have been studied of 

surface dust sampled across mineral deposits. Where 

residual soils are present there is invariably an anomaly which more or less parallels the conventional B 

zone geochemical anomaly. However, the problem of 

obtaining a ground sample, in areas of even modest 

vegetative cover, that is truly representative of airborne particulates is difficult because of the unknown 

mix between soil surface derived particles and plant

surface derived particles. Furthermore even in the 

case where the soil surface dominates, there may be 

a certain bias imposed by the selective winnowing of 

particles according to their aerodynamic shape and 

density.

Heavy metals are also released from the ocean 

surface by the bubble bursting mechanism due to the 

trace metal enrichment in the sea organic microlayer 

(Piotrowicz and others, 1972; Szekielda and others, 

1972; Barker and Zeitlin, 1972). However, not all of 

the trace metals in the marine atmosphere are derived 

from the ocean surface, since the finer metal carrying 

particles may originate from land sources (Hoffman 

and others, 1972). It is not known whether the trace 

metal content of surface organic films and of overlaying atmosphere particulates will increase in the 

presence of mineral deposits located beneath shallow 

water.

METEOROLOGICAL FACTORS AND 

CONTROLS

When carrying out atmospheric sampling of particulates for airborne geochemical purposes it is 

essential to ensure that particles being collected are 

of local derivation and that they have not been transported long distances. This requirement can be met 

partially by collecting only giant particles of greater 

than 10 p. in diameter, but this in itself is not completely satisfactory since particles cartstill be collected 

that have travelled many miles. Special techniques can 

be used for obtaining a highly localized sample providing that there is strong vertical mixing and the air 

is vigorously lifting particles from the atmospheric 

interface to appropriate sampling altitudes. These 

conditions tend to arise when there is sunshine and 

adiabatic or superadiabatic conditions in which the 

temperature decreases adequately with increasing 

altitude. Low-level inversions in which normal lapse 

of the temperature is reversed provide very unfavorable conditions which give rise to suppression of mixing and the trapping of atmospheric particulates at 

the inversion layer.

Under the correct survey conditions of sunshine 

and light winds, convective plumes are formed which 

are basically nonrotating columns of rising warm air 

which travel at a lower velocity than the mean wind 

speed (Taylor, 1958; Kaimal and Businger, 1970; 

Businger, 1972). These plumes are tilted in a downwind direction and show maximum vertical flux on 

their leading edge (fig. 2). Flights made with a lowflying aircraft carrying equipment for measuring 

temperature fluctuations, vertical acceleration, and
236 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

CONCENTRATION OF ELEMENTS IN SOILS, PLANTS, AND PLANT

B ZONE SOILS

Cd (ppm)

Zn (ppm)

Ni (ppm)

Cr (ppm)

Cu(ppm)

Ti (ppm)

P(ppm)

CONIFER BRANCHES 

AND NEEDLES

PARTICIPATES FROM 

CONIFER BRANCHES 

AND NEEDLES

23

5 

900

700 

37

10 

70

22

125

5 

2035

620 

1100

200

UUJ 5

or*-o ^JKMVJO

-

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555

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150

30

16

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J_ 00

1600

_L 60°

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TO

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JC

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rcoc

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175

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90

25

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280

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1810

900

LJLU 

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£553

frOOtM 0
AIRTRACETM—AN AIRBORNE GEOCHEMICAL EXPLORATION TECHNIQUE 237

PARTICULATES, OVER Zn MINERALIZATION, DEER LAKE, ONTARIO

B ZONE SOILS

Mn(ppm)

Fe (ppm)

Sr(ppm)

Co (ppm)

Mg(ppm)

K (ppm)

Al(ppm)

CONIFER BRANCHES

AND NEEDLES

PARTICULATES FROM 

CONIFER BRANCHES 

AND NEEDLES

780

130 

97000

17300

10

4 

4000

950 

3110

1000 

9000

370 

18500

8800

s^-£

rocvjC

-

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DC\JO> 

785

110 

255

70 

25

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8500

3200 

900

620 

520

150 

530

1 10

UJUI f-S

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tOCMO

-

-

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:*•> 

>cvja

230

45 

11300

L 3900

19

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5500

2500 

1610

770 

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4100

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LUU 3

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238 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

250

a 

a I

<3

1500n

1000-

500-

sample locations

FIGURE 1.—Nickel and copper in surface dust, Agnew, Western Australia.
AIRTRACETM—AN AIRBORNE CEOCHEMICAL EXPLORATION TECHNIQUE 239

UA = 5.0 m sec"1 

UB= 3.5 m sec'1 

WA = 2.0m sec"1 

WD =1.0 m sec"1

FRONT

FIGURE 2.—Two-dimensional model of the convective plume. 

(From Kaimal and Businger, 1970.)

participate loading show close correlation between 

all of these parameters (fig. 3). Temperatures were 

measured at two levels, with one sensor in the aircraft 

and the other 100 ft below in a towed bird. These 

sensors show the extent of vertical structure in the 

warm thermal peaks, and they also indicate that 

heavy dust loading are carried aloft by these rising 

vertical thermal structures. It has also been noted 

that when flights are made over a lake the thermal 

structures passing with the wind from land to water, 

tend to smooth out within 1,000 ft of the shoreline. 

Clusters of dust particles however can retain coherence for distances of at least 1 mile. This strongly 

suggests that when pockets of concentrated particulates are closely associated with parcels of warm air, 

then these particles have moved only a short distance 

from their ground source. Support for the concept 

that the mixing zone contains parcels of particulate 

matter of predominantly local origin surrounded by 

particulates from more distant sources is in part provided by the independent observation that the size 

distribution spectra of particles can vary widely in 

immediately adjacent air samples (Graedel and 

Franey, 1974).

In the AIRTRACE equipment, major emphasis has 

been placed on the development of methods for 

separating the particulates in rapidly rising warm air 

from the particulate burden in the cooler surrounding 

air. A very satisfactory thermal switching sampling 

technique has been evolved, and this is outlined in 

the section describing the AIRTRACE airborne equipment.

When the thermal switching and sampling system 

is used, it immediately becomes apparent that there

are often pronounced differences in the chemical composition of the adjacent warm and cool air samples. 

Geochemical anomalies will appear on both sets of 

data, but there is often a displacement downwind of 

the anomalies derived from cool air particulates, the 

displacement being a function of the terrain clearance 

and wind velocity.

The overriding need for some means of selectively 

sampling predominantly local material and rejecting 

the ambient background becomes obvious if one examines the mechanisms that contribute material to the 

near surface particulate loadings. There is a small 

global or continental background that occurs entirely 

in the minus 10 p. fraction that is derived from fallout 

of material that has spread in the stratosphere and 

upper troposphere. There is also a regional background that falls out from the middle troposphere in 

a size range mostly within the minus 10 //. range. Finally there is a local background generated in the zone 

of mixing which covers the entire size range up to 

100 /L (fig. 4). The ratio of regional to local background 

material is strongly controlled by meteorological conditions. In covering the climatic range from stagnant 

air through moderate mixing to strong mixing, the 

contribution of local background to the total burden 

increases drastically (fig. 5). At the same time the increasing thermal plume activity creates columns of 

particulates rich in very local material that is sampled 

by the AIRTRACE equipment as described above.

In addition to day-to-day variations in mixing conditions, there is also a marked diurnal cycle. At nighttime, when convective mixing ceases and still air 

conditions prevail, there is a steady settling of particulates within the lower troposphere. In the morning 

if the sun is shining and adiabatic or superadiabatic 

conditions prevail, active mixing will commence, 

building up by midmorning to high levels. This will 

raise particles into the air in thermal plumes at velocities which can amount to several metres per second, 

and there will be a continuous increase in the particulate burden. The upward flux of particles during active 

mixing is much greater than the downward flux since 

the latter is controlled substantially by sedimentation. 

By early afternoon even some of the giant particles 

may have moved considerable distances laterally making it imperative to reject the background material 

if sampling resolutions of fractions of a mile are to 

be achieved.

In general the great variability of the conditions 

which effect the contribution of regional material to 

the local particulate burden indicates the difficulties 

of gathering reliable data unless a thermal plume 

sampling technique is employed.
240 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

PARTICULATE COUNTER 

TOTAL OUTPUT

PARTICULATE COUNTER j 

HIGH-PASS FILTERED OUTPUT;

'I*M*VW*M^

TEMPERATURE IN AIR SCOOP ' * 

HIGH-PASS FILTERED OUTPUT rui'

**$***

TEMPERATURE IN BIRD 100' BELOW AIRCRAFT; 

HIGH-PASS FILTERED OUTPUT

ACCELEROMETER 

VERTICAL g

•I • i- f fTtr.ifi'11'

*-nstf-~m'.*<•» i'

~

TIME 0 10 20 30 40 50

_J

100 Sec.

DISTANCED I 2 3 Miles 

FIGURE 3.—Inflight analog record of participate count, temperature, and vertical g, Arizona, February 6, 1975, flying height 80 m.
AIRTRACETM—AN AIRBORNE CEOCHEMICAL EXPLORATION TECHNIQUE 241

STRATOSPHERE 

TROPOPAUSE

TROPOSPHERE 

lOktn (7 MILES)

GLOBAL BACKGROUND CONTRIBUTION 

FALLOUT FROM STRATOSPHERE

y CONTINENTAL BACKGROUND CONTRIBUTION 

FALLOUT FROM TROPOPAUSE AND UPPER 

TROPOSPHERE

REGIONAL BACKGROUND CONTRIBUTION 

FALLOUT FROM MIDDLE TROPOSPHERE

LOCAL BACKGROUND ^^ 

ZONE OF MIXING BENEATH INVERSION

FIGURE 4.—Contributions of global, continental, regional, and 

local backgrounds to near-surface particulate loadings.

Turning to the seasonal meteorological constraints 

placed upon the AIRTRACE system, these depend 

upon the region of operations. Whereas strong mixing 

can occur at all times of the year in warm climates, 

there are areas where much of the winter is unsuitable. However, satisfactory operations have been 

achieved in Canada at temperatures well below zero 

fahrenheit with total snow coverage on the ground. 

It appears that if sunshine is present strong mixing 

can occur even under these winter conditions, and an 

adequate particulate burden for airborne geochemical 

surveys can be provided by evergreens and the 

branches of deciduous vegetation.

The meterological constraints are of" course far 

less onerous if the AIRTRACE system is used for 

assessing regional geochemistry. This approach, however, has only limited applications.

AIRBORNE EQUIPMENT FOR THE 

AIRTRACE SYSTEM

Particulate collection is carried out in the AIRTRACE system with inertial devices and both cyclones 

and louvred collectors are employed (Stern, 1968). 

Lightweight cyclones can be manufactured to handle 

several hundred cubic feet of air per minute with 

good collection efficiency for the requisite particle 

sizes and louvred collectors can readily handle air 

volumes of as much as 12,000 ft Ymin in an airborne 

system. In one embodiment of the system particles 

are concentrated into an airstream and passed to a 

device which transfers them into an argon carrier gas 

(Barringer, 1974a). Spectroscopic analysis is then 

carried out directly inflight on the particles (Barringer, 

1973a, 1973b). This technique is primarily applied to 

the measurement of volatiles such as hydrocarbons 

and mercury.

One of the principal methods used is to impact the 

particles onto a special tape and to analyse this tape 

on a post-flight basis. The key factor in the system is 

the aforementioned separation of the incoming stream 

of particles into rising and falling air components 

(Barringer, 1974b). This selection is achieved by the

J

PARTICULATE

LOADING

BACKGROUND—

i

»-

TRAVERSE

WEAK

ACTIVITY

_ —— _x~ — — • — « — — s^

IN

~^ ^^^— -

TRAVERSE IN

MODERATE

ACTIVITY

/^f^^~~^

K

i

TRAVERSE IN

STRONG

ACTIVITY

\ L/*^v^

1 1 

0 IKM 20 IKM 20

30 SEC 60SEC 30SEC 60 SEC

-t- --,

^

IKM 2 

30 SEC 60 SEC

AIRCRAFT TRAVERSE AT 15 METRES TERRAIN CLEARANCE 

FIGURE 5.—Effect of mixing activity on particulate loading.
242 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

use of fast response thermal detectors at the air scoop 

inlets in conjunction with a suitable electrical filter, a 

digital delay line system and solenoid valve switching. 

Delays are adjusted appropriately so that switching 

of the particle stream can be accurately timed in 

relation to the transit delay for the particles passing 

through the piping of the system. This technique enables very small air parcels to be sampled with a 

resolution in the order of 5 ft. Samples are integrated 

into hot and cold spots on the tape using collection 

intervals that can be selected at either 5 or 10 s.

The effectiveness and precise resolution of this 

plume sampling technique is a function of the choice 

of the lower level of particle size collected, the selection of the wave filter functions applied to the 

temperature sensor, and the sensitivity settings of the 

thermal switching thresholds. The optimization of

these parameters has to be based upon extensive 

experimentation.

The equipment is usually mounted on a helicopter 

(fig. 6), and surveys are carried out at altitudes of 20 

or 30 ft above the treetops. This altitude turns out to 

be quite practical and is in fact used very commonly 

in crop spraying operations. Navigation of standard 

grid surveys at a quarter-mile spacing, for example, 

can be achieved in most terrains using conventional 

navigation from a photomosaic, providing that the 

navigator is skilled. Alternatively electronic navigation 

can be employed.

The equipment is also being operated in fixed-wing 

installations where surveys are carried out at 200 ft 

altitude. At this altitude the equipment is well suited 

for climates where there is very strong mixing such 

as in South Africa or Australia.

FIGURE 6.—AIRTRACETM equipment mounted on a 206B jet Ranger.
AIRTRACETM—AN AIRBORNE GEOCHEMICAL EXPLORATION TECHNIQUE 243

The basic AIRTRACE system is employed in conjunction with other geophysical equipment such as 

magnetometers in helicopters and an EM system in the 

case of a fixed-wing installation. Inflight monitoring 

is provided by a multichannel analog recorder for 

optical measurements of the particle stream, thermal 

monitoring, etc.

ANALYTICAL SYSTEMS

One of the problems of airborne geochemistry is 

the very small amount of material that is collected. 

This makes it necessary to use extremely sensitive 

analytical techniques. Relatively simple equipment has 

been developed that provides inflight analysis of absorbed hydrocarbon and mercury, and there are some 

valuable applications for this approach. However, as 

research on airborne geochemistry has proceeded, it 

has become obvious that a system capable of analysing for a large number of elements would provide the 

optimum. Specifications for such a system include 

multielement capability, very high sensitivity, wide 

dynamic range, and high speed of operation. These 

requirements are extremely difficult to meet in realtime analytical equipment due to the problems of 

weight, power consumption, complexity, and the difficulties of operation and maintenance in an aircraft. It 

was, therefore, decided to develop a post-flight 

analytical system.

In considering possible systems, one approach that 

at first seems obvious would be the use of X-ray 

fluorescence analysis. Unfortunately, however, even 

the most advanced of these systems have inadequate 

sensitivity for the particulate levels that are encountered under some climatic and terrain conditions, 

and, furthermore, the time taken for sample analysis 

tends to be long in comparison with the time taken 

to collect samples.

The solution that has been employed is the use of 

laser vaporization in conjunction with inductively 

coupled plasma spectroscopic analysis. These two 

techniques used together provide a very wide dynamic 

range, high sensitivity, simultaneous multielement 

capability for more than a dozen elements, good 

linearity, and an analysis time of seconds per sample. 

The operational equipment is capable of functioning 

in a fully automatic mode, and the output is on magnetic tape where it is directly available for use in the 

preparation of maps by computerized methods.

All readings on the equipment bear a fixed relationship to the mass of each element present on the 

analytical tape so that any pair of elements can be 

ratioed. The linearity of the system is demonstrated 

by figures 7 and 8 which show the plots of silicon

versus titanium and zinc versus titanium in a minus 200 

mesh soil sample through a 40:1 range of loadings. 

This degree of precision is duplicated for most of the 

elements that are recorded and applies to both organic 

and inorganic matrices. Elements currently being 

analysed include Cu, Zn, Ni, Cr, Mn, Fe, Ti, Mg, Ca, 

Na, K, Cd, Si, and C. It is hoped to expand this list 

shortly and to include uranium as well as certain 

volatile elements.

With regard to data handling, in a simple approach 

it is possible to plot the ratios of a given element pair 

such as copper and titanium to look for copper anomalies. However, in practice a more sophisticated 

method is used in which linear regressions are employed to plot the variations of elements such as 

copper against six other preselected elements. This 

provides a very satisfactory approach that is giving 

good results, but a number of other possibilities remain to be tested. These include statistical methods 

such as factor and cluster analysis.

FIELD RESULTS

An interesting example of the early research work 

carried out with the system was in a truck-mounted 

version of the equipment which was traversed across 

a small orebody at Limerick, Ontario. This mineralization was substantially covered by trees with very 

little exposed soil present. An important feature of 

the area was the presence of a seepage zone located 

to one side of the mineralization and which provided 

a strong cold extractable anomaly in the soils. The 

truck traverse results, which were obtained with an 

atomic absorption analytical system, are presented in 

figure 9. It will be noted that the main AIRTRACE 

anomaly occurs over the seepage zone and that the 

anomalies were present both in the absolute concentrations of metals in the atmosphere and also in the 

copper/zinc metal ratio. Since the area is heavily 

vegetated, it seems almost certain that the anomaly 

must be mainly biogeochemical in origin. Bulk collections of aerosol that were subject to sink and float 

separation in carbon tetrachloride (density 1.60) indicated a very high proportion of organic material being 

present. This substantiated the biogeochemical nature 

of the particulate anomaly.

An example obtained with the current equipment 

operating under very difficult geochemical conditions 

is shown in figures 10 and 11. This survey was flown 

over a deposit recently discovered with the INPUT 

airborne EM system by Selco Mining Corporation and 

Pickens Mather Incorporated in Brouillan township in 

Northern Quebec. The deposit is reported to comprise 

three separate zones with an unofficial combined
244 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

1.20

0.12 -

0.00

0.00 0.23 0.46 0.69 0.92 1.16 

Tl

1.39 1.62 1.85 2.08 2.31

FIGURE 7.—A test of linearity of laser analytical system for variations in loadings ot USCS soil (XRC-6), silicon versus titanium.

Date: 7/10/75.

tonnage in excess of 50 million tons. The first zone 

discovered contains an estimated 35,400,000 tons of 

ore averaging 0.39 percent copper, 2.30 percent zinc, 

1.04 oz silver, and 0.009 oz gold and lies beneath a 

minimum of 30 ft of glacial overburden. Ore grades 

in the other two zones are reported to be much higher 

in copper than the first zone, and they occur at greater 

depths.

The anomaly map was derived by a multiple regression technique carried out on a line by line basis for 

copper and zinc, and, in addition, spatial filtering was 

employed to smooth out noise and generate a contoured map.

The area was flown twice, both times under far 

from ideal weather conditions, since in this region 

weather conditions are frequently rather poor. Nevertheless, clear-cut delineation of an anomalous zone 

was obtained on both flights, in each case somewhat 

displaced but clearly relating to the location of the

airborne EM conductor. These results taken in conjunction with airborne geophysical data provide a 

definite indication of a drilling target in a region which 

contains large numbers of barren EM conductors that 

normally have to be disproven by expensive drilling. 

An interesting example of the AIRTRACE system 

applied to a hydrocarbon target is shown in figure 12. 

This traverse was chosen to cross a geochemical 

anomaly in carbon isotope ratios identified by T. 

Donovon of the U.S. Geological Survey (Donovon, 

1974). The survey covered the Cement field in Oklahoma which is named for the cementation by carbonate of the surface rocks over part of the oilfield. These 

surface rocks not only show anomalous Ci:! /C12 values 

but also a manganese anomaly. A ground truth survey 

carried out by collecting fine particulate material 

from the surface on a traverse line indicated a definite 

anomaly in the manganese/iron ratio across the oilfield, and this was subsequently duplicated in airborne
AIRTRACETM—AN AIRBORNE CEOCHEMICAL EXPLORATION TECHNIQUE 245

400.00

360.00 -

320.00 -

280.00 -

240.00 -

200.00 -

160.00 -

120.00 -

80.00 -

40.00 -

0.00

0.00 0.23 0.46 0.69 0.92 1.16 

Tl

1.39 1.62 1.85 2.09 2.31

FIGURE 8.—A test of linearity of laser analytical system for variations in loadings of USCS soil (XRC-6), zinc versus titanium.

Date: 7/10/75.

traverses with the AIRTRACE system. Additional tests 

have been carried out over other oilfields using the 

AIRTRACE technique for hydrocarbon volatiles Barringer, 1973a), and strong, highly localized anomalies 

have been observed—some apparently relating to 

faults and other structures over oilfields.

CONTINUING RESEARCH

A programme of research on botanical aspects of 

airborne geochemistry is continuing in the Botany 

Department of Imperial College, London, under a 

post-doctorate fellowship agreement with W. Beauford, a post-graduate scholarship with M. Luton, and 

with consulting assistance from J. Barber, Reader in 

the department. Current work is on the factors affecting the release of particulates from vegetation in situ 

as related to seasonal and diurnal factors, meteorological conditions, plant growth conditions, etc.

Research is also continuing on the atmospheric geochemistry over oilfields and the application of the 

AIRTRACE techniques to hydrocarbon exploration. 

On the analytical side, new methods of fingerprinting 

using spectro-fluorometric and mass spectrometric 

approaches are being studied in the laboratories of 

Barringer Research.

OPERATIONAL PLANS

The AIRTRACE equipment is now being used 

operationally in parallel with continuing testing over 

an increasing range of environments. Certain promising applications remain to be tested, including the use 

of the system for uranium, coal, and kimberlite 

exploration.

The system is being operated by Minsearch Surveys 

Limited for minerals and Barringer Hydrocarbons 

Limited for hydrocarbon exploration. Both companies
246 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

60

MORNING

AFTERNOON

EVENING

mineralization

\N7 IW 00 

/ see page zone

ROAD TRAVERSE

FIGURE 9.—Limerick prospect, near Bancroft, Ontario, AIRTRACETM Mk III—copper.

are joint ventures between Anglo American Corporation and Barringer Research Limited.

CONCLUSIONS

The AIRTRACE system for airborne geochemical 

prospecting has been evolved over a period of years 

in a series of parallel research programmes on particulates collection and sampling techniques, meteorological controls near the ground, analytical methods, 

biogeochemical studies, and ground truth geochemical 

programmes. Some of the earlier field studies and 

case histories programmes have been made obsolescent by the later development of greatly improved 

collection methods, thermal switching techniques, 

multielement analyses, etc. There is an immediate 

necessity therefore to gather a great deal more data 

with all of the new technology. Nevertheless a scientific basis has been established for the development

of multielement particulate anomalies over areas that 

are partly or completely covered by vegetation as well 

as in the more obvious regions of soil exposure. Surveys carried out over known mineral deposits in areas 

covered by glacial overburden and vegetation have 

yielded positive results. Furthermore the possibilities 

for atmospheric geochemistry being of value not only 

for mineral exploration but also for hydrocarbons has 

been demonstrated and anomalous effects have been 

seen in both organic and inorganic parameters over 

known oil and gas fields.

One of the more obvious potential applications of 

atmospheric geochemical exploration could be in the 

areas having difficult access such as tropical rain 

forests. It will be a great interest for example to see 

the effects of deep taproots and high transpiration 

rates on the overlying atmospheric geochemistry.

Some recent preliminary field data indicate that 

the principles of biogenic enrichments and depletions
AIRTRACETM—AN AIRBORNE GEOCHEMICAL EXPLORATION TECHNIQUE 247

SCALE-MILES

0

1

1 

I

2

, I

wind direction

360°/15-20mph

t

put 

nomaly

wind direction 

320°/10-15mph

I 5

I X

Area of

Reported

Drilling

Input 

Anomaly

Scale 

0 1 2

MILES

FIGURE 11.—Flight B AIRTRACETM activity contours Cu + Zn 

regression.

FIGURE 10.—Flight A AIRTRACETM activity contours Cu + Zn 

regression. release. A full understanding of this phenomenon 

should in the future allow a more fundamental apbetween plants and soil have a parallel in the enrich- proach to the interpretation of data gathered over

ment factors between plants and the particulates they vegetated terrain.
248 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

OIL AND GAS FIELD

GROUNDTRUTH

Mn/Fe Rotic

SCALE IN MILES

WIND DIRECTION AIRBORNE 

Mn/Fe Ratio FROM S-E 

8-10 KNOTS

FIGURE 12.—Cement comparison of AIRTRACETM data and ground truth.
AIRTRACETM—AN AIRBORNE GEOCHEMICAL EXPLORATION TECHNIQUE 249

ACKNOWLEDGMENTS

The writer has been associated with a number of 

colleagues within Barringer Research Ltd. who have 

contributed substantially to the research reported in 

this paper and to the development of the operational 

AIRTRACE system. These persons include the following. Geochemical investigations: P. M. Bradshaw, B. 

Smee, I. Thompson. Development of operation hardware and electronics: M. Failes,* M. Paul, F. Lanza. 

Analytical developments: M. Silvester, F. Abercrombie, H. Zwick. Microbiological research: A. 

Murray. All of the above are members of Barringer 

Research except as indicated.

The writer is especially indebted to Mr. D. 

Macourt** who has played a very important role in 

many phases of the AIRTRACE development programme from its inception.

Research on botanical and biological aspects has 

been carried out in the Botany Department, Imperial 

College, by J. Barber and W. Beauford.

The AIRTRACE development has only been possible through the joint efforts of all of the above 

together with the combined funding of Barringer Research Ltd., the Anglo American Corporation of 

Canada, and Hudson Bay Mining and Smelting Co. 

Ltd.

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PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

An Application of Satellite Imagery to Mineral Exploration

By Mark A. Liggett and John F. Childs, 

Cyprus Georesearch Company, 

Los Angeles, California 90071

ABSTRACT

The application of satellite remote-sensing techniques to mineral exploration is based on the ability to 

recognize a variety of geologic features characteristically associated with hydrothermal alteration and 

related mineralization. Such features can include 

favorable structural settings, lithologic associations, 

and alteration color or topographic anomalies. Successful application of satellite imagery, however, is 

dependent upon the size and expression of these 

characteristic features and their predictive value for 

narrowing the area of exploration to a practical size 

for economical evaluation using other exploration 

techniques. Landsat-1 MSS imagery has been effectively used in studying the regional tectonic controls of 

Cenozoic volcanism, plutonism, and related gold, 

silver, and base metal mineralization in part of the 

Basin and Range province of southern Nevada, eastern California, and northwestern Arizona. Within a 

volcanogenic province aligned along the Colorado 

River south of Lake Mead, Nevada, the locations of 

known mineral deposits appear in satellite imagery to 

be spatially associated with generally east-west structural trends, transverse to the north-south structural 

grain typical of the province. Field reconnaissance in 

this area has confirmed a temporal as well as spatial 

relationship between mineralization and the anomalous east-west structural trends. Assuming a genetic 

relationship between structure and mineralization, 

systematic analysis of Landsat imagery and subsidiary 

data has provided a basis for selecting new targets 

for ground-based exploration reconnaissance.

INTRODUCTION

Applications of satellite remote-sensing techniques 

to mineral exploration have generally been based on

the ability to observe characteristics of mineralization, 

associated alteration or other related features in 

synoptic imagery of relatively low resolution. Such 

characteristic features can include alteration color and 

topographic anomalies, distinctive lithologic associations, favorable structural settings, and vegetation 

changes caused by soil geochemical anomalies. The 

relative value of these features as exploration guides 

often varies with the genetic type of mineralization, 

geologic terrane, and climatic setting. The economic 

advantages of using satellite imagery depend both on 

the success of detecting these features and the costs 

of obtaining comparable information using alternate 

methods.

In the western United States, direct surface expressions of alteration and mineralization are likely to 

have been recognized long ago by conventional means. 

In such well-explored areas, it is necessary that the 

exploration methods used lead to the detection of 

blind or poorly exposed mineralization. One approach 

to reconnaissance exploration for such ore deposits 

is the selection of preliminary targets on the basis of 

favorable structural settings or other regional geologic 

associations.

This paper summarizes a study in which Landsat-1 

imagery was used in studying the regional structural 

settings of known gold, silver, and base metal deposits 

in part of the Basin and Range province of southern 

Nevada, eastern California, northwestern Arizona and 

southwestern Utah as shown in figure 1. The synoptic 

overview of regional geology and the identification of 

specific structural features expressed in the Landsat-1 

imagery has led to the development of a regional 

model for the tectonic control of Cenozoic volcanism, 

plutonism, and genetically related epithermal mineralization within a portion of the study area.

253
254 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

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Y U M A

-tK ,, he §eneralized P°sitions of th^ Black Mountains and Nye County volcanic 

are shown w.th the st.ppled pattern. The area of the Landsat mosaic of figure 2 (p. XXII) is outlined with a heavy line

LANDSAT-1 IMAGERY from black and white MSS transparencies using a

A false-color mosaic of Landsat-1 multispectral techniclue developed by MacGalliard and Liggett

scanner (MSS) composites which covers the area of (1973)-

fan^It f?Wn ^ fiST 2 !P' XXIIK ThS individual The fals^^lor composites used in figure 2 were

in finnrl^ £Ti .'" m°SaiC ar€ identified Produced with the following combination of MSS

m figure 6. The false-color composites were prepared bands and printing filters:
AN APPLICATION OF SATELLITE IMAGERY TO MINERAL EXPLORATION 255

34°N

FIGURE 3.—Index map showing the locations and identification numbers of the Landsat-1 MSS frames used in the false-color

mosaic of figure 2 (p. XXII). Area of study is outlined.

MSS band Spectral range Printing filter

4_____ Green and yellow (0.5-0.6 /urn) ____ Blue

5____ Red (0.6-0.7 M m) ___________ Green

7____ Near-infrared (0.8-1.1 /xm) _____ Red

As a result of this MSS band-filter combination, green 

vegetation appears as intense red due to the high 

reflectance of vegetation in the near-infrared portion 

of the spectrum. Most buff-to-brown rock or soil units 

in the composites reproduce in approximately their 

natural colors. Neutral colored igneous and sedimentary rocks appear with gray to slightly blue coloring; dark igneous and metamorphic rocks reproduce 

with dark-brown to steel-gray coloring. Red, iron-rich 

sedimentary rocks and iron oxide staining associated 

with hydrothermal alteration appear as yellow coloring, sometimes varying between greenish yellow and 

orange, depending on the mineralogy and moisture 

content of the surface material. Water bodies appear

dark blue or black due to water's high absorption in 

the spectral range recorded by the three MSS bands.

Individual Landsat-1 images in the form 1:500,000- 

scale false-color composites and spectral ratio images 

(Liggett and research staff, 1974) were studied in 

comparison with the geologic and structural maps 

referenced in the bibliography. Analysis of the satellite 

imagery focused primarily on structural lineaments 

considered to be possible faults of Cenozoic age. 

These structures were systematically compared with 

available geologic maps or checked in the field. The 

tectonic map of figure 4 is a compilation of those 

lineaments identified as faults or fault zones which 

have undergone Cenozoic movement. For the purpose 

of clarity, faults having traces less than 5 km in length 

have been eliminated from the compilation.

A map of Cenozoic volcanic and plutonic rocks (fig. 

5) was compiled from the referenced published
256 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

38°N_

II7°W II6°W II5°W II3°W 

L38°N

37°N -37°N

36°N

.'x • .- '"' /' / 'i!i ^

;^_, ^ / K^ -/

35°N-

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»\> Bar stow

34°N'

II7°W II6°W

-35°N

II5°W II4°W

F34°N 

II3°W

FIGURE 4.—Generalized map of the major Cenozoic fault systems visible in the Landsat-1 imagery of figure 2 (p. XXII). Sense 

of movement on major strike-slip faults is indicated by arrows; bars and balls are on the down-thrown sides of major 

normal faults.

sources and from reconnaissance mapping guided by rocks shown in figure 5 range in composition from

analysis of Landsat-1 imagery. The mapped distribu- granite to gabbro although most are of intermediate

tion of volcanic rock types has been generalized to composition.

distinguish between those of predominantly silicic to

intermediate composition (rhyolite and trachyte REGIONAL GEOLOGIC SETTING

through andesite) and those of predominantly basaltic The area shown in the Landsat-1 mosaic of figure

composition (olivine andesite and basalt). Plutonic 2 (p. XXII) is located along the border between the
AN APPLICATION OF SATELLITE IMAGERY TO MINERAL EXPLORATION 257

II7°W II6°W II5°W II4°W II3°W

38°N—

37°N— —37°N

36°N— —36°N

35°N—

34°N—

35°N

34°N

II7°W II6°W H5°W II4°W

FIGURE 5.—Generalized map of the Cenozoic volcanic and plutonic rocks in the study area. Solid black areas are plutonic bodies 

of predominantly intermediate composition; the outlined areas are volcanic rocks of generally silicic to intermediate composition; and the stippled areas are volcanic rocks of predominantly basaltic composition.

Basin and Range province to the west and the Colorado Plateau to the east. The physiography of the 

Basin and Range province, as expressed in the Landsat-1 imagery, is characterized by systems of northerly trending mountain ranges separated by deep 

alluvial valleys. The province forms a distinct physiographic and structural terrane that can be traced from 

southern Oregon into northern Mexico.

Much of the Basin and Range province is underlain 

by Precambrian, Paleozoic, and Mesozoic rocks which 

were deformed during several orogenies of late 

Paleozoic and Mesozoic age (Armstrong, 1968). The
258 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

formation of the characteristic Basin and Range physiography began in mid-Tertiary time with the onset 

of regional normal faulting and widespread volcanic 

and plutonic activity which followed a 60-million-year 

period of relative crustal stability.

The Cenozoic structure of the province is characterized by northerly trending systems of complex 

grabens, horsts, and tilted blocks bounded by normal 

faults (Stewart, 1971). Major range-front faults typically dip at approximately 60° toward the basins with 

the angle of dip decreasing at depth (Hamilton and 

Myers, 1966). However, range-front faults having 

large displacements and dips of less than 25° are not 

uncommon in the Basin and Range province (Longwell, 1945; Anderson, 1971; Liggett and Ehrenspeck, 

1974).

Within the area of study, much of the late Cenozoic 

volcanic activity is concentrated within two generalized areas referred to here as the Black Mountains 

and Nye County volcanic provinces (figs. 1 and 5). 

The volcanic rocks of these provinces are generally 

silicic to intermediate in composition and were 

erupted from fissure systems and caldera structures 

which are closely associated with the normal faults 

that characterize the Basin and Range province.

Within the Black Mountains volcanic province, erosion has exposed several large, late Cenozoic intrusive bodies which are genetically related to the widespread silicic and intermediate volcanic rocks (fig. 5). 

In several areas, massive dike swarms are exposed 

which cut both the crystalline basement and overlying 

volcanic rocks. These swarms are believed to have 

been feeders for at least some of the volcanic rocks, 

and their emplacement can be shown to be both 

temporally and spatially related to Basin and Range 

normal faulting (Liggett and Childs, 1974).

Systems of right- and left-lateral strike-slip faults 

are mapped within the Basin and Range province, 

generally striking at high angles to the northerly 

trends typical of the province. The estimates of lateral 

displacements on these fault systems range up to tens 

of kilometres. An example is the Las Vegas Shear 

Zone which can be traced from the southern margin 

of the Nye County volcanic province to the northern 

margin of the Black Mountains volcanic province, a 

distance of nearly 150 km (fig. 4).

Various theories which have been proposed to explain the origin of Basin and Range structure are 

discussed in excellent summaries by Nolan (1943), 

Gilluly (1963), Roberts (1968), and Stewart (1971). 

Most concepts can be separated into the following 

three categories:

1. Basin and Range structure has resulted from the 

collapse of the upper crust caused by such 

mechanisms as lateral transfer of lower crustal 

material (Gilluly, 1963) or eruption of huge 

volumes of volcanic rocks (Le Conte, 1889; 

Mackin, 1960).

2. Basin and Range structure has formed en echelon 

to movement on deep-seated, conjugate sets of 

right- and left-lateral strike-slip faults (Shawe, 

1965; Sales, 1966).

