GEORGIA FROM SPACEAN EXPLANATION OF THE NASA 

LANDSAT 1 SATELLITE IMAGE COLOR 

MOSAIC OF THE STATE OF GEORGIA 

Prepared in cooperation with the 

Georgia Department of Natural Resources, 

Geologic and Water Resources Division 

GEOLOGICAL SURVEY CIRCULAR 787 

Georgia From SpaceAn Explanation of the NASA 

Landsat 1 Satellite Image Color 

Mosaic of the State of Georgia 

By Sam M. Pickering, Jr., and Michael W. Higgins 

GEOLOGICAL SURVEY CIRCULAR 787 

Prepared in cooperation with the 

Georgia Department of Natural Resources, 

Geologic and Water Resources Division 

1979 
United States Department of the Interior 

CECIL D. ANDRUS, Secretary 

Geological Survey 

H. William Menard, Director 

Library of Congress Cataloging in Publication Data 

Pickering, Sam M. 

Georgia from space. 

(Geological Survey circular 787) 

"Prepared in cooperation with the Georgia Department of Natural Resources, Geologic and Water Resources 

Division." 

Bibliography: p. 

1. Remote sensing-Georgia. 2. Georgia-Maps. I. Higgins, Michael W., joint author. II. Georgia. 

Geologic and Water Resources Division. III. Title. IV. Series: United States. Geological Survey. 

Circular 787. 

QE75.C5 no. 787 [G70.5.U6] 557.3'08s 

Free on application to Branch of Distribution, U.S. Geological Survey 

1200 South Eads Street, Arlington, Va. 22202 
PREFACE 

In its continuing program of monitoring the Nation's natural resources and understanding the land we live on, the U.S. Geological Survey 

has now published six Landsat satellite color mosaics at scales suitable to 

show large areas such as entire States. More of these mosaics are planned, 

and with each new one the techniques and our ability to interpret the 

features seen on the mosa.ics are improving. We have chosen one mosaic, 

that of the State of Georgia, as an example of what can be seen and of some 

of the more general uses of these "pictures" from space. Both this circular 

and the mosaic were prepared as a joint effort of the U.S. Geological Survey 

and the Geologic and Water Resources Division of the Georgia Department 

of Natural Resources. 

iii 

CONTENTS 

Page 

Preface------------------------------------------------------------------ iii 

Introduction ------------------------------------------------------------- 1 

VVhat is Landsat? -------------------------------------------------------- 1 

VVhat do the colors on the Georgia mosaic mean? ---------------------------- 2 

How was the mosaic made? ----------------------------------------------- 2 

VVhat can be seen on the mosaic? ------------------------------------------ 2 

Culture -------------------------------------------------------------- 2 

Land use and land cover ---------------------------------------------- 2 

Landforms ----------------------------------------------------------- 5 

Geology ------------------------------------------------------------- 14 

Summary ---------------------------------------------------------------- 21 

References cited ---------------------------------------------------------- 21 

Other maps and products to aid in understanding the Landsat mosaic ------- Inside of 

