Hydrology of the 

Cavernous Limestones of 

the Mammoth Cave Area 

Kentucky

By RICHMOND F. BROWN

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1837

Prepared in cooperation with the 

Commonwealth of Kentucky, the 

University of Kentucky, 

Kentucky Geological Survey, 

Kentucky Department of Commerce, 

and the National Park Service

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1966
DEPARTMENT OF THE INTERIOR

MANUEL LUJAN, Jr., Secretary

GEOLOGICAL SURVEY 

Dallas L. Peck, Director

Any use of trade, product, or firm names in this publication is for descrntive purposes 

only and does not imply endorsement by the U.S. Government

First printing 1966 

Second printing 1991

Library of Congress catalog-card No. GS 66-271

For sale by the Books and Open-File Reports Section 

U.S. Geological Survey, Federal Center, Box 25425, Denver, CO 80225
CONTENTS

Page

Abstract__ ______________________________________________________ 1

Introduction. _ ____________________________________________________ 1

Scope and purpose.__ __________________________________________ 1

Location and extent.__________________________________________ 2

Previous investigations.________________________________________ 2

Well-numbering system._______________________________________ 3

Acknowledgments. --__-_______--__---______-_---_--___________ 4

Physiography _____________________________________________________ 4

Cave development-________________________________________________ 11

Geologic formations and their water-bearing properties.________________ 16

Paleozoic Era.________________________________________________ 27

Mississippian System._____________________________________ 27

Osage Series.____--_--__--___________---_--__--__-____ 27

Fort Payne Formation.____________________________ 27

Meramec Series.______________________________________ 27

Warsaw Limestone.________________________________ 27

St. Louis Limestone..---___________________________ 28

Ste. Genevieve Limestone_-__-_----_-___---_-------- 33

Chester Series.._______________________________________ 41

Girkin Formation._______________________________ 41

Big Clifty Sandstone Member of the Golconda

Formation.-____-_-_______-_-_----__-_-_-_--__-_ 42

Haney Limestone Member of the Golconda Formation_ 43

Hardinsburg Sandstone_____ ________________________ 43

Glen Dean Limestone.______-__--_--_--__-_-___-___ 44

Leitchfield Formation._____________________________ 44

Pennsylvanian System

Caseyville Formation....-____________________ __________ 44

Cenozoic Era.________________________________________________ 45

Quaternary System

Pleistocene and Recent deposits.________________________ 45

General hydrologic conditions.________-___-_-___--_-__---.__----__-__ 46

Fluctuations of water levels and underground-flow relationships. _ _ __ 49

Summary... -___________________-___-___-_--__---_-_------_---__-_ 61

Selected references.__ ______________________________________________ 62

Index __________________--__--__--_--___---_-----------_--_----_-. 63
IV CONTENTS

ILLUSTRATIONS

Page 

FIGURE 1. Sketch showing system of numbering wells and spnngs______ 4

2. Map showing major physiographic subdivisions of the Mammoth Cave area______________________________________ 5

3-8. Photographs of the Mammoth Cave area:

3. Sinkhole depressions and Dripping Springs escarpment

near Cave City________________________________ 7

4. Reentrant near Chaumont--_____-_--__----___-___ 8

5. Cedar Sink in Cedar Spring Valley.________________ 10

6. Hanging pendants in New Discovery in Mamoth Cave_ 14

7. Main Avenue in Mammoth Cave__________________ 15

8. Evaporite dam in New Discovery in Mammoth Cave_ 16 

9. Geologic map of the Mammoth Cave area.________________ 17

10. Map showing location of wells, springs, and dye tests in the

Mammoth Cave area___-_--__-__-__----_-____-__-____ 26

11. Diagrammatic section through the Mammoth Cav? plateau. _ 28

12. Hydrographs of wells, and precipitation, 1953-57___________ 29

13. Hydrograph showing relationship between water level in wells, 

stage of River Styx Spring and Echo River Spring, stage of 

Green River, and precipitation, January 10 to February 18, 

1954_______--_-__-_____--___--__---_----_-_____-____ 30

14. Hydrograph showing relationship between stage of River 

Styx Spring, stage of Green River, and precipitation, April 

30 to May 19, 1954__--__-_____-___--_______._________ 31

15. Hydrograph showing relationship between stage of River Styx 

Spring and stage of Green River; relationship between chloride concentration and stage in Echo River, Rive" Styx, and 