3. Basin and Range structure is the result of regional 

crustal extension in an east-west direction 

(Cook, 1966; Hamilton and Myers, 1966; Roberts, 1968; Stewart, 1971). This process is believed to have occurred by plastic extension of 

the lower crust, perhaps accompanied by intrusion of plutons beneath Basin and Range 

grabens (Thompson, 1966). The net amount of 

crustal extension has been estimated to be as 

great as 300 km, or 100 percent of the former 

width of the province (Hamilton and Myers, 

1966).

Most current theories of Basin and Range structure 

presume net crustal extension within the province 

during late Cenozoic time. Although the causes, mechanisms, and amounts of extension in the province remain controversial, evidence of extension has been 

documented by geologic mapping and geophysical 

studies.

TECTONIC MODEL

Based on analysis of Landsat-1 imagery and data 

published by Fleck (1970a), a tectonic model was proposed by Liggett and Childs (1974) in an attempt to 

explain the temporal and spatial relationships observed for strike-slip deformation on the Las Vegas 

Shear Zone and normal faulting, plutonism, volcanism, and related mineralization in the Black Mountains and Nye County volcanic provinces.

Figure 6 shows by means of a simplified model 

how the Las Vegas Shear Zone is believed to have 

functioned as an intracontinental "ridge-ridge transform fault" (as defined by Wilson, 1965) which formed 

in response to east-west crustal extension in the 

Black Mountains and Nye County volcanic provinces. 

The geology and chronological development of the 

Las Vegas Shear Zone and the two areas of inferred 

crustal extension are summarized below.

LAS VEGAS SHEAR ZONE

A major zone of right-lateral strike-slip deformation passing through Las Vegas Valley was first pos-
AN APPLICATION OF SATELLITE IMAGERY TO MINERAL EXPLORATION 259

100 KILOMETERS

FIGURE 6.—Diagrammatic model relating right-lateral strike-slip movement on the Las Vegas Shear Zone to crustal extension 

in the two volcanic provinces (stippled patterns). The crustal extension is expressed in the model by major low-angle normal 

faulting which has caused anomalous thinning of the crust beneath the volcanic provinces. The amount of extension is represented by the increase in length of X-Y to X'-Y'.

tulated by Gianella and Callaghan (1934) in their discussion of the regional implications of the Cedar 

Mountain earthquake of 1932. The existence of this 

fault zone was supported by detailed mapping and 

named the Las Vegas Valley shear zone by Longwell 

(1960) (see fig. 4).

Indirect evidence suggesting more than 40 km of 

right-lateral strike-slip on this structure has been cited 

by several workers. These estimates have been based 

on displacements of stratigraphic isopachs and sedimentary facies (Longwell and others, 1965; Fleck, 

1967; Stewart and others, 1968) and offset of distinctive thrust faults of the Sevier orogenic belt (Longwell and others, 1965; Fleck, 1967). At the scale of 

the Landsat-1 imagery, evidence for the shear zone 

is expressed in the flexure of the range trends immediately north and south of the zone. Compensating for the effect of flexure along the shear zone, 

Fleck (1967) estimated approximately 70 km of rightlateral displacement of features across the deformed 

belt bordering the shear zone. Of this total, a net slip 

of 30 km has been estimated for features along the 

trace of the structure.

The eastern termination of the Las Vegas Shear 

Zone is thought to lie in the vicinity of Lake Mead 

where major right-lateral slip on the shear zone gives 

way to a system of left-lateral oblique-slip faults (fig. 

4). Immediately north of Lake Mead, Anderson (1973) 

has mapped two halves of a Miocene stratovolcano 

which are displaced left-laterally a distance of approximately 19 km along a northeast-striking fault 

zone. This structure, called the Hamblin Bay Fault, 

strikes at a low angle to the easternmost mapped 

branch of the Las Vegas Shear Zone.

East of the Hamblin Bay Fault, the Gold Butte, and 

Lime Ridge Faults of Longwell and others (1965) are 

considered by Anderson (1973) to be left-lateral 

strike-slip faults. This hypothesis is supported by the 

flexure of hogback ridges observed adjacent to these 

faults in the Landsat-1 imagery. The amount of leftlateral strike-slip deformation in this region is poorly 

known, although it is believed to exceed 19 km 

(Anderson, 1973). The spatial relationship of these 

structures to late Cenozoic normal faulting, volcanism, and plutonism in the Saint George-Cedar City 

area of Utah, suggests that the strike-slip deforma-
260 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

tion may be mechanically related to localized crustal 

extension in that area (figs. 4 and 5). An alternate 

model which involves differential subcrustal flow of 

the mantle has been proposed by Anderson (1973).

The duration of movement on the Las Vegas Shear 

Zone has been estimated (Fleck, 1967) from radiometric age determinations of rock units exposed along 

its trace. A radiometric age date of 15 million years 

from deformed beds of the Gale Hills Formation suggests that significant movement has occurred on the 

shear zone since that time. Undeformed basalts of the 

Muddy Creek Formation along the shear zone have 

been dated at 10.7 million years. From these dates 

and field evidence, Fleck (1967) concluded that most 

strike-slip movement on the Las Vegas Shear Zone 

probably occurred during the period from 17 to 10 

million years ago.

BLACK MOUNTAINS VOLCANIC PROVINCE

The Black Mountains volcanic province is a distinctive igneous and structural terrane which extends 

southward along the Colorado River from Lake Mead, 

Nevada, to near Parker, Arizona (figs. 1 and 5). Reconnaissance maps of portions of this region have 

been published by Longwell (1963), Longwell and 

others (1965), Wilson and others (1969), and Volborth 

(1973). Detailed studies of mining districts within the 

province have been published by Schrader (1917), 

Ransome (1923), Callaghan (1939), Hansen (1962), 

Anderson (1971), and Thorson (1971).

The Black Mountains volcanic province is characterized by thick deposits of ignimbrites, flows, and 

volcaniclastic sediments of generally silicic to intermediate composition, although thin basalt flows are 

locally widespread. Near Nelson, Nevada, the composite thickness of the late Tertiary volcanic sequence 

is estimated to be over 5 km (Anderson and others, 

1972).

The volcanics were deposited on an erosional surface developed on a crystalline basement of Precambrian gneiss and granite. In parts of the province, 

the Precambrian basement may have been subjected 

to metamorphism during a Jurassic orogeny (Volborth, 1973). Both the pre-Tertiary crystalline basement and the overlying volcanic rocks have been intruded by plutons of Miocene age (Anderson and 

others, 1972; Volborth, 1973). The plutons are generally elongate north-south, and range in composition 

from leucocratic granite to gabbro, although granite, 

quartz monzonite, and quartz diorite predominate 

(Anderson and others, 1972).

Structurally controlled, northerly striking dikes of 

rhyolite, andesite, and diabase cut both the crystalline

basement and the volcanic cover throughout much 

of the province. In the Newberry Mountains, 25 km 

southeast of Searchlight, Nevada, a massive swarm 

of dikes is especially well-exposed forming a belt 

over 10 km wide. These dikes form a bimodal suite 

consisting of porphyritic rhyolite and hornblende 

diabase. Near Nelson, Nevada, dikes of similar compositions are exposed in the lower portions of the 

volcanic cover, generally decreasing in number upward in the stratigraphic section. It is probable that 

these dike swarms fed much of the volcanic cover 

and were in part synchronous with plutonism (Lausen, 

1931; Volborth, 1973; Liggett and Childs, 1974).

A close genetic relationship between Tertiary intrusive rocks and chemically equivalent volcanic facies 

was suggested as early as 1923 by Ransome in a reconnaissance study of the Oatman mining district, 

Arizona. This conclusion has been supported by more 

recent mapping and geochemical studies in that district by Thorson (1971). Callaghan (1939) suggested 

a genetic relationship for an intrusive body and adjacent volcanic rocks in the Searchlight district, Nevada. Based on detailed geochemistry and radiometric age date analysis, Volborth (1973) has proposed a genetic interrelationship for plutonism, hypabyssal dike emplacement and volcanism in nearly 

the entire western half of the Black Mountains volcanic province. Most of this igneous activity occurred 

during the period from about 18 to 10 million years 

before present (Thorson, 1971; Anderson and others, 

1972; Volborth, 1973).

The structure of the Black Mountains volcanic 

province is dominated by northerly striking normal 

faults, many of which dip at angles of 10° to 20°. 

This style of deformation has been mapped in detail 

near Nelson, Nevada, by Anderson (1971) who attributed the low-angle faulting to extreme east-west 

distension of the upper crust.

Individual normal faults within the Black Mountains volcanic province are estimated to have displacements of 2 to 5 km (Anderson, 1971; Anderson 

and others, 1972). Within many of the uplifted blocks, 

erosion has removed the volcanic cover, and exposures of crystalline basement are commonly juxtaposed against thick sequences of late Tertiary volcanic rocks.

Although there is insufficient stratigraphic evidence 

upon which to base accurate estimates of dip-slip 

on most of the faults in the Black Mountains volcanic 

province, the frequency of major low-angle normal 

faults suggests that crustal extension may exceed 70 

km. Estimates of similar magnitude have been made 

for other portions of the Basin and Range province
AN APPLICATION OF SATELLITE IMAGERY TO MINERAL EXPLORATION 261

by Hamilton and Myers (1966); Proffett (1971), and 

Davis and Burchfiel (1973).

Based on a seismic-refraction profile recorded 

across the Las Vegas Shear Zone from near Kingman, Arizona, toward the Nye County volcanic province, Roller (1964) has suggested that an anomalously 

thin crust, 27 km thick, underlies the Black Mountains 

volcanic province. North of the Las Vegas Shear 

Zone, the thickness of the crust increases rapidly to 

32 km. The seismic-refraction pattern is supported by 

the existence of a northerly trending Bouguer gravity 

high (U.S. Air Force, 1968) which is aligned with the 

trend of the Black Mountains volcanic province. The 

gravity anomaly suggests an upward bulge of the 

mantle beneath the volcanic province, possibly the 

result of isostatic compensation for a thin, distended 

crust. The high gravity anomaly, like the volcanic 

province, terminates north of Lake Mead along the 

Las Vegas Shear Zone and Hamblin Bay Fault systems.

The southern end of the Black Mountains volcanic 

province is complex and indefinite. The pattern of 

volcanism, plutonism, and normal faulting within the 

volcanic province appears to terminate in the vicinity 

of Parker, Arizona, against a broad zone of northwesterly striking faults. Although this fault system 

is poorly mapped, field reconnaissance by the authors 

near Vicksburg, Arizona, and geologic mapping of the 

Quartzite quadrangle, Arizona, by Miller (1970) indicate right-lateral strike-slip on many of the northwesterly striking faults. The total amount of displacement 

on this fault system is unknown.

NYE COUNTY VOLCANIC PROVINCE

The Nye County volcanic province lies northwest of 

the Las Vegas Shear Zone in southern Nye County, 

Nevada (figs. 1 and 5). This province contains 10 

known volcanic centers, at least 5 of which are believed to have formed caldera structures (Ekren, 

1968). Detailed geologic studies have been conducted 

in several mining areas including Rhyolite and Beatty 

(Cornwall and Kleinhampl, 1964) and Goldfield (Ransome, 1909; Cornwall, 1972; Ashley, 1974). Detailed 

mapping, stratigraphic, and geophysical studies have 

been conducted by the U.S. Geological Survey in the 

U.S. Atomic Energy Commission's Southern Nevada 

Test Site (Eckel, 1968).

The Tertiary ignimbrites and flows recognized 

withih the Nye County volcanic province are estimated to have a composite thickness of approximately 9 km and a volume of over 11,000 km3 (Ekren, 

1968). Most of these rocks range in composition from 

dacite to rhyolite, although andesite and basalt flows

are locally abundant (Anderson and Ekren, 1968; 

Ekren, 1968). The volcanic units unconformably overlie a basement of Paleozoic carbonate rocks, which 

were folded, thrust faulted and metamorphosed during pre-Tertiary time. Several Mesozoic plutons have 

intruded this Paleozoic basement.

Numerous small plugs, domes, and dikes which 

range in composition from rhyolite to andesite with 

minor diabase have intruded the Tertiary volcanic 

cover. These intrusives are similar in composition to 

the volcanic rocks and many are believed to have 

been feeders (Ekren and others, 1971). Most of the 

volcanism and plutonism within the Nye County volcanic province was synchronous with major normal 

faulting in a time span from approximately 26.5 to 11 

million years ago (Ekren and others, 1968).

The Tertiary deformation within the Nye County 

volcanic province is dominated by Basin and Range 

normal faults which have produced a complex horst 

and graben structure similar to that of the Black 

Mountains volcanic province. This structural pattern is 

locally interrupted by caldera subsidence structures, 

domes, and radial faults related to separate volcanic 

centers in the province. Arcuate faults which rim caldera structures have displacements estimated on the 

basis of gravity anomalies and drill hole data to be 

as great as 2 km (Orkild and others, 1968). Much of 

the Basin and Range structure is masked by the 

youngest volcanic rocks, and the full extent of normal faulting is unknown. On the basis of gravity data, 

several basins are estimated to be filled with as much 

as 4.8 km of volcanic rock (Healey, 1968); structural 

control of these basins is suggested by the pronounced northerly trends of the gravity anomalies.

The southern margin of the Nye County volcanic 

province is formed by the western end of the Las 

Vegas Shear Zone. Within this area of complex structural intersection, several short northeast-striking 

faults have been mapped which are believed to have 

undergone left-lateral strike-slip movement of from 

3 to 5 km (Ekren, 1968). No continuation of the Las 

Vegas Shear Zone has been recognized west of the 

Nye County volcanic province.

CHRONOLOGY

The structural model proposed here for lateTertiary deformation in the southern Basin and Range 

province is supported by the synchronism of strikeslip movement on the Las Vegas Shear Zone and 

volcanism, plutonism, and normal faulting in the two 

areas of inferred crustal extension. The chronology of 

these events is summarized in figure 7.
262 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

STRIKE-SLIP DISPLACEMENT 

ON THE LAS VEGAS 

SHEAR ZONE

BASIN & RANGE 

NORMAL FAULTING: 

Black Mtns. volcanic province

Nye Co. volcanic province

SILICIC TO INTERMEDIATE 

VOLCANISM & PLUTONISM: 

Black Mtns. volcanic province

Nye Co. volcanic province

PRECIOUS & BASE METAL 

MINERALIZATION: 

Black Mtns. volcanic province

Nye Co. volcanic province

BASALTIC VOLCANISM: 

Black Mtns. volcanic province

Nye Co. volcanic province

7Z7Z7

30 25 20 15 10

x 10^ million years before present

FIGURE 7.—Generalized chronology of strike-slip movement on the Las Vegas Shear Zone and normal faulting, igneous activity, 

and related mineralization in the Black Mountains and Nye County volcanic provinces.

Within the area of study, the folding and thrust 

faulting of the Sevier orogeny is believed to have been 

confined to a relatively brief time span between 90 

and 75 million years ago (Fleck, 1970b). The Sevier 

orogeny appears to have been followed by a long 

period of relative stability and moderate erosion 

which by mid-Tertiary time had resulted in a broad 

terrane of subdued topography.

During mid-Tertiary time the area south of Lake 

Mead appears to have been the site of a broad arch 

which shed arkosic conglomerates and fanglomerates 

containing fragments of Precambrian rock toward the 

northeast. These sediments overlie an erosional surface cut in the Paleozoic rock of the western Colorado 

Plateau northeast of Kingman, Arizona. The sediments are conformably overlain by the Peach Springs

Tuff of Young (1966) which has been variously dated 

at 18.3±0.6 and 16.9±0.4 million years (Young and 

Brennan, 1974). These relationships indicate that by 

Miocene time erosion had unroofed Precambrian 

basement in the arch south of Lake Mead and that 

major normal faulting had not yet separated depositional areas on the Colorado Plateau from source 

areas in the ancestral Basin and Range province. 

Following deposition of the Peach Springs Tuff, Basin 

and Range faulting disrupted the northeast-flowing 

drainage, leading to formation of a new pattern of 

isolated structural depressions filled by basin deposits 

(Lucchitta, 1972).

According to Anderson and others (1972), in the 

core of the Black Mountains volcanic province ffie 

oldest volcanic rocks overlying the Precambrian
AN APPLICATION OF SATELLITE IMAGERY TO MINERAL EXPLORATION 263

crystalline basement are tuff units believed to be 

18.6 million years old; the youngest volumetrically 

significant volcanic units in the area consist of tuffs 

and flows dated at 12.7 million years; and most of the 

epizonal plutonic rocks in the Black Mountains volcanic province range in age from 17 to 12 million 

years.

In the Nye County volcanic province, the chronology of volcanism and structural deformation is similar 

to that in the Black Mountains volcanic province. An 

erosional surface of low relief developed on the folded 

and thrust faulted Paleozoic basement in early Tertiary 

time. This surface was covered by a widespread 

welded tuff unit dated at 26.5 million years (Ekren and 

others, 1968). Shortly after the eruption of this tuff, 

normal faults with northeast and northwest strikes 

began to develop. The typical north-trending Basin 

and Range normal faults first began to form in the 

Nye County volcanic province after deposition of a 

tuff breccia dated at 17.8 million years. The present 

mountain ranges are believed to have been well defined prior to eruption of the Thirsty Canyon Tuff 

dated at 7 million years (Ekren and others, 1968), 

although minor normal faulting has continued to the 

present.

Albers and Kleinhampl (1970) have studied the 

genetic relationships between precious metal mineralization and spatially associated volcanic centers of 

Cenozoic age throughout Nevada. On the basis of 

radiometric age determinations these workers suggest 

that mineralization was at least temporally related 

to the late stages of igneous activity in the associated 

volcanic centers. The available evidence suggests 

similar relationships in the Black Mountains volcanic 

province.

In summary, the first major normal faulting, volcanism, and plutonism in the Black Mountains and 

Nye County volcanic provinces began in the period 

from approximately 26 to 18 million years ago. Rightlateral strike-slip movement on the Las Vegas Shear 

Zone appears to have begun about 17 million years 

ago and to have continued with synchronous igneous 

activity and extensional normal faulting in both volcanic provinces. Major strike-slip movement, igneous 

activity, and related mineralization ended by approximately 10 million years ago, although Basin and 

Range normal faulting and intermittent basaltic volcanism have continued to the present time.

STRUCTURAL CONTROL OF

MINERALIZATION IN THE BLACK

MOUNTAINS VOLCANIC PROVINCE

The gold, silver, and base metal mineralization of 

Cenozoic age in the Black Mountains and Nye County

volcanic provinces is both spatially and temporally 

related to the igneous activity and structural deformation of these two areas. The structural control of 

mineralization in the Black Mountains volcanic province is of particular interest since both the regional 

structural setting of the province and the key structural trends which have localized mineralization are 

visible in the Landsat-1 imagery.

The major ore production in the Black Mountains 

volcanic province has come from the Eldorado and 

Searchlight districts in southern Clark County, Nevada, 

and the Oatman and Katherine districts east of the 

Colorado River in Mohave County, Arizona (fig. 8). 

Small mine workings and prospects are found throughout the province. The local geology and structural 

controls of mineralization in these districts are summarized below.

ELDORADO MINING DISTRICT

The Eldorado mining district is located in southern 

Clark County, Nevada, approximately 35 km south 

of Lake Mead. Most of the mines in the district are 

located within a 10-km radius of the town of Nelson 

(fig. 8). The host rocks for mineralization include Precambrian gneiss and Miocene plutonic and volcanic 

rocks of silicic to intermediate composition.

The structure of the Eldorado mining district is 

dominated by closely spaced, northerly striking normal 

faults, which commonly have dips of less than 30°. 

Anderson (1971) has attributed this system of lowangle normal faults to tensional rifting and distension 

of the upper crust, possibly related to the intrusion 

of a granitic pluton at shallow depth. In spite of the 

strong north-south structural grain, mineralization in 

the district is in almost all cases controlled by a system of steeply dipping, east-west striking faults. This 

transverse structural trend is well expressed in the 

Landsat-1 imagery.

The mineralization occurs in veins of fault breccia 

cemented with quartz and calcite gangue. The gold 

and silver are believed to have been contained in disseminated pyrite with minor galena, sphalerite, and 

chalcopyrite; however, the original sulfide minerals 

are now largely oxidized (Hansen, 1962). The veins 

typically show evidence of multiple episodes of fault 

movement followed by cementation and mineralization; many of the transverse faults along which the 

veins were formed are known to have undergone 

strike-slip movement (Anderson, 1971).

Total production from the Eldorado mining district 

during the period 1907-1945 is cited by Hansen (1962) 

as 101,522 oz gold and 2,339,353 oz silver, with minor 

production of copper and lead.
264 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

3°W

Jj/. ,7,

/ 0

i ' ° 

•A/ ^--'/ ^

miles

25

^ 25——

kilometers

5

50

H

36°N

/ i 

. \ ••

36°N

Searchlight

i mm

.." ^...

'••V.

: \Kingman

35°N—, "lr $ ^ <

\ mK"A:

t i \

!i *

.—t35°N

II5°W II4°W

FIGURE 8.—Areas of late Cenozoic precious and base metal mineralization (stippled) in the Black Mountains 

volcanic province in relation to the Cenzoic fault systems visible in the Landsat imagery.
AN APPLICATION OF SATELLITE IMAGERY TO MINERAL EXPLORATION 265

A relatively small mining area known as the Weaver 

district is located in the northern Black Mountains of 

Arizona due east of the Eldorado mining district. Like 

the Eldorado district, precious metals and minor 

copper occur in quartz and calcite vein systems which 

generally strike from N. 45° to 100° E., transverse to 

the structural grain of the province. Host rocks include 

Precambrian gneiss, Miocene volcanic rocks, and 

granites of probable Tertiary age. Although exact 

production figures are unavailable, total production 

from the Weaver district is believed to be small.

SEARCHLIGHT MINING DISTRICT

The Searchlight mining district is located at the 

southern end of the Eldorado Mountains, approximately 30 km south of the Eldorado mining district (fig. 8). 

The most prominent geologic feature of the district 

is a large quartz monzonite pluton of Miocene age 

which intruded a crystalline basement of Precambrian 

gneiss and granite and Tertiary volcanic rocks of intermediate composition (Callaghan, 1939). Although the 

shape of the pluton is generally controlled by the 

northerly structural grain of the Black Mountains volcanic province, the pluton is terminated on the south 

by a major east-west striking fault (Volborth, 1973).

Gold, silver, copper, and lead mineralization in the 

Searchlight district occurs in structurally controlled 

vein systems in and adjacent to the quartz monzonite 

pluton. Approximately 25 of the 34 productive veins 

in the district strike between N. 80° and 123° E.; most 

of these dip steeply to the south (Callaghan, 1939). 

The veins contain clasts of brecciated country rock 

usually cemented with quartz gangue although calcite 

and adularia occur locally. As in the Eldorado district, 

the veins show evidence of multiple episodes of fault 

movement followed by cementation and mineralization. Although the sense and amount of movement on 

the east-west striking faults is not known, these transverse structures contain the principal mineralization 

of the district.

Production from the Searchlight district for the 

period 1902-1934 is reported by Callaghan (1939) to 

be 207,570 oz gold, 219,596 oz silver, 650,550 Ib copper, and 1,675,560 Ib lead.

An area of numerous small gold and silver mines 

is located in Tertiary volcanic rocks east of the Colorado River, approximately 30 km east-northeast of the 

Searchlight district. The largest producing mine in this 

area is known as the Golden Door mine. The major 

mineralized quartz-calcite veins in the area strike 

generally eastward with generally steep dips; subordinate veins are irregular in strike and have shallow

dips. Recent development and exploration work in 

the Golden Door mine area has concentrated on flatlying volcanic units which have been preferentially 

silicified and mineralized.

OATMAN MINING DISTRICT

The Oatman mining district is located east of the 

Colorado River on the western slope of the Black 

Mountains, approximately 115 km south of Lake Mead 

(fig. 8). Most of the production from the Oatman district has come from vein systems within a thick sequence of late Tertiary volcanic rocks of silicic to 

intermediate composition. These volcanic rocks unconformably overlie a crystalline basement of Precambrian granite and gneiss. Both the crystalline 

basement and overlying volcanic rocks were locally 

introduced by dikes and small granitic plutons which 

are believed to be genetically related to the volcanic 

cover (Thorson, 1971).

The mineralized veins were formed within transverse fault zones, most of which range in strike from 

west to northwest and dip steeply toward the north 

or northeast. Several of the northwest-striking faults 

have undergone right-lateral strike-slip movement. 

The veins range in width from a few centimetres to 

several metres, and typically contain clasts of country 

rock cemented with a gangue of coarsely crystalline 

quartz and calcite with smaller amounts of microcrystalline adularia and fluorite. The veins commonly 

show a pronounced banding in cross section, produced 

by successive episodes of fault movement, cementation, and mineralization. Lausen (1931) reported five 

distinct stages of quartz deposition in the mineralized 

veins of which the later stages generally contain the 

highest ore values. Host rocks adjacent to the veins 

commonly show evidence of propylitic alteration.

A small amount of gold and silver has been produced from several mines in an area known as the 

Katherine mining district, located approximately 25 

km north-northwest of Oatman. The veins in the Katherine district are similar in mineralogy to those at 

Oatman, although unlike the Oatman veins, they occur 

primarily within the Precambrian granitic basement 

which has been locally intruded by dikes and plugs 

of rhyolite (Lausen, 1931). The mineralized veins in 

the Katherine mining district generally strike at high 

angles to the northerly structural grain of the Black 

Mountains volcanic province.

The combined value of gold and silver production 

from the Oatman and Katherine mining districts is 

reported by Lausen (1931) as $35,417,926 for the 

period from 1897 through 1928. This is estimated to 

represent a metal production of approximately
266 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

1,714,000 oz t gold and 870,000 oz t silver from ore 

averaging approximately 0.6 oz of gold and 0.3 oz of 

silver per ton.

DISCUSSION

Field reconnaissance and study of geologic literature guided by analysis of Landsat-1 imagery have led 

to a model which relates strike-slip deformation on 

the Las Vegas Shear Zone to normal faulting, volcanism, and plutonism in the Black Mountains and 

Nye County volcanic provinces. The Las Vegas Shear 

Zone is believed to have functioned as a ridge-ridge 

transform fault, which separated these two areas of 

east-west crustal extension. Geochronology and field 

evidence indicate that the right-lateral strike-slip movement on the Las Vegas Shear Zone was synchronous 

with normal faulting, igneous activity, and related 

mineralization in both volcanic provinces.

The east-west crustal extension in the Black Mountains volcanic province is represented by northerly 

trending systems of normal faults, dike swarms, and 

shallow plutons. The pronounced north-trending structural grain of the province is locally crossed by 

transverse fault systems, several of which are known 

to have undergone strike-slip movement. These transverse structures are well expressed in the Landsat-1 

imagery and have played an important role in localizing late Cenozoic precious and base metal mineralization within the volcanic province.

In several areas within the Black Mountains volcanic 

province a complex interrelationship has been observed between the normal and strike-slip fault 

systems. Many of the northerly striking normal faults 

terminate against transverse strike-slip faults without 

apparent offset. In addition, transverse strike-slip 

faults are frequently observed to end by turning 

abruptly in strike to merge with north-striking normal 

faults. Examples have been mapped by Anderson 

(1971) and Volborth (1973) in parts of the Boulder 

City and Nelson 15' quadrangles. This interrelationship of strike-slip and normal faults suggests that 

these structures may be mechanically related as 

illustrated in the diagrammatic model of figure 9. 

This model suggests that the transverse strike-slip 

faults in the Black Mountains volcanic province may 

have formed as minor transform faults which separated areas of differential crustal extension.

The mechanisms by which the transverse faults have 

controlled the location of mineralization are not well 

understood. It is possible that the steep dips of these 

structures provided effective conduits for ascending 

hydrothermal solutions. Because each transverse fault 

is mechanically linked to a system of normal faults, it

FIGURE 9.—Diagrammatic mode! illustrating the mechanical interrelationship of strike-slip and normal faulting believed to 

exist in the Black Mountains volcanic province. Note that 

movement on the strike-slip fault zone is mechanically linked 

to slip on the system of low-angle normal faults.

would remain active, and thus open to ascending solutions, over prolonged periods of extensional deformation. In contrast, individual gently dipping normal 

faults could be easily sealed by a variety of processes 

and are not likely to have afforded direct channelways 

for mineralizing solutions.

The model proposed here for the regional structural 

setting of the Black Mountains volcanic province unifies many of the temporal and spatial relationships 

recognized for the Cenozoic tectonics, igneous activity, 

and mineralization in this part of the Basin and Range 

province. Although many details of the structural deformation and the physicochemical controls of magma 

genesis and mineralization are not understood, the 

structural model and specific structural features expressed in the Landsat-1 imagery provide an effective 

basis for extrapolating mineralized trends and for 

selecting blind or poorly exposed targets for further 

investigation.

The application of satellite remote-sensing techniques to mineral exploration is not likely to replace 

the use of conventional methods. However, the 

synoptic perspective of satellite imagery can provide 

a valuable framework for synthesizing diverse geologic data and for guiding field research to test working hypotheses. Integrated with other exploration
AN APPLICATION OF SATELLITE IMAGERY TO MINERAL EXPLORATION 267

techniques as part of a systematic program, satellite 

imagery can be a valuable tool in reconnaissance 

exploration.

ACKNOWLEDGMENTS

This investigation benefited greatly from the work 

of R. E. Anderson, R. J. Fleck, C. R. Longwell, A. 

Volborth, and the other individuals cited in the references. Wally MacGalliard prepared the false-color 

composites of Landsat-1 MSS imagery used in this 

investigation, and H. E. Ehrenspeck compiled much 

of the data presented in figures 4 and 5. The authors, 

however, are solely responsible for errors in fact or 

interpretation.

This research was supported jointly by Cyprus 

Mines Corporation and the National Aeronautics and 

Space Administration under Contract NAS5-21809.

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AN APPLICATION OF SATELLITE IMAGERY TO MINERAL EXPLORATION 269

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PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Mineral Exploration Applications of Digitally Processed

Landsat Imagery

By R. J. P. Lyon,

Stanford Remote Sensing Laboratory, 

Stanford University, Stanford, California 94305

ABSTRACT

Enhancement processing of Landsat CCT digital 

data can markedly increase its application in mineral 

exploration in two principal ways: (1) by producing 

enhanced images with higher contrast and resolution, 

and hence higher information content for the photogeologist and (2) by pattern-recognition techniques 

applied by computer directly to the four-band digital 

spectra.

Of these, by far the greatest use will be the photogeological usage of enhanced images because of the 

simplicity of analysis in requiring only the mind of a 

creative photogeologist. The use of computers in geological analysis of these images is complicated because of the inability of the creative photogeologist to 

specify mathematically the decisionmaking process by 

which he arrives at an analysis. Algorithms can be 

created for some of the steps only, but by using an 

interactive computer display system, under the control 

of the geologist personally familiar with the problem 

and area being studied, the man-machine interaction 

can extract the benefits of both.

This paper describes the use of such a system 

(STANSORT) to mineral exploration problems, in 

zero vegetation cover (Yerington; Goldfield, Nev.), 

mixed cover of pinon pine and juniper (Pine Nut Mtns., 

Nev.), heavy birch forest (Karasjok, Norway), and full 

tropical cover (Tifalmin, New Guinea). Clearly the increasing vegetation cover makes the recognition process more complex. The inclusion of geobotanical 

(and biogeochemical) information in exploration is 

essential. Landsat data are an excellent base for this 

purpose, but ground information must be secured for 

their full application.

INTRODUCTION

Over two-thirds of the land surface of the world is 

covered with vegetation, of which 42 percent is forest, 24 percent is grasslands, and 21 percent comprises 

a cover of desertic shrubs and grasses in semiarid 

terrains (Draeger and Lauer, 1967). In any mineral 

exploration program, therefore, to neglect this obscuring cover is naive. Many of the applications of 

digitally enhanced Landsat data unfortunately have 

been made in areas devoid of vegetation cover (Pakistan, Peru, etc.) and consequently the effect of such 

cover has not been considered. This paper speaks to 

this point and shows the application of this emerging 

technology to areas of sparse desertic cover (Nevada), 

moderate cover of pines and juniper (Nevada), and 

full cover of birch forest (northern Norway), and rain 

forest-jungle (central New Guinea Highlands).

We must consider vegetation in our Landsat analysis or we will be dealing essentially with only one part 

of the total exploration problem. The principal measurement problem is a familiar one—sampling—and 

revolves around making sure that the coverage of the 

field equipment adequately expresses what is seen by 

the satellite in one pixel (0.4 ha or 1 acre) resolution. 

Clearly one must evolve techniques which include 

soils and vegetation in the right proportions, and this 

is difficult at ground level.

A secondary, but very real, problem is- that no one 

technique of data enhancement (stretching, ratioing, 

etc.) works all the time in every area, mainly because 

of the variable effect of differing vegetation cover. 

One must use a group of techniques to obtain the 

maximum benefits from the computer compatible 

tapes (CCT's) from Landsat.

271
272 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

BACKGROUND

The principal attraction of the Landsat satellite system to a modern mineral exploration program is, that 

for the first time, a calibrated and quantitative spectrally filtered photographic system is available with 

coverage of almost any part of the land surface of the 

Earth. Unlike traditional aerial photography, one does 

not have to question the film type, filters, the development practices which were used, or by what means 

were numerical data extracted from the film-base 

materials. We can directly compare spectra. The spectral response is fixed and constant, the gray-scale 

characteristics identifiable, no matter whether we are 

looking at Norway or New Guinea, Australia, or 

Argentina. In addition, as an important corollary, any 

software algorithms developed to process the digital 

data from the satellite apply equally to any other geographic locality.

Spatially with Landsat we have to modify our thinking somewhat, as each resolution cell (the highest 

resolution unit possible) covers 0.4 ha (1 acre) and is 

seen at scales smaller than those with which we have 

had most of our prior experience. This can be looked 

at in at least two ways. Normally we use a higher 

resolution element—say 10 cm2 and a scale of 

1:40,000—because our decisionmaking process in 

photointerpretation requires this degree of spatial 

resolution for shape identification. Even when using

color film we base most of our photogeological analysis on shape and neglect the discriminant power of 

the spectral color. This conditioned reflex has come 

about because our color reproduction in printing 

leaves much to be desired, and we have not been able 

to state (or remember) precisely what spectral colors 

we were viewing. Landsat with its quantitative reproducibility has changed much of that. Furthermore, 

although the pixel is 0.4 ha in area, there are still 

250/km- (640/mi-). If decisions can be made on the 

spectral information content of each pixel, then we 

can consider this resolution as giving 250 decisions/ 

km- (640 decisions/mi-)—a very different way of 

looking at data. Each Landsat scene contains about 

7 million pixels covering 34,000 km2 , and any set of 

pixels in that or adjoining tapes can be rapidly evaluated by the same algorithm, thus markedly broadening the usefulness of this search approach in exploration.

In our work at Stanford, we have continually 

worked at high resolution with the Landsat data, often 

using only 100 pixels or so to perform analyses relating ground measurements to those of the satellite. 

Our basic study areas are 20 km2 (7.6 mi2 ) presented 

on a video-display and on paper printout at about 

1:20,000 scale. For larger coverages, at the district 

level we prepare film images of 300-360 km2 (125 

mi 2 ) at a scale of about 1:220,000, to which we have

Trees

Water Serpentine

Colum n

TRAVERSE A - A1 ( Row 1234 ) 

I I 280 I Serpentine i Tract

66O

Column 

TRAVERSE B - B' (Row 1248)

FIGURE 1.—Channel-by-channel spectral plots for picture elements (pixels) along a raster line. T=trees; K=Crystal Springs reservoir (water); S=serpentine; F=freeway (I-280); H^housing tracts. From Levine (1976).
MINERAL EXPLORATION APPLICATIONS OF LANDSAT IMAGERY 273

made the required geometric correction. We thus 

continually remind ourselves that the field problems 

to which we are applying these techniques require 

detailed answers for 20-300 km2 areas at scales between 1:24,000 and 1:100,000 to be of use in the 

typical exploration program.