back cover 

ILLUSTRATIONS 

Page 

FIGURE 1. Band 5 Landsat mosaic of Georgia ----------------------------- 3 

2. Generalized land-cover map of Georgia ------------------------- 4 

3. Map showing landform divisions of Georgia -------------------- 6 

4. Enlarged Landsat band 7 image of parts of northern Georgia, 

North Carolina, and Tennessee ---------------------------- 8 

5. Map showing interpretation of figure 4 ------------------------- 9 

6. Enlarged Landsat band 7 image, Fall Line -------------------- 10 

7. Map showing interpretation of figure 6 ------------------------- 11 

8. Enlarged band 7 image, northwestern Georgia ------------------ 12 

9. Topographic map of the area of figure 8 ------------------------ 13 

10. Block diagram illustrating general relation of ridges and valleys 

to anticlines and synclines -------------------------------- 14 

11. Enlarged Landsat band 5 image, Pelham Escarpment ----------- 15 

12. Enlarged Landsat band 7 image, Lake Seminole ---------------- 16 

13. Explanation and location map for figure 12 --------------------- 17 

14. Enlarged Landsat band 7 image, Okefenokee Swamp ------------ 18 

15. Map showing interpretation of figure 14 ----------------------- 19 

16. Landsat band 7 and band 5 images, marshes and estuaries ______ 20 

v 

GEORGIA FROM SPACEAn Explanation of the NASA Landsat 1 Satellite Image 

Color Mosaic of the State o,f Georgia 

By Sam M. Pickering, Jr.,t and Michael W. Higgins 

INTRODUCTION 

Just a few years ago the prospect of a single 

view of an entire State the siz·e of Georgia 

s·eemed science fiction. With the launching of 

the Landsat 1 (formerly called ERTS 1) sattelite into orbit ~around the Earth and the technological developments that have allowed its 

images to be successfully pieced together into a 

mosaic, this "science fiction" ha:s become reality. 

The new Landsat color mosaic of Georgia (U.S. 

Geological Survey, 1973-74) is an excellent example of what we can now see from space. 

Lands,at images and mosaics are valuable to 

g·eologists, soil scientists, foresters, ecolo·gists, 

lamd-use planners, mapmakers, and the general 

public. They allow us to see things too large and 

too widespread to be seen accurately and inexpensively by other techniques. Until the 1600's 

scientists could study only objects that could be 

seen with the naked eye. Then, in 1632, the 

microscope was invented, and a whole new 

world of microscopic life was revealed. The 

ability to see dearly the very large features of 

our Earth has given us similar opportunities. for 

new discoveries about our planet. 

This circular illustrates many of the uses and 

details of the Georgia Landsat mosaic. It gives 

examples of how Landsat images can help people understand the areas in which they live, 

work, and travel. One of the basic problems 

today is keeping pace with the changes we make 

on the face of the Earth. We build, harvest, 

mine, clear, reclaim, impound, and channelize 

without 1an overall view of what we are doing. 

We never before had a comprehensive look at 

1 Georgia Department of Natural Resources. 

1 

our natural resources and their development 

until Landsat provided such an overview. 

This circular is keyed directly to the large 

color mosaic of Georgia. To use the circular, 

refer to the indi,cated areas on the large mosaic. 

Addresses for obtaining the large mosaic, a 

more detailed, interpretative space atlas of 

Georgia, and other maps that are helpful in 

understanding the State are listed inside the 

back cover of this circular. 

WHAT IS LANDSAT? 

The Lands'ait 1 satellite, launched by the National Aeronautics and Space Administration 

July 23, 1972, circles the Earth in an orbit that 

passes approximately over the North and South 

Poles. At an altitude of 570 miles, it orbits over 

any point on Earth once every 18 days. The instruments on Landsat 1 ceased functioning 

January 6, 1978. While still functioning, instruments aboard the satellite continuously scanned 

the land and water beneath in four color bands 

and ,transmitted the signals back to receiving 

stations on Earth. Thus Landsat 1 functioned 

somewhat like a detailed television broadcast 

from space. At the present time (1978) Landsats 2 and 3 are functioning. When the signals 

reach Earth they are converted into black and 

white film images. Two of the four multispectral scanners on a satellite detect infrared radiation or light (bands 6 and 7). This type of 

light is not visible to the human eye, but shows 

differences in ground moisture and terrain. The 

remaining two scanners detect visible light 

(green, band 4, and red, band 5) and show patterns of vegetation and cultural development. 
Individual black and white images or combinations of the images in different color bands 

show forests, cities, wetlands, cultivated fields, 

superhighways, and many other features. Each 

image transmitted by the satellite covers. an 

area of 13,500 square miles. Fourteen images 

are needed to cover all of Georgia. 

WHAT DO THE COLORS ON THE 

GEORGIA MOSAIC MEAN? 

The Georgia mosaic is a color combination of 

red (band 5) and infrared (band 7) images. 

These combined images of each scene· were 

tinted in shades of blue, black, and red to resemble a color-infrared photograph. This method shows cultural features and vegetation more 

clearly than a single black and white or a 

natural-color image. Forest and vegetative 

cover show as red, and cleared land is white or 

bluish. The reddest patterns on this mosaic are 

evergreen forest or winter pasture: the hardwood trees were leafless and summer crops had 

been harvested when these late fall or winter 

scenes were made. Woodland that had been 

clearcut recently shows as light bluish purple. 