Green River; and precipitation, January 18 to February 6, 

1959_---_-_--_---___-------_---__----_-_--__________ 32

16. Hydrograph showing effect of precipitation on stage of River

Styx, Echo River Springs, and Green River______________ 33

17. Photograph of Ste. Genevieve Limestone exposed on south side

of Cedar Sink________________________________________ 38

18. Graph showing effect of pumping on water level____________ 39

19. Photograph showing outlet of Echo River_________________ 47

20. Photograph showing outlet of River Styx__________________ 48

21. Map showing cave passages, major subsurface streams, and

gaging stations.______________________________________ 51

22. Graph showing relation of chloride concentrations in water 

samples from ground-water to surface-water sources, January 22-29, 1959----_-------__--___--_----___-___.____ 56

23. Diagram showing relation of discharge and time to concentration of chloride in water from Echo River Spring, 1955-59- _ 59

24. Diagram showing chloride concentrations in water samples 

taken from ground-water and surface-water sources, November 3-4, 1958_-_---___-_-_---__-____-___-_-__.____ 60
CONTENTS V

TABLES

Page 

TABLE 1. Generalized section of the geologic formations exposed in the

vicinity of Mammoth Cave National Park_______________ 18

2. Records of wells in the vicinity of Mammoth Cave Nation?,!

Park__ _ _____________---_-__-__---_-----_--_-______-_ 20

3. Records of springs in the vicinity of Mammoth Cave Nation?!

Park________________________________________________ 24

4. Chemical analyses of water from wells, springs, and the Green

River in the vicinity of Mammoth Cave National Park- _ __ 34
HYDROLOGY OF THE CAVERNOUS LIMESTONES OF THE 

MAMMOTH CAVE AREA, KENTUCKY

By RICHMOND F. BROWN

ABSTRACT

The Mammoth Cave National Park in central Kentucky offers a unique opportunity to study the occurrence of ground water in limestone under natural conditions. Ground water occurs as perched and semiperched bodies in alternate sandstone, shale, and limestone formations and under water-table conditions at the 

approximate level of the Green River in thick soluble limestone. Three continuous recorders that operated for 5 years indicate that precipitation on the Mammoth Cave plateau recharges the underlying sandstone rapidly. Ground w^ater 

from the sandstone discharges horizontally to the edges of the plateau arcl vertically to underlying formations. Some of the precipitation recharges underlying 

formations almost immediately through overland flow to sinkholes and free fall 

through open shafts to pools at the water table.

Much of the precipitation on the Pennyroyal plain flows overland into sinkholes and then through solution openings to the Green River. Water from the 

G'.een River flows into limestone solution channels under Mammoth Cave plateau 

at some stages, and this water discharges again to the Green River dowrstream. 

The presence of salt water, high in chloride in the Green River, makes it possible 

to trace the movement of the river water through the underground streams. 

Graphs show relationships of chloride concentration, stage of the Green River, 

time, precipitation, ground-water levels, and stratigraphy.

INTRODUCTION

SCOPE AND PURPOSE

In order that the use and conservation of the water resources of the 

Commonwealth of Kentucky may be planned most effective^, the 

Commonwealth, through the Kentucky Department of Commerce 

(formerly the Department of Economic Development) and the Kentucky Geological Survey, has entered into cooperative agreements with 

the U.S. Geological Survey providing for studies of the water resources. This report, prepared as a part of the cooperative g~oundwater investigations, is a progress report of a basic research project 

which will yield information on the principles of the occurrence and 

movement of ground water in cavernous limestone.