RATIOING CONCEPTS AND ADVANTAGES

Of all the concepts presently used in enhancing 

Landsat digital data that of ratioing any pair of the 

four channels has proved the most significant. This has 

several immediate advantages—it tends to normalize 

the spectral data, removing "brightness" contrasts between any two pixels and enabling a better comparison of their hue or color. Such ratioing has been 

performed optically before (Whitaker, 1965) by 

simultaneously printing a positive transparency of one

channel and a negative of the other, but many assumptions as to linearity of response of the two film 

records have to be made. By far the more positive and 

simpler task is to use the digital data and perform the 

single ratio step in the computer. At the same time 

one often stretches the data in each channel to make 

maximum use of the full dynamic range (0-255) before 

ratioing.

A small exercise is useful at this point to elucidate 

further the physical meaning of Landsat spectra and 

the ratioing process and, at the same time, to show 

the high resolution capabilities of spectral analysis of 

this system. To illustrate these points figures 1 and 2 

have been taken from a more detailed analysis 

(Levine, 1976) of the concept initially developed by 

Honey and others (1974).

The upper traverse (A) in figure 1 represents a plot 

of 50 pixels along a single raster line (pixels 610-660;

BOct724Jan 10May 28 May 28May 3JuI 3Jul 21Jul 21 Jul 26Aug 26Aug73

FIGURE 2.—Time series of averaged spectra and radiance (upper) and normalized reflectance (lower). Spectra for averages 

of 10 pixels. Dashed spectra are for burned-over areas (soil areas). From Levine (1976).
274 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

row 1234) for a San Francisco Bay scene (1075- 

18173). The lower traverse (B) represents a similar 

traverse of 40 pixels (pixels 660-700; row 1248) 

slightly farther to the southeast.

Each small zigzag pattern is a radiance plot of all 

four Landsat channel values for a single pixel, with 

the digital numbers joined to give a low resolution 

spectrum. The spectra can be easily classed into similar shapes, by passing the eye rapidly from left to 

right along the raster line, using the well-developed 

shape-recognition features of the human eye-brain 

system (Step 1). As Step 2, we can correlate these 

pattern classes precisely with mapped land-water interfaces by locating them on large-scale topographic 

maps (1:24,000 scale) or, preferably, if available, on 

orthophoto maps at the same scale. The pattern (T) 

could be identified with tree-covered slopes, (KJ with 

the western arm, and (K2 ) with the eastern arm of 

Crystal Springs reservoir. Similarly (Si) and (S2 ) were 

identifiable with patches of serpentine outcrops cut 

by Interstate 280 (F), and (H) as a housing tract which 

lay to the east.

To adapt this eye-recognition method to machine 

operation an automatic, unsupervised clustering 

algorithm was written by Honey which simulates 

Step 1 in the computer and forms the basis of our 

STANSORT program (Honey and others, 1974). Steps 

1 and 2 together when performed manually help the 

worker gain confidence in the credibility of Landsat 

spectra and in possible pattern recognition processes. 

This part of the exercise has important teaching applications.

Atmospheric corrections, which remove the effects 

of back scattering of sunlight by the atmospheric 

column, were performed (Step 3) by subtracting the 

observed apparent brightness in each channel from 

over a large area (45 pixels) of zero-reflectivity carbon-black refinery waste lying on the south shore of 

Carquinez Bay (northeast of San Francisco but still 

on the same Landsat scene and tape; see (Lyon and 

others, 1975). Reduction of the atmospherically 

corrected values of reflectance is performed in Step 

4 by observing the apparent brightness of a known 

reflectance target—the concrete parking aprons of 

Moffett Field, on the southwest edge of San Francisco 

Bay, in the same Landsat tape. As the bidirectional 

reflectance of the concrete has been measured by us 

(28 percent, 31 percent, 30 percent, 32 percent in each 

channel, 4-7) a linear interpolation between the zeroreflectance target (<0.5 percent in all channels) and 

the concrete "bright" target enables us to convert any 

other pixel spectrum to reflectance.

Figure 2 (upper) shows radiance spectra (averaged 

over 10 pixels) from another nearby grassy/soil area, 

in a time-series (plotted as the abscissa) from fall 

(October 6, 1972) through summer (August 26, 1973). 

Only the solid curves, like (1) and (2), need concern 

us; the dashed curves (3) are for burned-over areas of 

significance later in the year. By performing the ratioing (Step 5) much more familiar spectral shapes 

appear. Here in figure 2 (lower), Channels 5, 6, and 

7 have been divided by Channel 4, although equally 

well any other channel, the total of all channels, etc., 

could be used, and particularly so if Channel 4 is 

noisy.

Ratioing removes the varying absolute levels of 

brightness (see within pattern T in fig. 1) which are 

from the sunlit and shaded sides of hills covered with 

a constant terrain material—in this case, trees. Steps 

3 and 4 may be omitted if one does not require atmospheric corrections and reflectance data and comparable shadow-free "flat earth" spectral images may 

be made. Ratioing thus enhances the spectral-color 

information (Whitaker, 1966) in Landsat data by suppressing the relative brightness due solely to topography. Obviously in structural analysis this would not 

be an asset where shadows materially aid in the 

analysis, but the later discussion of applications will 

show the merit of ratioing for lithological differentiation. We retain both structural and lithological information by making three-color imagery, with two of 

the three color-guns assigned to ratio images (say 

Ch 7/4* = green and Ch 5/4 = blue) and with the red 

gun assigned to our "edge-enhancement" procedure, 

which produces nondirectional symbols at spectralcontrast edges in the four-channel data matrix (Honey, 

Prelat and Lyon, 1974). The human eye again is used 

to connect the edge dots into meaningful lineaments. 

These may or may not parallel lithologic contacts as 

seen in the other two ratio images in the three-color 

print.

APPLICATION CASE HISTORIES

Where the surface materials over a mineralized 

area are residual and contain alteration minerals— 

clays, iron oxides, etc.—typical of that style of mineralization, the techniques for use of Landsat digital 

data in a search mode are relatively straightforward. 

These have been well documented by Goetz and 

others (1975), Vincent (1973), and by ourselves (Lizaur, 

1975; Ballew, 1975a, 1975b; Lyon and others, 1975; 

Lyon, 1976). However where the mineralized targets 

of search are covered—either by glacial debris, wind-

* Ratios may be shown as Ch 7/4 or R74, etc.
MINERAL EXPLORATION APPLICATIONS OF LANDSAT IMAGERY 275

blown sand, alluvial outwash, etc., or more often, by 

even minimal amounts of vegetation—their discovery 

is much more complicated.

This selection of our case histories is oriented to 

these points and is arranged in order from essentially 

zero vegetative and surficial cover (Yerington, Nevada, pit and dumps), through light desertic cover

(Singatse Range, and Goldfield, Nevada), to moderate pinon pine and juniper forest (Pine Nut Mountains, Nevada), and, finally, heavy forest of birch in 

an Arctic environment with a full cover of glacial till 

(Karasjok, Norway), and jungle at Tifalmin, New 

Guinea.

The localities are tabulated in table 1.

TABLE 1.—Localities and results of case histories

Very low to zero cover:

Yerington copper pit, dumps, and surrounding Singatse Range, Nevada. Oxidized and 

nonoxidized ore (sulfide) may be differentiated in the pit and the sulfide rock "discovered" in the tailings pond using Landsat data in a search mode (STANSORT/ 

SEARCH).

Goldfield, Nevada. Alteration zones and gossans surrounding gold-alunite mineralization. Outline of alteration zone can be mapped by Landsat image enhancements.

Moderate cover:

Pine Nut Mountains, Nevada. A molybdenum-bearing skarn with a biogeochemical 

anomaly in the pinon pine and juniper, independently located by color-ratio images 

prepared from Landsat data.

Heavy cover:

Karasjok, Norway. A known copper-bearing biogeochemical anomaly was relocated by

the Landsat data and now has been extensively studied in the field. 

Tifalmin, New Guinea. A known set of copper-bearing intrusives under full jungle

cover. So far very little success in determining any vegetative anomaly.

VERY LOW TO ZERO COVER

YERINCTON COPPER PIT AND DUMPS, MASON VALLEY, 

NEVADA

General description.—The simplest example which 

can be chosen for analysis, and which is still of significance to mineral exploration, is that of an open-pit 

mine and its surrounding dumps. Here, single rock 

type materials cover enough area as to be statistically 

significant (>8-10 pixels) in the pit itself (generally 

a single type of intrusive rock with one or two superposed alteration or oxidation mineralogies). The 

dumps have been carefully segregated during mining 

and represent waste rock, low-grade ore, and tailings 

from the metal extraction.

Yerington pit in Lyon County, Nevada, about 80 km 

south-southeast of Reno, satisfies all of these criteria. 

This pit, while small (2x1 km), may be considered to 

have an oxidized upper portion and a nonoxidized sulfide-bearing lower portion (fig. 3). The southern dumps 

are made up of alluvial overburden and waste rock 

(largely granodiorite). The northern dumps (from 

northwest to northeast) are respectively oxide tailings 

from leach ore, sulfide tailings pond (T) and low-grade 

mixed oxide-sulfide leachable ore. All the northern 

dumps represent varying grades of oxidation of the 

quartz monzonite and granodiorite. From the pit, to

the south, the dumps are alluvial outwash and cover. 

The housing settlement of Weed Heights (W) and the 

irrigated river-bottom lands of the Mason Valley (M) 

and Walker River show patterns typical of vegetation 

(gardens, lawns, fields, etc.).

The Singatse Range (S-S) has a typical Nevadan 

Basin and Range topography bounded on the east by 

several range-front faults. The geology of the range is 

complex and is composed of Jurassic granodiorites 

and sediments to the southwest of the pit, with predominantly Tertiary volcanics (ignimbrites, etc.) to the 

west and northwest of Weed Heights.

The vegetated cover of the pits and dumps is zero. 

The cover on the Singatse Range is sparse (mainly 

sagebrush and other desertic shrubs) typically 3 to 5 

bushes per 10 m2 . From above, less than 10 percent of 

the ground would be covered.

Analysis.—Single band images prepared on a lineprinter, with each pixel value being encoded as a symbol (lighter toned for higher value = brighter areas, 

darker for lower value = darker areas) with 14 steps 

or gray tones, are shown in figure 4. These resemble 

over-enlarged photographs but are very useful as 

"road maps" for locating specific pixels or areas for 

detailed analysis.

Figure 4 shows a typical output stage of data each 

for 20 km2 of Channel 5 (left) and Channel 7 (right).
276 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 3.—Yerington pit area, Nevada, aerial photograph from 20 km. T=tailings pond; Fe=acidified ferric 

sulfate leach liquor; D=rdumps, D1=oxide leach waste, D2=leach dumps, low-grade oxide and sulfide; D3 & D4=mixed alluvial and waste rock, mainly granodiorite; M=Mason Valley; VV=:Weed 

Heights housing area for the mine; f-frr range-front fault; S-Sr=Singatse Range. In pit: 1=:sulfide, 2rz 

oxide, 3:=mixed, 4=leached ore. Original copied from a color photo (RB57-MX248) taken August 11, 

1973.
MINERAL EXPLORATION APPLICATIONS OF LANDSAT IMAGERY 277

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FIGURE 4.—Raw lineprinter output for channels 5 (left) and 7 (right), Yerington pit area, Nevada. t=tailings pond; d=dumps, 

oxide waste; p=Yerington pit; w^VVeed Heights housing area; m=Mason Valley; a=agriculture along the Walker River; 

S-S:=Singatse Range. Reduced about 5 times; approximate scale, 1:24,000.

Each figure represents a (5:1) photoreduction of raw 

lineprinter output.

Vegetation in the Mason Valley (m) is dark in Channel 5 (left) and lighter in Channel 7 (right), if growing 

well (as at a) where some field shapes can be seen.

The eastern flanks of the Singatse Range occupy the 

left edge of each image. Weed Heights housing area 

(w) for the mine is also dark in Channel 5 and light in 

Channel 7.

The pit area (p), dumps (d) and tailings pond (t) ap-
278 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

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FIGURE 5.—Effect of varying the tolerance level in STANSORT/ 

CLUSTER. Data for the immediate Yerington pit area, showing 

the decreasing number of classes (letters) of materials as 

the tolerance is increased, from 6 percent to 9 percent, 

thereby simplifying the pit classifications. Landsat CCT 1397- 

18051, smoothed.

pear in varying shades of gray in each channel. Some 

water (black in Channel 5 and Channel 7) lies at the 

north (uppermost) end of the tailings pond inside the 

lighter toned dikes.

This represents the simplest form of Landsat enhancement—stretching and density encoding—and is 

presented at an original scale of about 1:24,000.

In figure 5, the next step of classification is shown. 

The clustering algorithm used in STANSORT/CLUSTER (Honey, Prelat, and Lyon, 1974) operates with a 

gating technique to make a "like/unlike" decision on 

the four-band spectra of each pixel, commencing at 

the upper left corner of the matrix and proceeding to 

the lower right. The gating value is an input variable 

and may be modified at will by the user, in an interactive mode. Wider tolerances (say 15 percent) allow 

most spectra to pass into a few classes—tighter tolerance produces many classes. The system uses the 26 

alphabetical symbols and then blanks for all above 26. 

The clustering step is very fast and takes 10-30 s. If 

the pattern produced on the video screen has too few 

symbols one closes up the tolerance—if there are too 

many blanks one opens the tolerance. Up to 20 kmmay be classified at once.

The key to the method is that the operator decides 

which pattern best fits his knowledge of the training 

area he has selected. In the case shown in figure 5, of 

the area immediately surrounding the Yerington pit, 

we felt that T (tolerance) = 8 or 9 percent gave the best 

fit, permitting segregation of class 'B' for oxidized 

quartz monzonite and 'P' for unoxidized ("sulfidebearing") quartz monzonite. Class 'A' correlates with 

the surface dumps, while class 'C' represented the 

alluvial outwash from the Singatse Range to the west.

With this best-fit decision made, the spectra are 

"frozen," and can be used to search the rest of the 

34,000 km- on the tape. Figure 6 shows the subsequent

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FIGURE 6.—Clustering analysis using STANSORT/SEARCH, tolerance:=8 percent after training on the immediate pit area. This 

map starts at row 1140/col. 707, Landsat CCT 1397-18051, 

training area was as shown in fig. 5. T=tailings pond; P= 

pit; WzrWeed Heights housing area; MrrMason Valley irrigated land; A=agriculture in the valley along the Walker 

River. Pit classification symbol "P" appears only in the 

tailings pond area, with symbol "B" only in the pond dikes 

and on some of the dumps. Most of the southern dumps 

have a symbol "A" which matches some of the leach residues.
MINERAL EXPLORATION APPLICATIONS OF LANDSAT IMAGERY 279

patterns developed in STANSORT/SEARCH using 

the frozen spectra in a supervised mode of pattern 

recognition but retaining the same tolerance (T = 8). 

The following points are significant:

1. The vegetated areas of Weed Heights housing area 

(W) and the Mason Valley (M) and (A) are similarly identified.

2. The nonoxidized, sulfide-bearing monzonite (P, 

also labelled with a #5 arrow only occurs elsewhere in the tailings pond (T)—exactly where 

one would expect to find it after the copperflotation step. Only a few other isolated pixels in 

the entire Singatse Range are so classified and 

are considered as noise.

3. The oxidized monzonite (B symbol), on the other 

hand, appears mainly on the dikes around the 

tailings and in patches between the pond and the 

pit. Elsewhere in the Singatse Range this symbol 

occurs principally at the dumps of the Ludwig 

mine off to the southwest.

4. The "low-oxide copper" and other dump materials 

(symbol A) occur immediately to the south of 

the pit, to the north near the leach liquor pond 

(blank), and on the east flank of the tailings pond.

Thus patterns selected in the pit (training area) can 

be used to classify and segregate similar materials 

nearby on the mine property or in the rest of the 

Singatse Range itself. Potentially the system can 

search the whole Landsat scene, covering 3.3 million 

ha (8.2 million acres).

A slightly different technique is shown in figure 7 

(p. XXIII). Black and white enhanced images of Channels 5, 6, and 7 of Landsat data over the YeringtonSingatse Range area were combined into a color print 

using the Dicomed image-forming process. Digital data 

preprocessed for enhancement were fed sequentially 

into the Dicomed unit using a blue filter for Channel 5, 

a green filter for Channel 6, and a red filter for Channel 7. The resulting false color infrared image is shown 

as figure 7B (p. XXIII), which can be directly compared 

with an aerial color photograph (fig. 7A, p. XXIII) 

taken from 20 km (65,000 ft) 13 days earlier. A close 

match geometrically is evident, and the increased contrast more clearly reveals features like roads and 

desert washes.

To make figure 7D (p. XXIII), which is a color ratio 

print, the ratio channel data were prepared for the 

Dicomed unit. This time ratio R54 was coded with a 

blue filter, R64 with a red filter, and R74 with a green 

filter.

This color ratio print (fig. 7D, p. XXIII) differs markedly in information content from the color-infrared

print (fig. 7B, p. XXIII), although pixel-by-pixel the data 

locations are the same.

The ratioing "smooths out" the topography, removing the shadowed-side effects, and emphasizing the 

spectral content of the data. Now irregular patches of 

color replace the topographic-dominance in figure IB 

(p. XXIII) and in figure 7A (p. XXIII), too. Careful comparison with the geological map (fig. 1C, p. XXIII) 

(Moore, 1969) reveals that the ratioing has enabled a 

close correlation of similarly colored areas with the 

regional geology to be prepared using Landsat digital 

data alone.

We are planning a much more detailed ground 

measurement program in this area to relate better the 

geology with the ratio images, but even the initial results shown here are most significant of the role of 

Landsat digital processing in regional geology.

COLDFIELD, SOUTHWEST-CENTRAL NEVADA

The old mining camp of Goldfield had its heyday 

around 1906 but is now becoming something of a 

celebrity again as a test site for Landsat analysis techniques (Rowan and others, 1974; Goetz and others, 

1975; Lizaur, 1975; Ballew, 1975b). These several efforts are based upon the painstaking studies of Roger 

Ashley who mapped the 45 km2 (17 mi2 ) area in the 

1968-1971 period under the U.S. Geological Survey's 

Heavy Metal Program. Ashley's geological maps (Ashley, 1971, 1974) and especially the map of the argillic 

alteration, which is so pervasive at Goldfield, form the 

ground calibration data for most of the studies. Figure 

8A shows the typical low vegetative cover of the 

desert area.

Figure 9 compares three map products to emphasize 

their similarities. Figure 9A is taken from Ashley's caldera study (Ashley, 1974) and shows the premineralization structural pattern with the dominant ring fracture systems, central fractures (northeast in the northern half and swinging to southeast in the southern half 

of the caldera), and the tangential "taillike" fracturing 

extending out to the east-southeast. The premineralization intrusive centers (hatchured) are strongly clustered on the inferred ring-fault system.

Figure 9B is an outline map (from Ashley, 1971) of 

the same area at about the same scale but, with the 

outcrop zone of the argillic alteration in the volcanics, 

shaded a darker tone. This bull's-eye and tail pattern is 

the key to the search for ore mineralization at Goldfield, showing a strong structural control for both the 

alteration and mineralization stages.

The same spatial pattern (of the argillic alteration 

zones) can be defined directly from the Landsat digital
280 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 8.—Comparison of vegetation covers. 8A; Coldfield, Nevada, with sagebrush. 86; Pine Nut Mountains, Nevada, with pinon pine and juniper, and some 

sagebrush in the foreground. This area is closer to the Sierras and has a higher 

rainfall, although still a semidesert.

data, by ratioing Channel 5/Channel 4, as prepared 

from CCT 1342-18003 (June 30, 1973, fig. 9C). This 

ratio (R54) may be used to emphasize iron-oxide-rich 

areas which show high ratios with these bands. White 

areas in the caldera ring and east-southeast tail have 

ratios above 1.20 whereas darker areas, and the Malpais basalt to the southwest, have values around 0.90- 

0 95 (tables 2, 3, 4, and 5).

Similar comparisons for other ratios (although not 

so striking) can be found in the ground-measured Goldfield data, shown in table 4A—Altered samples, and 

4B—Unaltered samples.

The ratio image (R54, fig. 9C) used to emphasize 

iron-rich areas, shows the ring fracture (and eastsoutheast tail) features clearly (inside the solid black 

arrows), although on this image the central bull's-eye 

pattern is very subtle. The white patch to the northeast shows the argillic alteration and gossans of the 

North Diamondneld district, outside the main structure, again indicating how a pattern developed for one
MINERAL EXPLORATION APPLICATIONS OF LANDSAT IMAGERY 281

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TABLE 2.—Typical ratio R54 values for Goldfield 

(after Lizaur, 1975)

LANDSAT-derived data (1342-18003, June 30, 1973) Ratio

Iron-oxide-rich areas _____________ Above 1.20

Malpais basalt ____________________ 0.90-0.95

FIELD-measurement data

Iron oxide gossan soils _____________ 1.60±0.20

Montmorillonite soils (average) _________ 1.22±0.13

Montmorillonite soils (selected) _________ 1.30±0.04

Kaolinite soils (average) ______________ 1.22±0.16

Kaolinite soils (selected) ______________ 1.17±0.08

Most altered rocks (average) ___________ 1.30±:0.17

Unaltered rocks (average) _____________ 1.10±0.11

TABLE 3.—Ratio comparisons for Goldfield, Nevada 

(after Lizaur, 1975)

R54 Landsat R54 Ground

Unaltered rock

Malpais basalt _.

Milltown andesite 

Background

Cray volcanics _. 

Altered (targets)

Traverse areas _.

Gossan soils __.

Below 0.92 __ Not measured 

__do ____ 1.00-1.20

1.00-1.11 __ 

Above 1.19 __

1.10-1.19

1.18-1.42 

1.48-1.74

locality can be used to locate other similar areas 

elsewhere.

A large map of R54 values was made by Lizaur 

(1975), and several background areas were selected 

along access roads to establish the character of these 

areas as seen from Landsat. Tables 2, 3, and 4 have 

been calculated from his field measurements over 

areas shown to be anomalous by R54 ratio maps prepared from Landsat data (CCT 1342-18003, June 30, 

1973) and have been segregated by him to be field 

checked. In three traverses in sec. 4 he crossed a 

typical quartz-alunite (silicified) ridge, locally called a 

"ledge." These are usually gold ore .bearing and surrounded by a kaolinite-rich selvage (15-20 m wide), 

grading outwards into a montmorillonite zone more 

than 100 m wide. Table 5 lists published data for several alteration minerals.

Of the altered rocks seen in these traverses and at 

localities in sees. 21, 22, the gossan soils clearly were 

anomalously high in R74, R65, and R64 as well as R54, 

although these rocks differed from the unaltered or 

background samples in almost every ratio.

MODERATE COVER

Geobotanical anomalies which have been carefully 

studied and described in the literature may be used as

test targets to establish the credibility of Landsat detectability (for example, Billings, 1950). We have 

worked with two such areas ("copper-barrens") in 

Norway as well as with a mapped bio-geochemical 

anomaly (high molybdenum values in the leaves of 

vegetation) in western Nevada. Our aim was to define 

the correlation between (1) the anomalously high 

metal content in the soils, which affects the types and 

species-proportions of the vegetation populations near 

such metal deposits, (2) their reflectance characteristics as measured with Landsat bandpass equipment on the ground, and (3) the Landsat satellite data 

taken over the same areas. The two areas differ, as the 

Pine Nut Mountains area in western Nevada has a 

moderate cover (about 16 trees/ha) whereas the 

Karasjok locality in northern Norway has a total cover 

of birch forest or grass.

A third type of area, at Tifalmin, central western 

New Guinea, also with a total cover (jungle trees and 

grasses) did not show any evidence in the vegetation, 

as seen by Landsat, which would enable the detection 

of the copper mineralization known in the rocks and 

soils beneath the cover (Press and Norman, 1972).

PINE NUT MOUNTAINS, CENTRAL-WEST NEVADA

Being closer than Goldfield to the Sierra Nevada 

mountains of California which lie 30 km to the west, 

the Pine Nut Mountains enjoy a higher moisture content (mainly snowfall, about 20-25 cm/yr). The hills lie 

between 2,100-2,300 m in elevation and are covered 

with evenly mixed pinon pine (Pinus monophy/la) and 

juniper (Juniperus utohensis), at about 16/ha (40/acre). 

The area between these trees is predominantly sagebrush, 1-1.5 m in height, with some rabbitbrush 

(Chrysothamnus sp.) (fig. 8B).

The bio-geochemical anomaly which patchily covers 

about 1-2 km2 on the eastern flank of a low ridge of 

intermediate volcanics and limestones has been described in detail (Lyon, 1976). The anomaly takes the 

form of anomalously high (from 75-500 ppm) molybdenum levels in the ash of juniper and pine needles 

extending down slope from a molybdenum-bearing 

skarn mineralized zone in the rocks surrounding a 

small quartz monzonite intrusive (see stippled area, 

fig. 10) (De Long, 1971; Noble, 1962).

A 3-5 times larger anomalous area, covering about 

4.5 km2 and located centrally over the bio-geochemical 

anomaly, was independently found directly from the 

Landsat digital data, without prior knowledge of the 

specific location of the molybdenum-bearing vegetation pattern (Lyon and Honey, 1974). The STANSORT 

interactive computer program was used to identify the
MINERAL EXPLORATION APPLICATIONS OF LANDSAT IMAGERY 283

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MINERAL EXPLORATION APPLICATIONS OF LANDSAT IMAGERY 285

TABLE 5.—Published ratio values for some alteration minerals

Alteration mineral

Reflectance

x100

Ch4 7 R76 75 74 65 64 54

Hematitic limonite*

Coethitic limonite

33

67

43

18

5

7

50

72

61

38

9

10

60

73

71

44

12

10

56

72

71

46

12

7

93

99

100

105

100

74

112

100

116

121

133

74

170

107

165

256

240

108

120

101

116

116

133

100

182

109

165

244

240

146

154

107

14?

?14

180

146

Digitized from Rowan and others (1974, fig. 20) from data originally in several papers. 

N —samples in place.

FIGURE 10.—Locality map of Landsat-detected anomaly and the Mo-anomaly in the vegetation. Sections 

are in T. 12 N., R. 21 E., Mt. Siegel quad, Nevada. NW-trending linears are limestone outcrops; NEtrending linears are strongly developed joints (?faults). Quartz monzonite outcrop is in solid black 

near the Alpine mine mill. Stippled anomaly area is 75 ppm Mo in the juniper needle ash. Landsat 

anomaly is outlined in heavy dashes. Divide and Cherokee mines are also shown.
286 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

features and ratio images (especially R74) mode which 

showed the shape and location of the anomaly.

We have performed a considerable amount of 

ground measurements in the field in the area, both 

with cut branches and with trees in place, to attempt 

a correlation with tree reflectance and Landsatderived ratios. The ground data show higher ratios for 

vegetation inside the anomaly relative to similar trees 

outside the area (0.5-1 km away). These higher values 

are offset, however, by a lowered tree spacing per 

hectare inside the anomalous area (12-14/ha inside 

versus 16-20/ha outside). The specific percentages of 

trees versus sagebrush and soils has not been determined, but clearly increased sagebrush or soil coverages, with R74 ratios of 150-180 (instead of 400-500 

as with the trees), would lead to a darker area on a 

ratio image, comparable to that which we found in the 

Landsat data (Lyon, 1976).

FULL COVER

KARASJOK, NORTHERN NORWAY

A locality in northern Norway in heavily birch covered glacial till areas, contains several copper sulfide 

bearing strata in the Karasjok group of hornblende 

schists (fig. 11B). These "copper layers" in turn produce copper-rich, ground-water springs which poison 

the birch trees where the springs issue beneath the 

till cover (Lag and Bolviken, 1974). This well-documented, poisoned area covering approximately 100 m 

in width by 1 km in length was successfully located on 

Landsat image 1365-09430, shown in figures HA 

(Channel 5, red) and 11C (Channel 6, infrared). The 

locality is circled on the 1:250,000-scale geological 

map (fig. 11B) cut from the larger Karasjok sheet prepared by the Norwegian Geological Survey.

Channel 5 data (fig. HA) show a pronounced lightgray banding to the north and east of the letter "A," 

which closely approximates the S-curved stratigraphic 

strike of the granodiorite/metasediment boundary 

(gd/m). Bright white patches on the inner side of the 

river curves are low-lying river gravels, with a sparse 

tree cover, but having a heavy coverage of reindeer 

moss, a white lichen form.

Channel 6 data (fig. 11C), however, show principally 

the patterns of vegetation and much less information 

on the stratigraphy. Strong ENE and SSW fracturing is 

brought out by thin bright lines along the drainage. 

Several portions of the river towards the top of the 

image also show the east-northeast trend.

The anomaly of Lag and Bolviken lies inside the 

open arrows, in figures 1 ID and E, and inside the open 

circle in figure 11B. Insets 11D and E are enlargements. The ground location for this was defined for us 

on aerial photographs at about 1:16,000 scale and 

referenced to topographic maps at 1:50,000 scale. 

Our role was to see if the patterns observed on the 

ground, and in large-scale airphotos, could be seen in 

the Landsat-imaged data. In this we were very successful. The anomaly is more clear on figure HE.

Ground measurements taken in the summer of 1975 

are being interpreted and will be presented in a paper 

submitted to the International Geological Congress, 

Sydney, Australia (Bolviken and others, 1976).

TIFALMIN, CENTRAL WEST NEW GUINEA

Landsat-1 multispectral scanner (MSS) data in CCT 

format were acquired for scene 1028-00134 which 

covers an area in Papua, New Guinea, containing a 

number of porphyry prospects. Only two of these, 

however, Kennecott's Tifalmin prospect and Carpenteria Exploration's Freida prospect, were sufficiently 

free of cloud cover during data acquisition to provide 

adequate data for remote-sensing investigations. Work 

to date has been confined to the Tifalmin prospect, 

since basic ground-acquired geological and geochemical data, though limited, are available for that site 

only (Bamford, 1974).

Data manipulations were carried out using the 

STANSORT computer program. Specific output generated in the current study was Channels 4, 5, 6, and 7 

shadeprints; R47, R45, and R75 reflectance ratio prints 

(with minimum values of ratios subtracted and step 

intervals selected to maximize print contrast in areas 

of interest); and cluster analysis prints (Channels 4, 5, 

6, and 7 data clustered using a ± 14 percent tolerance). 

A complete set of these data was derived for each of 

two centers of copper mineralization, the Olgal-Futik 

and Unfin areas of the Tifalmin prospect. A single lineprint page (approximately 1:20,000 scale and covering 

an area about 3.8 by 5.4 km) provided adequate coverage of each mineralized area and adjacent surroundings to facilitate definition of reflectance anomalies (if 

any) within that area (fig. 12). All shadeprints and 

ratio prints in this study were color coded to aid 

interpretation using brown to yellow colors of graduated density. Dark colors were used for delineation of 

higher values. Cluster analyses were coded using progressively darker colors to define progressively smaller (more anomalous) areas.

Figure 12 shows part of data generated for the 

Olgal-Futik and Unfin mineralized areas. Figures 12A 

and 12B are uncolored MSS 7 shadeprints for these 

areas showing the locations of the mineralized intrusions and principal drainages. Copper geochemistry
MINERAL EXPLORATION APPLICATIONS OF LANDSAT IMAGERY 287
288 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

A-MSS-7 B-MSS-7 C-MSS 4/7

D-MSS 4/5 E-MSS 7/5 F-CLUSTER ANALYSIS

FIGURE 12.—Examples of Landsat CCT-generated lineprinter images, compared with the only geological map available (12A), 

for the Unfin area, Tifalmin prospect, New Guinea. The map shows the approximate location of mineralized intrusives 

(cross hatched) and the principal drainages. Figure 126 is an uncolored Channel 7 shadeprint, 12C a R47 ratio print, 

12D a R45 ratio print, 12E a R75 ratio print, and 12F a normalized cluster analysis. All prints cover the same geographic 

area.

over the mineralized intrusions commonly averages Systematic geochemical grid sampling, however, has

1,000 to 2,000 ppm in creek outcrop, rock chip sam- not been completed for these areas,

pies, and about 500 ppm in ridgetop soil and rock sam- The MSS raw data shadeprints, band ratio prints,

pies which are frequently oxidized and leached, and cluster analyses for the Olgal-Futik and Unfin
MINERAL EXPLORATION APPLICATIONS OF LANDSAT IMAGERY 289

areas do not appear to provide evidence of correlation between reflectance and known mineralized 

areas.

Explanations for the lack of detection of reflectance 

"anomalies" include the possibilities that: (a) reflectance modifications may have taken place as suggested 

by previous work (Press and Norman, 1972) but are of 

insufficient magnitude to be resolved in Landsat-1 

MSS data and (b) vegetation assemblage over the 

mineralized area may have adapted to the base metalanomalous soils by survival of tolerant species only 

and thus may not be significantly more stressed than 

surrounding vegetation. Work to test these tentative 

explanations is desirable but not practical at present 

due to the remoteness of the test locality. It should 

also be noted that atmospheric corrections have not 

yet been made, hence reflectance calculations have 

not been attempted. Such refined data could possibly 

reveal reflectance anomalies not resolved by the raw 

data. Lack of information on areas of zero reflectance 

or other calibrated reflectances precluded determination of an atmospheric correction factor.

EFFECT OF VEGETATION ON INTERBAND 

CORRELATIONS AND RATIOS

In tables 6 and 7 various reflectances and interband 

ratios for 575 ground-measured spectra of four main 

data sets (A = Goldfield, B = 3 Spanish sites, C = Pine 

Nut (horizontal), and D = Norway) are compared with 

their cross correlations (table 6) and their individual 

variabilities, expressed as coefficient of variability 

(COV) = CT/X. The progression A-D represents increasing numbers of vegetation spectra in each total set, 

either as pure vegetation-only spectra (Pine Nut) or 

increasing leaf-cover in the field of view (Norway). 

Each locality is mineralized, and they form typical exploration targets. All sets contain some soils and rock 

spectra. Table 6 shows two partial sets of the 144 

cross-correlations calculated—those of band correlations (Channels 4, 5, 6, and 7) are those of the interband ratios (R76, 75, 74, 65, 64, and 54). Solid contours serve to emphasize the higher positive value, 

dashed lines enclose the higher negative sets.

TABLE 6.—Correlation between variables in data sets with increasing vegetation content

[COV values derived using BMD02D program. Solid lines enclose higher positive values;

dashed lines enclose higher negative values.]

A. GOLDFIELD (0% vegetation in set; N=113)

Ch 5

83 80

77

77

77

87

R75

34

74

30

58

65

f— 42

70

34

64

^3^0

81

60

54

xs^06

^<— -26}

62

—28

59

R76

75

74

65

64

B. SPANISH TEST SITES (3) (29% vegetation in set; N=229)

Ch 5

96 83

86

77

78

98

R75 74 65 64 54

62 36 —48

C. PINE NUTS (83% vegetation in set; N=151)

Ch 5 R75 

86

74 65 64 54

D. NORWAY (85-90% vegetation in set; N=82)

Ch 5

87

83

85

R76 

75 

74 

65 

64

R76

75

74

65

64

R75

09

74

37

70

65

(36^

59 s64

03

^\

v^3j)

70

54

26

—38

28

— 44

21

R76

75

74

65

64
290 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

TABLE 7.—Means and variability in data sets with increasing vegetation content

Percentage vegetation in 

set _ _

N _ _

Ch4

Ch5 _ _

Ch6 __ __ _ _ __ _

Ch7 _______ __ ____ _ __

NX __ _ _ __ _____

NY _ __ „ _ _

R76 _ _ _ _ _

R75 _ _ _ _

R74 _ _

R65 __ _ _____ _ _

R64

R54 _ _ _ _ _

Set A 

Goldfield

0%

113

*212(.33)

260(.36)

317(.32)

285(34)

335(.08)

403(.05)

900(.10)

11K.13)

136(.16)

124(.13)

152(.17)

123(.13)

Set B

Spanish sites

(3)

29%

229

*120(.70)

143(.78)

208(.60)

240(.59)

307(.17)

344(.20)

115(.13)

204(.65)

226(.57)

171 (.55)

191 (.47)

115(.19)

Set C 

Pine Nuts 

(horiz)

82%

151

96(.88)

115(.96)

214(.44)

283(36)

237(.23)

253(30)

137(.12)

368(.45)

408(.41)

258(38)

287(34)

113(.10)

Set D 

Norway

85-90%

81

54(31)

6U65)

159(.76)

212(.76)

267(.17)

264(.15)

134(.12)

350(35)

413(30)

261(36)

306(.28)

122(30)

*Group mean values; COV in parentheses. (Ch 4-Ch 7, x10; rest, x100); coefficient of 

variability (COV)=<r/x; if >0.40, data are widely spread. Calculated using BMDO2D output, ungrouped within sets. NX=Ch 4/(Ch 4+R5 + R7); NY=Ch5/(Ch4+R5+R7); NX+NY 

+ NZ=1.00. Data sets presumed to be Gaussian populations.