Clear water shows as black; muddy or turbid 

water is light blue. Cities appear as white or 

light blue .. gray. Surfac.e mines show as white 

areas. Mountains and ridges are cast in high 

relief by their shadows. In all images, the sun 

was in the southeast, ·so shadows are on the 

northwest side of the terrain. The fine lines almost east-west across the mosaic are scan lines 

produced when the image was trans·mitted back 

to Earth. These scan lines distinguish the image 

from a photograph, which is not produced by 

scanning. 

HOW WAS THE MOSAIC MADE? 

Although two or three separate Landsat 

scenes can be fitted accurately together, the assembly of large groups of scenes into a single, 

precise mosaic demands an elaborate control 

system. The Georgia mosaic is one of the first to 

have control provided by .computer processing. 

Several indices at the bottom of the mosaic 

show how the 14 separate sat-ellite images are 

fitted together and the dates of the coverage. 

Some detail has been lost in the printing, but 

the mosaic is remarkably accurate. High-contrast features as small as 25 acres can be seen. 

2 

WHAT CAN BE SEEN ON THE MOSAIC? 

CULTURE 

One of the first things most people want to 

know about a map such as the Geo·rgia mosaic is 

where they live and where some of the places 

and features they are familiar with are located. 

The Landsat mosaic of Georgia (fig. 1) shows 

many of the towns and ci·ties, reservoirs, and 

major highways. One of the unusual cultural 

features is the circular woodland area in South 

Carolina along the State line. This area surrounding the Savannah River Nuclear Plant is 

government-owned land that has not been 

farmed for many years and has. grown up in 

heavy forest. Another prominent man-caused 

feature on the mosaic is the white circular area 

in Tennessee near the State line. This is an area 

where the forest was killed many decades ago 

by overcutting and smelter fumes at the Ducktown-Copper Hill mining district. Although 

much reclamation work has been done recently, 

the area still shows as 80 square miles of barren 

ground (fig. 2). 

LAND USE AND LAND COVER 

The mosaic allows an informative new look at 

Georgia's complex patterns of land cover (figs. 

1 and 2). These patterns of woodland, timbe·red 

areas, cultivation, and pasture land reflect a 

long history of productive but changing agriculture and forestry. The patterns are continually 

in the process of adjusting to current economics, farming practices, land ownership, and 

other variables. Knowledge of the local area 

will greatly aid users in interpreting the subtle 

patterns on the mosaic. Changes may be identified by comparing this mosaic with earlier 

Landsat images or aerial photographs. 

VALLEY AND RIDGE 

The northwestern corner of Georgia is often 

called the Valley and Ridge area. The valleys 

are extensively cleared and cultivated, and the 

ridges are heavily forested. In :this November 

image, the valleys contain many patches of 

white that indicate freshly cultivated bare soil. 

The well-drained valleys of this area have no 

extensive ·swamps or wetlands. 

To the .east of the Valley and Ridge area is 

the rugged southern end of the Blue Ridge 

Mountains. The sharp shadows cast in the early 

morning (eastern) sun by th.e mountains show 
0 10 20 30 40 KILOMETERS 

FIGURE 1.-Band 5 Landsat mosaic of Georgia. Areas outlined are shown in other figures as indicated by the 

numbers. 

the rugged relief of the area. The steep slopes 

are heavily forested, with small farms in rare 

flat stream valleys. The lack of vegetation at 

the tops of some high mountains gave them the 

name "bald." Patterns of clearcut timbering can 

3 

be seen in par ~ of the mountains. The evergreen understory beneath leafless hardwoods 

and the sides of mountains toward the ·sunlight 

(east and southeast facing slopes where reflectance is greatest) show as lighter red areas. 
as· 