A preliminary investigation of the occurrence and movement of 

ground water in the vicinity of Mammoth Cave National Park was
2 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

made during the summer of 1953 for the National Park Service. During the remainder of 1953 and continuing to the present (September 

1959), data were obtained from recording gages installed on selected 

wells and from gage-height readings of water bodies in the cave, 

streams, and springs in cooperation with the Kentucky Department of 

Commerce, the Kentucky Geological Survey, and the National Park 

Service.

Beginning in 1958, large quantities of oil were prodned in Green 

County, upstream from Mammoth Cave National Park. Considerable 

brine, high in chloride, was produced with the oil, and much of this 

brine discharged into the Green River. For the first time since investigations began in the Mammoth Cave area, the water in the Green 

River could be easily distinguished by its chemical character from 

the waters of the underground streams in the park area. As a part 

of an investigation of the geochemistry of natural waters of the upper 

Green River basin, samples were collected in 1958 and r 959 from the 

underground rivers and springs and from streams in the area. At 

the same time, additional data were obtained from stream gages 

and water-level recording gages. The combination of two distinctive 

chemical types of water and a limestone aquifer that h?s been extensively dissolved by ground water offers a unique opportunity for a 

better understanding of the occurrence of ground water in limestone. 

This paper presents the results of the investigation to September 1959.

The investigation included that part of Mammoth Cave National 

Park lying south of the Green River and the areas adjoining the park 

to the south and east. It included parts of Barren, Edmonson, and 

Hart Counties (fig. 2).

LOCATION AND EXTENT

The area investigated is about 100 miles southwest of Louisville, Ky. 

It includes about 80 square miles and is divided into two parts by the 

Dripping Springs escarpment (fig. 2). On the south and southeast 

side of this escarpment lies the Pennyroyal plain or sinkhole plain. 

North and northwest of the escarpment is the Mammoth Cave plateau, 

lying about 250 feet above the Pennyroyal plain. The incorporated 

towns in the area, Park City, Cave City, and Horse Cave, are all on 

the Pennyroyal plain.

PREVIOUS INVESTIGATIONS

Mammoth Cave and the national park area have been described in 

numerous publications over a period of years. The most definitive 

work in the area is by James Marvin Weller (1927). T1>(?, physiography of the region is described in a report by A. K. Lobeck (1928). An
INTRODUCTION 3

excellent popularized discussion of the geology and cave features has 

been published by the Kentucky Geological Survey (Livesay, 3953). 

None of these reports describe ground-water conditions in detail, 

though Lobeck noted that water availability was a major problem in 

the area. Ground-water movement in the area and the general processes of solution in limestone are discussed in papers by Davis (1930), 

Bretz (1942), Dicken (1935), and Pohl (1955). Each of these papers 

has served as an important reference for the present study.

WELL-NUMBERING SYSTEM

The wells and springs tabulated in this report are numbered to conform to the Kentucky plane-coordinate numbering system used by 

the Ground Water Branch throughout Kentucky.

Under this system, the State is divided into two zones, a north and 

a south zone, each consisting of two sets of parallel straight lines that 

intersect at right angles to form a grid.

The gridlines in each zone are 10,000 feet apart and are numbered 

in feet from arbitrarily assigned datum lines. The numbers assigned 

to the east-west gridlines increase to the north, and are determined by 

the distance that these lines are from an east-west datum line lying to 

the south of each zone. The numbers assigned to the north-south gridlines increase to the east, and are determined by the distance that these 

lines are.from a north-south datum line lying to the west of each zone.

Each well or spring is designated by a letter followed by a number. 

The letter assigned is "N" if the well or spring is in the north zone and 

"S" if it is in the south zone.

The number following each letter is in two parts. The first part of 

the number is obtained by adding the distance in feet the well or spring 

is east of the nearest north-south gridline to the number of that line 

and dividing the sum by 1,000 to shorten it. The second part of the 

number is obtained by adding the distance in feet the well or siring 

is north of the nearest east-west gridline to the number of that line and 

dividing the sum by 1,000.