Table 7 lists the group mean values for each of 

the 12 variables used and shows the variability 

(COV = (7/x)* in parentheses (where COV is >0.40 

the data are widely spread). 

Analysis — Table 6: Cross-Correlations 

I. Channel correlations are high (>0.70) in all four

data sets, but increase with vegetation content. 

Correlations between Channels 6 and 7 are higher

with increasing vegetation content. 

3. Correlations between Channels 5 and 4 are high

even where vegetation is dominant. 

Interband correlations markedly change in value

with even a slight increase (29 percent) in vegetation content (see absolute values in table 7), in

some cases doubling in value. 

High (>80 percent) vegetation sets (C and D) show

varying correlation patterns, which may mean

each relationship is specific for one data set

only. This is being investigated. 

Analysis — Table 7: Mean (Absolute) Levels of 

Variables 

I. Variability (COV) of the values must be considered

for data dispersions, when comparing means.

2.

4.

5.

*The COV values were derived using the BMDO2D (UCLA 

Biomedical Division) statistical package, which examjnes all the 

spectra as a set in an ungrouped mode and differs slightly from 

the BMDO7M discriminant program, which also develops a correlation matrix, but uses grouped data leading to consistently 

higher values for <r and for the linear correlation coefficient, r. 

Data sets were presumed to have normal distributions.

For example, even though mean values for each 

channel vary sympathetically with increasing 

vegetation, their COV's are very high.

2. The normalized color index (NX, NY, NZ, where 

NX + NY + NZ=1, NX = Ch 4/(Ch 4 + R5 + R7), 

etc., is sensitive to vegetation, being high (330 

NX: 400 NY) in altered rock (Set A) and declining to lower values (260 NX: 260 NY) with increasing vegetation. (Vigorous, green plant materials would have values as low as 150:170 respectively, for "pure" fields of view). This index 

is a version of the International CIE color index 

used for color standardization in the visible 

region, adapted by us for use in the near-infrared, e.g., Ch 4 + Ch 5 + Ch 7 are used (Lyon and 

others, 1975).

3. Ratios R75, 74, 65 and 64 are vegetation-sensitive 

(Lyon, 1976) and rapidly change with vegetation content, especially R75 and R74.

4. Ratio R54 usually drops with increasing vegetation, 

but also rises rapidly with bare exposures of 

iron-rich soils. The fact that all four sets contain 

these soils, as well as vegetation, somewhat obscures this effect with these data sets.

5. Criteria of "usefulness" (e.g., which variable is the 

most useful, as in table 7) such as that used successfully by Goetz and others (1975) (a high 

COV of a set of group means for a variable) 

must also take into account the dispersion of 

each population from which the means were de-
MINERAL EXPLORATION APPLICATIONS OF LANDSAT IMAGERY 291

rived. Following their practice, however, one 

would decide that R74 with the highest COV of 

0.46 was the best ratio, although the COV for 

the R74 mean in Set B-Spanish was 0.57 indicating widely varying data in that total set.

CONCLUSIONS

Digital processing of Landsat data is of great significance to mineral exploration. It may be used to produce enhanced images of mosaics of large areas which 

by computer manipulation now have better definition 

or increased contrast which will aid the interpretational analyses of photogeologists.

Of much greater import is the fact that Landsat is a 

four-band set of radiometers which in addition to producing imagery also produce quantified and calibrated 

measurements of any terrain in the world. As the data 

are readily available on digital tape, any number of 

algorithms may be used to remove atmospheric scattering effects or stretch densities (both to increase 

contrast and, hence, interpretability) or to prepare 

computational products like ratios. Statistics may be 

calculated and search programs (like STANSORT) 

written to automatically locate comparable reflectances elsewhere.

At Stanford our approach to the mineral exploration 

applications has been concentrated in high resolution 

studies of small 1-100 km2 areas testing the ultimate 

limits of the Landsat system because this scale of representation (1:24,000) and areal size is that most often 

of use in exploration.

Vegetation must become a part of mineral exploration/Landsat studies. Very few areas of interest are 

devoid of vegetated cover and that cover must be considered in defining the "average Landsat spectrum" of 

any 1 pixel area (0.4 ha). The principal problem facing 

us at this stage of the studies is sampling, or how we 

can integrate enough terrain in our "ground" measurements to be equivalent to the Landsat pixel size. Clearly the next step involves helicopter-sampling.

A second real problem is that no one technique 

works all the time and a group of approaches must be 

used. Landsat with its four-quantified channels materially broadens the usual data base available to the 

explorationist used to working with black and white 

film.

As a corollary to this, an interactive, video-display 

system, "driven" by the geologist who is personally 

familiar with the area and problem is essential to extracting the most from the Landsat system. For a while 

we called our program H-ERTS, because it put the 

geologist in the "driver's" seat. Man-machine interactions are essential in Landsat analysis, preferably the 

man should be the field geologist himself.

SELECTED REFERENCES

Ashley, R. P., 1971, Preliminary geological map of the 

Goldfield mining district, Nevada: U.S. Geol. Survey Open-File Map.

————1974, Goldfield mining districts: Nevada Bur. 

Mines and Geology Rept. 19, p. 49-66.

Ballew, G. I., 1975, A method for converting LANDSAT-1 MSS data to reflectance by means of 

ground calibration sites: Stanford Remote Sensing Lab. Tech. Rept. 75-5, p. 90.

————1976, Correlation of LANDSAT-1 multispectral data with surface geochemistry, in Internat. 

Symposium on Remote Sensing of Environment, 

10th, Ann Arbor, Mich. 1975, Proc. (in press).

Bamford, R. W., 1974, Band reflectance ratio maps 

from ERTS-1 data over two copper prospects in 

New Guinea: Stanford Remote Sensing Lab. 

Tech. Rept. 74-13, 4 p.

Billings, W. D., 1950, Vegetation and plant growth as 

affected by chemically altered rocks in the western Great Basin: Ecology, v. 31, no. 1, p. 62-74.

Bolviken, B., Honey, F. R. Levine, S. L, Lyon, R. J. P., 

and Prelat, A., 1976, Detection of naturally heavymetal poisoned areas by LANDSAT-1 digital data 

(abs.): Internat. Geol. Congress, 6th, Sydney, Australia 1976, Proc. sec. 10 B (geochemistry).

Draeger, W. C., and Lauer, D. T., 1967, Present and 

future forestry applications of remote sensing 

from space: Am. Inst. Aeronautics Astronautics, 

4th Mtg., Anaheim 1967, Paper 67-765.

Goetz, A. F. H., Billingsley, F. C, Gillespie, A. R., 

Squires, R. L., Shoemaker, E. M., Lucchitta, I., and 

Elston, D. P., 1975, Application of ERTS images 

and image processing to regional geologic problems and geologic mapping in northern Arizona: 

Pasadena, Calif. Inst. Tech. Jet Propulsion Lab., 

Tech. Rept. 32-1597, p. 1-188.

Honey, F. R., Prelat, A., and Lyon, R. J. P., 1974, 

STANSORT: Stanford Remote Sensing Laboratory Pattern Recognition and Classification System, in Internat. Symposium on Remote Sensing 

of Environment, 9th, Ann Arbor, Mich., 1974, 

Proc., p. 857-905.

Howard, J. A., Watson, R. D., and Hessin, T. D., 1971, 

Spectral reflectance properties of Pinus Ponderosa in relation to copper content of the soil— 

Malachite mine, Jefferson County, Colorado, in 

Symposium on Remote Sensing of Environment, 

7th, Ann Arbor, Mich. 1971, Proc., p. 285-296.
292 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Lag, J., and Bolviken, B., 1974, Some naturally heavymetal poisoned areas of interest in prospecting, 

soil geochemistry, and geomedicine: Norges Geol. 

Unders., v. 304, p. 73-96.

Levine, S., 1976, Correlation of ERTS spectra with 

rock/soil types in California grassland areas, in 

Internat. Symposium on Remote Sensing of Environment, 10th, Ann Arbor, Mich. 1975, Proc. (in 

press).

Lizaur, P., 1975, Study of the alteration zone around 

Goldfield mining district by means of ERTS satellite multispectral scanner data: Stanford Remote 

Sensing Lab. Tech. Rept. 75-3, p. 284.

Lyon, R. J. P., 1975, A comparison of observed and 

model-predicted atmosphere perturbations on target radiances measures by ERTS, in Inst. Electrical and Electronics Eng. Symposium on Application Remote Sensing Digital Imagery to Mineral and Petroleum Exploration, Houston, Tex. 

1975, Proc., 6 p.

———— 1976, Correlation between ground metal analysis, vegetation reflectance, and ERTS brightness 

over a molybdenum skarn deposit Pine Nut Mountains, western Nevada, in Internat. Symposium on 

Remote Sensing of Environment, 10th, Ann Arbor, 

Mich. 1975, Proc. (in press).

Lyon, R. J. P., and Honey, F. R., 1974, Multispectral 

signatures in relation to ground control signature 

using a nested sampling approach (abs.): Natl. 

Tech. Info. Service (NTIS), NASA Earth Resources Survey Prog., Weekly Govt. Abs., E74- 

10690, p. 132.

Lyon, R. J. P., Honey, F. R., and Ballew, G. I., 1975, 

Evaluation of ERTS multispectral signatures in 

relation to ground control signatures using a 

nested sampling approach: Final Report, NAS 

5-21884, June 1975, 600 p. (contains 16 separate 

reports).

Moore, J. G., 1969, Geological map of Lyon, Douglas 

and Ormsby Counties, Nevada: Nevada Bur. 

Mines Bull. 75, pi. 1.

Noble, D. C., 1962, Mesozoic geology of the southern 

Pine Nut Range, Douglas County, Nevada: Stanford Univ., Ph.D. thesis, 200 p.

Press, N. P., and Norman, J. W., 1972, Detection of 

ore bodies by remote-sensing the effects of 

metals on vegetation: Inst. Mining and Metall. 

Trans., Sec. B, v. 81, p. 166-168.

Rowan, L. C., Wetlaufer, P. K, Goetz, A. F. H., Billingsley, F. C., and Stewart, J. H., 1974, Discrimination of rock types and altered areas in Nevada 

by the use of ERTS images: U.S. Geol. Survey 

Prof. Paper 883, 35 p.

Vincent, R. K., 1973, Spectral ratio imaging methods 

for geological remote sensing from aircraft and 

satellites, in Symposium on Management and 

Utilization of Remote Sensing Data, Sioux Falls 

1973, Proc., p. 377-397.

Whitaker, E. A., 1965, Colors and the meso-structure 

of the Maria, in Ranger VII, pt. II, Experimenter's 

analyses and interpretations: Pasadena, Jet Propulsion Lab. Tech. Rept. 32-700, p. 29-39.

————1966, The surface on the moon, chap. 3, in 

Hess, W. N., Mensel, D. H., and O'Keefe, J. A., 

eds., The nature of the lunar surface: Johns Hopkins Press, p. 79-98.
PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Tradeoff Considerations in Utilization of SLAR 

for Terrain Analysis

By Louis F. Dellwig and Richard K. Moore,

University of Kansas Center for Research, Inc.,

Remote Sensing Laboratory,

Lawrence, Kansas 66045

ABSTRACT

Optimum SLAR system parameters for terrain data 

extraction have been suggested by previous investigators on the basis of comparison of imagery from 

several different systems with a wide diversity of parameters. For some determinations this proves satisfactory. However, the determination of any optimum 

system parameter can best be made only on the basis 

of utilization of a single system, imagery of which 

could be generated with multiple polarizations, depression angles, look directions, or frequencies, or 

which could be manipulated to alter such parameters. 

Extraction of data from imagery showing a range of 

variations in such parameters by discipline-oriented 

interpreters has enabled us to shed some light on the 

effect of variations in radar system parameters on extraction of geologic, hydrologic, geographic, and botanical data.

INTRODUCTION

Following the imaging of Panama in 1967 by the 

U.S. Army Corps of Engineers, serious evaluation of 

side-looking airborne radar (SLAR) as a geologic tool 

was initiated. Earlier numerous small test sites 

throughout the United States for the NASA Earth Resources Survey Program resulted in the generation of 

imagery over a variety of terrains, and, with the general availability of this imagery to the geoscience community, interest in its evaluation and utilization was 

accelerated. Following the entrance of Aero Service, 

Grumman Aircraft Corp., and later Motorola Aerial 

Remote Sensing, Inc., into the commercial field which 

had been established initially by Westinghouse Aerospace Corp., imagery of several systems became available to the geoscience community and a not unexpected evaluation and comparison of these systems 

began. Now with the reduction of the lower limit of 

resolution from 35 to 10 ft (11.6 to 3 m), imagery of 

additional systems is becoming available to the researcher and will inevitably be competing with better 

known systems for the "best in show" award.

Recognizing a great diversity of capabilities and 

limitations, we embarked upon a study under the sponsorship of the Jet Propulsion Laboratory to determine 

optimum system parameters for a spacecraft radar. At 

about the same time we initiated A Demonstration and 

Evaluation of the Utilization of Side Looking Airborne 

Radar for Military Terrain Analysis for the Engineer 

Topographic Laboratories. Through the conduct of 

these two studies and with the availability of imagery 

not previously available, it had been our hope that we 

would be able to determine the optimum SLAR system 

parameters for terrain analysis. But as the projects 

progressed we became faced with the problem which 

had faced us on many occasions, optimum SLAR system parameters for what?

To a large degree the requirements for tactical military terrain analysis are those of the civilian segment 

of the population, only two basic requirements being 

critical in military terrain analysis: (1) Near or real time 

data acquisition and (2) target detection and identification. Many civilian uses of airborne monitoring, reconnaissance, or mapping systems also require near 

real time data and identification of specific or unique 

features in both urban and rural environments.

The optimum parameters for military or civilian operation is only one of the choices which must be made. 

Optimum for the geologist who prefers a wide swath 

width is not optimum for the city planner who wishes

293
294 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

to acquire as much detail as possible in a relatively 

small urban area. Thus recognizing that optimum for 

the geologist is not optimum for other geoscientists, 

rather than define a series of hard and fast parameters 

such as was done by the National Aeronautics and 

Space Administration (NASA) in the selection of the 

Landsat Multispectral Scanner (MSS) bands (and satisfying no one), it seems most reasonable to evaluate 

variations in parameters and not attempt to define 

optimum parameters for a single system. With such an 

approach the reader will essentially have a do-it-yourself kit and can define the parameters (including cost) 

which best enables him to realize maximum data content for any specified mission.

RESOLUTION

Few parameters have been devoted the attention 

which has been received by resolution. In an early geologic study (Dellwig and others, 1966), it was stated 

that there appeared to be some value in the degradation of resolution, but, in a more recent paper by Rydstrom (1970), it was pointed out that high resolution 

radar imagery contained not only the same but more 

data than did imagery of lower resolution systems. It 

is not the authors' intention to resurrect this problem, 

for sufficient data are not available for either author 

to pursue the point further. Rather, we would prefer 

to look at the needs of terrain analysts and evaluate 

systems on their own merit. We can begin by looking 

at the Phoenix, Arizona, area as imaged by the 

AN/APQ-152 (fig. 1A) and the AN/APS-94D (fig. IB). 

There is an obvious strong contrast in resolution, but 

there are also other perhaps not so obvious contrasts. 

Both images show full swath width. For the urban 

planner there is an obvious advantage in the utilization 

of the AN/APQ-152, but for the geologist who is concerned with tracing major linear patterns or in conducting reconnaissance studies in heretofore uncharted 

areas, the wide swath width of the AN/APS-94D 

(which cannot be obtained with the AN/APQ-152) 

provides a more desirable format and presents him 

with adequate data for mapping purposes. On the 

coarser resolution image no difficulties are encountered in defining the urban areas and adjacent field 

patterns nor in the separation of industrial from residential areas. In general, swath width cannot be increased without suffering some degradation of resolution, and thus the user must consider the relative 

values of fine resolution and wide swath width.

In considering resolution, one must look at both spatial resolution, which we normally consider, and grayscale resolution, which is seldom considered in photography because it is usually good, but is always 

important for radar. The problem is that a radar image 

produced with the best possible synthetic-aperture 

resolution has an extremely speckled appearance. This 

comes about because of the same phase-interference 

phenomenon that causes radio signals to fade, and 

that is particularly evident in nighttime standardbroadcast signals and in FM signals received in a car. 

Shine a laser on a moderately rough surface like a 

blackboard and you will see this speckle phenomenon 

dramatically displayed.

To reduce speckle and thus improve the ability to 

determine the average gray scale in a region, one must 

look at the target element many times and average 

the results together to make the image. This can be 

done with a radar by the panchromatic technique 

(Moore and others, 1969) as in optics, but most radars 

do not have this capability. A tradeoff must be made 

between reduced speckle (improved gray-scale resolution) and finer spatial resolution. With properly configured systems this is a direct tradeoff: doubling the 

two linear dimensions of the spatial resolution cell improves the standard deviation of the speckle by a 

factor of two. To determine gray scale within 10 percent of the mean at any point requires 100 looks, 

resulting in 10 times poorer spatial resolution. With 

20-percent uncertainty in the gray level of a single cell, 

the penalty in spatial resolution is only a factor of 5. 

Even ±50 percent uncertainty is often good enough, 

and in this case the spatial resolution is degraded only 

by a factor of 2. Probably one would never be satisfied with this for a single cell, but the eye does the 

averaging over homogeneous areas to improve the net 

effect to much better than ±50 percent, and having 

the spatial resolution allows one to determine which 

areas the eye should average in a way that would not 

be possible if the averaging were done automatically.

The standard deviation of the gray scale turns out 

to be a relatively poor indicator of the interpretability 

of an image that has a lot of speckle; a better indicator is the ratio of the brightness exceeded 90 percent of the time to that exceeded 10 percent of the 

time (Moore, 1975). With most systems in use today 

these values can be obtained from a chi-square distribution of 2N degrees of freedom, where N is the 

number of samples averaged. When this definition is 

applied, the ratio between the resolutions required for 

equal interpretability with a fully coherent single-look 

synthetic-aperture radar and a radar with photographic quality (infinite number of looks) is found to 

be 4.7. That is, if 30.4 ft (10 m) resolution is required
TRADEOFF CONSIDERATIONS IN UTILIZATION OF SLAR FOR ANALYSIS 295

0

I ——

0

1 2

————— I ————— ' ——————————————— ' 

1 2 KILOMETERS

2 MILES

15 KILOMETERS

FIGURE 1.—Two radar images of Phoenix, Arizona. A, AN/APQ-152 (X-band) SAR (Synthetic aperature radar) imagery. 6, 

AN/APS-94D (X-band) SLAR imagery. Area outlined indicates aproximate coverage of A. Apparent distortion of outlined 

area results from the transfer of one image in slant range format to another, also in slant range format.
296 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

for the single-look system, one can get by with 142.8 

ft (47 m) in the photographic-quality system.

A recent study at the University of Kansas (Moore, 

1975) disclosed that the numerical interpretability of 

an image can be related to the size of a square pixel 

by the relation

I = Ioexp(-rz /r=)

where r is the pixel dimension and rc is a critical pixel 

dimension for the type of application. Figure 2 illustrates how well this relation (indicated by the solid 

regression line) fits the experimental data for four 

different areas and two classes of target. Note that the 

critical value of resolution for the single-look picture 

(point of 37-percent interpretability) is at around 30 ft 

(10 m) for both kinds of application, and that the corresponding "Photographic" resolution is nearly 150 ft 

(50 m).

Another result of the study was the discovery that 

the area of the pixel is the key factor in its interpretability, that is, a long, narrow pixel and a square one 

having the same area turned out to have the same 

interpretability. This is illustrated, using only the fully 

coherent image data (fig. 3). The largest length/width 

ratio used was 10 in this study.

From this study, and others like it that remain to be 

done, the equivalent resolution required for a given 

mission can be calculated for any radar whose averaging characteristics are known once the single-look or 

photographic-quality critical resolution has been determined. One interesting result of the study is that the 

azimuth resolution for a radar that averages 10 looks 

can be 10 times as great as for a single-look system 

and achieve the same interpretability, provided the 

range resolution is the same as for the single-look 

system. This means that for most aircraft radar applications to earth science a real-aperture radar that is 

properly designed can be just as effective as a singlelook synthetic-aperture system. A 3-look synthetic system, however, is significantly better than the 10-look 

system (synthetic or real aperture). Hence, if one really wants to determine whether a particular system can 

do the job, one must determine the required equivalent 

photographic resolution and from this calculate the 

capability of the system under consideration.

FREQUENCY

Currently plans are being formulated to fly a twofrequency radar aboard a shuttle mission. Defense is 

being mustered for an X(~3 cm)- and L(~25 cm)-band 

system on the basis of its capability for mapping 

geology. Partly in defense of this has been presented

the results of an excellent study by Schaber, Berlin 

and Brown (1975), who have pointed out that L-band 

radars rather dramatically effected the separation of 

coarse (>2.0-3.5 cm) from fine (<2.0-3.5 cm) gravel. 

In a similar manner, it was pointed out in earlier 

studies at Pisgah Crater (Dellwig, 1969; MacDonald 

and Waite, 1972) that the smoothness of playa lake 

surface and adjacent lavas and alluvial fans in the 

basin and range country of the Western United States 

could be defined on the basis of the return from such 

surfaces on K(l. 18-1.67 cm)- or X-band radars. From 

these studies it becomes quite obvious that the optimum frequency for an imaging radar is that frequency 

which enables the investigator to derive the necessary 

terrain data for his particular discipline. From the point 

of view of general geologic mapping, one finds difficulty in defending the utilization of an L-band system 

as opposed to a C(~5 cm)- or even P(77-136 cm)- 

band system, for geologic studies do not necessarily 

require the separation of material of a size range 

smaller than 2.0-3.5 cm from material of a size range 

larger than that figure. A problem of infinitely more 

general importance than the separation of materials of 

varied size ranges is the determination of soil moisture 

content. Studies concurrently being conducted at the 

University of Kansas using the Microwave Active Spectrometer (MAS) system rather dramatically demonstrate that the indication of soil moisture content 

which one might expect to be reflected in radar backscatter is strongly frequency dependent (Batlivala and 

Ulaby, 1975). Whereas the data required by geologists 

for the most part are not particularly frequency dependent, a wide range of earth scientists interested in 

soil moisture content will undoubtedly show a strong 

preference for radar imaging in the C-band range.

POLARIZATION

A parameter never fully investigated, and unfortunately not subject to investigation by most earth scientists due to a lack of data, is that of polarization. The 

evaluation of numerous AN/APQ-97 images generated during the NASA Earth Resources Survey Program flights failed to reveal any significant difference 

from the point of view of geologic investigation between parallel-vertically and parallel-horizontally polarized signal return in Ka(~.86 cm)-band. Comparisons between like and cross polarized images, however, showed considerable potential for the revelation 

of data not available in a single image. In studying a 

variety of rock outcrops in the Western United States, 

McCauley (1972) identified surface roughness as the 

cause of polarization reversals in a variety of rock
TRADEOFF CONSIDERATIONS IN UTILIZATION OF SLAR FOR ANALYSIS 297

Combined hard target

Coherent 

V Noncoherent

10 20 30 40 50 60 70 80 90 

RESOLUTION OF EQUIVALENT COHERENT RADAR roN (FEET)

50 100 150 200 250 300 350 400 450

_|______I_____I_______I______I______I______I______I_____l_

100

500

RESOLUTION OF EQUIVALENT "PHOTOGRAPHIC" RADAR r eN (FEET)

Combined roads and transportation

10 20 30 40

RESOLUTION OF EQUIVALENT COHERENT RADAR reN (FEET)

0

I

50

I

100I

150

I

2(X) 250

I

300

I

350

I

400

I

450

I

500 

I

RESOLUTION OF EQUIVALENT "PHOTOGRAPHIC" RADAR reN (FEET)

FIGURE 2.—Interpretability vs. equivalent resolution for hard targets, roads, and other transportation—all data sets

combined.

types (fig. 4), all of which showed similarity in surface and cross polarized return signal of manmade linear

configuration. The studies of cultural features by Lewis features (fig. 5). In the Gulf Coast (fig. 6), MacDonald

(1968) also revealed a significant contrast in the like and Waite (1971b) noted strong contrasts in the return
298 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

3

tr 

a. tr

> \-

UJ tr.

D

D

I i r iiii

Roads and transportation

• Square cells

D Rectangular cells

n • D

n

n

D D

I__I

50 150

LENGTH OF SIDE OF EQUIVALENT SQUARE CELL (FEET)

i 3

m

tr 

a.

£ 2

\ I I 

Hard targets

D

nan

n

n

a 

i

n

i i i

50 100 

LENGTH OF SIDE OF EQUIVALENT SQUARE CELL (FEET)

FIGURE 3.—Comparison of square and rectangular cells.

150

in the near range between the like and cross polarized 

signal, a contrast which they attributed to a difference 

between moist and dry terrain surface. Utilizing the 

MAS system, Ulaby and others (1974) and Batlivala 

and Ulaby (1975) have recorded such contrasts in 

return signal.

In order to place a value on dual polarization imaging one must first define the cause for tonal reversals, 

and secondly must be able to utilize this contrast regardless of the subtlety of expression. For example, on 

casual examination of the like and cross polarized 

imagery of Freeport, Texas (fig. 7), some tonal con-
TRADEOFF CONSIDERATIONS IN UTILIZATION OF SLAR FOR ANALYSIS 299

4 KILOMETERS

FIGURE 4.—Mono Craters, California, AN/APQ-97 (ka-band) SLAR imagery. Flows a and b are blocky lavas and have lower 

returns on cross polarized (HV) imagery. Flows c and d are covered by ash and appear the same on both polarizations.
300 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

4 MILES

I

4 KILOMETERS

FIGURE 5.—Bountiful, Utah, AN/APQ-97 (Ka-band) SLAR imagery. Urban and industrial areas are more apparent on HH (like) 

polarization. Communication networks are more accurately mapped on HV (cross) polarization.
TRADEOFF CONSIDERATIONS IN UTILIZATION OF SLAR FOR ANALYSIS 301

10 KILOMETERS

FIGURE 6.—Atchafalaya River Basin, Louisiana, AN/APQ-97 (Ka-band) SLAR imagery. Areas of high soil moisture appear dark 

in near range HH (like) polarization imagery. Dry areas appear light in tone. Soil moisture differences are not detectable 

on HV (cross) polarized imagery.
302 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

0 5 KILOMETERS 

FIGURE 7.—Freeport, Texas, AN/APQ-97 (Ka-band) SLAR imagery. Area of figure 8 outlined in HV image.

trasts may be obvious but others will escape the interpreter's naked eye. However, by adding these two 

images in contrasting colors, the interpreter can easily 

define the extent of any unique signature and rapidly 

effect interpretation (fig. 8, p. XXI).

LOOK DIRECTION AND DEPRESSION 

ANGLE

The need for control of look direction and depression angle has been well established by numerous
TRADEOFF CONSIDERATIONS IN UTILIZATION OF SLAR FOR ANALYSIS 303

10 15 MILES

I I I I

0 5 10 15 KILOMETERS

FIGURE 9.—Phoenix, Arizona, AN/APS-94D (X-band) SLAR imagery. A, North look of Phoenix and mountains and alluvial fans 

(middle to far range) to the northeast. B, Northeast look of Phoenix. C, Northeast look of alluvial fans (near to middle 

range).

investigators, among them, MacDonald and Waite 

(1971a) who pointed to the desirability of selecting 

specific ranges of depression angles for regions of 

varying relief. However, relief is not always uniform

throughout an area and in areas that in general may 

be of relatively low relief, occasionally local high 

relief will result in excessive shadowing if low depression angles (deemed best for relatively flat terrain) are
304 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

10 20 MILES

0 10 20 KILOMETERS 

FIGURE 10.—Denver-Colorado Springs corridor, Colorado, SC-01 (X-band) SAR imagery.

used. The significance of control of look direction and 

depression angle is indicated once again in the Phoenix 

area over which two looks at the city (fig. 9A,B), one

the other to the northeast and oblique to the overall 

north-south, east-west street pattern give strongly contrasting views of the urban area. Similarly, two differto the north and normal to the overall street plan and ent looks at natural terrain features as is indicated in
TRADEOFF CONSIDERATIONS IN UTILIZATION OF SLAR FOR ANALYSIS 305

16

12

UJ

cr

o

CO 

CO

cr

o

Q

1:12,000

i '

Notes:

1. Photo prices based on single-engine 

aircraft.

2. Photo contractor allowed 2 or more 

seasons for jobs over 9,000 sq. mi.

3. Photo prices do not include mosaic work, 

radar does

4. Figures apply to the Western United 

States

I i i i i I i ' i ' I i——L I I I——I——I——I—L

5 10 15 20

SQUARE MILES(OOO'S)

FIGURE 11.—Price comparisons—photos vs. radar, spring 1975.

25 30

another pair of Phoenix images (fig. 9A,C) give contrasting indications of the degree of relief that should 

be expected in the area covered by alluvial fans. In 

the one image, because of look direction and depression angle, little contrast is seen between the arroyos 

and the interfluve areas, whereas in the second image, 

due to a change in look direction and depression angle, 

the contrast between the arroyos and the interfluve 

areas is sharp. The extensive shadowing behind isolated mountain peaks and the revelation of terrain data 

in the shadow area through a look from the opposite 

direction, further points to the desirability of obtaining two looks of an area in order to obtain the maximum amount of terrain data. Such was first demonstrated by MacDonald (1969) in the Darien Province, 

Panama, where it was determined that, with each 

additional look, additional data were revealed.

TIME

Numerous investigators utilizing ERTS imagery have 

been able to document data increase through second 

and even third or fourth season imagery evaluation. 

Such should also be true for radar imagery especially 

in vegetated terrain due to seasonal variations in dielectric properties and surface configuration of the

vegetal cover (fig. 10). Not only is the change in data 

content of winter and spring imagery documented, but 

also it emphasized the need for selection of imaging 

season depending on the nature of the desired data.

COST

Perhaps not a system parameter, but an important 

factor to be considered in the determination of optimum system parameters for specific types of earth 

science investigations is cost. Mobilization charges and 

flight line density control to a large degree the cost of 

imaging—a cost which is essentially prohibitive for 

the obtaining of detailed data in relatively small areas. 

Even assuming that imaging systems of resolutions not 

presently available would become available in the 

future, it appears that cost would be prohibitive when 

compared with aerial photography. Only when real 

time or near real time (13 seconds between imaging 

and viewing on a currently operating experimental 

Dutch imaging radar and instant viewing at the end of 

a frame on the Kansas University radar [Eichel and 

others, 1975]) data are absolutely necessary (although 

certainly to be desired under most conditions) could 

the utilization of radar for small-scale mapping be 

justified (fig. 11). Conversely, for mapping large areas,
306 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

unless the resolution now only achieved by aerial photography is absolutely necessary, one finds difficulty in 

justifying the utilization of any system other than radar.

OPTIMUM RADAR-PARAMETERS

You would like 1-ft resolution, wide swath width, 

multiple polarization, controllable depression angles, 

opposite looks and a range of frequencies and a real 

time display? Dream away! Even Uncle will have 

trouble affording that system.

REFERENCES

Batlivala, P. P., and Ulaby, F. T., 1975, Effects of 

roughness on the radar response to soil moisture 

of bare ground: Univ. Kansas Center for Research, Inc., RSL Tech. Rept. 264-5, 50 p.

Dellwig, L. F., 1969, A geoscience evaluation of multifrequency radar imagery of the Pisgah Crater 

area, California: Modern Geology, v. 1, p. 65-73.

Dellwig, L. F., Kirk, J. R, and Walters, R. L, 1966, 

The potential of low resolution radar imagery in 

regional geologic studies: Jour. Geophysical Research, v. 71, p. 4995-4998.

Eichel, L. A., Moore, R. K., Weilert, M., and Schlude, 

F., 1975, An inexpensive side-looking radar with a 

novel display, in Institute of Electrical and Electronic Engineers Internat. Radar Conf., Arlington, Va., April 21-23, 1975, Proc.

Lewis, A. J., 1968, Evaluation of multiple polarized 

radar imagery for the detection of selected cultural features: U.S. Geol. Survey Tech. Letter 

NASA-130, 52 p.

MacDonald, H. C, 1969, Geological evaluation of radar imagery for Darien Province: Modern Geology, v. 1, p. 1-62.

MacDonald, H. C, and Waite, W. P., 1971a, Optimum 

radar depression angles for geological analysis: 

Modern Geology, v. 2, p. 179-193.

————197 Ib, Soil moisture detection with imaging 

radars: Water Resources Research, v. 7, p. 100- 

110.

————1972, Terrain roughness and surface materials 

discrimination with SLAR in arid environments: 

Univ. Kansas Center for Research, Inc., RSL 

Tech. Rept. 177-25, 37 p.

McCauley, J. R., 1972, Surface configuration as an 

explanation for lithology-related cross-polarized 

radar image anomalies, in NASA Manned Spacecraft Center, Annual Earth Resources Program 

Review, 4th, Houston 1972, Proc., v. 2, p. (36-1)- 

(36-9).

Moore, R. K., 1975, SLAR image interpretability— 

Tradeoffs between picture element dimensions 

and non-coherent averaging: Univ. Kansas Center 

for Research, Inc., RSL Tech. Rept. 287-2, p. Bl91; p. 11-11.

Mcore, R. K., Waite, W. P., and Rouse, J. W., Jr., 1969, 

Panchromatic and polypanchromatic radar: Inst. 

Electrical Electronic Eng. Proc., v. 57, no. 4, p. 

590-593.

Rydstrom, H. O., 1970, Capabilities of advanced radar 

systems for monitoring land resources: Goodyear 

Aerospace Rept. GERA-1604, Arizona Div., 10 p.

Schaber, G. G., Berlin, G. L, and Brown, W. E., Jr., 

1975, Variations in surface roughness within 

Death Valley, California: Geologic evaluation of 

25 cm wavelength radar images: U.S. Geol. Survey Interagency Rept., Astrogeology 65, 63 p.

Ulaby, F. T., Cihlar, J., and Moore, R. K., 1974, Active 

microwave measurement of soil water content: 

Remote Sensing of Environment, v. 3, p. 185-203.
PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Worldwide Indexing and Retrieval of Landsat Images

By Floyd F. Sabins, Jr.,

Chevron Oil Field Research Company,

La Habra, California 90631

ABSTRACT

More than 100,000 Landsat images have been produced since the first satellite was launched in July 

1972. In order to select images on a worldwide basis, 

index maps are necessary. Manual sorting and plotting 

lists of images onto base maps are tedious, time-consuming and error-prone tasks. Computers, however, 

are ideally suited for this work. The Landsat Index 

Map System described here employs a computer mapping program and the EROS Landsat digital index tape 

to produce a series of 22 index maps covering the 

world at a scale of 1:5,000,000.

Only the highest quality images are plotted. One set 

of maps is plotted for images with zero cloud cover. 

Other sets are plotted for 10-, 20-, and 30-percent 

cloud cover, if necessary, to provide complete coverage. The index maps are updated periodically from 

new index tapes. In addition to locating images, the 

maps indicate areas that lack coverage and image centers located away from the nominal image center 

points.