C A R 0 L I N A 83• _ __-

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EXPLANATION 

1 Agriculture Valleys and Forested Ridges 

2 Copperhill Barren Land 

3 Northern Forested Mountain Region 

:4 Piedmont Region of Mixed Pasture, Forest, and Cultivation 

5 Central Forested Region 

6 Major Urban Areas 

4 

7 Coastal Plain Region of Mixed Pasture, Cultivation, and Forest 

8 Swampy Forested Flood Plains along Major Rivers 

9 Coastal Forested Region 

10 Okefenokee Swamp 

11 Coastal Salt Marsh 

12 Sea Islands 

13 Forested Savannah River. Plant Area 
PIEDMONT I ographic Map of Georgia (Clark and Zisa, 

South of the Valley and Ridge area and the 1976) . Most of these divisions. are closely reBlue Ridge Mountains, the Piedmont province lated to the slope of the land, which is clearly 

extends across the State. Woodland, unim- shown on the 1975 Slope Map of Georgia. The 

proved pasture, and cultivated land in the Pied- terrain features are interpreted extensively in 

mont appear as a mixture of red, gray, and "Georgia, A View from Space" by Clark, Zisa, 

white patches on the mosaic. Atlanta and other and Jones (1976). Because landforms and slope 

cities appear as complex patterns of white and are chiefly the result of the rock formations 

pal'e blue. The dens·e commercial area along which underlie the land, the 1976 Geologic Map 

Peachtree Street in Atlanta appears bluest. of Georgia is also a valuable tool for underCOAST A·L PLAIN 

South of the Piedmont is a band of low, sandy 

hills which are heavily forested. Between the 

Piedmont and these sand hills is. the Fall Line 

zone, where the wide Coastal Plain swamps begin. Thes·e hardwood swamps show as dark 

bands along most of south Georgia's rivers and 

are as much as 6 miles wide. The dozens of 

bright white areas east of Macon are large 

open-pit kaolin clay mines, which produce more 

than $200 million worth of valuable industrial 

clay each year. 

South of the Fall Line hills is the middle 

Coastal Plain. Most of the upland of this area 

is cultivated, and the moist stream valleys are 

wooded. A myriad of small dark-blue specks are 

farm ponds, sinkholes in limestone and Carolina Bays (water-filled depressions of debatable 

origin). 

COASTAL AREA 

A 50- to 75-mile-wide zone of dense, poorly 

drained pine forest ext,ends along the Georgia 

coast and inland to well beyond the Okefenokee 

Swamp. Standing out white against the redappearing woodland, Interstate 95 parallels the 

coast just inland from the dark brown-grayappearing salt marsh. Scattered along either 

side of the interstate highway is a double row 

of blue specks that are water-filled dredge pits 

from which sand has been removed for road-fill 

material. Northwest of Savannah, clear examples of raised shorelines and beach ridges 

show as bands of parallel red and white patterns. The Okefenokee Swamp appears as blue, 

black, and red swirls of wetlands, open-water 

bodies, and forest. 

LANDFORMS 

Figure 3, keyed to the color mosaic, shows the 

primary landform divisions from the PhysiFIGURE 2.-Generalized land-cover map of Georgia. 

5 

standing what can be seen on the mosaic. 

GREAT SMOKY FAULT 

The escarpment of the Great Smoky Fault is 

strikingly apparent on the Landsat mosaic, individual Landsat enlargements, and the Slope 

Map of Georgia. It is the boundary fault between the folded limestones, shales, and sandstones of the Valley and Ridge province (figs. 4 

and 5) and the steep, rounded peaks formed on 

granites, schists, and gneis.ses of the Blue Ridge 

and Cohutta Mountains. 

BLUE RIDGE MOUNTAINS 

Figure 4 (also see fig. 5) shows most of 

northeast Georgia and parts of Tennessee and 

North Carolina. The southern end of the Blue 

Ridge Mountains stands out clearly in contrast 

to the gentler slopes of the Piedmont to the 

south. The edge of the mountains, called the 

Blue Ridge Front, is an area of spectacular 

waterfalls such as, Amicalola Fa.Ils. 

Winding southward between the Blue Ridge 

and Cohutta Mountains is a lowland with low 

ridges: the deep downfold of the Murphy Syncline. This enormous downfold contains extensive deposits of valuable white, orange, and 

gray marble, which is more easily eroded than 

the gneis,ses, schists, granites, and quartzites 

which surround it. Thus, a natural valley-a 

transportation corridor through the mountains 

has been formed, and marble quarries have been 

developed extensively along the syncline. 