In the Mammoth Cave area in the south zone, for example, a siring 

(River Styx outlet) that is 5,500 feet east of the 1,890,000-foot gridline and 1,000 feet north of the 310,000-foot gridline is numbered S1,895.5-311.0 (fig. 1). Because the distance of the well or spring from 

the gridline is usually computed to the nearest hundred feet, there is 

only one decimal place in the number. However, the number may be 

carried out to 2 or 3 decimal places if it is necessary to locate the well 

or spring more accurately. By this method each well or spring is 

assigned a number which is not only unique to that well or siring 

but precisely expresses its location on the map.
HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY. 

Q 9 o

320,000

310,000

300,000

1884.0-304.7

O

1888.1-302.1

1895.5-311.1

1895.5-308.1

FIGURE 1. System of numbering wells and springs.

ACKNOWLEDGMENTS

Many residents in the area gave information about their wells and 

permitted measurements to be made in their wells. Appreciation is 

expressed to personnel of the National Park Service for their cooperation and to W. Ray Scott, National Park Concessions, Inc., for the use 

of photographs of the area. The Louisville Gas & Electric Co. furnished several maps and reports from their files which were valuable 

in some areas. Dr. E. R. Pohl, Director, Mammoth Ony Cave, gave 

helpful advice and information on the geology and physiography of the 

region.

PHYSIOGRAPHY

The topography of the area is controlled by the geologic succession, 

the structure, and the present position of major drainage channels. 

The major physiographic features in the Mammoth Cave area are 

shown in figure 2. From oldest to youngest, the general geologic 

sequence is rocks of the Osage, Meramec, and Chester Series of the 

Mississippian System and Caseyville Formation of the Pennsylvanian
86°10' 86°00' 

37°10'F

37°05'h

Base map from Kentucky Dept of Highways

FIGURE 2. Major physiographic subdivisions of the Mamm
6 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

System. The rocks of the Osage and the lower part of the Meramec 

Series are relatively insoluble in ground water. The rocks of the upper 

part of the Meramec are very soluble in ground water, and it is in this 

part of the series that most of the solutional features in the area are 

developed. Lying above these soluble limestone rocks is the Girkin 

Formation in the lower part of the Chester Series, which apparently is 

as soluble as rocks in the upper part of the Meramec; but above this, the 

rocks are relatively insoluble and are eroded principally by processes of 

normal erosion. These rocks above the Girkin consist of alternating 

beds of sandstone and limestone and some interbedded shale; they are 

capped with a sand and gravel conglomerate of Pennsylvanian age. 

All these beds dip northwestward about 25 feet per mile.

Within the Mammoth Cave National Park south of the Green River, 

the Big Clifty Sandstone Member of the Golconda Formation, lowest 

formation of the middle part of the Chester Series, caps most of the 

ridges. Extensive solution has taken place beneath this COD, generally 

to approximately the level of the Green River. West of the park, the 

Big Clifty Sandstone Member is much lower relative to the Green 

River, and there is, therefore, not a thick section of soluble rocks in 

which an extensive solution drainage pattern can be formed. Accordingly, in this area the drainage is generally normal surface drainage 

dendritic and continuous. East of the park area, the rocks of Osage 

age are exposed, and, inasmuch as they are relatively insoluble, only 

slight solution action has taken place in this area. Just below the 

escarpment to the south and east, drainage is through solution channels ; but 2 miles or more southeast of the escarpment the relatively 

insoluble rocks of the Osage are exposed, and here the drainage is 

superposed.

The sinkhole depressions (funnel-shaped openings through which 

surface water drains into underground solution channels) in the 

Pennyroyal plain range in depth from about 1 foot to about 100 feet. 

In a plan view they range in size from about 1 foot to about 2,000 feet 

in their longer dimension. In general, sinkholes less thr.n 20 feet in 

diameter have steep sides, sometimes nearly vertical; the larger sinkholes have gently sloping sides. Most are approximately round in plan 

view, but solution action sometimes causes adjacent sinkholes to 

coalesce and ultimately to form a series of sinkholes with their long 

dimensions in the direction of the major underground drainage (fig. 