INTRODUCTION

BACKGROUND

Since the launch on July 23, 1972, Landsat-1 has 

transmitted approximately 100,000 images covering 

much of the land area of the world. Landsat-2, 

launched on January 22, 1975, is supplying additional 

images. The 18-day repetition cycle of each satellite 

results in many areas being imaged numerous times. 

For users requiring many images of large regions, especially in foreign areas, the plotting of images onto 

index maps is a time-consuming, tedious, and errorprone operation. This paper describes an index map

system developed by Chevron Oil Field Research 

Company that greatly simplifies and expedites the 

location and selection of Landsat images throughout 

the world. Numerous other papers have described the 

Landsat vehicles and imagery, which are not discussed 

here.

CONVENTIONAL INDEXING METHODS

The National Aeronautics and Space Administration 

provides monthly index listings for domestic and 

foreign Landsat images. In addition, the EROS Data 

Center at Sioux Falls can provide, upon request, computer printouts of image coverage for specific geographic areas. For the conterminous United States, 

EROS also provides an index map based on "nominal 

image" center points. This map does not show specific 

images but rather the center points at which the 

repetitive images are positioned. This system originated at the Canada Centre for Remote Sensing. 

Microfilm browse files of Landsat images are maintained for public use at various U.S. Geological Survey 

offices. Useful Landsat indexes are prepared by the 

U.S. Agricultural Stabilization and Conservation Service aerial photographic laboratory in Salt Lake City. 

Images for each 18-day cycle are positioned on a U.S. 

base map to form a photo index mosaic. In addition to 

ground coverage, image quality and cloud cover can 

be determined directly. I understand that the laboratory is no longer updating these indexes.

For foreign areas, the index data consist of lists of 

Landsat identification numbers which must be sorted 

and plotted on a base map. Sorting is done on the 

basis of image quality and cloud cover in order that 

the best image can be selected for each center point. 

For mosaic preparation, it is desirable to use images

307
308 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

acquired at the same time of year to minimize tonal 

changes between adjacent images. This involves a 

separate sorting step. All of these sorting and plotting 

operations are tedious and error prone when done 

manually but are ideally suited for computer processing. The balance of this paper describes the system 

developed at Chevron Oil Field Research Company 

(COFRC) for producing Landsat index maps on a 

worldwide basis.

ACKNOWLEDGMENTS

My role in this work was to recognize the need for a 

worldwide Landsat index map system and suggest the 

approach described here. The actual programming 

and plotting was accomplished by the following 

COFRC colleagues to whom I am deeply indebted: 

H. L. Haines, E. B. Hill, L. C. Bonham, C. D. Boyd, 

C. C. Davis, W. T. Miller, and G. S. MacKenzie. Personnel at the EROS Data Center were very helpful in 

explaining the format of their index tape.

INDEX MAP SYSTEM

One of the truly unique features about the COFRC 

system is that we have not seen fit to title it with an 

acronym. The system comprises two essentially separate operations: (1) preparation of a base map showing coastlines, drainages, and political boundaries together with a latitude and longitude grid and (2) plotting of Landsat center points and identification numbers on the base map.

BASE MAP PLOTTING

Figure 1 shows the location of the 23 individual 

maps which we use to index the world. Most of these 

maps are plotted to the same scale (1:5,000,000) and 

projection (Lambert conic conformal) as the Global 

Navigation Charts (GNC) published by the U.S. Air 

Force Chart and Information Center and distributed 

by the Distribution Division, National Ocean Survey, 

Washington, D.C. 20235. By plotting the index maps 

on translucent paper, they may be overlain on the 

GNC to determine coverage of particular mountain 

ranges, sedimentary basins and other features not 

noted on the index maps.

As shown on the flow chart, figure 2, two digital 

files are used in base map plotting: (1) world map file 

containing land outlines and (2) political boundaries 

and drainage file. Latitude and longitude coordinates 

are designated for the specific index map, which on 

figure 2 happens to be Index Map 11 covering southern

FIGURE 1.—Location of COFRC Landsat index maps. Note portion of Index Map 11 that is shown on figures 4-9.
WORLDWIDE INDEXING AND RETRIEVAL OF LANDSAT IMAGES 309

LANDSAT PLOT BASE MAP PLOT

LANDSAT

INDEX TAPE,

EDITED

RETRIEVE

DATA FOR

INDEX MAP

AREA

DRAINAGE & 

BOUNDARIES 

FILE

CONVERTED 

LANDSAT 

SUBFILE

SELECT 

DATA FOR 

INDEX MAP 

AREA

DESIGNATE 

MAP SCALE 

PROJECTION & 

ANNOTATION

SPECIFY

% CLOUDS &

TIME INTERVAL

1408.5871 1407.5870 1406.5862

+ + + 

1408.5875 1407.5874 1406.5865

PLOT LANDSAT 

IDENTIFICATIONS 

& CENTER POINTS

1408.5875 107.5874 1408.5865

PLOT LAND OUTLINES, 

BOUNDARIES, DRAINAGES, 

LAT & LONG

COMPLETED

LANDSAT

INDEX MAP

FIGURE 2.—COFRC Landsat index map plotting routine.
310 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Africa. The scale and map projection are designated 

and the base map is plotted preparatory to adding the 

Landsat information.

LANDSAT IMAGE PLOTTING

The first step is to acquire from the EROS Data 

Center a copy of their Landsat index tape which lists 

all the images on file at the Data Center. The latest 

Landsat tape we acquired lists 126,005 images covering the period from launch through April 1975 and 

cost $135. EROS also provides a description of the 

tape format. The first step is to edit the tape and 

delete nonstandard and duplicate entries. Using the 

edited tape as a source, a subfile tape is created listing only the images located within the boundaries of 

the particular index map (fig. 2). At this stage we eliminate images with poor quality or significant cloud 

cover.

A listing of all these images in numerical (time) sequence is also produced. This printout eliminates much 

of the information on the original index tape (such as 

image corners, scale and altitude) which is not required for retrieval. On the sample printout of figure 3, 

an explanation is provided for the various entries. The 

Landsat identification number (ID. No.) which is unique 

for each image, is employed on all of our index maps 

and merits a description. The nine-digit number (example, 1055.08041) originates as follows:

1—Landsat-1 (This digit is a 5 for 1000 days and more after

launch) 

055—Days after launch (July 23, 1972). This day is September

16, 1972.

08—Hour of observation (Greenwich time) 

04—Minute of observation 

1—tens of seconds

On our index maps, the leading zeros are deleted on 

the time code. This image is plotted as 1055.8041.

The digital tape subfile for the index map area is 

then converted to a format compatible with our plotter. Before plotting the Landsat center points on the 

base maps, we determine from the listing the approximate number of images in the subfile. Owing to the 

18-day repetition cycle there would be much overprinting of identification numbers if an entire subfile were 

printed on one map. By referring to the listing, we 

designate time intervals, each of which is plotted on a 

separate map with a minimum of overprinting. For the 

southern Africa map, the following intervals were plotted and are illustrated:

Figure Days after launch 

4________ 0-73 _______. 

5_________ 74-144_______. 

6________ 145-248_______.

Dates

72/07/23-72/10/10 

72/10/11-72/12/14 

72/12/15-73/03/28

March 28, 1973, was the latest entry on the initial 

index tape. Updating the maps is described later.

For ease of illustration, these maps are the portion 

of the entire southern Africa index map indicated on 

figure 1. This series of maps is restricted to images 

with 0-percent cloud cover. Successive map series can 

be plotted for 10, 20, and higher percent cloud cover 

if needed to provide complete coverage.

On figure 4, note that the center points for paths 

1050 and 1068 (18 days apart) nearly coincide. Any additional images plotted along this path would be overprinted and produce an illegible map. Where minor 

overprinting occurs (fig. 5), the index numbers are 

readily resolved by referring to the printout list. On 

figure 6 note that the center points for paths 1177, 

1178, and 1179 are located between the normal positions for these paths. This would present a problem on 

an index map based on nominal image centers and is 

discussed later.

The 115- by 115-statute-mile outline on figure 4 

shows coverage of a Landsat frame. By centering this 

template over an image point with east and west borders parallel with the orbit path, the ground coverage 

of each image can be determined.

UPDATING THE INDEX MAPS

To maintain a current set of index maps, we order 

new Landsat index tapes at intervals. Each tape is 

cumulative from the day of launch. We observed that 

later index tapes commonly list images taken within 

the time span of an earlier tape, but which are not 

listed on the earlier tapes. Using the southern African 

maps (figs. 4, 5, and 6) as an example, our initial tape 

extended through 248 days after launch (March 28, 

1973). A later tape extending through 478 days (November 13, 1973) included 33 images acquired during 

the first 248 days but not listed on the early tape covering that period. For this reason we always search 

each new index tape for earlier entries which are 

plotted. Figure 7 is a retroactive plot of the 13 cloudfree images that were missing from the initial index 

tape, but present on the later tape. The other 21 

earlier images have higher cloud cover percentages. 

One explanation is that the EROS Data Center enters 

images on the tape as they are received from the 

processing facility at Goddard Space Flight Center, 

and the images are not necessarily received and entered into the data base in a strict time sequence. They 

are listed sequentially by Landsat index number, however. Another explanation is that the retroactive points 

may have contained nonstandard characters on the 

initial tape which would have eliminated them during
WORLDWIDE INDEXING AND RETRIEVAL OF LANDSAT IMAGES 311

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312 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

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FIGURE 4.—Landsat-1 index map of southern Africa, 0-73 days. This is a portion of Index Map 11 located on figure 3 and was

reduced from the original 1:5,000,000-scale computer plot.

74-144 DAYS AFTER LAUNCH 

(72/10/11 - 72/12/14)

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COVER IMAGES

FIGURE 5.—Landsat-1 index map of southern Africa, 74-144 days.
WORLDWIDE INDEXING AND RETRIEVAL OF LANDSAT IMAGES

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FIGURE 7.—Retroactive index map for first 248 days plotted from second index tape. These 13 cloud-free images were not listed

on initial index tape.
314 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

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COVER IMAGES

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FROM 72/07/23 - 73/11/13

X IMAGES NOT CENTERED 

ON NOMINAL IMAGE POINT

FIGURE 9.—Composite of 0% cloud cover index maps to indicate areas lacking cloud-free images. Also note images positioned

between nominal image points.
WORLDWIDE INDEXING AND RETRIEVAL OF LANDSAT IMAGES 315

our editing operation. Subsequent correction at EROS 

Data Center would make these images available on 

the later index tape.

Figure 8 is the updated index map for the period 

following the initial index map (March 29-November 

13. 1973). Landsat-1 has acquired little foreign 

imagery since the later date because of malfunctioning of the onboard image tape recorder which had exceeded its design life.

Figure 9 is a composite index map of cloud-free 

images showing the nominal center points that have 

coverage and those that lack coverage. Also indicated 

are the 11 image center points mentioned earlier that 

are not positioned at nominal center points. An index 

map system based on nominal center points would 

have difficulty locating these images.

WORLD ZONE MAPS

In addition to the 23 individual index maps, we also 

routinely plot "World Zone Maps" for the four geographic zones or quadrants of the world. The zones 

are designated as follows:

1. Northeast.

2. Northwest (includes United States).

3. Southeast.

4. Southwest.

The maps are plotted on a smaller scale to display the 

large area on a single map sheet Image center points 

are plotted without index numbers to avoid clutter 

and enable us to plot long time intervals. The example 

on figure 10 is a portion of the southeast world quadrant (zone 3) showing Australia. All the cloud-free

FIGURE 10.—Portion of COFRC world zone map for southeast qu adrant (zone 3). All cloud-free Landsat-1 images of Australia 

acquired during first 478 days (through 73/11/13) are shown. Index numbers are omitted for clarity. Note scatter of points 

about nominal centers. Also note areas lacking cloud-free images.
316 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

0 500 KM

FIGURE 11.—Landsat mosaic of southern part of Sudan, compiled from images selected using COFRC index maps. Courtesy

of Chevron Overseas Petroleum, Inc.

images acquired during the first 478 days (through 

November 13, 1973) by Landsat-1 are shown.

Although Landsat-1 is still in orbit, this time period 

includes almost all the foreign imagery acquired prior 

to failure of the onboard tape recorder that stored 

foreign data until the satellite came within range of an

Earth receiving station.

Zone maps such as this are useful for rapidly determining the status of image availability before consulting the individual index maps. Figure 10, for example, 

shows that parts of Australia, especially in the west, 

lack cloud-free imagery, and we must resort to higher
WORLDWIDE INDEXING AND RETRIEVAL OF LANDSAT IMAGES 317

degrees "of cloud cover, if available, for complete coverage. The clustering of image center points indicate 

multiple coverage, which is useful information for 

conducting seasonal analyses of Landsat images. This 

map also illustrates the typical scatter of image centers from the nominal center points, which was described earlier in the southern Africa example.

APPLICATION

The greatly reduced Landsat-1 mosaic of southern 

Sudan shown on figure 11 was compiled by Chevron 

Overseas Petroleum, Inc., from images selected using 

Index Map 9. The 55 cloud-free images were selected 

in a short time by this method. The images were also 

selected to cover the same season of the year to provide optimum uniformity for the mosaic. The Landsat 

mosaics are especially valuable in areas lacking adequate base maps. Towns, roads, drainage, and other 

features important to field operations are commonly

presented in more detail and accuracy than on existing maps. The major problem is that the latitude and 

longitude marginal annotations on the images are not 

accurate.

SUMMARY

The COFRC index map system is a rapid and reliable method for locating Landsat images of any area 

in the world. It eliminates the time-consuming, tedious, 

and error-prone manual sorting and plotting of the 

100,000-plus Landsat-1 and Landsat-2 images. The 

maps are readily updated as new imagery becomes 

available.

Being a private research institution, COFRC does 

not have the capability to provide index maps or programs. The concepts described here, however, should 

be sufficient for computer-oriented users to prepare 

their own index maps.

PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Intercrossing Crustal Structure and the Problem of 

Manifestation of its Deep-Seated Elements on the

Surface 1

(as exemplified by Tien Shan and the Turan plate)

By V. I. Makarov and L. I. Solov'yeva,

Geological Institute of the USSR Academy of Sciences,

Moscow, U.S.S.R.

ABSTRACT

Recent years have been characterized by an ever 

increasing inculcation of means of space technology, 

including those of space imagery (photography and 

television), into practice of geological studies. One of 

the achievements of space geology is the identification 

of certain elements of deep crustal structure on space 

images of the Earth. These elements range from the 

features of buried folded foundation of a platform or 

ancient complexes of folded mountain systems down 

to those of the Conrad discontinuity and the Mohorovicic discontinuity (Lowman, 1966, 1968; Skaryatin, 

1970; Bashilova, 1971; Bashilova et al., 1972; Makarov 

et al., 1974; a number of papers published in "The 

study of natural environment by space means " (1973), 

v. 1 and (1974), v. 2; also papers published in the 

Soviet journal "Izvestya Vysshikh Uchebnykh Zavedenii, ser. geologiya i razvedka" (1973), no. 7; (1974), 

no. 12; (1975), no. 2.

At the same time, many investigators still have their 

doubts regarding the validity of such identification, 

questioning the very possibility of seeing through the 

Earth's crust, especially if the ancient buried structures 

are concerned, which are supposed to have ceased 

their evolution a long time ago. These doubts are, to a 

large extent, due to the fact that the meaning of generalization of an image of the Earth's surface with the 

increasing distance of its observation is yet unknown.

The mechanism, by which information about deep 

crustal structure is conveyed to the surface, is also unclear. Because it is primarily the Earth's surface that 

is expressed in the visible band of electromagnetic 

radiation on space images or, for that matter, on any 

other photographic or television image, regardless of 

their scale and their degree of generalization.

This surface, or "the face of the Earth," is a result 

of the entire history of the geologic development of 

the continents, which has been imprinted in the character of landscapes. A landscape reflects the resulting 

geological structure, as transformed by the whole 

variety of exogenetic processes. 2

In viewing the geological structure of a surface, one 

should clearly distinguish its ancient elements from 

those produced by neotectonic movements. The latter 

elements have, to a greater or lesser degree, used and 

transformed the ancient structures. Having thus acquired the specific character of their morphology, they 

have generated the main features of the terrestrial 

relief, which are, in turn, the basic elements of landscapes and which are expressed in space images. Reflecting primarily the total result of neotectonic deformations of crustal layers, the relief, first of all, conveys the largest amount of information about the 

youngest structure, including the deep-seated one.

1 Printed verbatim as received from the authors, except for 

minor changes in format and spelling.

2 The role of the exogenetic factors in landscape formation 

is not considered here, as we are discussing not the differences 

in manifestation of identical structural forms in different climatic 

zones, but the principle of their manifestation; for example, 

under similar climatic conditions.

319
320 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

This fact manifests itself very distinctly in the areas of 

intensive orogenesis, where it is not uncommon that 

the total amplitude of the vertical movements exceeds 

5 or even 10 kilometres and where separate fragments 

of once unbroken ancient complexes have been found 

displaced with respect to one another by hundreds or 

even thousands of metres. New forms have become 

distinctly pronounced both in relief and structure, for 

example, warpings of great radius of curvature combined with and complicated by faults of various orders 

of magnitude. At the present time, by using diverse 

methods, among them the geomorphological ones, it 

has been established that the neotectonic deformations of the Earth's crust and its surface manifest 

themselves everywhere not only in the mountain areas, 

but also on the plains, in the platform areas.

We think it necessary to emphasize that the deepseated structures of contemporary platforms and foldmountain regions represent chiefly the youngest deformations of deep crustal layers, which reproduce, in 

near-surface layers, only some individual features of 

their Hercynian, Caledonian, or more ancient structures, which have been transformed by the processes 

of subsequent geotectonic cycles.

Another important, though not so prominent, endogenous factor affecting landscape formation is the 

geochemistry of the Earth's surface, which is decisively predetermined by the chemical composition of more 

or less ancient substratum, as well as by the fluids 

that have ascended toward the surface from various 

depths and that appear to yield some information 

about both their sources and those layers through 

which they have passed.

From this standpoint, the study of deep-seated crustal structures by analyzing their surface manifestations, in particular those observed on space images, 

appears quite realistic and highly promising.

Interpretation of space images, obtained for various 

regions of the Earth's surface and by various investigators, has revealed a dense network of differenttrending, intersecting lineaments of various orders of 

magnitude, which can be found in every area. These 

lineaments partly correspond to zones of more or less 

significant crustal fractures, which have been recognized (or are supposed) from various geologic and 

geophysical data. When placed on the crustal structure pattern depicted on the previously published geologic maps, these lineaments have especially clearly 

indicated the superimposed character of structure both 

of fold-mountain and platform regions, thereby revealing new structural relationships between their 

elements. Such a valuable quality of space images as 

their great coverage favours the long-attempted explanation of the regional and planetary regularities 

governing the spatial arrangement of variously scaled 

forms of tectonic structure and relief. More or less 

distinctly formulated in their various versions, the 

concepts of superimposed crustal structure have their 

roots deep in the history of geology (Elie de Boumont, 

1830; Buch, 1867; Karpinsky, 1883; Argand, 1924). 

Properly speaking, it is a question of the principal deformational trends of the Earth, which in the long run 

determine the complicated mosaic of the Earth's 

surface.

The conceptions of spatial and temporal regularities 

governing the surface manifestations of some or other 

deformational directions are various. There are two 

extreme concepts maintaining either that the differenttrending dislocations have occurred at different periods of time and that they may be associated with one 

or another tectonic stage or that they took place during a single period of geologic time and that they are 

conjugated, differing only in the intensity and form of 

their manifestation. In the spatial aspect, these tectonic trends are considered by some investigators as 

either local or regional, while the other classify them 

as planetary.

In recent years, the concepts of superimposed crustal structure have been developed essentially along 

two lines. The first of them is concerned with planetary jointing (Shults, 1966, etc., see also in "Planetary 

Jointing"), the other is dealt with in an ever-increasing number of papers devoted to the so-called transverse structures. Of particular interest is the study of 

the transverse structures, because they are ore-concentrating and seismically active. Such studies, 

stressing one or another aspect of the problem, have 

been carried out in the Caucasus (I. V. Anan'in, M. G. 

Lomize, M. A. Kashkai, and G. P. Tamrazyan, E. E. 

Milanovsky, L. M. Rastsvetaev, V. Z. Sakhatov, V. G. 

Trifonov, V. E. Khain, Yu. K. Shchukin, and others), 

in Kazakhstan and the Soviet Middle Asia (N. P. Kostenko, V. I. Knauf, N. V. Lukina, V. I. Makarov, R. I. 

Pavlov, E. I. Patalakha, K. D. Pomazkov, D. P. Rezvoy, 

Z. A. Svarichevskaya, V. M. Sinitsyn, L. I. Solov'yeva, 

O. K. Chediya, G. N. Shcherba, Yu. K. Shchukin, and 

others), in the region east of Baikal and in the Primorski Territory (M. A. Favorskaya, E. P. Izokh, I. K. Volchanskaya, N. T. Kochneva, E. A. Radkevich, I. N. 

Tomson, and others). Much evidence for the transverse 

zoning, transverse folding, and local transverse structures has been reported also for other regions, both
INTERCROSSING CRUSTAL STRUCTURE AND DEEP-SEATED ELEMENTS 321

fold-mountain and platform. The transverse or crosscutting 3 structures, the existence of which is still 

debated by many geologists, have been distinctly delineated on space images and, finally, they have attracted attention of numerous geologists, geophysicists, and geomorphologists.

In what follows, we consider some elements of the 

youngest superimposed crustal structure, as exemplified by Tien Shan and the adjacent areas. The Paleozoic structure of the Soviet Middle Asia and Kazakhstan very clearly suggests that the structural character 

of the Paleozoic basement of the epiplatform orogen 

of Tien Shan and that of the Turan platform are common (Petrushevsky, 1955). The area of Caledonian 

folding, which is bounded in the south by the KaratauTurgai deep fault, forms a smooth arc embracing the 

northeastern margin of the Turan platform and Northern Tien Shan. Parallel to this area, the zones of Hercynian folding also form arcs extending from the 

north, from the Urals and Turgai through the Turan 

plate into the region of Tien Shan, where they occupy 

the central and southern areas.

So far as the general plan of the above-mentioned 

concentric arcs of different-aged folding of Paleozoic 

basement is concerned, the Tien Shan orogen occupies 

the southeastern sector, the northwestern sector being 

taken up by the Turan plate. The boundary between 

these sectors is formed by the western Tien Shan geosuture zone, which has first been delineated by A. V. 

Peive (1947) and which has been characterized subsequently by O. M. Borisov (1962, etc.), D. P. Rezvoy 

(1962, etc.), B. B. Tal-Virsky (1964-1972), and by a 

number of other investigators.

TIEN SHAN

The Tien Shan sector belongs to the planetary Sayany-Hindu Kush (or, according to D. V. Nalivkin, 1936, 

Turkestan-Sayany) belt of epiplatform orogenesis, 

stretching along the northeastern trend from the Hindu 

Kush to Baikal and intersecting the area of finished 

folding of various ages. The first-order elements of 

the youngest structure of Tien Shan are represented 

by sublatitudinal and northeast-trending system of uplifts and troughs, which are fractured and faulted crustal upwarpings and downwarpings of large radius of 

curvature. They are formed by linearly extending 

zones of young elevations and depressions, that is, by 

second-order structural elements. The latter, in turn,

3 The latter term we consider to be more exact when we have 

in mind various discordant structural trends, only some of which 

are in fact transverse.

are represented by en echelon conjugated, individual 

depressions or elevations, which, in general, are independent megafolds of lesser radius of curvature (according to S. S. Shults, basement folds) or their 

fragments.

Within the general framework of the neotectonic 

structure of Tien Shan, any area can be characterized 

by a simultaneous manifestation of two or more 

structural trends (Makarov and Solov'yeva, 1975). But 

to this characteristic one should add that, of several 

intersecting trends, one or, less frequently, two stand 

out like the principal ones, determining the strike of a 

structural form as a whole and its overall configuration 

in plan, whereas the other trends are subordinate, 

forming merely details of its structure and morphology. In various districts of Tien Shan this principal trend 

varies from sublatitudinal to northeastern and northwestern. In previous publications, when analyzing the 

youngest structure of the Susamyr-Dzhumgol district 

of Northern Tien Shan, we paid attention to the intensive fragmentation, mosaic arrangement, as well as 

isometric, often rhombic outlines of individual elevations and depressions. We believe that these features 

have been predetermined by the presence of two 

intersecting structural trends of about equal intensity, 

one of which is sublatitudinal and the other northwestern (Kostenko et al., 1972).

The northeastern trend plays the principal role in 

Southeastern Ghissar, in the Ugam-Chatkal system of 

elevations, and also in the eastern part of Central Tien 

Shan. In other areas, this trend is less pronounced, 

interrupted, or local. At the same time, it should be 

mentioned that the northeast-trending deformations, 

which do not always give rise to independent structures (at least, obvious ones), run through the entire 

orogenic region and can be traced into the adjacent 

platforms (fig. 1). Omitting the characteristics of 

northeast-trending zones, which have been given in 

our preceding paper (Makarov and Solov'yeva, 1975), 

we only note that in elevation systems this trend manifests itself as alternating zones of gentle uplift and 

relative subsidence, which are conjugated with crosscutting fractures. When going out into depressions 

covered by Mesozoic and Cenozoic sedimentary rocks, 

this trend is no longer subsidiary, but becomes principal. It should be borne in mind, however, that not 

everywhere the northeastern trend is neogenetic. It 

was distinctly pronounced already in the orientation 

of Hercynian linear zones of geosynclinal troughs and 

uplifts (Chatkal, Atbash, Eastern Kokshaal, and other 

ranges). This trend manifested itself also as zones of 

cross-cutting faults during the late Hercynian stage of
322 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 1.—Scheme of intercrossing structure of the Turan platform and Tien Shan based on the results of interpretation of 

space images, structural analysis of the relief, and geologic data.

1—Crustal fractures and crustal zones of ruptural-flexural dislocations determining the trend and configuration of the neotectonic structural forms (a, leading; b, subordinate); 2—surface exposures of Paleozoic and Pre-Paleozoic rocks; 3—areas 

of outcropping Mesozoic deposits; 4—areas of outcropping Cenozoic deposits.

The names of structural forms mentioned in the paper. Fractures or zones of ruptural—flexural dislocations (denoted 

by ciphers in circles): 1—Kopet Dag; 2—Mangyshlak—Central Ustyurt; 3—Nuratau; 4—Karatau—Fergana; 5—Dzhalair— 

Naiman; 6—Aksu—Hi; 7—Southern Emba; 8—Sarykamysh—Uspensk; 9—Western Bukantau; 10—Western Nuratau; 11—Western Tien Shan; 12—Aral; 13—Turkestan-Akchai; 14—Keles—Oksu; 15—Karakul—Balkhash; 16—Emba—Chu; 17—Taldybulak.

Neotectonic elevations: 1—Dzhusaly; 2—Karatau; 3—Fergana; 4—Chu—Hi; 5—Kuragata; 6—Kirghiz; 7—Ugam—Chatkal; 

8—Moldotau; 10—Karabaur; 11—Bukatantau; 12—Zirabulak; 13—Nuratau; 14—Chissar—Alai; 15—Aldyyar—Namazdek; 

16—Orgocher—Dzhetyoguz.

Neotectonic depressions: 17—Chu; 18—Southern Mangyshlak-Ustyurt; 19—Susamyr; 20—Fergana.

orogenesis (Pavlov, 1972; Voronich, 1964; Porshnyakov, 1973). The trend is well-pronounced in the seismicity of the region, too (fig. 2).

The northwest-trending structures, like the northeast-trending ones, are expressed also as zones of 

elevations, depressions, and cross-cutting fault-andflexure dislocations. Within Tien Shan, the KaratauFergana zone of elevations, which is conjugated with 

a deep fault zone, is morphologically best pronounced. 

The manifestation of other zones is less certain; however, these zones can be recognized by structural and 

geomorphologic analyses as well as from a number of 

indirect indications (Kostenko et al., 1972). In contrast 

to the northeastern trend, the northwestern is not recognized as the principal one within the mountain structure of Tien Shan, with the exception of the Fergana 

Range uplift. But beyond the system of deep marginal

faults, forming its northwestern boundary, this trend 

in places becomes principal.

Such are elevations of the ranges Nuratau, Karatau, 

and Chu-Ili mountains, which are conjugated with 

deep fracture zones (Nuratin, Karatau, and DzhalairNaiman). These fracture zones appear to be planetary. 

They are repeated every 300 or 400 km, dividing Tieri 

Shan into several sectors of different strikes, different 

morphology of the modern structure, and also different regime of tectonic movements. Between these 

global zones, there occur the transverse zones of regional significance, which are spaced at 50 or 60 km 

intervals (Makarov and Solov'yeva, fig. 1).

The northwestern trend of the modern structures of 

Tien Shan, like the northeastern one, inherits more or 

less completely (and with different intensity in different areas) the Caledonian and Hercynian structures.
INTERCROSSING CRUSTAL STRUCTURE AND DEEP-SEATED ELEMENTS 323

FIGURE 2.—Scheme showing the location of zones of higher seismic activity in Northern and Central Tien Shan. According to 

V. I. Knauf (1962) and supplemented by data of the present authors.

1 through 5: The number of earthquake epicenters per 625 km- registered between 1929 and 1956 (after Knauf, 1962): 

1—from 1 to 2; 2—from 2 to 4; 3—from 4 to 8; 4—from 8 to 16; 5—epicenters undetected; 6—seismic stations; 7— 

zones of increased seismic activity; 8—Barskaun and Orgocher zones of cross-cutting dislocations recognized using other 

criteria (Makarov and Solov'yeva, 1975).

The maximum density of earthquake epicenters is observed at the knots of zone intersections.

In the latter, this trend has also manifested itself in 

various regular "disturbances" of longitudinal (main) 

structural elements, including zones of higher mobility 

and permeability of the Earth's crust, which are 

marked by a regular spatial arrangement of magmatogene formations (Pomazkov, 1962). The other important indications are a considerable narrowing or 

even (which is not uncommon) wedging out of Paleozoic troughs in elevated zones. On the other hand, 

relatively lowered transverse zones are characterized 

by broadened areas of Late Paleozoic troughs, in particular, by red-coloured, residual and superimposed 

troughs, as well as by fields of development of Paleozoic volcanic rocks. Right-lateral flexural warpings of 

Paleozoic structure-and-facies zones and marginal 

faults, concentrations of Late Paleozoic faults, as well 

as the manifestation of the anomalous northwestern 

trend of minor folds in the Paleozoic basement,

are all confined to zones of recent fault-and-flexure 

dislocations.

The recent zones of northeast- and northwesttrending fractures, which intersect sublatitudinal Paleozoic zones, are incorporated in the ancient structure 

in such a manner that they inherit northeastern or 

northwestern fragments of Paleozoic fractures where 

the latter are geniculately curved.

Let us discuss at greater length the characteristics 

of some north-south-trending elements of the recent 

structure of Tien Shan, because this trend and those 

close to it have been studied here less than the other 

ones, despite the fact that they deserve considerable 

attention.

Within the area under consideration and within the 

adjacent territories, the north-south trend is practically nowhere the leading one, though it determines many 

important features of different-trending structures, as
324 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

well as the relationships between them. In general, it 

manifests itself as zones of higher jointing and fragmentation, faults, flexures, and, associated with them, 

more or less pronounced negative undulations of basement folds, and also as other structural and morphological features, thus enabling us to associate with this 

trend a preferable tension stress.

As an illustration, let us consider the KarakulBalkhash submeridional 4 zone of dilatation. On smallscale space images, with the aid of which this zone 

has been detected (Skaryatin, 1973; Makarov and 

Solov'yeva, 1975), it appears as a lineament zone °, 

which can be traced with some interruptions from the 

Hindu Kush through the Pamirs and Tien Shan. This 

zone is especially prominent in the area extending 

from the Karakul lake in the Northern Pamirs to the 

western end of the Balkhash lake. It will be noted that 

the latter trends here correspondingly and also has 

the maximum width. It seems that the confinement of 

the lake basin to the lineament zone is not coincidental, since the structures of relative subsidence are its 

main feature, at least, so far as Cenozoic is concerned. 

This is a wide submeridional trough G between the 

Kuragata swell of the Muyunkum region and the Kendyktas uplifts (which form a structurally single zone). 

Here the basement of the Eastern Chu trough occurs 

at the greatest depth. Also, a wide bench of young 

piedmont elevations, which are developed to the east, 

at the foot of the Kirghiz Ridge, falls off abruptly 

here (incidentally, this repeats the difference in the 

hypsometric position of Paleozoic basement in the 

Kendyktas-Kuragata elevation zone). Farther to the 

south there follow the meridional through-going valleys of the Karabalty and Aksu Rivers, which cut 

through the situated en echelon and going far behind 

one another structures of the complicated Kirghiz 

Ridge. These valleys become aligned, which is accompanied by an abrupt broadening of the Susamyr trough 

jutting out far to the south as a wide bay. Here the 

Susamyr trough is superimposed on a series of sublatitudinal and northeast-trending, relatively narrow 

basement up- and down-warpings of the Susamyr4 It should be mentioned that the submeridional lineaments 

found in the Pamirs and Tien Shan mostly tend somewhat to 

the east (clockwise).

c By the lineament zone we understand here sufficiently long 

(on a regional scale) bands of concentration of comparatively 

short lineaments, which intermittently follow one another (often 

en echelon) along the strike of the zone.

0 To this trough a submeridional part of the Chu river valley 

is confined, which has a clear antecedent behaviour and in 

which a wide fan of streams flowing from the northern slope 

of the Kirghiz Ridge converges.

Dzhumgol system. This superposition (or rather interference) has given rise to an abrupt subsidence of 

anticlinal structures, as well as to the deepening and 

geomorphologic merging of synclinal zones.

Still farther to the south, the Karakul-Balkhash zone 

is marked by a distinctly pronounced negative undulation of the Kokirim-Moldotau anticlinal zone, to 

which a meridional antecedent gorge is confined 

(through this gorge the rivers of the entire Naryn basin 

are drained from the Naryn system of intermontane 

troughs into the Toktogul and, then, into the Fergana 

troughs). Still farther to the south, there lies the triangle of the Toguztorau trough, which, in many features, is similar to the Susamyr trough.

Changing its direction apparently in the zone of 

Talas-Fergana deep fault and in the conjugate diagonal zone of elevations, the Karakul-Balkhash lineament 

zone goes out into the Pamirs through the Gulcha 

graben in the Alai system of elevations and through 

the Kyzylart depression in the structure of the Zaalai 

elevation. Within the Pamirs, the lineament zone is also 

marked by negative deformations, in particular, by the 

basin of Karakul lake. This part of the Karakul-Balkhash zone seems to correspond to a deep division between the Western and Eastern Pamirs, which has 

been described by B. A. Petrushevsky (1961, 1969), 

V. N. Krestnikov (1961, 1962), N. P. Kostenko (1964), 

and L P. Vinnik and B. A. Lukk (1974). One may suppose that the Karakul-Balkhash submeridional zone is 

linked directly with the Hindu Pamirs deep fault zone 

(B. A. Petrushevsky, 1969), which can be traced far to 

the south in the structure of the Hindustan platform 

and the Indian Ocean.

When tracing the Karakul-Balkhash zone northward, 

one may suppose that its continuation is fixed by the 

major bends of the Irtysh valley near Omsk, going out, 

through the system of the Great Yugan, into the Surgut 

area and farther north into the Ob Bay. The complex 

of data, which is available for this zone and which has 

partly been outlined above, enables one to describe it 

with sufficient certainty as a part of the planetary zone 

of deep-occurring tension.

Another major submeridional zone, characterized 

by flexures and breaks in continuity, has been interpreted on space images in the area of extreme western spurs of Tien Shan, about 500 km west of the 

Karakul-Balkhash zone. This is the Turkestan-Akchai 

lineament zone (after V. D. Skaryatin, 1973). The previously published geologic and geomorphological 

characteristics of this zone (Makarov, 1973, 1974) permit us to regard it as a tension zone, too. As an 

interesting detail, which has not been noted before,
INTERCROSSING CRUSTAL STRUCTURE AND DEEP-SEATED ELEMENTS 325

we can mention the probably genetic confinement to 

the zone of numerous large karst caverns in the massive (massif, ed.) of the western slope of Kugitangtau. 