BREVARD FAULT ZONE 

In addition to the previously mentioned Great 

Smoky Fault, other ancient faults can be seen 

on this image (fig. 4). A zone of crushed rock 

(known as a eataclastic zone), several miles 

wide, marks a portion of the Brevard Fault 

Zone. The W arwoman. Shear Zone cuts a. series 

of parallel knife-sharp valleys across the Blue 
L____~_ -------- -

A. Lookout Mountain District 

B. Chickamauga Valley District 

C. Armuchee Ridges District 

D. The Great Valley District 

E. Cohutta Mountains District 

F. McCaysville Basin District 

G. Blue Ridge Mountains District 

H. Cherokee Upland District 

N 0 R T H C A R 0 ll-N- . ---- ~ .• - .• -:_/ - ~----------~----------r---~ 

0 

EXPLANATION 

I. Dahlonega Upland District 

J. Hightower-Jasper Ridges District 

K. Central Uplands District 

L. Gainesville Ridges District 

M. Winder Slope District 

N. Washington Slope District 

0 . Greenville Slope District 

P. Pine Mountain District 

6 

.. 

STATE OF GEORGIA 

--···---··- -=::.:= 

0 

Q . Fall Line Hills District 

R. Fort Valley Plateau District 

S. Dougherty Plain District 

T. Tifton Upland District 

U. Vidalia Upland District 

V. Bacon Terraces District 

W. Okefenokee Basin District 

X. Barrier Island Sequence District 
Ridge Froot and the Brevard Zone. At the 

southern edge of this image, the Chattahoochee 

River zigzags across the edge of the Brevard 

Fault Zone in the Palisades area. 

FALL LINE 

The Fall Line, the boundary between the 

harder granites, gneisses, schists, and quartzites of the Piedmont and the more or less. flatlying soft sedimentary rocks of the Coastal 

Plain, shows as the boundary between gentle 

slopes and low linear ridges and the low sandy 

Coastal Plain hills. North of the Fall Line, the 

rivers flow over crystalline granites and metamorphic rocks. Here they are relatively straight 

and flow in rapids and riffles over a rocky bed. 

Immediately at the Fall Line, the rivers flow onto the soft sand, clay, and lim.estone of the 

Coastal Plain. At this line (figs. 6 and 7) the 

rivers immediat;ely start to meander in snakelike bends across swampy, forested flood plains 

several miles wide. 

ARMUCHEE RIDGE>S 

Figure 8 (also see fig. 9) is an enlargement of 

a very clear Landsat image of the Armuchee 

Ridges area (Taylor Ridge, Johns Mountain, 

Horn Mountain, and so on) of northwest 

Georgia. The sinuous ridgelike mountains are 

made up of sandstone that has resisted erosion. 

The flat valleys between the ridges are under·-

lain by shale and limestone that are more easily 

eroded. The contorted, hairpin-shape of the terrain is the result of folding and faulting of the 

Earth's crust (fig. 10). One of the most unusual 

features is the oval shape of the Rock Mountain-Lavender Mountain area (figs. 8 and 9). 

The semicircular rims are formed by a syncline 

(downward fold, fig. 10). Hard sandstone formations form a nearly perfect oval, almost like 

an enormous ancient castle, standing high because they have resisted erosion. On the west of 

the image another synclinal sandstone ridge, 

Pigeon Mountain (figs. 8 and 9), is a spur at 

the eastern edg.e of the Cumberland Plateau. 

East-west fractures, which have been enlarged 

to form a network of caverns deep beneath the 

surface, can be traced across the ridge. 

FIGURE 3.-Map showing landform divisions of Georgia 

(modified from the Physiographic Map of Georgia by 

Clark and Zisa, 1976). 