Measurements of strikes of the karst caverns made in 

one of them have revealed their general confinement 

to and extension along meridionally striking cracks, 

which can clearly be seen on the cave ceiling. The 

measurements have also revealed their confinement 

to the places of intersection of meridionally striking 

cracks with WNW-ESE ones.

A less prominent submeridional fault-and-flexure 

zone can be recognized on small-scale phototelevision 

space images for the area lying somewhat to the east. 

This is the Keles-Oksui zone, which distinctly bounds 

the Ugam-Chatkal elevation system and clearly separates benches of relief of different height. The contrast in their elevations somewhat decreases within 

the Ghissar-Alai elevation system, though it still remains quite perceptible.

This brief outline of the Tien Shan recent structure 

indicates that it is constituted by the forms of diagonal 

and orthogonal trends, conjugated and simultaneously 

manifested practically everywhere, although these 

manifestations are different, as is their intensity. And 

the trends of structures of different order do not coincide generally. The study of numerous examples of 

different orientation of structural forms of different 

orders has shown that one of the causes of this phenomenon resides in the peculiar transformation and 

adaptation of Paleozoic structures to the recent process of orogenesis.

THE TURAN PLATE

The superimposed structure of Tien Shan passes 

directly into (and is continued by) a similar structure 

of the region of less active neotectonic movements 

lying to the north and northwest the Turan plate and 

Central Kazakhstan (fig. 1).

The Turan plate together with the outer troughs setting off the epiplatform orogen of Tien Shan, is characterized by a highly differentiated mosaic structure 

of its sedimentary cover and basement.

Vast domes and troughs representing here firstorder structural forms, have outlines, which can be 

called isometric only in a general sense. Actually, their 

outlines are highly complicated, abounding in numerous protrusions and "bays," which are well reflected, 

for example, on "The map of neotectonics of the 

South of the USSR" (1972). Analysis of this map, as 

well as of various geologic, geophysical, and geomorphological data, enables one to conclude that all 

the above-mentioned complications are caused by

the mutual superposition and interference of zones of 

uplift and depression of several trends. In the order of 

decreasing activity, these trends are northwestern, 

northeastern, submeridional, and sublatitudinal.

The northwestern trend corresponds to the strike of 

the Caucasus-Kopet Dag alpine epigeosynclinal orogen bounding the Turan plate from the southeast. The 

northeastern trend is parallel to (and, probably, closely 

linked with) the Sayany-Hindu Kush belt of epiplatform orogenesis. The orthogonal trends are subordinate, manifesting themselves only as fragmentary segments. The intensity of manifestation of all these 

trends decreases from south to north, or, to put it 

more exactly, in the direction running from the orogens—Sayany-Hindu Kush in the eastern sector and 

Caucasus-Kopet Dag in the western one, which are 

separated by the Urals-Oman meridional planetary 

zone of troughs and dislocations (Argand, 1924; Furon, 

1941; Amurskyetal., 1966).

The superimposed character of the platform structure is best pronounced in the Mangyshlak-Ustyurt and 

Karatau-Kyzylkum regions representing the most active and elevated parts of the plate.

The northwestern trend, which, as has been mentioned above, manifests itself in Tien Shan mostly 

indirectly, gives rise to independent structures beyond 

the "official" boundary of Tien Shan. There are, first 

of all, the Dzhusaly-Karatau and the MangyshlakNurata systems of elevations.

The Dzhusaly-Karatau system, sharply limited in the 

northeast by the Karatau-Fergana planetary fault zone, 

is well traced in the sedimentary cover and relief 

structure from Tien Shan to the southern termination 

of the Urals. The development of this system of elevations in the relief has led to isolation of the river 

valleys of Turgai, Sarysu, Chu, and Talas from the 

Aral Sea basin, which started in Late Pleistocene. This 

resulted in the formation of a chain of drainless basins 

in the relief, which distinctly mark, as can be seen also 

on space images, a synclinal zone cojugated with the 

elevation system.

About as far as the lower course of Sarysu, the 

elevation zone under consideration runs along the 

boundary of the Ulutay-Northern Tien Shan region of 

occurrence of Caledonian structures, inheriting their 

trend. But farther it can be traced directly to the 

northwest and is sharply discordant with the edge of 

the Caledonian massive (massif, ed.), which deflects 

here northward forming an arc (the Ulutau Ridge). 

The Dzhusaly-Karatau elevation system, which generally sinks toward the northwest, in this area is 

somewhat uplifted and expanded, thus giving rise to
326 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

the isolation of the so-called Dzhusaly dome. The 

dome is situated at the intersection of the elevation 

zone under consideration with the less distinctly manifested zone of elevations of the northeast trend, to 

which, in particular, the Sarysu-Teniz divide is confined. It should also be noted that some features of 

the overall configuration of the Dzhusaly dome have 

been predetermined by the fact that it was, as it were, 

inscribed in a grid formed by intersecting fractures 

belonging to the two above-mentioned elevation systems, as well as by less developed orthogonal trends 

(fig. 3, example 5). The knots of intersection of some 

fractures are marked by minor salt-bottom depressions, which set off the dome in a chain.

The Mangyshlak-Nurata linear system of elevations 

is confined to the Mangyshlak-Central Ustyurt deep

\

\ X

\ \

\ \

x\

FIGURE 3.—Some examples of interference between the elevation (depression) zones of various trends.

1—Principal structural trends; 2—subordinate structural 

trends; 3—the same for subsidiary structures; 4—generalized 

contours of local elevations (depressions); 5—axes of local 

elevations (depressions); 6—not explained [ed.].

fault, representing a link in the Donets-Tien Shan belt 

of deep crustal dislocations (Karpinsky, 1883). Against 

the background of general subsidence of the system 

from the southeast to the northwest, it undergoes, like 

the Dzhusaly-Karatau system, repetitive undulations of 

various orders of magnitude. The most significant subsidence occurs in the Urals-Oman submeridional zone 

and also in the similarly trending Caspian belt.

Transverse troughs of much less order are clearly 

expressed in the neotectonic structure of the eastern 

part of the zone in question, which borders on Tien 

Shan and which represents a direct structural and orographic continuation of the Turkestan-Alai elevations. 

The transverse troughs may be typified by the Western 

Nuratau group of troughs (between the ZirabulakNuratau and Central Kyzylkum elevations) and the 

Tadzhikazgan depression, separating the elevations of 

Central Kyzylkum from those of Sultan-Uizdag. These 

troughs separate and emphasize in the relief the areas 

of positive undulations of Zirabulak-Ziaetdin mountains, Gobduntau, Nuratau, Central Kyzylkum, SultanUizdag, Karabaur, and Mangyshlak, which form in the 

general system of elevations a series of sinistral and 

dextral en echelon structures (fig. 4).

Analysis of spatial arrangement of cross-cutting deformations has revealed that they are confined mainly 

to more or less extensive zones of relative uplift and 

subsidence of northeast trend. In contrast to the similar structures of northwest trend, they, however, do 

not give rise to sharply distinct independent structural 

form. An exception to this rule is the outward, marginal area of the Turan plate which borders on the 

epiplatform orogen of Tien Shan. The zones of crosscutting lineaments, parallel to the Western Tien Shan

FIGURE 4.—Scheme of echelon-like structure of elevation 

(depression) zones.

1—Principal structural trends; 2—subordinate structural 

trends; 3—the same for subsidiary structures; 4—generalized contours of local elevations (depressions); 5—axes 

of local elevations (depressions).
INTERCROSSING CRUSTAL STRUCTURE AND DEEP-SEATED ELEMENTS 327

deep-seated geosuture, confined, as it were, the steps 

of progressively expanding Tien Shan Uplift, a consistent penetration of its fore-uplifts into the platform, 

which takes place primarily along the above-mentioned zones of northwest trend. The northeasttrending zones of elevations, representing the direct 

continuation of Tien Shan elevation zones, have been 

formed parallel to the zone of the deep geosuture in 

the structure of sedimentary cover of marginal troughs 

of the platform (Tashkent, Beshket, etc.).

Within the inner parts of the Turan plate, the significance of the northeast trend is much lower. On space 

images received from the space ships "Soyuz-8" (cosmonauts V. A. Shatalov and A. S. Eliseyev), "Soyuz-9" 

(cosmonauts A. G. Nikolaev and V. I. Sevast'yanov), 

"Soyuz-12" (cosmonauts O. G. Makarov and V. G. 

Lazarev), and from meteorologic satellites of "Meteor" 

type, one can clearly trace the highly extensive Western Nuratau and Sarykamysh-Uspensk lineament 

zones, as well as a series of regional northeast-trending lineaments of Ustyurt and Mangyshlak, which have 

first been recognized with the help of space images 

(see also, Beregovoi et al., 1972; Bogorodsky et al., 

1973; Florensky, 1973; Abrosimov et al., 1974; Makarov et al., 1974).

The Western Nuratau lineament has been called so 

provisionally, after the zone of regional transverse dislocations, which is situated at the western termination 

of the Zirabulak and Nuratau elevations, described 

and named by R. I. Pavlov (1972). This lineament is a 

fragment of a lineament zone of the same name, 

which can be traced to the southwest through the 

lower course of Zeravshan river and the delta of 

Murgab river in the direction of the Meshkhed basin 

in Iran. Toward the northeast, the lineament is traced 

in the low of the Karatau Ridge, corresponding structurally to an area of conjugation between two echelons. Within the Chu-Sarysu syneclise the lineament 

limits the Akkum-Talas elevation.

The Sarykamysh-Uspensk lineament zone bounds 

from the southeast the mountains of Tuarkyr and the 

Ustyurt Plateau, controls (fixes) the southeastern coast 

of the Aral sea. It can farther be traced through a 

sharp bend of the Syr Dar'ya river along the southern 

flank of the Mynbulak depression, where it is marked 

in the relief by a straight-line "chink" (border scarp) 

and by a "thousand springs" (Mynbulak) at its foot. 

Within the Central Kazakhstan massive (massif, ed.) 

the lineament runs through the upper part of the Sarysu valley and, apparently, through the Uspensk crush 

zone (Suvorov, 1968) or the Spassk crustal fracture 

zone.

Local lineaments of northeast trend of the Ustyurt 

and Mangyshlak, which have first been recognized on 

space images, are identified (Bogorodsky et al., 1973; 

Florensky, 1973; Abrosimov et al., 1974) as regional 

fractures in the basement. This is evidenced by the 

configuration of gravity and magnetic anomalies within the area (Artamonov and Isayev, 1971). Moreover, 

the lineaments are distinctly inscribed in the structures 

of sedimentary cover, which have been recognized 

from deformations in reflecting horizons.

The orthogonal trends in the structure of the Turan 

plate have little been studied so far. The meridional 

trends of fracture and fold structures are especially 

marked in the structure and relief of the Turan plate 

in the zone of the Urals - Oman lineament, where they 

play the part of the principal trend of dislocations. 

West and east of this zone, these trends gradually 

grow weaker. For example, within the Ustyurt Plateau 

these trends already manifest themselves as subordinate (Bogorodsky et al., 1973).

The sublatitudinal trend is expressed within the 

Turan plate by several extensive lineaments, which 

have been identified on space images as the Southern 

Mangyshlak, Erbent-Donguzsyrt, and Karabal crustal 

fractures belonging to the extensive system of Southern Mangyshlak-Ustyurt troughs.

Let us consider the morphology of superimposed 

structures of the platform regions by taking the Central Ustyurt Plateau as an example.

The recent elevations of the Mangyshlak-Karabaur 

system have the west-northwest (sublatitudinal) trend, 

running along the Mangyshlak-Central Ustyurt deep 

crustal fracture zone, which has been developed during a long time. However, just as it has been mentioned for the Tien Shan elevation systems, individual 

elevations of Karatau, Western Chink, and Karabaur, 

constituting these systems, appear here as dextral 

echelon-like structures of northwest orientation, making an acute angle (about 30°) with the fracture zone 

and the elevation system as a whole. Only the core of 

the Karatau anticlinorium, composed of Permian and 

Triassic rocks, strictly retains the strike of Paleozoic 

crustal fracture. But, as the interpretation of space 

images from "Soyuz-12" has revealed, it is also dissected by a system of recent northwest-trending fractures and, like the structures of the upper stage, forms 

a system of dextral echelon-like structures.

Zones of highly extensive lineaments of northeast 

and, more seldom, submeridional trends, which intersect the Central and Southern Ustyurt and which have 

been recognized on space images (Bogorodsky et al., 

1973), fall within the transverse zones of relative sub-
328 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

sidence, embracing transverse troughs isolated both in 

the relief and in structure, while the elevation system 

as a whole undergoes gentle subsidence at the intersection with these zones. Local structures forming the 

elevation system are arranged here in echelons.

Thus, the systems of intersecting trends, developing 

in time and space and represented by flexure-and-fault 

zones (these zones correspond to relative lows in 

structure and relief) and by zones of elevation, underlie the highly differentiated mosaic structure of the 

Turan plate. Where the intersecting zones of different 

sign (up and down) are superimposed, there occur 

structures of intermediate amplitude, whereas in 

places of mutual superposition and interference of 

different-oriented structures of the same sign there 

are formed either the lowest (- -) or the highest 

(+ +) structures of the basement and its mantle. And, 

as the analysis of superimposed structure has shown, 

the areas of maximum uplift or subsidence correspond 

to the triple coincidence of structures of the same 

signs. For example, the Sarykamysh depression, which 

is an area of intensive contemporary subsidence (absolute elevation of its surface is minus 38 m), lies at the 

intersection of regional depressions: the northeasttrending Sarykamysh-Uspensk zone, the sublatitudinal 

trough system of Southern Mangyshlak and Ustyurt, 

where the Paleozoic basement occurs predominantly 

at depths between -3,000 and -5,000 m, and the 

highly extensive submeridional trough zone of Sarykamysh and Barsakelmes. As a rule, the boundaries of 

structural forms are predetermined by the framework 

in the interfering zones. The interference pattern of 

different-trending zones of elevations and troughs just 

considered is completely analogous to that observed 

in the Pamirs and Tien Shan (Kostenko, 1964; Chediya, 

1964; Kostenko et al., 1972; Makarov, 1969; Solov' 

yeva, 1971; Makarov and Solov'yeva, 1975), evidently 

representing a general regularity.

Thus, it is clear that in the overall superimposed 

crustal structure of both platforms and orogens, the 

localization, configurations, boundaries, and orientation of structural elements have been predetermined. 

The configuration and orientation of structural elements is determined by the most intensively developing trend. Within Tien Shan, under the 

conditions of intensive vertical movements and horizontal compression there have been formed differenttrending linear structures naturally inscribed in warpings of large radius of curvature. The influence of 

superimposed trends has manifested itself in the echelon-like 'character of linear structures of all orders:

systems, zones, and local forms. It can be noticed that 

the width of the linear structures is inversely related 

to the degree of compression, which is maximum in 

zones of transverse elevations. The length of structural forms is dependent upon the manifestation of 

cross-cutting trends, too. Generally, it is determined 

by intervals between the cross-cutting zones and by 

the degree of their manifestation. For example, the 

cross-cutting zones, giving rise to negative undulations 

in anticlines break the extensive linear zones of elevations into separate echelon-like links, the orientation 

of which, being affected by the cross-cutting trends, 

usually does not coincide with the general strike of the 

zone. A similar situation can be observed also on the 

platform, for example, in the Central Ustyurt and in 

other linear elevations, where subordinate cross-cutting trends are expressed in the orientation of echelonlike structures, constituting the elevation zones.

When equally manifested trends interfere with one 

another, there arise isometric structures, for example, 

arches, domes, basins, and other similar attributes of 

the so-called intermittent folding. And not only in the 

conditions of weak recent uplift of the platform can 

such configurations be produced, but also in areas of 

intensive folding and orogenesis. For example, in Tien 

Shan, in the southeastern part of the Fergana intermontane trough, there are known the isometric structures of the Aldayar and Namazdek domes, which have 

been formed under conditions of intensive recent deformations at the intersection of longitudinal (northeastern) and transverse (northwestern) elevation 

zones. Such are the elevations of Orgocher and Dzhetyoguz in the Issyk Kul' trough.

Analysis of the neotectonic structure of such vast 

regions as Tien Shan and the Turan plate has convincingly shown that there are no structural forms determined by a single trend, but that they are generally 

caused by the more or less active development of 

two (or more) trends. And, as is evidenced by various 

structural sections, the cross-cutting trends vary both 

in intensity and with time.

In various stages of development, the overall (principal) trend (configuration) of troughs and elevations 

may change significantly.

Taking into consideration the peculiarities of interference between different-trending structures is obviously of great practical value, because it provides a 

basis for a directed structural forecast in searching 

for a number of useful minerals, in particular, for oil 

and gas.

A comparative analysis of structural elements, recognized on variously scaled space images of the Cau-
INTERCROSSING CRUSTAL STRUCTURE AND DEEP-SEATED ELEMENTS 329

casus, Tien Shan, and other regions, has shown that, 

as the distance from the object photographed increases (or as the image resolution decreases), the 

structural elements of the increasingly deeper crustal 

layers (down to those of the upper mantle) come into 

focus of space images. And these deep-seated structural elements do not always coincide in trend with 

one another or with the main elements of near-surface 

structures. This fact has enabled the investigators to 

suppose (and this has been confirmed by a variety of 

geophysical and seismological data) that definite elements of disharmony between different structural 

stages and crustal layers manifest themselves on space 

images (Makarov et al., 1974).

The causes of this disharmony are probably different for different crustal layers. For the structural 

groups of upper crustal layers composed of Phanerozoic and Late Pre-Cambrian sedimentary and volcanic 

(to a greater or lesser degree metamorphosed) rock 

complexes, this disharmony has been predetermined 

by different-trending deformations that occurred in 

different tectonic cycles. As for the deeper crustal 

layers and those of the upper mantle, the causes of 

the differences in the behaviour of their boundaries 

still remain obscure and may be essentially different.

It should be emphasized that the above-mentioned 

disharmony is not absolute. One may only point out 

that separate structural groups of crustal layers are 

autonomous, but that, at the same time, they are 

united by certain, more general, structural relationships, which are predetermined, in particular, by interactions between the continental blocks. This structural 

unity of deep and near-surface crustal layers is supported, in particular, by the similarity between data on 

tensions in earthquake focuses located at various 

depths in deep crustal layers and those on tensions 

manifested in near-surface structures and imprinted 

in peculiarities of arrangement and morphology of 

faults and folds. Furthermore, the comparative analysis of structural trends indicates that practically all 

these trends are inherent to all structural stages. The 

differences (sometimes, very significant) lie only in the 

degree of activity and in the form of manifestation of 

a particular trend. It may be assumed that all these 

considerations go also for the deeper crustal layers. 

In any case, the trends observed in them by some or 

other means are not exceptional and can be detected 

more or less clearly in structures of upper crustal layers and on the surface. We should like to mention, for 

instance, a striking resemblance of the surface structure of Central and Northern Tien Shan (fig. 1) with a 

generalized arrangement of zones of higher seismic

activity, which reflect the structure of much deeper 

crustal layers (fig. 2).

Therefore, not only in plan does the structure of 

crustal layers display its superimposed character, but 

also in section. This characteristic should evidently 

determine and explain many features of the interrelated and inherited development of crustal structures 

of different ages and depths of occurrence. The essential similarity between the main structural features of 

platforms and those of orogens, which have passed 

through different histories of tectonic development, 

convincingly bears out the conclusions made by S. S. 

Shults (1971, 1973) regarding the existence of planetary fractures of various orders forming "the canvas 

on which tectonics embroiders its pattern." Knowledge of such regularities facilitates a purposeful 

search for structures with which commercial minerals 

are associated.

II

When studying a possible mechanism of conveyance 

of some features of deep-seated structure to the surface of the Earth (for it should once again be emphasized that the observer sees principally and primarily 

the Earth's surface), we come to the conclusion that 

this conveyance can be realized through mechanical 

deformations and geochemical transformations of the 

surface, which are imparted from various depths of 

the Earth's interiors. It is evident that the gravity, magnetic, and thermal local fields, created by crustal heterogeneities and by processes operating at great depths, 

play a definite, though entirely unknown role in forming the surface structure and its landscapes. These 

fields are obvious surface manifestations of the abovementioned abyssal factors and thus can be of assistance in expressing the latter on space images.

Turning our attention to the problem of how the 

deep-seated structures can appear through the Earth's 

surface, we should emphasize that by the deep-seated 

structures we understand not so much the structures 

of ancient buried Pre-Paleozoic and Paleozoic complexes and not only deformations of the surface of 

buried folded basement, but also the modern structure 

of deeper crustal layers.

The determining factor of the mechanical mode of 

transmitting deformations from great depths to the 

surface of the Earth is the continuity of tectonic movements at all levels of the Earth's crust and upper mantle. In this way, most of the structural sutures of quite 

different orders of magnitude are kept "alive," thus 

ensuring the crustal plasticity.
330 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

Neotectonic deformations of deep crustal layers, 

(among them quite recent deformations), have caused 

some distortions in all overlying horizons, comprising 

the day surface (surface, ed.). The most intensive 

mechanical transformation of crustal layers and, consequently, of the surface takes place in the regions of 

modern orogenesis and within young platforms. Within orogens, the total amplitude of the neotectonic 

movements is as high as 10 or even 15 km; within 

young platforms it usually does not exceed 2 km. The 

evolution of the neotectonic structural forms of orogens and platforms, for example, folds of great radius 

of curvature complicated by faults, has modified the 

structure and morphology of formations of previous 

stages of development. In the process, they have to 

some extent, used elements of old structures, developing in accordance with their trends and inhomogeneities, thereby renewing, though in a new combination, 

some features of these. Examples of utilization of elements on the Tien Shan Paleozoic structure by neotectonic deformations have been described elsewhere 

(Makarov and Solov'yeva, 1975).

The study of the recent structure of Tien Shan has 

shown that the response of various crustal layers to 

the submeridional compression, which is characteristic 

of the recent orogenesis of this region taken as a 

whole, is different. Deep-lying layers, for example, 

Pre-Cambrian crystalline basement and even deeper 

layers, which appear to be more homogeneous than 

the overlying ones, respond to compression by forming rather simple, elongated, in general, normally to 

the direction of compression, linear folds of basement 

(as conceived by E. Argand), systems of elevations and 

troughs, which directly reflect deformations of the 

Conrad and Mohorovicic deep-seated discontinuities. 

The deep crustal fractures, which confine the basement folds or are conjugated with them, directly reflect the canvas of the deep-seated structure. They 

represent deformations of shear and tension. The 

former are expressed by thrust and upthrown faults 

aligned with the strike of basement folds, and also by 

lateral faults which are diagonal with respect to the 

folds strike. The tension fractures are expressed on 

the surface by systems of normal faults, flexures, 

grabens, zones of higher jointing and permeability 

elongated in the direction of compression. The dynamic characteristic of fractures is confirmed by various seismological data on stress and deformations in 

earthquake focuses (Shirokova, 1962, 1963; Panasenko 

and Meshkova, 1964).

This category of major fold and faults, which, as a 

rule, are expressed on space images as modified in the

structure of near-surface formations, is far from being 

expressed everywhere sufficiently clearly in the intricate pattern of relatively small deformations of 

Paleozoic series constituting most of the surface of 

Tien Shan. Repeatedly changed by the above-mentioned details, the deep crustal fractures often disappear (on aerophotographs and, especially, in field observations) when a close-up of the locality is taken. 

Therefore, the deformations under consideration 

(megafolds and deep crustal fault zones) may remain 

unnoticed on large-scale photographs. Moreover, the 

immediate manifestations of these deformations may 

quite be related to structures of different genesis or 

order and thus will also be lost. The foregoing considerations are especially important in recognizing 

concealed deep crustal faults which do not come to 

the day (surface, ed.) (as, for example, the TalasFergana and San Andreas faults do) but die out as 

breaks in continuity at some depth in the crust. Being 

represented in the overlying layers as diverse deformational derivatives and other structural features, they 

scatter into more or less wide (up to several tens of 

kilometres) zones of deformations with indistinct 

boundaries. Such zones were recognized from a number of indirect indications; for example, in Paleozoic 

structures of Kazakhstan and the Soviet Middle Asia 

such zones have been referred to as deep mobile 

zones (Shcherba, 1955; Pomazkov, 1962). In the neotectonic structure of Tien Shan, this category comprises the zones of cross-cutting regional disturbances, 

which have also been recognized from indirect data of 

integrated geologic-geophysical and structural-geomorphological analyses (Kostenko et al., 1972; Makarov and Solov'yeva, 1975). Similar concealed systems 

of disturbances, the systems of "through-going" deep 

crustal fractures of a peculiar type have been discovered in structures of the Soviet Far East and the 

area east of Baikal (Tomson, 1962, 1964; Tomson and 

Favorskaya, 1968; Favorskaya et al., 1969, 1974).

On the whole, one may conclude that recent deformations of deep crustal layers, being imparted to 

the overlying strata, are modified by numerous details 

of old structures and near-surface topography, thus 

becoming to a greater or less degree masked and concealed from the ground observer. But a generalization 

of the surface pattern, which is due to photographing 

from space, makes these deformations visible. Using 

(and thus reviving to a greater or lesser degree) separate elements of old structures (including the buried 

ones) the neotectonic movements assist in expressing 

these elements on the surface, thereby ensuring their 

appearance on space images.
INTERCROSSING CRUSTAL STRUCTURE AND DEEP-SEATED ELEMENTS 331

On the vast platform territories, where the basement (or folded foundation) is overlain by more or less 

thick sedimentary cover, the deep-seated crustal structures, like those of orogens, also appear as generalized outlines of landforms. And it is not uncommon 

that in such a case they are recognized even more distinctly, because the weak deformations of sedimentary 

cover reflect practically directly the modern deformations of the buried folded foundation and deeper crustal layers. In other words, here the masking Effect of 

deformations of the sedimentary cover is minimum, as 

compared with that observed in folded complexes of 

fold-mountain regions.

It should be added that with the increasing distance 

of such concealed deformations in the platform regions 

from active tectonic regions they become less pronounced. This can clearly be observed in the Turan 

plate, where it seems to be associated with the corresponding decrease in the intensity of excitation of 

"inert" tectonic areas by their more active neighbors. 

Such regularities also suggest that active regions (in 

the given case, orogen), and platforms are not separated by an impenetrable screen. For example, the 

boundary between the epi-Hercynian Turan platform 

and the Tien Shan orogen (the regions of a single preNeogene history, but of different activity of manifestation of neotectonic orogenesis) appears as an extensive transitional zone, whose deformational intensity 

gradually increases toward the orogen. These two 

regions are closely linked structurally, but at different 

structural levels and along different trends the activity 

of their association is different. Thus, notwithstanding 

all existing differences between these geostructural 

regions, one may speak about their peculiar "intergrowth," or at least, about the more active region 

growing into the less active one.

Let us now turn to the geochemical mode of conveying information from deep crustal layers to the surface. The possibility of such conveyance is defined by 

the following main conditions:

1. Constancy of abyssal geologic processes and related ascending flows of abyssal degassing products and heat fluxes.

2. Difference between various layers and parts of the 

crust in the chemical composition.

3. Non-uniform permeability of crustal layers.

Among the geologic processes operating throughout 

the Earth's crust and upper mantle, the most important 

for the problem in hand are the constant mobility, 

repeated renewal (reactivation) of mechanical movements, embracing all crustal layers, as well as physicochemical changes in crustal matter, accompanied by

the release, transformation, and vertical migration of 

various fluid components and the heat flux.

The material, geochemical difference between various crustal layers may be considered in two aspects. 

This is, first of all, the result of development of crustal 

layers over the whole period of geologic history, reflecting separate stages of their formation and longcontinued transformation. Among such differences are, 

for example, the well-known structural-formational 

and geochemical differences between variously aged 

structural stages and between their various blocks 

(zones, regions). In this connection, it is appropriate to 

mention the well-known differences in the mineralization and chemical composition of waters contained in 

various structural, stratigraphic, and hydrogeological 

complexes. Such geochemical distinctions may conditionally be classified as static, relatively stable factors.

In addition, there are differences in physico-chemical processes occurring at various structural levels, 

under various thermodynamic conditions, and in 

chemically different environments. These processes 

of transformation of the crustal substance at various 

lithospheric levels, including the Earth's surface, taking place under the influence of ascending from depth 

solutions and gases, may be classed as the dynamic 

factors. The above-mentioned geochemical differences of the two categories may be both qualitative 

and quantitative.

The permeability of crustal layers is assured by its 

"live" intercrossing structure, and primarily by the 

network of mutually intersecting (both in plan and in 

section) joints and fractures of various genesis, order 

of magnitude, and depth of occurrence (from the 

planetary jointing to regional and local fractures). 

These fractures are of principal importance, because 

they form the framework of the intercrossing structure. The continuity of tectonic movements (in the 

given case, amplitudes are unimportant) supports 

"life" of these fractures, thereby keeping the Earth's 

interiors open.

The concepts of the significant role played by the 

ascending flows of heat and products of abyssal degassing have long been advanced within the framework of tectonomagmatic hypotheses, proceeding 

from the supposition that the evolution of the Earth's 

crust is associated with magmatic differentiation of 

the lithospheric substance. The problems of vertical 

migration of fluids in the crust of the Earth (its 

"gaseous breath," as V. I. Vernadsky put it) have 

been discussed by numerous investigators, among 

them metallogeny studiers and, especially, petroleum 

geologists. But whereas the latter, along with the 

search for directions of fluid motion and areas of their
332 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

flow, are highly interested in the areas of "closed" 

interiors, it is of great importance for the problem 

under consideration to study the places of outflow 

(points of issue) and the peculiarities of the fluid surface distributions, as well as the fluid composition, 

which would enable the investigators to relate some 

or other components of this ascending flow to the 

deep sources generating them.

The wealth of information about the regularities 

governing the areal and sectional changes in the 

chemical composition of fluids (water, oil, gases, 

especially helium, argon, hydrogen, nitrogen, and so 

on), which has been accumulated in hydrogeology, 

petroleum geology, and volcanology, clearly testifies 

to their intensive vertical migration, taking place primarily in zones of "live" fractures and shaping geochemical and geothermal anomalies on the Earth's 

surface. Here, we should bear in mind that the vertical migration occurs not only along through-going 

straight-line ducts whose role may be played by certain fractures. A multitude of facts suggest,—and 

this we endeavored to demonstrate by examples of 

Tien Shan and Turan,—that fractures, breaks in continuity, and fissures change their activity of manifestation and their amplitudes both in strike and with 

depth, as changes the mode of motion along them; 

the open ones turn into the closed, and so on. But, as 

has been stressed above, dying out in one direction, 

their activity shifts to another, in order to return subsequently (perhaps, having changed their trend many 

times) to the initial one. (This may be a channel that 

either continues the old one or runs parallel to it.) It 

is this complicated, repeatedly changed, and practically unlimited way, formed in the above described 

manner, that assures the vertical migration of fluids 

reaching the surfaces with some or other losses. This 

is confirmed, for example, by emanations of inert 

gases, which, no doubt, have the abyssal origin 

(Yakutseni, 1968; Eremeyev et al., 1969; Nikonov, 

1972; Voitov, 1975; Korobeinik and Yanitsky, 1975).

The way passed by fluids from the deep interior 

upward to the day surface may be compared to a 

bed of a stream, which, running down an inclined 

surface of a structurally and lithologically inhomogeneous substratum, repeatedly changes its direction 

in conformity with these inhomogeneities in order to 

take the easiest path.

We may suppose that the fluid flow from the deep 

interiors toward the surface has a regional diffusive 

character, i.e., it is practically continuous. Its density 

and composition, however, vary both in area and 

time. This non-uniformity has the primary (genetic), 

as well as the secondary (superimposed) causes. It

is known, for example, that the density of regional 

flow of helium, which of all inert gases of deep origin 

is the best studied in this respect, varies as a function 

of the original concentration of radioactive elements 

in the substratum, above all, in the granitic layer. The 

secondary non-uniformity is determined by structural 

features, being associated with the fact that in its 

way the fluid flow passes through numerous "filters." 

Even if we assume that initially the flow was uniform 

and chemically homogeneous, its final heterogeneity, 

observed on the surface, should reflect, in one way 

or another, the spatial distribution of these filters, 

which is largely due to the deep-seated structure. 

Thus, the peculiarities of landscapes (soils, vegetation, 

and so on) contain a specific "record," which manifests itself on aerospace images and lends itself to 

the geologic interpretation. The previous attempts at 

such interpretation permits us to state that it is both 

feasible and necessary. This is confirmed by the results of investigations of the chemical composition 

and peculiarities in the distribution of gases both in 

area and in section, which have been carried out in 

various regions. Thus, the study of the presence of 

helium in the layers making up the Turan plate 

(Bakirov et al., 1970) has enabled those investigators 

to assert that a correct and unambiguous geologic 

interpretation of abnormal values in helium distribution is feasible.

Thus, the fluids, which ascend from various depths 

of the Earth's crust toward its surface, shape its contemporary geochemistry by interacting with the 

geochemical structure of the surface that has already 

been formed in the previous geologic epochs. Therefore, the complex geochemical spectrum of a particular part of the Earth's surface (hence, some features 

of its landscapes) contain a highly diverse information, 

including that carried by fluids, telling about their 

source media and the crustal layers through which 

they have passed on their way toward the surface.

The fundamental possibilities of expressing some 

features of the deep crustal structure in the character 

of the Earth's surface that we have just considered, 

are realized in different ways, depending on the geologic and climatic conditions. And this fact must 

determine what specific method should be used in 

every particular case.

In most cases, the mechanical deformations of the 

Earth's surface are reflected in the features of its 

relief. Given the conditions of sufficiently active neotectonic (including contemporary) movements, we are
INTERCROSSING CRUSTAL STRUCTURE AND DEEP-SEATED ELEMENTS 333

justified in expecting that the deep deformations 

directly manifest themselves in those of the day surface. Depending on their intensity, the latter may 

develop as conerosional, condenudational, and, finally, 

consedimentational forms.

In order to elucidate the character of structures of 

the first group, one may use the whole diversity of 

techniques of the structural-geomorphologic analysis, 

which allows one to recognize the developing structures of the platform mantle, to map them sufficiently 

reliably, to study their arrangement, conjugative 

peculiarities, character of development, and so on.

The identification of condenudational and consedimentational structures is somewhat more difficult, 

especially when the latter are found in the regions 

of active sedimentation, for example, in the Syr 

Dar'ya and Chu syneclises, and in the central part of 

the Fergana intermontane trough. In these cases, the 

surface deformation is negligibly small. But the facieslithological peculiarities of sedimentation, which are 

determined by the developing structural form and 

which, in turn, characterize it, are expressed in the 

more or less distinct hydrogeological and lithologicgeochemical features and, through them, in those of 

the soil and vegetational cover. Thereby, they also determine some features of the landscape and may appear on high-altitude images in some or other spectral 

band.

The reason for the appearance of consedimentational structures on space images is essentially the 

same. When the image resolution is sufficient, the 

pattern of these structures becomes complicated by 

the old deformations of the folded basement if the 

latter is exposed in cores of such elevations.

Thus, in the cases of consedimentational and 

condenudational development of mechanical deformations, they become expressed more or less 

distinctly in the pattern of the Earth's surface indirectly, through the material composition of deposits 

making up the surface. The ensuing possibilities of 

identifying on space images major consedimentational 

structures, including consedimentational elevations, 

which are highly promising as possible places of oil 

and gas accumulation, attract special attention to the 

development of methods for studying such structures 

by means of remote sensing.

That the structures of consedimentational type 

occur widely in the region under consideration is 

clearly suggested by the following facts. The relative 

elevation in the relief of the Turan plate is not more 

than 300 to 500 m. The platform basement topography, however, is characterized by amplitudes of 

movements, which are higher by an order of magnitude. The total amplitude of movements that took

place in the Neogene-Quaternary epoch within the 

Mangyshlak varies from 200 to 2,000 m. Whereas the 

total amplitudes of Meso-Cenozoic movements in 

certain areas of the Turan plate are as high as 6 or 

even 8 km. Because of more active tectonic movements of the platform during the Neogene-Quaternary 

time, consedimentational elevations have partly passed 

into the condenudational and then into the conerosional stage of development in the relief. However, 

a large number of local structures of the sedimentary 

cover retain their previous consedimentational regime 

of development and, therefore, are not reflected 

directly in the elevations of the relief.

The geochemical relationships between the Earth's 

surface and its deep interiors manifest themselves in 

finer peculiarities of landscapes (especially soils, and 

vegetation), which are far from being always open 

to the eye. And, since these relationships also have 

some significance in the relief formation, they are expressed in landscape features as inseparable from the 

mechanical factor, which is by far predominant in the 

areas of orogenesis. On the contrary, within the platform regions the geochemical factors begin to play 

a more significant role in forming the appearance of 

the Earth's surface, because for them to be active the 

amplitudes of displacements are of no importance 

provided the crustal layers are permeable throughout.

The specificity of methods for investigating deepseated structures within both the platforms and the 

orogens has already become apparent in groundbased studies and in the interpretation of space 

imagery data.

An analysis of the network of the main regional 

fractures, which (as a rule, though not always) are 

pronounced in the relief sufficiently distinctly, gives 

us the most general idea of the character of the deepseated structure of platforms. Mapping based on 

images showing the network of lower order fractures 

and jointing, which are inscribed in the framework of 

deep crustal fractures, enable one to disclose the 

peculiarities in the composition of individual forms. 

Of great importance in such studies is the determination of regional slopes which can be restored from 

the grade of surface and subsurface waters, manifested in the trend of river drainage, as well as in 

the overall pattern of drainage systems. Areas sloping 

in one direction are, as a rule, united structurally, too. 

The boundaries separating areas of different slopes 

usually coincide with deep crustal fracture zones. 

This can be exemplified by deep crustal fractures 

within the Turan plate, for example, those of Amu 

Dar'ya and Repetek.

Let us dwell in more detail upon the peculiarities 

of "X-raying" the deep crustal fracture zones through
334 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

a thick cover of sediments of the platform. The recent 

reconstruction of the intercrossing structure of the 

region with respect to the structures of the preceding 

geotectonic cycles gives rise to changes in the leading, most active trends. Those of the deep crustal 

fracture zones which have coincided in the new platform structure with the most active trends become 

distinctly expressed in the modern structure and, 

therefore, in the relief. Such are the fracture zones 

of predominantly northwest trend, which disturb the 

entire sedimentary cover and which are directly pronounced on the surface as a system of ruptural dislocations and folds.

The orthogonal deep crustal fractures, for example, 

the submeridional fractures of the Urals-Oman dislocation system, are not expressed so distinctly in the 

neotectonic structure. They serve as boundaries for 

consedimentationally developed structures, and these 

boundaries are of smooth or flexural character. Because of low activity of the modern movements, these 

zones, being active and highly permeable in the 

Hercynian structure, have turned out to be sort of 

sealed under the sedimentary cover. But, although 

ultimately these zones have not been expressed directly in the overlying layers (even as zones of lowamplitude dislocations of flexural-ruptural type), they, 

as a rule, are accompanied by a system of conjugated 

joints developed in the sedimentary cover. It is just 

these joints, that, being altered under the influence 

of varied factors of the exogenetic processes, create 

a picture of lineaments, which can be recognized on 

photographs from a set of indirect characteristics. In 

the neotectonic structure of the Turan plate one can 

observe a large number of flexural zones of this type. 

Their surface manifestation is extremely veiled, they 

are barely traceable in a series of indirect features 

of the landscape, which, at first glance, have little to 

do with one another and are hardly remarkable.

Being generalized on space images, all these features of the landscape taken as a whole, delineate 

such structures by distinct changes in the density of 

photographic tone or become apparent in geometric 

peculiarities of minor drainage patterns. The change 

in the photographic tone may, as a rule, be associated 

either with a change in the composition of sediments, 

of ground waters, their regime and geochemical composition, which determine different soils and vegetation.

Thus, the information about the deep crustal structure is transmitted either mechanically, by deformations of deep crustal layers being reflected in all 

overlying strata, including the Earth's surface, or 

geochemically, by ascending flows of fluid products

arising from transformations of matter constituting 

deep layers of the Earth's crust and upper mantle.

Both mechanical and, especially, geochemical mode 

of expressing the deep-seated structure in the appearance of the Earth's surface are afforded by the 

intercrossing character of crustal structure, by its 

high mobility, and, as a consequence of both these 

factors, by its permeability in every area.

Such an approach toward the study of the Earth's 

surface allows one to explain possible mechanisms 

by which deep crustal layers "appear" on the surface 

and by which deep crustal structure, or, at least, some 

of its elements are depicted on space images. This 

makes space images highly promising not only in 

comparing maps of the Earth's surface, but, what 

perhaps is more important, in studying deep crustal 

layers and associated minerals.

Of particular interest in this respect is the geochemical aspect of the problem at hand. It may be 

supposed that some time in the future the geologists 

will be able to recognize quite easily the components 

of the geochemical field observed on the surface, 

which are associated with sources of various depths 

of occurrence. At present, it is required that we 

should discuss the essential possibility of such a 

mechanism of formation of the structure of the 

Earth's surface in order to broaden the aspects of 

geologic interpretation of space images, and also to 

put on the agenda the geotectonic aspects of landscape geochemistry, and to attract attention to the 

underestimated geochemical factor in structural and 

geomorphological studies.

It seems to us that the possibility of recognizing 

the genetically different components in the geochemical spectrum of the Earth's surface may have farreaching practical consequences for the search for 

minerals. Such a decomposition of the geochemical 

spectrum will possibly be carried out using multispectral imagery, including space imagery. For the 

prospecting potentialities of various bands of electromagnetic radiation (their addition, subtraction, and 

other manipulations with them) have little been 

studied so far and, of course, are far from being exhausted. In other words, the time has come to raise 

the question of application of space imagery to the 

direct purposeful prospecting for zones of various 

depths of occurrence and metallogenetic significance.

Along with the importance and fundamental possibilities of employing space images in studying the 

deep crustal structure, the problems raised in the 

present paper attract attention also to the independent 

and not yet quite understood significance and possibilities of geomorphological and geochemical studies
INTERCROSSING CRUSTAL STRUCTURE AND DEEP-SEATED ELEMENTS 335

of the Earth's surface in order to gain a deeper insight into the structure of the Earth's interiors.

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PROCEEDINGS OF

THE FIRST ANNUAL WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Combined Formalized Processing of Space Image and Geologic-Geophysical Data 

in Connection with the Study of Deep Structure of Petroliferous Platform Regions *

By P. V. Florensky, A. S. Petrenko, and B. P. Shorin-Konstantinov, 

Moscow Institute of Petrochemical and Gas Industry

INTRODUCTION

Analysis of space images made with the purpose of 

recognizing the geologic features of some or other 

region has become one of the indispensible elements 

of regional geologic studies. This is an entirely new 

element, which neither removes the necessity of carrying out all other works nor does it lower the requirements to their comprehensiveness, but permits their 

more definite coordination, as well as the extraction 

of new information. For the present, these observations are being performed, as a rule, merely for individual regions. Such specific work, which is sufficiently 

subjective and in each case unique, is unquestionably 

justified in developing the required procedures. The 

amount of the diverse material obtained from space is, 

however, so large that confining our attention to such 

processing alone would mean that we leave out of 

consideration tens, hundreds and sometimes even 

thousands of TV and photographic images covering 

vast territories. Therefore, our most immediate task is 

to bring about a formalized computer processing of 

space images which would enable us to encompass a 

significantly greater amount of information.

Of all useful minerals contained in the platform 

mantle, only oil and gas are extracted from depths 

exceeding two or even three kilometres. It is natural 

therefore that the petroleum geologists are to a large 

extent interested in the character of basement surface 

and basement internal structure. Accordingly, much 

credit for the study of the platform basement buried 

under sedimentary mantle goes just to them.

1 Printed verbatim as received from the authors, except for 

minor changes in format and spelling.

The importance of such study was emphasized by 

Academician I. M. Gubkin who illustrated it by considering the petroliferous province between the Volga 

and the Urals. Subsequently, the behaviour of the 

basement in question in the course of time has been 

analyzed (Bakirov, 1957) and its comprehensive geologic and geophysical study carried out (Belyaevsky, 

1974; Borisov, 1967; Krats, Nevolin, and others). It is 

just on this territory that the problem of petrographical 

study of basement rocks from core samples taken 

from deep boreholes supplemented by geophysical 

data has first been stated and, in principle, solved. 

The problem is being further investigated at the department of petrography of the Moscow Institute of 

Petrochemical and Gas Industry under the guidance of 

T. A. Lapinskaya (until 1956 the work was directed by 

V. P. Florensky). At present, the study of basement is 

one of the most important elements of the comprehensive study of all petroliferous provinces of the 

Soviet Union.

As has been demonstrated by considering the Turan 

platform (Florensky, 1973; Trifonov et al., 1973; Makarov et al., 1974; Bogorodsky et al., 1974), small-scale 

photographs of the Earth made from space allow one 

to judge about the deep-seated structure of the platform regions. The present work is devoted to a combined, sufficiently formalized, processing of geologic 

and geophysical materials in conjunction with space 

image data in order to clarify the deep-seated structure of the Lower Volga region (fig. 1). The purpose 

of the work is to evaluate just to what extent is a 

space image of a part of the Earth's surface illuminating in regard to the study of the deep structure of a 

platform and to establish criteria for comparing space

339
340 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 1.—Southern Russian plain. TV image obtained by the Soviet Earth-orbiting satellite "Meteor."

images with geomorphological, geologic, and geophysical information.

In the course of this study, we have used television 

and scanner images of the region under consideration, 

which have repeatedly been transmitted from the 

Soviet automatic satellites "Meteor" (resolution about 

1.5 km (fig. 1)), and earlier objects of the "Meteor" 

series (resolution from 0.8 to 1.0 km), as well as a 

scanner image (fig. 2), transmitted in July 16, 1973, 

from the American automatic satellite ERTS-1 (resolution about 0.1 km). The latter images have thoroughly been processed photometrically and the results of 

the deciphering thus made have been compared with 

the various geologic and geophysical data for the 

region. In the final geologic interpretation, the results

of deciphering of other space images of the region 

have been taken into account as well.

The photometric measurements were made by B. P. 

Shorin-Konstantinov, the geophysical data were reduced by A. S. Petrenko and subsequently analyzed 

geologically by Petrenko together with P. V. Florensky.

PROCEDURE OF PHOTOGRAPHIC AND

PHOTOMETRIC PROCESSING OF SPACE

IMAGES

In working with space images there arises the necessity of artificial improvement of deciphering properties 

of the images with respect to some or other objects. 

Ways of such a transformation of images are various
COMBINED PROCESSING OF SPACE IMAGE WITH STRUCTURE STUDY 341

44°06'08"E 46°37'25"E

50°48'07"N

49°40'06"N

43°25'02"E

'49°17'47"N 

45°51'53"E SCALE 1:3,369,000

FIGURE 2.—Lower Volga region. TV image transmitted from the American satellite ERTS-1 on

16 July 1973.

(Mikhailov, 1972; Kuchko, 1974). One of the most extensively employed methods is that based on the separation between zones with different photometric densities, which is more distinct than one seen on the 

original image.

In the present paper, account has been taken of the 

data on specialized processing and photometry of 

space images to allow the evaluation of the amount 

and quality of geologic information contained in the 

space images. The images of the Lower Volga region 

we have selected are of interest not only from the 

standpoint of geology but also from the standpoint of 

the development of methods for processing and photometry of space images.

On the original image one clearly sees arable land 

mottled with small fields of various coloration. At the 

same time, bedrocks here do not come out to the day 

(surface, ed.), in contrast to those of the mountainous 

regions. In the course of this work it was necessary to 

identify regional geologic objects and, with this purpose, to suppress, in particular, the local differences 

in brightness associated, for example, with the distribution of arable land, i.e., to generalize the image 

and, simultaneously, to increase the contrast with 

which elements of larger geologic structures manifest 

themselves on these images. To achieve both these 

aims, we have employed a combined method of photographic filtration of photometry and photometric processing of the image.

The photographic positive image of the region in 

question has been obtained on a sheet phototechnical

film of T-41 type at 1:1,500,000 scale (developer—62, 

cuvette development), which has made it possible to 

raise the degree of image contrast at a comparatively 

small value of haze density D = 0.14. As a result, the 

double positive obtained on the sheet film had only five 

fields of the light wedge, in contrast to the original 

image (also obtained on the sheet film) that had fifteen 

fields of the wedge. This artificial increase in image 

contrast has resulted in filtration and generalization of 

the initial information contained in the photographic 

image. However, because of the increase in the general image contrast, the brightness characteristics of 

the varying elements (such as sown fields, districts) 

have also become exaggerated.

It has been possible to get rid of unnecessary details 

by varying integrally the optical densities of images 

along the profiles. The system of the profiles has been 

chosen to cover uniformly the whole area of study, 

with the distance between two profiles about 20 or 25 

km. This assured a sufficiently detailed picture and 

permitted compilation of the scheme of optical densities for the territory (fig. 3). Measurements were made 

using a registering microphotometer 0-451. The defining slit of the microphotometer was opened as 

much as possible (18 by 4). From the photometric 

curves along the profiles, the values of relative maxima of density (D max) were taken, which have subsequently served for constructing the scheme of photographic anomalies. The maximum values of optical 

density were used to eliminate the influence of cloudiness, whose density on the measured positive corres-
342 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

•*) *t_

/- 

.——«-^<

"*tw XJw'ijf

wo 

too

500

400

JOO

• ZOO

.100

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100

200

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(+JWOO

FIGURE 3.—Example of a composite profile of geologic-geophysical and photometric information. 1—Optical density; 2— 

coefficient of correlation between the gravity field and the 

optical density.

44°06'08"E

ponds to that of the haze (Dclouds = D0 = 0.14). The 

scheme was compiled using the averaged values of the 

relative maxima of optical density, which, in turn, has 

led to artificial filtration. In constructing the scheme, 

the Volga itself was disregarded. The interpolation 

step was 0.2 (D = 0.2), which is greater than the gradients of random variations of the optical density.

The fully opened defining slit (18 by 4) has ensured 

generalization of the ciphers obtained, which has 

weakened the influence of fractional and small-in-area 

elements of the image on the positive measured. The 

scheme of photographic anomalies has been constructed by taking into account all the above-mentioned artificial alterations introduced while processing the images along the profiles. Interpolation made 

in the scheme compilation was controlled all the time 

directly from the photographs.

On the scheme of photographic anomalies (fig. 4), 

which has been compiled with considerable generalization, the northern half is lighter than the southern 

one. The gradients of variation of the optical density 

are insignificant almost everywhere on the scheme; as 

spots, they outline various areas, forming an arbitrary 

photometric "surface." The orientation of trends of 

the photographic anomalies varies from northwestern 

in the northwest of the area to north-south in the east 

to sublatitudinal in the south.

This scheme of photographic anomalies, which is 

the first interpretation, has been compared with the 

geologic and geophysical data available.

46°37'25"E 

»<:—I—I 50°48'07"N

49°40'06"N 49°17'47"N

43°25'02"E SCALE 1:3,369,000 45°51'53"E

FIGURE 4.—Photometric scheme of the image shown in figure 2 in arbitrary units (clouds removed); isolines and coloration are in arbitrary balls, lineaments are shown by the solid 

lines.
COMBINED PROCESSING OF SPACE IMAGE WITH STRUCTURE STUDY 343

GEOLOGIC AND GEOPHYSICAL FEATURES

The general description of blocks is presented in 

table 1.

RELIEF

The area under consideration forms in plan a somewhat elongated toward NNE square 180 by 190 km. 

Its central part is occupied by the Don-Medveditsa 

Ridge bordering on the Volga Upland whose absolute 

elevations range from 250 to 300 m. These uplands 

separate the basins of the Medveditsa and Ilovlya 

rivers flowing into the Don from the valley of the 

Volga whose floor is occupied here by the Volgograd 

reservoir. The right bank rises above the Volga by 100 

to 150 m; on the Volga's left bank there lies a plain 

elevated by only 50 m above sea level, i.e., only slightly above the water level in the Volga.

SCALE 1:3,369,000

s iinnn 4

FIGURE 5.—Geologic map for the Lower Volga region 

(from the Geologic Map of the USSR). 

1—Lower Quaternary deposits; 2—neogenic deposits; 

3—ecocenic deposits; 4—oligocenic deposits; 5—Upper 

Cretaceous deposits; 6—Lower Cretaceous deposits; 7— 

Upper Jurassic deposits; 8—Mid-Jurassic deposits; 9— 

Carboniferous deposits; and 10—bed of the Volga river. 

Same area as that shown in figure 2.

GEOLOGIC SURFACE STRUCTURE

Geologically, the area under study is the bordering 

one between the Voronezh anteclise in the west and 

the Cis-Caspian depression in the east. Within the area, 

Carboniferous deposits outcropping in the roof of the 

Linevsk Elevation are overlain by Jurassic, Cretaceous, Paleogene, and (on the left side of the Volga) 

Quaternary deposits (fig. 5). These Carboniferous bedrocks, however, are almost everywhere covered by 

soil (arable land). The section of the platform mantle 

displays here complicated paleofacial replacements 

(Bushetal., 1968).

NEOTECTONICS

By analyzing the variations in topography, peculiarities of river beds and of ravines and other geomorphological features, V. P. Bukhartsev (1974) and A. V. 

Tsigankov (1971) have compiled variously detailed 

maps showing the amplitudes of neotectonic movements. On the presented scheme, due to Tsigankov 

(fig. 6), one can recognize a single submeridional band,

SCALE 1:3,369,000

E>"-.T-.'| 3 E^^J 4

T HS

FIGURE 6.—Scheme of neotectonic movements of the 

Lower Volga region shown in arbitrary isolines (after 

A. V. Tsigankov, 1971).

Elevations: 1—1,000 to 800 m; 2—800 to 600 m; 3— 

600 to 400 m; 5—200 to 0 m. Areas of depression: 

6—0 to —200 m; 7——200 to —400 m; 8— 

—400 to —600 m; 9—isolines of equal amplitudes of 

neotectonic movements; 10—flexures; and 11—fractures. 

Scale 1:3,369,000.
TABLE 1.—Quant/tat/Ve characteristics of the identified blocks

Geophysical characteristics

Zone

I.

W

es

t

e II.

rn

Photometric 

block characteristic 

(fig. 4)

Northern _ — — _ _ — South- Average (0.4-ern. 1.0) dark

sublatitudinal

anomalies

in the west

and light

southeastern

submeridional in

the east.

Age of the 

rocks 

exposed

(fig. 5)

Carboniferous, Jurassic and

Cretaceous

overlain

by

Neogenic

and

Quaternary.

Upper Cretaceous.

Relief and

neotectonic 

movements 

(fig. 6)

Uplift, especially intensive in

the central

part.

Slight uplift,

moreprominent

to the east

and south.

Gravity 

field

High-gradient, positive isometric anomalies.

Positive, elongated submeridional

anomalies.

Magnetic 

field

Steep-gradient, positive, nearly

isometric

anomaliessublatitudinal in thenorthwestand submeridional

in the east.

High positive

submeridionalelongatedanomalies.

Correlation 

between the 

gravity and

magnetic

fields

Positive __ _ Positive, high

in thenorth and

negative in

the south.

Relationship (correlation) with the optical density

With 

topography With the 

and gravity

neotectonic field

movements

Alternating — _ __ —— sign in the

north, highnegative in

the south.

Positive, high. Positive, low

in the central partpassing

into negative on the

periphery.

With the

correlation 

With the coefficients 

magnetic for the

field gravity and

magnetic

fields

Positive __ _ Alternating

sign, but

mainly

negative.

Negative and Positive, high.

slight positive in the

west.

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COMBINED PROCESSING OF SPACE IMAGE WITH STRUCTURE STUDY 345

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346 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

which corresponds tectonically to the zones of the 

Umerovsky graben and the Kamyshin projection. It is 

here where the maximum erosion of ancient deposits 

has taken place during Quaternary time, reaching 

1,000 m in the north, in the area of the Linevsk Elevavation. The area lying on the left side of the Volga has, 

on the contrary, been a zone of subsidence and sediment accumulation during a long time.

GRAVITY FIELD

The character of Bouguer anomalies is determined 

chiefly by the internal structure and chemical composition of basement and by the basement surface topography, i.e., by factors operating at depth, as well 

as by structural and lithologic inhomogeneities inside 

the sedimentary cover, which give rise to density differentiation of rocks. So far as the gravity field is concerned, the territory is divided into two parts: northwestern area characterized by a weakly differentiated 

gravity field and southeastern one—an area of very 

low, exceedingly separated gravity anomalies. The 

boundary between these two areas is very distinct and 

is commonly drawn along a gravitational bench coinciding roughly with the right bank of the Volga, where 

in a band 10 km wide the gravity intensity decreases 

by a factor of 3 or 4 in the southeastern direction. This 

boundary corresponds to the flange of the Cis-Caspian 

depression. According to some concepts, the boundary corresponds to the zone of a major fracture and 

abrupt subsidence of the basement, whereas by other 

concepts it reflects a relatively gentle sinking of basement and the appearance of thick low-density saltbearing strata in the platform mantle section, which 

were the cause of the gravity bench formation.

In the right-bank territory there are three areas. The 

northern area bounded by the line running through the 

Melovatsk-Ilovlensk oil fields and by the Volga bank is 

characterized by variously trending anomalies of low 

amplitudes. Here the character of gravity anomalies is 

the most mosaic. The central area, which is bounded 

by the lines Melovatsk-Ilovlensk, Severo-DorozhenskYuzhno-Umetovsk and by the Volga bank, displays 

predominantly northwestern-trending elevated anomalies. The most intensive are the isometric anomalies 

observed south of the Ilovlensk oil-and-gas field and 

southwest of the Melovatsk gas field. Whereas in the 

north of the central area northwestern-trending 

anomalies prevail, in the south submeridional anomalies are encountered. According to the results of 

gravity field recalculation into the upper semi-infinite 

space (Gilod et al, 1970), a single elevated-density 

massive was isolated here, in the zone of the southeastern slope of the Voronezh anteclise, which was 

given by these authors the name of the Lower Volga 

core.

The southern area has high-amplitude west-northwest-trending elliptical anomalies extended in a chain.

Within the Cis-Caspian depression, east of the gravity bench, there are small-in-area negative anomalies 

of high amplitude, which are elongated subparallel to 

the bench trend.

MAGNETIC FIELD

The character of magnetic anomalies is mainly due 

to the chemical composition and structural features of 

the folded basement, as well as to the behaviour of its 

surface. The differences in shape and amplitude between magnetic anomalies found within the neighbouring blocks may be attributed to the different types of 

rocks, of which these blocks are composed, and to 

their differing metamorphism. The latter factor may 

lead, for example, to the secondary enrichment of 

basement rocks in magnetic minerals, which, in turn, 

is one of the causes of elevated magnetic anomalies.

CORRELATION BETWEEN THE GRAVITY 

AND MAGNETIC FIELDS

A simple visual comparison between the gravity 

field and the magnetic field does not allow one to establish any relationship between the parameters under 

consideration for each locality. Accordingly, a scheme 

showing the correlation between the gravity field and 

the magnetic field has been constructed (fig. 7) using 

the computer program "Ankor" and employing the 

procedure suggested by M. S. Zhdanov and V. I. 

Shraibman (1973) for the Turan platform.

A calculation of correlation between these two geophysical fields reflecting the integrated characteristic 

of the density and magnetic properties of the upper 

layers of the Earth's crust, which was carried out by 

the procedure suggested, has made it possible to establish the direction of change in these fields in various localities. On the scheme, positive and negative 

areas have a largely mosaic character. But whereas 

the areas of positive correlation are mainly isometric, 

those of negative correlation are, as a rule, elongated. 

Since the character of both the gravity field and the 

magnetic field in the area under consideration is chiefly determined by the composition and topography of 

the basement, which, in turn, was formed under the 

influence of tectonic processes, one may suppose that 

the same factors are reflected on the presented 

scheme, too.
COMBINED PROCESSING OF SPACE IMAGE WITH STRUCTURE STUDY 347

44°06'08"E

FIGURE 7.—Scheme of isolines showing the correlation coefficients for the gravity and magnetic fields.

46°37'25"E

50°48'07"N

49°40'06"N

43°25'02"E SCALE 1:3,369,000

49°17'47"N 

45°51 '53"E

A simultaneous analysis of the correlation scheme 

presented in fig. 7 and of the structural map showing 

the basement surface has revealed that areas of both 

positive and negative correlation correspond to positive and negative features of the basement structure. A 

weak resemblance can be observed between -the 

patterns of depth isolines and isolines of correlation 

coefficients. This suggests that the constructed scheme 

reflects but weakly the basement surface structure. 

At the same time, when matching the scheme of correlation coefficients with the petrographical scheme of 

Pre-Riphean basement, due to Bogdanova, Lapinskaya, and Podoba (1971), one can note that the localities of both individual intrusive bodies and fields of 

occurrence of definite rock complexes coincide. Thus, 

in particular, over intrusions of gabbonorites in the 

northwestern part of the photograph under examination one can observe an increase in positive correlation up to 0.79 which suggests rather a close relationship between gravity and magnetic anomalies in the 

localities indicated. Another extensive area of positive 

correlation found in the southwestern part of the photograph corresponds to a granulitic block of the basement recognized from drilling data (Bogdanova et al., 

1973). In the northeastern part of the photographic 

sheet, isolines of positive correlation (correlation coefficient here is as high as 0.89 or even 0.97) outline a 

body of granitoids of the granulite facies of metamorphism (plagiogranites containing garnet and cordierite). In the central part, a submeridional zone of 

negative correlation can be observed.

BASEMENT STRUCTURE

In regard to structure, the area under study is made 

up of major elements differing one from another (fig. 

8). In the west of the area, there is a periclinal termination of the Voronezh anteclise, where the basement 

occurs at a depth of 2.5 km; on the southeast, the CisCaspian depression slopes down, where the basement 

has sunk down to 10 or even 11 km. In the boundary 

zone between these major structural elements, there 

are several projections and troughs in the basement 

surface, which are complicated by local structures. 

Generally, these structures fall within the Saratov offset of the Pachelmsk aulacogen stretching, according 

to Nevolin (1971), towards Volgograd. On the northwest, a ramification of the other elements borders on 

the Cis-Caspian depression. The western and northwestern boundaries of the depression are drawn in 

conformity with a drastic decrease in the amplitudes 

of gravity anomalies.

The basement has been stripped by deep boreholes 

only in the relatively elevated western part of the territory (fig. 8). Most of core samples have been studied 

in detail at the department of petrography of the 

Moscow Institute of Petrochemical and Gas Industry, 

where a group headed by V. P. Florensky and T. A. 

Lapinskaya has systematically processed during many 

years practically all the core samples taken from the 

basement of the Volga-Urals region (Florensky, Lapinskaya, Knyazev, and others, 1956). The above-mentioned boreholes have stripped a variety of deeply 

metamorphosed rocks (Lapinskaya, Bogdanova, and
348 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

44°06'08"E 46°37'25"E

50°48'07"N

49°4Q'06"N

43°25'02"E SCALE 1:3,369,000 45°51 '53"E

49°17'47"N

FIGURE 8.—Basement surface topography (after N. N. Nevolin, 1974).

Podoba, 1971). In the southwest of the area, there 

have been stripped Archean high-alumina gneisses of 

the granulite facies pierced by granitoids. In the extreme southwest, these rocks are overlain by Proterozoic phyllites, shales, and metasandstones (Bogdanova, Podoba, and Serova, 1973). To the north of this 

area, there has been stripped a field of rocks of the 

amphibolite facies (biotite-amphibolic gneisses, microclinic granites, etc.) containing relics of rocks of the 

granulite facies. This testifies to a deep diaphthoritic 

reworking of a part of the granulitic block in the presence of amphibolitic facies. A large massive (massif, 

ed.) of granitoids of Archean age has been stripped in 

the north of the area. In the central and eastern parts, 

where the basement occurs at a great depth and has 

not been stripped by boreholes, the composition and 

structure of the basement can be judged only indirectly from the geophysical materials available. It has 

been assumed that in the central part of the area there 

occur gneisses of decreased density which were reworked by the Svecofennian-Karellian folding (Gafarov, 1973; Nevolin, 1971).

The structure of the Pre-Cambrian basement of 

southeastern area has only been hypothesized tentatively. Specifically, east of the zone of decreaseddensity gneisses R. A. Gafarov (1973) recognizes a 

stable block made up of rocks that have not experienced the secondary reworking.

COMPARISON BETWEEN THE SCHEME OF

PHOTOANOMALIES AND A COMPLEX OF

GEOLOGIC AND GEOPHYSICAL DATA

A relief of the studied area is very gentle; being 

shaded by contrasting spots of vegetation, it is reflected very weakly in the distribution of optical 

densities.

The surface exposures of sedimentary rocks shown 

in the geologic map are also weakly reflected in the 

optical density distribution, which may be associated 

with the fact that the bedrock composition is monotonous, while the bedrocks themselves are covered by 

soil (mainly plowed).

Neotectonic movements shown in isolines of the 

erosion section (fig. 6) perhaps are best reflected in 

the optical density distribution (fig. 4). There emerges 

a single submeridional zone corresponding to a band 

of the greatest neotectonic uplifts and erosion. The 

areas of accumulation situated on the left bank of the 

Volga are lighter in tone; it would appear that the 

overlying sediments should have concealed the distinctions in this territory; nevertheless, it is differentiated photometrically, thus allowing its separation.

So far as the pattern of anomalies is concerned, the 

gravity field has in general a number of features similar to those of the optical density distribution. This 

similarity, however, manifests itself differently in different parts of the area. In order to compare them 

more objectively, a scheme of two-dimensional correlation of the gravity field with the optical density has
COMBINED PROCESSING OF SPACE IMAGE WITH STRUCTURE STUDY 349

been constructed (fig. 9) along the direction of the 

photometric profiles. The values of the gravity field 

and optical density along the profiles were taken from 

a sliding interval 45 km long using a step of 30 km. 

The results of the calculations along the profiles have 

been extrapolated.

The curve showing the correlation of gravity with 

optical density is not high, but it is not smooth and 

usually oscillates by ±0.7 or even ±0.9 in some parts. 

From the sign of correlation, however, it turns out 

possible to single out only several individual zones. 

Across the central part of the photograph, there extends a wide submeridional band of positive correlation (its width reaches 70 km), which ramifies in the 

south of the photographed area into two branches, one 

of them being sublatitudinal and the other submeridional. In some parts of the above band, within the 

Kamyshin protrusion and northeast of the Kudinovsk 

elevation, the correlation increases up to 0.98. A second area of positive correlation occurs in the northwest and roughly corresponds to the eastern slope of 

the Voronezh anteclise. Zones of negative correlation 

found in the east are typical of the left-bank area, 

where in some parts the correlation coefficient 

reaches —0.95. The aforesaid allows a distinct division 

of the region discussed into three submeridional zones 

and, further, into a number of subzones, which is 

based on the correlation between gravity and optical 

density.

The magnetic field also exhibits a varying relationship with the optical density, which enables one to

44°06'08"E

isolate in the territory under consideration several 

zones, which partly coincide with those isolated 

previously.

When comparing the map of magnetic anomalies 

with that of photographic anomalies, one cannot help 

seeing that the two are considerably related. In this 

case, as in comparing the scheme of optical density 

with the map of-gravity anomalies, one may isolate 

various zones. The central part of the photograph is 

taken up by a submeridional zone of negative correlation coinciding with the zone of positive correlation 

between the optical density and the gravity field. The 

other parts of the area display, however, a more complicated and differentiated pattern. In particular, the 

area of positive correlation coincides with the slopes 

of the Voronezh anticlise, the left-bank region of the 

Volga is also characterized by the positive correlation 

between the optical density and the magnetic field.

The scheme showing the correlation between the 

magnetic and gravity fields (fig. 7) makes it possible to 

single out a submeridional zone bounding the darkest 

part in the southwest of the area, as does the scheme 

for optical densities (fig. 4). The principal trends of 

correlation anomalies coincide with those of optical 

density anomalies. The area of positive correlation between geophysical fields is relatively dark in the west 

(D = 0.8 to 1.0), while in the east, the areas of negative 

correlation between these fields are light (D = 0.4). 

Thus, areas of different correlation of geophysical 

fields (fig. 7), as well as those between geophysical 

fields and optical density (fig. 9), yield additional geo46°37'25"E

50°48'07"N

49°40'06"N 49°17'47"N

43°25'02"E SCALE 1:3,369,000 45°51'53"E

FIGURE 9.—Scheme of isolines showing the coefficient of correlation of the 

gravity field with the optical density.
350 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

logical information, which may be used in territory 

regioning.

Finally, comparison of the scheme of photographic 

anomalies with a complex of original geologic and 

geophysical materials enables one to consider the territory from the standpoint of the character of the 

relations established. The secondary schemes of correlations we have constructed are significantly different from the original ones. The reality of the new 

recognized fields is evidenced by the similarity in 

their patterns as observed in various, almost independent schemes. When analyzing the results obtained, 

it should be borne in mind that the photometric characteristics of space images of the platform territory 

reflect not so much surface geological objects, as 

regional tectonic elements of structure of both the 

sedimentary strata and the basement.

LINEAMENT IDENTIFICATION

When separating various fields, we have not discussed the character of their boundaries. However, it 

is just the geological boundaries between areas of contrast in some or other properties that are deciphered 

with the most certainty on space images.

In small-scale observations of the Earth's surface, 

the existence of the so-called lineaments has been 

established, i.e., lines of structural significance recognized from the gradients of photographic tone. These 

lines are only partly associated with the geologic and 

geomorphological structures visible on the surface in 

field observations. This applies primarily to fractures, 

whose deciphering on space images has been developed especially well for different tectonic regions and 

images of the different degrees of generalization 

(Skaryatin, 1973; Trifonov et al., 1973; Makarov et al., 

1974). In mountainous and folded areas with abruptly 

changing topography or with distinct boundaries between the occurrences of different rocks, the recognition of fractures by conventional geological techniques 

and of lineaments by deciphering space images reduces, in effect, to the identification of one and the 

same structures and structural trends. In the platform 

regions, however, the methods of lineament recognition are quite different, as are the recognized structures themselves. Indeed, on the platforms, lineaments 

are expressed as slight (of several metres) changes in 

topography elevations, as bends in the river and ravine 

network, or as merely insignificant changes in the 

composition of outcropping rocks. Such geologic 

boundaries, even when confined to fractures, have 

very often stratigraphic rather than tectonical significance. Thus, the search for the geologic and geomorphological criteria for the identification of lineaments in the platform regions is a highly contradictory 

task. At the scale used in direct geological observations in field work, most of lineaments are unrecognizable at all. Thanks to space images of the platform 

regions, it has turned out possible to recognize especially many lineaments heretofore unknown. It 

appears that a considerable number of lineaments are 

not accompanied by anywhere near essential onedirectional displacements of blocks, which would immediately be reflected on structural maps based on 

drilling data. One gets the impression that zones of 

extremely low-amplitude, but, probably, systematically 

different in direction, displacements, reducing merely 

to an extended band of increased jointing, are confined just to such lineaments. The latter probably intersect the Usturt Plateau leading to formation of straight 

parts of its chinks (border scarps) (Florensky, 1973; 

Bogorodsky et al., 1974).

On small-scale television images transmitted from 

satellites such as "Meteor" and "Meteor-Priroda" (fig. 

1) a submeridional lineament can be seen, which 

strikes along the general direction of the Volga bed 

and corresponds geologically to the northwestern 

flange of the Cis-Caspian depression. There appears 

also a secondary (with respect to the meridional one) 

northeastern trend of lineaments.