7 

PELHAM ESCARPMENT 

In the southwestern part of Georgia (fig. 11), 

on the Coastal Plain, is a long escarpm.ent as 

much as 100 feet high. This feature, called the 

Pelham Escarpment, separates a low limestone 

plain from a higher loamy upland for almost 

100 miles. The clay formation underlying the 

upland allows very little rainfall to soak into the 

ground; thus there is a well-developed system 

of streams and rivers. In contrast, the low plain 

w·est of the escarpment is underlain by limestone honeycombed with water-filled caverns 

and passageways that have collapsed locally to 

form sinkholes. Thus., most of the rainfall 

drains into and saturates the limestone. There 

are few surfac'e streams. 

WATER BODIES 

Reservoirs and lakes on the color mosaic show 

as various shades of light blue to black. The 

blue tones indicate how muddy the water was 

when the satellite passed over and scanned the 

scene. Black indicates clear water; th·e lighter 

the blue tone, the more susp·ended sediment was 

in the water. Areas of rapid eros:ion can be 

identified along some small streams draining 

into some of the ~eservoirs. An especially interesting example of the distribution of muddy 

water in reservoirs is that of Lake Seminole in 

the southwest corner of Georgia. A great differ-

·ence in the two source rivers, the Chattahooche 

and the Flint, can be seen particularly well in an 

enlargement of a Landsat image (fig. 1.2). 

The Chattahoochee River has a rather normal 

course in comparison to the Flint which flow·s 

through extensive upstream swamps and then 

drains the limestone country of the Dougherty 

Plain (fig. 3). The swamps act as. natural biological purifiers and settling basins, and drainage from the lim.estone adds clear waster to the 

river. Thus, the Flint River has been purified 

naturally, is very clear, and shows. as black on 

the image. However, the Chattahoochee is muddy and shows as gray. Note that the waters 

from the two rivers do not mix in the reservoir 

but remain separate to the dam. The many 

ponds and lakes miles from the reservoir were 

created when damming the river caused the 

water table to rise and fill the limestone sinkholes with water. 
FIGURE 4.-Enlarged Landsat band 7 image of part.s of northern Georgia, North Carolina, and Tennessee. The 

Great Smoky Fault cuts across the left edge of the image. 

8 
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FIGURE 5.-Map showing interpretation of figure 4. 

9 
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FIGURE 6.-Enlarged Landsat band 7 image showing development of hardwood-forested wetland on swampy flood 

plains along major rivers at the Fall Line. 
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FIGURE 8.- Enlarged Landsat band 7 image of part of the Armuchee Ridges area of northwestern Georgia. 

12 
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FIGURE 9.-Topographic map of the area of figure 8. (U.S.G.S. National Topographic Maps 1: 250,000-scale 

series.) 

13 
2 

0 0 0 0 

Shale (5) 

Sandstone (4) 

Shale (3) 

Limestone ( 2) 

Syncline ~ 

Anticline--=---~ 

FIGURE 10.-Block diagram illustrating general relation of ridges and valleys to anticlines 

and synclines. Rock units are numbered from oldest ( 1) to youngest ( 5). This diagram essentially represents a slice through a folded section of the very upper part of 

the Earth's crust. Note that the most resistant rock unit holds up the ridges. Unit 4 

is a hard sandstone layer. 

OKEFENOKEE SWAMP 

The complex pattern of drainage and vegetation of the Okefenokee Swamp includes more 

than 700 square miles of wetlands and is the 

largest swamp in the United States (figs. 14 and 

15). At a time of former higher sea level many 

thousands of years ago, this swamp was a shallow arm of the sea. A long barrier i'Sland was 

built across the east edge aiiJ.d remains today to 

prevent drainage to the Atlantic Ocean. Known 

as Trail Ridge, it shows clearly on both the enlarged image (fig. 14) and the mosaic. The old 

island is now a drainage divide between the 

Gulf of Mexico to the southwest and the Atlantic Ocean to the east. 