On ERTS-1 images (fig. 2) lineaments appear quite 

differently. The meridional lineament is scarcely traceable; only straight parts of it on the Volga's right-bank 

are present on the images. One succeeds, however, in 

recognizing a number of other, less significant, lineament systems (fig. 10). The best pronounced is the 

northeast trending lineament traversing the image. In 

the western and central parts of the image, a bank of 

clouds is confined to this lineament; the boundary 

which is known to mark a change in weather in this 

district coinciding with northeast trending structures 

also corresponds to this trend. The remaining lineaments are expressed on the space image as very thin 

lines of change in photographic tone; only some of 

them can be identified with straight-line valleys of 

rivers and streams. Not always can such lineaments 

coincide with geological boundaries of a locality.

After independent identification of the lineaments 

on both space images followed by independent identification of them by different geologists (V. P. Bukhartsev, A. S. Petrenko, P. V. Florensky, and others), 

an attempt has been made to correlate their position 

with the gradients of geophysical fields, as well as 

with the basement surface structure and composition.
COMBINED PROCESSING OF SPACE IMAGE WITH STRUCTURE STUDY 351

44°06'08"E 46°37'25"E

50°48'07"N

49°40'06"N 49°17'47"N

43°25'02"E SCALE 1:3,369,000 45°51'£3"E 

FIGURE 10.—Scheme of lineaments (of various degrees of expression on images).

One can observe a definite relationship between the 

northwest-trending fractures and the gradients of the 

gravity and magnetic fields. Two lineaments coinciding 

in trend with the fractures form the southwestern 

slope of the Saratov ramification of the Pachelmsk 

trough. Other lineaments striking parallel to them separate blocks of the basement composed of rocks of 

different compositions, which have already been described in the paper. Northwest-trending fractures are 

mainly characteristic of the right-bank region, whereas 

in the left-bank region northeast-trending fractures are 

especially prominent, only one of which can be traced 

from the right-bank area. The zone separating the 

areas of manifestation of lineaments trending predominantly northwest or northeast corresponds geographically to the Volga bed. Here fractures form 

something like branches of a fir tree whose trunk is 

the valley of the Volga, the acute angle of their intersection opening toward the south.

Thus, the lineaments that have been identified on 

the territory under consideration very weakly control 

its geomorphological structure. Not all of them affect 

the structure of the sedimentary cover. Almost all of 

the most prominent lineaments, however, appear to 

control the degree of metamorphic reworking of the 

basement, the structure of its surface and, in places, 

even the boundaries of variously aged pre-Riphean 

folding. One gets the impression that the inhomogeneities in the basement composition turn out to be just 

those weak spots along which there have developed 

the inherited zones of slight displacements taking

place in the course of the entire platform stage, up to 

the recent time. When these displacements are inherited, singly directed and significant, only then are 

local structures confined to these lineaments. Where, 

however, the displacements along fractures have different directions, a zone of higher jointing is formed, 

which controls the character of reservoir. From this 

standpoint, the identification of such "fractures without displacements" is advantageous, as it has allowed 

a more exact determination of the position of jointy 

zones possessing improved reservoir properties. Wells 

that have been drilled in such zones are characterized 

by high yields.

IDENTIFICATION OF BLOCKS AND THEIR 

GEOLOGIC INTERPRETATION

As a result of the integrated analysis of diverse 

data, it has turned out possible to recognize on the 

territory under investigation a number of blocks characterized by different values of optical density, different surfaces, different geologic and geophysical parameters, and their different relationships (fig. 11, 

table 1). The structural elements identified in this way 

have different amplitudes of neotectonic movements, 

different characters of gravity and magnetic anomalies and varying optical densities of images. But they 

are recognized especially distinctly when the technique of pairwise correlation of the indicated parameters is applied The method of local correlation of 

geologic and geophysical, as well as photometric, pa-
352 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

44°06'OB"E 

51°11'18*N

49°40'06"N

46°37'25"E

50°48'07"N

49°17'47"N

43°25'02"E SCALE 1:3,368,000 45°51'53"E

FIGURE 11.—Zoning scheme for the crystalline basement of the Lower Volga region compiled 

from a complex of geologic and geophysical data and taking into account the results of 

deciphering and photometry of TV-space images.

1—Zone of Svecofennian-Karellian reworking of the basement; 2—areas of metamorphic 

amphibolite fades; 3—areas of metamorphic granulite facies; 4—granitoids; 5—basic rocks; 

6—boreholes that stripped the basement; 7—structure contours of the basement as shown in 

fig. 8; and 8—lineaments as shown in fig. 4.

rameters has proved to be the most effective in territory regioning. Generally speaking, the whole area 

under study is divided into three submeridional bands: 

Western, corresponding to the periclinal closure of 

the Voronezh anteclise, central, and eastern, corresponding to the western flange of the Cis-Caspian syneclise. These zones, in turn, are divided, according to 

the internal structure of the basement, into blocks, 

which, in places, are outlined by fractures.

The combined geologic-geophysical and photometric characteristics of these blocks are given in the 

table and, therefore, are not discussed in the text.

In what follows, some considerations concerning 

the internal, block-type structure of the basement are 

outlined, which are based on a generalization of the 

whole material investigated.

The Western zone, which is the periclinal closure of 

the Voronezh anteclise, is distinguished by the homogeneous character of the gravity and magnetic field. Its 

eastern boundary coincides with a system of meridional and submeridional fractures, identified as lineaments on space images and coinciding with gradients 

and local anomalies of the geophysical fields. With respect to the orientation of gravity and magnetic anomalies, the zone is divided into two blocks by a sublatitudinal fracture, to which steep gradients in the 

gravity and magnetic fields are confined.

The Southern block is characterized by sublatitudinal geophysical anomalies and by an increased 

optical density. Within the territory of the block, within the Korobkovskoye elevation, wells have stripped 

deeply metamorphozed rocks of the granulite facies 

(crystalline shales with granite) weakly changed by 

diaphthoresis. Here, local anomalies correspond to 

granitoid bodies. In the southwest of the area (within 

the Kudinovsk structure and in the Panin wells 74, 

152, 154, etc.), younger (Proterozoic) phyllite shales 

spreading farther to the west have been stripped (Bogdanovaetal., 1974).

The Northern block is remarkable for submeridionally trending geophysical anomalies and for its lighter 

colored surface. Within the territory of the block 

(within the Zhirnovskaya, Linevskaya, Severo-Dorozhanskaya, and Mishinskaya structures), diaphthorites 

of the granulite facies have been stripped; for example, bi-amphibolitic plagiogneisses, granodiorites, 

and amphibolites.
COMBINED PROCESSING OF SPACE IMAGE WITH STRUCTURE STUDY 353

The Central zone is characterized by rather low 

gravity and magnetic anomalies, as well as by their 

negative correlation. For this zone, the tendency to 

uplift and the positive correlation between gravity 

anomalies and optical density are characteristic. Along 

its strike, the zone is especially dissected by fractures 

and is noted for the lowered values of gravity anomalies and for the presence of an extensive negative magnetic anomaly. These features are not at variance with 

the suppositions that here there occur rocks reworked 

last by the Svecofennian-Karellian folding (Gafarov, 

1973), which resulted in lowered densities of these 

rocks and in their intrusive injections. If the supposition is correct, the identified zone is a submeridional 

branch of the Pachelmsk trough, bordering on the 

southeastern slope of the Voronezh anteclise.

As a result of a comprehensive comparison of the 

geologic and geophysical data available with those of 

visual deciphering, and as a result of a formalized 

processing of space images of the area under consideration, it has turned out possible to establish that 

the correlative analysis enables one to make the most 

complete use of the information one possesses to study 

the deep-seated structure of parts of the ancient platform. Further, the conventional techniques for processing and generalizing the geologic and geophysical 

information have made it possible to outline, by using 

the results of direct study of core samples of the 

basement rocks, some features of the tectonic structure of the basement of the Lower Volga region and 

to add new details to the existing schemes. Thus, it has 

been possible to outline one of the sides of the relationship between the character of space images and 

the features of the internal structure of the region 

under study realized through neotectonic movements, 

which have evidently been caused by a compensated 

uplift of the decreased-density zones in the basement.

The presented complex of data on the deep-seated 

structure of a part of the Lower Volga region permits 

one to compare the information capacity of a space 

television image with that of other sources in regard 

to understanding of the deep-seated structure of the 

region.

First, in recognizing lineaments, fractures, and dislocations with a break in continuity and in specifying 

their positions space images have no equal sources of 

information. It is likely that the introduction of space 

images into scientific use signifies an essentially new 

stage in fracture study. This is especially true of the 

platform regions, in which displacements along the 

fractures are insignificant and their traces are concealed by the sedimentary cover.

Second, when taken by itself, the analysis of variations in optical density has shed but little light on the 

regioning of the studied territory, but when integrated 

with the analysis of geophysical data, its informative 

capacity has radically increased. It is likely that, at 

least for the platform regions, the informativity of 

space images for our understanding of the deep-seated 

structure of the area under consideration and its regioning approaches the informativity of regional geophysical investigations. And only in a combination with 

the results of regional geophysical studies can the 

space image information be interpreted.

This work has been done at the laboratory for Deciphering Aerospace Images (Institute of Geology, the 

USSR Academy of Sciences) under the general guidance of V. G. Trifonov, to whom the authors express 

their deep gratitude.

REFERENCES

Bakirov, A. A., Present-day concepts of the geologic 

structure of the crystalline basement of the Russian platform. Trudy Akad. neftyanoy promyshlennosti, issue 1, 1957.

Bogdanova, S. V., Lapinskaya, T. A., and Podoba, 

N. V., Petrographical characteristics of basement. 

In: "The study of the geologic structure of the 

East European platform by geophysical methods," 

Moscow, Nedra Publishers, 1971, pp. 69-84, 

illus.

Bogdanova, S. V., Poboda, N. V., and Serova, A. D., 

On the deep-seated structure and composition of 

the basement of eastern Russian platform. Izvestiya Akad. Nauk SSSR, ser. geol., 1975, no. 12, pp. 

19-31, illus.

Belyaevsky, N. A., The earth's crust within the USSR 

territory. Moscow, Nedra Publishers, 1974, p. 

283, illus.

Borisov, A. A., The deep-seated structure of the USSR 

territory according to geophysical data. Moscow, 

Nedra Publishers, 1967.

Bukhartsev, V. P., Geological prerequisites for the 

probabilistic forecast of oil- and gas-bearing 

zones from local ruggedness of relief of platform 

territories. In: "Mathematics, Computers, and 

Automatic Control Systems in petroleum geology." Moscow, Institute of Fuel Mineral Geology* 

and Prospecting, 1973, p. 130, illus.

Bush, E. A., Kuznetsov, V. G., Ryabchenko, F. M., 

Sokolov, V. L., and Shornikov, B. Ya., Geologic 

structure and objects of search for gas in the 

flange zone of the cis-Caspian depression in
354 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

southern Volga region. "Geol. nefti i gaza," no. 5, 

1968.

Gafarov, R. A., The basement structure of the East 

European platform and some problems of comparative tectonics of ancient platforms. In: "Tectonics of basement of ancient platforms." Moscow, Nauka Publishers, 1973, pp. 82-94, illus.

Gilod, D. A., Vostokov, E. N., and Dabizha, A. I., On 

some features of the basement structure of the 

south-eastern slope of the Voronezh anteclise (according to geophysical data). Vestnik MSU, ser. 

geol. no. 5, 1970, p. 115-120, illus.

Zhdanov, M. S., and Shraibman, V. I., A correlation 

method for separating geophysical anomalies. 

Moscow, Nedra Publishers, 1973, p. 128, illus.

Kuchko, A. S., Aerophotography. Moscow, Nedra Publishers, 1974.

Makarov, V. I., Skobelev, S. F., Trifonov, V. G., Florensky, P. V., and Shchukin, Yu. K., Deep crustal 

structure as seen on space images. In: "The study 

of natural environment from space," issue 2. 

Geology and geomorphology. Moscow All-Union 

Institute of Scientific and Technical Information, 

1974, pp. 9-42, illus.

Mikhailov, V. Ya., Photography and aerophotography. 

Moscow, Geodezizdat, 1972.

Nevolin, N. V., The main features of the geologic structure of the basement of the East European platform. In: "The study of the geologic structure of

the East European platform by geophysical methods." Moscow, Nedra Publishers, 1971, pp. 87- 

91, illus.

Skaryatin, N. D., On the study of rupture tectonics 

from a set of variously-scaled space images of 

the Earth's surface (the multistep generalization 

technique) Geologiya i razvedka, 1973, no. 7, p. 

34-50, illus.

Trifonov, V. G., Byzova, S. D., Vedeshin, L. A., Derevyanko, O. S., Ivanova, T. P., Kopp, M. L., Kurdin, N. N., Makarov, V. I., Skobelev, S. F., and 

Florensky, P. V., Concerning the procedure of 

geologic deciphering of space images of the 

Earth. In: "The study of natural environment from 

space," issue 2, Geology and geomorphology, 

Moscow, All-Union Institute of Scientific and 

Technical Information, 1973, pp. 8-78, illus.

Florensky, P. V., Lapinskaya, T. A., and Knyazev, 

V. S., Some results of the petrographic study of 

the crystalline basement of the Volga-Urals petroliferous region. Trudy Moskovskogo Instituta 

Neftekhimicheskoy i Gazovoy Promyshlennosti 

(Moscow Institute of Petrochemical and Gas Industry) Gostoptekhizdat, issue 26, 1969.

Florensky, P. V., Deciphering of the deep structure of 

the Turan platform from space images in connection with the prospecting for oil and gas fields. 

Izvestiya Vysshikh Uchebnykh Zavedenii, Geologiya i razvedka, 1973, no. 7, pp. 112-117, illus.
PROCEEDINGS OF

THE FIRST ANNIML WILLIAM T. PECORA MEMORIAL SYMPOSIUM, 

OCTOBER 1975, SIOUX FALLS, SOUTH DAKOTA

Geological Studies by Space Means in the U.S.S.R. 1

By V. G. Trifonov, V. I. Makarov, V. M. Panin, S. F. Scobelev,

P. V. Florensky, and B. P. Shorin-Konstantinov,

Geological Institute of the Academy of Sciences of the U.S.S.R.

Moscow, U.S.S.R.

Wide spectrum of the geological tasks requires the 

using of various methods of research: from studies 

of the atomic, molecular, and crystal structure of minerals and rocks to studies of the large structural forms 

and distribution of them in the planet. In the recent 

stage of the development of geology the solution of its 

many problems (first of all tectonic problems) is possible only by studies and correlations of the geological 

objects and events in the planetary scale and taking 

into consideration of peculiarities of the Earth as a 

space body. Such planetological aspect of the geological studies is provided (beside the traditional 

means and methods) with the new source of information on principle, that is the Earth's pictures from the 

satellites and orbital stations. These images are in 

visible and infrared parts of spectrum and are received 

by photographic, televisional and scannering means.

Geological using of the space visible information 

that started about 10 years ago, now has achieved 

large successes in the USSR, USA and number of the 

other countries. We don't want here to review the 

common progress in this branch of studies, but limit 

ourselves by observation of some works carried out 

in the Geological Institute of the Academy of Sciences 

of the USSR.

First of all the space images started to be used for 

compiling and correction of geological, structural, and 

tectonic maps, for mapping and correlation of the 

large structural forms and zones. So, the map of the 

major faults and zones of deformations of southeastern Kazakhstan, Middle and Central Asia was compiled with help of TV images with resolution 1-2 km

1 Printed verbatim as received from the authors, except for 

minor changes in format and spelling.

from meteorological satellites. The geological map of 

the central part of Tadjik depression (figs. 1 and 2) 

was compiled by deciphering of space photos from 

"Sojuz-9" with the higher resolution (100-200 m). The 

rather good quality of picture and integration of the 

brightnesses of the individual layers permitted to map 

objectively the lithological-stratigraphic units, folds 

and faults. The results of interpretation checked by the 

field observations. The comparison showed that deciphered map required essentially less of time and 

means than the earlier geological maps of the area in 

the same scale; but it didn't yield them in image of 

details, excelled them in exactness of image of faults 

and represented more objective generalization of the 

fold structure.

The further development of the structural-geological 

trend of the space information using is connected with 

analysis of images in different spectral bands and its 

combinations. In the examples of images with resolution about 100 m of Eastern Fergana and the northwestern foreland of Pamir in Middle Asia we can see 

that in bands 0.5-0.7 mkm the Quaternary deposits 

and the more old rocks with rather high collector 

ability are deciphered better than all (figs. 3 and 4). 

In arid conditions of the Middle Asia the most evaporation occurs from these formations, because of it and 

peculiarities of vegetation they are seen as the more 

or less light places independently to the real color of 

the rocks.

In near infrared part of spectrum the Prequaternary 

formations are deciphered better. The surface geological structure is reflected with essential detailness 

in the images in band 0.8-1.1 mkm (mainly because of 

the reflection of various formations in the relief). In

355
356 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 1.—Large-scale space photo of Babadag-Karatau region of the central part of the Tadjik depression (spacecraft

"Sojuz-9," cosmonauts A. G. Nikolaev and V. J. Sevastianov)

band 0.7-0.8 mkm both the relief and the color of the 

rocks have the indicative role. The possibility of deciphering of details is less than in band 0.8-1.1. It 

permit to find the main structural elements, for example, the large tectonic lineaments (figs. 5 and 6) 

that are not seen in surface sometimes, but reflect the 

deep structure that we shall discuss below. Such lineaments are deciphered better in images that are received by combination of various bands, for example 

by "subtraction" of bands from each other.

It is especially productive to use the space images 

for studies of the geomorphology, the NeogeneQuaternary deposits and the modern structure of the 

Earth's surface. In the erogenic areas there can be 

deciphered the genetic types and sometimes the age of 

relief; the units of the Quaternary cover (1, figs. 8, 9); 

and the modern folds and faults (figs. 7 and 8). It is 

possible to see not only large structural forms, reflected by deformations of the modern deposits and 

the erosional forms, but very gently sloping uplifts
GEOLOGICAL STUDIES BY SPACE MEANS IN THE U.S.S.R. 357

FIGURE 2.—Structural-geologic map of the central part of the 

Tadjik depression compiled using space photos.

1—Holocene and Upper-Pleistocene alluvium and proluvium;

2—Mid-Pleistocene loesses and loess-like deposits; 3—LowerPleistocene conglomerates (dashed lines are the boundaries 

of the geomorphological levels); 4—Mid-Miocene-Pliocene 

conglomerates and sandstones; 5—Oligocene-Lower-Miocene 

sandstones, alevzolites, and conglomerates; 6—Eocene-Oligocene deposits mainly clays; 7—Campan-Bukhara clays, gypsum, 

and limestones (k-p); 8—Alb-Santon clays with limestones, 

sandstones, and gypsum (k); 9—Mesozoic and Cenozoic deand limestones (k-p); 8—Alb-Santon clays with limestones 

by geological methods; 12—found by geomorphological methposits, undivided; 10—Paleozoic deposits. Faults: 11—found 

by geological methods; 12—found by geomorphological methods; 13—masked by the Quaternary deposits and supposed. 

Geological boundaries: 14—mapped; 15—masked by the 

Quaternary deposits and inner boundaries in units; 16— 

supposed; 17—axes of the anticlines; and 18—axes of the 

synclines.

among intermountain basins. The same uplifts are 

found also in space pictures of platform, where they 

reflected the masked structures of the plate cover that 

are in prospect for search of oil and gas (figs. 9 and 

10). 

It is possible to receive the essential information

from space pictures on a modern volcanism. In Kamchatka and Caucasus, the faults, the eruptive fractures and various types of the volcanoes are 

deciphered. In Landsat-1 images of Iceland, it can be 

seen not only volcanoes, volcanic chains, and faults of 

rift strike, but some hidden transverse elements of 

structure, not found before by land observations.

The information from small-scale space images is 

uniform and independent on approachness of regions. 

It gives us the possibility to map and correlate the 

major neotectonic forms and zones and finally to compile the pattern of modern structure of the continents 

as a whole. It will permit to give answer such significant questions of geotectonics as the planetary regularity in localities and strikes of various modern structural elements, and, at last, sources and mechanism 

of structural formation.

The good expressiveness of modern structural 

forms, deposits, and relief, the minimum of the latest 

complications, and the general distribution made them 

the best subject for the solution of the tasks of the 

detail planetary correlation of the tectonic processes. 

The role of the space information for the solution of 

such tasks is not so large, but some utilizations can be 

presented. At first, the mapping of structural forms 

and fault zones and the determination of age of deformed deposits are the elements of correlation themselves. At second, the studies in Middle Asia showed 

that forms of relief of different ages have the specific 

peculiarities and indicative features permitting to map 

them on the large distance and by this way to correlate the modern structural elements of the distant 

regions.

New possibilities of the geological application of the 

space pictures that differ them from airphotos on principle are due to peculiarities of the generalization of 

image with the decrease of scale of the survey. The 

correlation of the results of deciphering of the space 

pictures with the geological, geomorphological, and 

geophysical data show that structural elements that 

one can see on them, are not only large, but located in 

deep horizons of the Earth's crust and its basement.

Geological manifestations of such zones of deep deformations are often masked by the numerous surface 

deformations, so they can't be found by field researches and on airphotos. They are reflected better 

in the modern structure, but here the fragmentation of 

manifestations prevents to compile the common picture that is seen in space images only.

Let us observe that problem on the data of Eastern 

Caucasus. Space pictures of it were received from 

spacecrafts "Sojuz-9" and "Meteor" series. The elements of "Caucasus" strike predominate in the geological and modern surface structure of this region.
358 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

71°46'50"E 

41°16'16"N

39°45'12"N

71°15'15"E

73°53'20"E

40°57'34"N

39°27'01"N 

73°19'03"E

FIGURE 3.—Scanner image of Eastern Fergana, Landsat-1, June 24, 1973, band 5.

They are reflected on space photos with resolution 

300-400 m, but the transverse lineaments are seen 

here beside them (fig. 11). The last correspond to the 

surface faults only partly, but often represent the 

boundaries of the different facies and thicknesses of 

deposits and the areas with different tectonic styles. 

Increasing of the intensivity of surface deformation, 

the Late Quaternary displacements and concentration 

of the air volcanoes occur along some lineaments. 

They correspond to the zones of high gradients of 

dipping, boundaries and bends of structural forms of 

the surface of the crystalline basement (where it is the 

deepest) and of the Conrad surface. The analysis of 

instrumental and microseismic data shows that the 

zones of abnormal going out of the seismic waves (fig.

12) and zones of high density of epicenters (mainly of 

shallow earthquakes) strike along the lineaments.

The lineaments seem to reflect the zones of deformations on the depths 5-20 km.

On the "Meteor" pictures with resolution about 1 

km (fig. 13) the more part of those lineaments are seen 

badly absent. The lineament of "Caucasus" strike are 

seen here the best of all. They correspond to the long 

zone of southern slope of Big Caucasus where the 

area of strong and relatively deep (10-60 km) earthquakes is located (fig. 14) according to the data of I. V. 

Ananjin. Along this zone the thickness of the Earth's 

crust is essentially changed. Two lineamental zones of 

NE-SW strike are deciphered less clearly. They correspond to the areas of epicenters on depths to 20-30 

km.
GEOLOGICAL STUDIES BY SPACE MEANS IN THE U.S.S.R. 359

71°46'50"E 

41°16'16"N

39°45'12"N

71°15'15"E

73°53'20"E

40°57'34"N

39°27'01"N 

73°19'03"E

FIGURE 4^—Geological interpretation of the image figure 3. Points are the various Quaternary deposits; lines dipped to right 

mations °Wer"Cretace°US deP°sits ; horizontal lines are Upper-Cretaceous deposits; crossing lines are the Paleozoic forThus, the structural elements of the various depths 

are deciphered on the space pictures. The more the 

degree of generalization of image is, the deeper elements of structure are reflected on it. The differences 

found in the structures of various depths permit sometimes to assume the structural disharmony between 

the different depths. At the same time the tectodynamic analysis of the geological structural of surface 

and its comparison with the results of determination of 

the earthquake focus mechanisms and the directions 

of displacements in the Late-Quaternary faults, 

striked along the lineaments, give the arguments to 

suppose that the various horizons of the Earth's crust 

are under the same stresses and differ only by the 

types of the rock deformations created by them.

The analogous picture takes place in Tjan-Shan. On 

the space images of this mountain country there are 

two types of the modern structural forms: (1) various 

bands that correspond to ridges-uplifts and intermountain basins and (2) the lineaments of the different orders. On space photos with the relatively high resolution the ridges and basins that correspond to the 

individual foundation folds (anticlines and synclines), 

are seen. With the generalization of image there are 

observed the anticline and syncline zones and then 

only the up-warping and down-warping systems, that 

are the major elements of the modern structure. According to the geological, geomorphological, and geophysical data, the individual ridges-anticlines and 

basins-synclines and their zones are the deformations 

of the folded basement surface and reach only the 

Conrad surface; while the anticline and syncline systems are fixed by the changes of depth of 

Mohorovicic surface.

The longitudinal lineament corresponding to the 

zone of sharp change of basement depth, is deciphered 

on the space photos with resolution 300-400 m of 

Southwestern Tjan-Shan. On the TV-pictures with 

resolution 0.8-1.5 km this lineament is absent, but the 

long lineament of NE-SW strike is seen. The last cor-
360 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

71°46'50"E 

41°16'16"N

73°53'20"E

40°57'34"N

39°45'12"N *'''*- 

71°15'15"E

'39°27'01"N 

73°19'03"E

FIGURE 5.—Scanner image of Eastern Fergana, Landsat-1, June 24, 1973, band 6.

respond to the zone of the essential change of the 

Earth's crust thickness, to the boundary of high seismic 

activity area, and to zones of abnormal going out of 

the seismic waves.

On the relatively large-scale space photos of Tadjik 

depression (resolution 100-150 m; "Sojuz-9" and 

Landsat-1) the elements of surface geological structure with longitudinal folds are deciphered well. When 

the degree of generalization of image increases, the 

transverse lineaments are seen better and better. They 

reflect the disposition of the geophysical anomalies 

and correspond to the deformations of the crystalline 

basement surface and the deeper horizons of the 

Earth's crust.

The data under consideration show the possibility 

to advance with help of space pictures the problem of

the structural and genetic relations of the different 

horizons of the lithosphere. Space pictures can't claim 

to be the only source of information about deep structure, but results of their deciphering permit to interpret the geophysical data more objectively. Of course, 

we can see on visible and infrared space pictures only 

the different elements of landscape, but the elements 

reflecting the structure of various deep horizons, are 

"in focus" on pictures with various degrees of 

generalization.

Space pictures permit also a new interpretation of 

the correlation between the lithosphere and the atmosphere. On the images of Tjan-Shan, Turan plate, Mongolia, and northeastern part of the Russian platform 

there is observed the coincidence between the elements of the cloud cover and the large disturbed zones
GEOLOGICAL STUDIES BY SPACE MEANS IN THE U.S.S.R. 361

71°46'50"E 

41°16'16"N

39°45'12"N

71°15'15"E

73°53'20"E

40°57'34"N

9°27'01"N 

73°19'03"E

FIGURE 6.—Geological interpretation of the image figure 5. Points are the various Quaternary deposits; lines dipped to right 

are the Lower-Cretaceous deposits; horizontal lines are Upper-Cretaceous deposits; crossing lines are the Paleozoic formations.

of the Earth's crust, the last reflected on the surface 

only indirectly sometimes. The relief can't define such 

localities of the clouds in these cases.

The process of geological deciphering of the space 

pictures can be conditionally divided into three stages. 

The task of the preliminary stage is to represent the 

materials of the space survey in the most informative 

and convenient forms. The photographic filtering is 

very useful, for example "addition" or "subtraction" 

of the pictures in various spectral bands. The specific 

kind of filtering and of the objective analysis of pictures is its photometry in various scale.

In the stage of deciphering (in basis of brightness 

and geometry of the images of the geological objects) 

the essential significance belong to the comparison of 

the pictures of various spectral bands and their combinations, of the different degrees of generalization, 

and of the different season. So, the snow on the winter pictures masks many geological details, but emphasizes some large linear elements of the structure.

In the stage of interpretation the comparison of the 

results of deciphering with the geological, geomorphological, and geophysical data is carried out. The interpretation is found on the studies of the indicative signs 

of the geological objects of the region under researches and of the similar ones. For studies of the 

indicative signs is useful the observation of the objects 

with different degrees of generalization (on land, from 

helicopters, aircrafts, on air and space pictures) is useful. As usual, the field check of the results of deciphering and interpretation is necessary.

Let us consider the operations of each stage in the 

example of the studies of space pictures of the Lower 

Volga region (southeastern part of Russian platform). 

We have used as a basis the scanner color picture of 

the area with resolution about 100 m (fig. 15). Almost 

all the surface is the combination of the agricultural 

lands with the different brightnesses, so it does not 

permit to decipher geological elements, the larger, but 

poorly differed in brightness. It has been necessary to 

decrease the influence of brightness differences of the 

agricultural lands and to develop the features of picture that reflect the geological structure. For this the 

contrast has been developed by the photographic
362 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

FIGURE 7.—Middle-scale photo of the Issik-Kul region (spacecraft "Sojuz-9," cosmonauts A. C. Nikolaev and V. I. Sevastianov).

means. The received picture has been photometried 

along the frequent net of profiles. The using of the 

most open split of the photometer and big step of 

interpolation have permitted to exclude the small fluctuations of the density and to develop the differences 

connected with the geological structure. It is the generalization and the specific photometric filtering of the 

primary picture.

The received map of the conditional brightness (fig. 

16) has been compared with the maps of the geology 

the neotectonics and the basement surface structure, 

the gravimetric and magnitometric data. The comparison has been carried out by the calculation of the coefficients of correlation, represented on the special 

maps. The geological map is not correlated with the 

photometric one, but the magnitometric and partly 

gravimetric data are in accordance with the last. It has 

been shown by the correlation of the data that distribution of the brightnesses reflect the structure of the 

basement of this part of the plate. The application of 

the materials of the deep bore holes and the geophysical data permit to compile (with using of the other

space images of the area) the hypothetic structuralgeological scheme of the basement (fig. 17). The modern movements of the Earth's crust correlate partly 

with structure of basement.

All the operations under consideration (beside the 

compiling of the final scheme) are formalized and can 

be carried out by the computer. Thus, the last can be 

widely used for the solution of some tasks of deciphering, the signals of TV and scanner systems not been 

necessary to present in visible form.

So, the geological deciphering and interpretation of 

space images can be used for the solution of the main 

matters of recent geology. The practical significance 

of the geological application is in the possibility to 

cheapen and to increase the quality of the geological 

survey, to plan the expensive geophysical researches 

better and to interpret their results more objective. 

Space pictures can be used for correction of the maps 

of seismic danger; for finding of structural forms and 

zones that are in prospect to search the underground 

waters, oil, gas, and number of the ore deposits; at 

last, for solution of the tasks of the engineer geology,
GEOLOGICAL STUDIES BY SPACE MEANS IN THE U.S.S.R. 363

FIGURE 8.—Geological-geomorphological interpretation of the photo figure 7.

1—Limneous and alluvium-proluvium plains of Late Pleistocene and Holocene; 2—fragments of the high accumulated plains of Mid-Pleistocene; 3—marginal and inner uplifts in basin, mainly Neogene deposits; 4-5—systems 

of modern uplifts built by the Paleozoic formations (4—zone of the young relief, steep deeply eroded slopes of 

uplifts; 5—zone of the fragments of the old" relief of intervalley areas); 6—zones of intermountain narrow faultbasins; 7—faults; 8—figures of structural forms (1, 3, 4, 7-13, anticline forms; 2, 5, 6, syncline forms); and 9— 

area of detail observations.

that is the election of the routes of communications, 

the places for reservoirs, dams, et cetera.

BIBLIOGRAPHY

Trifonov, V. G., Bysova, S. L, Vedeshin, L. A., Derevjanko, O. S., Ivanova, T. P., Kopp, M. L, Kurdin, 

N. N., Makarov, V. L, Scobelev, S. F., Florensky, 

P. V., Problems of techniques of geological investigation of space images of the Earth. Investigation of the natural environment by space 

means. Geology and geomorphology. Printing 

house VINITI, Moscow, 1973 (in Russian).

Makarov, V. I., Scobelev, S. F., Trifonov, V. G., Florensky, P. V., Shchukin, Yu. K., Plutonic structure 

of the Earth's crust on space images. Proceedings 

of the Ninth International Symposium on Remote 

Sensing of Environment, vol. I. pp. 369-438. 15- 

19 April 1974. Ann Arbor, Michigan.
364 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

51 °E

FIGURE 9.—Large-scale photo of the eastern coast of Caspian Sea, Manghyshlak Peninsula, and Ustjurt 

(spacecraft "Sojuz-12," cosmonauts V. C. Lasarev and O. G. Makarov).
GEOLOGICAL STUDIES BY SPACE MEANS IN THE U.S.S.R. 365

FIGURE 10.—Structural map of Manghyshlak and Ustjurt compiled using photos from 

"Sojuz—8" and "Sojuz—12." There are shown the anomalies on space photos that 

correspond to local structures being in prospect for search of oil and gas. 

1—Isolines of the surface of the Permian-Triassic deposits; 2—fault found by 

various methods; 3—faults found on space photos; 4—bore holes reached the 

Pre-Jurassic deposits; 5—photo-anomalies corresponding to local structures (their 

figures are on the map); 6—scarps of Ustjurt plateau; 7—boundaries of space 

photos from "Sojuz-8." Scale 1:3,250,000.
366 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM
GEOLOGICAL STUDIES BY SPACE MEANS IN THE U.S.S.R. 367

44°N

44°N

48°E

40° N

48°E

40°N

FIGURE 12.—Correlation of lineaments deciphered on 

"Sojuz—9" photos and zones of deep seismic deformations of Eastern Caucasus (the last are shown 

according to the data of Gu. K. Shchukin, 1973). 

Thick lines are the major lineaments, middle lines 

are the other lineaments, and thin lines are the 

isolines of the density of deep seismic deformations in conditional figures.
368 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM
GEOLOGICAL STUDIES BY SPACE MEANS IN THE U.S.S.R. 369

48" E

44°N

O^@ A o«rast

FIGURE 14.—Correlation of lineaments deciphered on TV and scanner "Meteor" images of Eastern Caucasus 

and epicenters of earthquakes 1911-1966 (the last are shown according to the data of I. V. Ananjin). 

1—Lineaments, well seen and repeated on different images and 2—lineaments, seen worse or on some 

images only. See the other symbols on figure 12. The circles show the location of epicenters.

44°06'08"E 46°37'25"E

50°48'07"N

49°40'06"N

43°25'02"E

49°17'47"N 

45°51 '53"E

SCALE 1:3,369,000 

FIGURE 15.—Scanner image of Lower Volga region, Landsat-1, July 16, 1973. Scale 1:3,369,000.
370 FIRST ANNUAL PECORA MEMORIAL SYMPOSIUM

44°06'08"E 

51 011'18"N

49°40'06"N

43°25'02"E

46°37'25"E

50°48'07"N

Ji titJ3 

• l4»V-l« »•>

1:3,369,000

49°17'47"N 

45°51'53"E

FIGURE 16.—Photometrical map of image figure 15 in conditional figures without clouds. Scale 1:3,369,000. 

1-8—Different magnitudes of the optical density of image; 9—isolines of the optical density in conditional figures; 10—lineaments. Volga River is shown.

44°06'08"E 46°37'25"E

50°48'07"N

49°40'06"N

43°25'02"E 49°17'47"N

:3,369,000

- ;

45°51'53"E

FIGURE 17.—Schematic structural-geologic map of crystalline basement of Lower Volga region using 

geological and geophysical data and space photo interpretation. Scale 1:3,369,000. 

1—Zone of Sfekofen-Karelian rebuilding of basement; 2—areas of amphibolite facea of metamorphism; 3—areas of granulite facea of metamorphism; A—granitoides; 5—basic rocks; 6—bore 

holes reached the basement; 7—isolines of basement surface according to the data of N. V. Nevolin, 1974; and 8—lineaments.