GEORGIA COAST 

Figure 16 shows identical scenes from two of 

the Landsat scanners, band 5 (red light) and 

band 7 (infrared light). Band 7 shows open 

water as black, the extensive salt marshes as 

dark gray, and high, dry ground as shades of 

light gray. Drainage of rivers and estuaries is 

clearly shown. Band 5, however, shows a very 

different picture. Clear water and forested land 

show black. Beaches and sand spits, roads, and 

cities show as white and light gray. The gray 

plumes diffusing seaward from the marshes and 

estuaries and into the open ocean are suspended 

sediment. This sediment is largely derived from 

the saLt marshes and is very rich in nutrient 

material from decomposed marsh grass. These 

nutrients make marine life unusually prolific 

along Georgia's coast, and the salt marshes 

serve as breeding grounds for many valuable 

fish, shrimp, and shellfish. 

GEOLOGY 

For detailed geologic interpretations the 

reader should obtain a copy of the 1976 Geologic 

Map of Georgia (see iiJlside back cover), which 

is at ,the same scale as the Landsat mosaic. 

Culture, physiography, slope, drainage, soils, 

land use, land cover, and geology are all so intricately interrelated that it is impossible to 

consider one without the others. Nevertheless, 

the Earth is made up of rocks, even where they 

are covered by soils or other materials. Thus, 

the most important factor in determining why 

the terrain features of a region are where they 

are is the geology. For example, one limiting 

factor for successful farming is soil. Soils are 

14 
r------- < 

\ \ • Atlanta .. 

\ Augu~>. 

\ • Macon '\\ 

"Columbus \ 

~ ' / Savannah~ 

(, [I' AREA OF FIGURE I ·L---------._r:~ 

0 2'12 5 MILES 

0 2'12 5 KILOMETERS 

FIGURE H.-Enlarged Landsat band 5 image illustrating the abrupt change in drainage at the edge of the 

Pelham Escarpment. 

15 
FIGURE 12.- Enlarged Landsat band 7 image and interpretation of Lake Seminole, showing 

sharp separation between muddy and clear water. 

16 
ALABAMA -----y-- ~ 

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FIGURE 13.-Explanation and location map for figure 12. 

17 
FIGURE 14.-Enlarged Landsat band 7 image of the Okefenokee Swamp. 

18 
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MINE 

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FIGURE 15.-Map showing interpretation of figure 14. 

19 

TITANIUM 

MINE 

5 
0 10 MILES 

10 KILOMETERS 

FIGURE 16.-Landsat band 7 image (left) of the area from Jekyll Island to St. Catherines Island showing the 

extent of salt marshes (gray); and Landsat band 5 image (right) of the same area showing muddy, 

nutrient-rich water being washed from the marshes and estuaries by a falling tide. 

20 
derived from the slow decomposition of rock. 

Thus, the type of rock determines the type of 

soil, which in turn partly determines suitability 

for agriculture. Slope, which is a faotor of the 

relative resistance of erosion of the rocks, must 

also be considered. Given the same soil, one 

slope may be ideal for agriculture, whereas another may be too steep. Drainage, intimately related to geology and slope, is also an important 

factor. Some areas with perfectly good agricultural soils may be too poorly drained for crops. 

Other examples of how g.eology has affected 

land us:e in Georgia can be s:een along the Fall 

Line. With the exceptions of Atlanta and Charlotte, North Carolina, all of the major inland 

cities on the Atlantic seaboard from New York 

south are located along the Fall Line. From the 

Landsat mosaic, one can see that Columbus, 

Macon, and Augusta are all Fall Line cities. The 

cities were built here largely because the Fall 

Line is generally the upper limit for river navigation by all but small boats. In addition, the 

rapids and waterfalls formed by the southeasternmost exposures of the crystalline rocks of 

the Piedmont supplied waterpower for mills 

and other industry. Thus, these Fall Line rapids 

determined the location of the cities. 

Geology and its resulting topography determined the location of cities such as Atlanta in a 

different way. Atlanta grew up as a railroad 

center. The high, rugged Blue Ridge and Great 

Smoky Mountains form a natural northeasttrending barrier from north Georgia to Pennsylvania. Bordering this mountain barrier on 

the southeast is the much flatter Piedmont. The 

railroad companies laid their rails from the 

industrial northeast southwestward through the 

Piedmont, and many Piedmont cities owe their 

existence to the geologic and topographic difference between the Blue Ridge and Piedmont. 

Atlanta was doubly fortunate, how·ever. Located 

just south of the southwestern end of the high 

Blue Ridge Mountains, it was also a logicallocation for railroad lines to the West and Midwest. 

Moreover, ,the Chattahoochee River provided a 

good water supply for a rapidly growing town. 

These are just a few examples. of how geology 

has affected development in Georgia .. Close examination of the mosaic and the State geologic 

map will show many others. 

SUMMARY 

The Landsat 1 satellite circles the Earth in a 

nearly north-south orbit at an altitude of 570 

miles, passing over any point once every 18 

days. While functioning, the instruments 

aboard the satellite transmitted ima,ges, each 

covering 13,500 square miles. Fourteen scenes 

were precisely joined by computer to make the 

mosaic of Georgia. On the mosaic, high-contrast 

features as small as 25 acres. can be seen. The 

mosaic shows the cultural feature·s of the State 

such as cities, roads, and other developments. It 

shows land use and land cover-woodlands, wetlands, cultivated areas, reservoirs, and so forth. 

Landforms and geologic £eatures are easily 

seen. Thus, this image from space allows us to 

look at the State of Georgia from a vantage 

point we never had before. It allows us to see 

features too large and widespread to be seen 

any other way. 

21 

REFERENCES CITED 

Clark, W. Z., Jr., and Zisa, A. C., 1976, Physiographic 

map of Georgia: Georgia Department of Natural 

Resources, Geologic and Water Division, scale 

1:500,000. 

Clark, W. Z., Jr., Zisa, A. C., and Jones, R. C., 1976, 

Georgia, a view from Space-An atlas of Landsat1 imagery: Georgia Geological Survey, 33 p. 

U.S. Geological Survey, in cooperation with the National A·eronautics and Space Administration and 

the Georgia Department of Natural Resources, 

Geologic and Water Resources Division, 1973-

1974, Georgia Satellite Image Mosaic: U.S. Geological Survey, scale 1: 500,000. 

1:J U.S. Government Printing Office: 1979-281-359/4 

OTHER MAPS AND PRODUCTS TO AID IN 

UNDERSTANDING THE LANDSAT MOSAIC 

The following five maps and reports can be ordered from: 

Georgia Dept. of Natural Resources 

Geologic and Water Division 

19 M. L. King, Jr. Drive SW. 

Atlanta, Georgia 30334 

1. Geologic Map of Georgia, 1976, scale 1: 500,000. 

2. Slope Map of Georgia, 1975, scale 1: 50,000. 

3. Clark, W. Z., Jr., and Zisa, A. C., 1976, Physiographic Map of 

Georgia, scale 1: 500,000. 

4. Clark, W. Z., Jr., Zisa, A. C., and Jones, R. C., 1976, Georgia, a view 

from Space-An atlas of Landsat-1 imagery: Atlanta, Georgia Geological Survey, 33 p. 

5. Individual images at 1:250,000 scale on band 7 of the Georgia Blue 

Ridge, Valley Ridge, Okefenokee Swamp, and Coastal area, 1977. 

The following U.S. Geological Survey maps are available from: 

Branch of Distribution 

U.S. Geological Survey 

1200 South Eads Street 

Arlington, Va. 22202 

1. Georgia Satellite Image Mosaic, 1973-1974, U.S. Geological Survey 

in cooperation with NASA and the Georgia Department of Natural 

Resources, scale 1: 500,000. 

2. Topographic base map of the State of Georgia (showing rivers, 

cities, railroads, counties, National and State parks and forests, 

highways and contours-generally at 200-ft intervals, locally at 

100-ft intervals, 1970, scale 1:500,000. 

3. U.S. Geological Survey National Topographic maps 1: 250,000-

scale series. 

4. U.S. Geological Survey, Greater Atlanta Region Topographic Map, 

1974, scale 1: 100,000. 

5. U.S. Geological Survey 7.5-minute topographic maps, various 

dates, scales 1 : 24,000. 

Individual Landsat images at various scales are available from: 

User Services Unit 

EROS Data Center 

U.S. Geological Survey 

Sioux Falls, South Dakota 57198 

Prices of the above maps are available on request from the sources 

listed. 
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