3). The sinkholes are present over almost the entire area of the plain 

that is underlain by limestone of the upper part of the Meramec Series. They are evenly spaced and have no obvious areal pattern. Pohl 

(1955, p. 13) ascribes their origin to a process of vertical sl^aft development now taking place at valley heads on the Mammoth Cave plateau.

In the southern part of the area, which is underlain by the Warsaw 

Limestone of early Meramec age, there are relatively few sinkholes.
PHYSIOGRAPHY

^^^^^^^-^M:^,^

'"--- ^.-^

*&* "'S^1^?^**U4A

" ~- is '^! --

* ^fc.. ^fc- -&«« ^^j^^s,s

.j^P*^ 

r-..*r ^^iaa.-VljSgKS'

 lil^i^*-.^*-*-*?- ^ ~s-~-**?^

^r^A a^i

1L

FIGURE 3. Sinkhole depressions and Dripping Springs escarpment near Cave 

City. Dripping Springs escarpment, capped by Big Clifty Sandstone Member of 

Golconda Formation, is the wooded area to the right; the Pennyroyal plain lies 

to the left. The sinkholes are developed in Meramec rocks. The series of sinkholes that trend from central left diagonally up to the escarpment (marked in 

part by trees) overlie a major subsurface channel. The bottom of the sinkhole 

in the foreground is plugged, and the water is perched above the local water 

table. Photograph by W. Ray Scott.

Several streams in this area flow north and northwest toward the 

escarpment. Some are perennial streams, but all terminate in one or 

more sinkholes. Even after torrential rains during late winter, these 

streams cannot maintain a surface flow on the St. Louis Limestone. 

Both surface erosion and solution action are lowering the surface and 

extending the Warsaw-St. Louis boundary progressively northwestward. As a result, the area drained by surface streams is increasing, 

and the area of sinkhole drainage is decreasing. Seemingly, the present stream valleys are remnants of former subsurface channels. They 

are alined to joint systems and do not show evidence of dendritic 

development.

The deepest sinkholes are near the edge of the Dripping Springs 

escarpment. These include Monroe Sink, east of Kentucky State 

Koute 70, and Mill Hole (S-1,893.0-283.3), about 4 miles west of Park 

City. Monroe Sink is about half a mile in length and 200 feet deep.
8 HYDROLOGY, CAVERNOUS LIMESTONES. MAMMOTH CAVE AREA, KY.

FIGURE 4. Reentrant near Chaumont. Mammoth Cave Ridge, capped by the 

Big Clifty Sandstone Member of the Golconda Formation, shows in background 

above the Dripping Springs escarpment. Minor sinkholes are developed in 

the base of the reentrant. Water that drains out of these sinkholes flows 

northward through subsurface channels under the escarpment. Photograph 

by W. Ray Scott.

It is the largest single sinkhole in the region and is typical of several 

others along the edge of the escarpment. Mill Hole is similar in many 

ways; however, Mill Hole is deeper and the floor intersects a throughflowing subsurface stream. Several of the sinkholes along the edge of 

the escarpment are elongated, have coalesced with other sinks, and 

form large reentrants into the escarpment. The orientation of these 

reentrants is controlled by two factors. Some are parallel to joint systems through part of their length, but the agreement with fractures 

or structure is not everywhere apparent. Some reentrants, particularly the one near the Chaumont well (8-1,907.4-289.0), are alined 

with the valleys that are cut into Mammoth Cave plateau (fig. 4). 

From the Dripping Springs escarpment to the Green River, the upland surface is capped with the Big Clifty Sandstone Member of the 

Golconda Formation. The dip slope of the surface is toward the 

northwest at about 25 feet per mile. Large northwest-trending closed 

valleys dissect this upland surface. These are subsequent valleys
PHYSIOGRAPHY 9

superposed on cavernous limestone. Each valley consists of numerous 

sinkholes coalesced to form one large depression. The altitude of the 

base of each of these valleys is close to that of the Green River, but 

only Cedar Sink (S-1,882.2-297.1) in Cedar Valley is deep enough to 

intersect this level. There is no surface flow in any of the valleys, 

except during periods of extreme precipitation when some water may 

overflow from one sinkhole into adjacent ones. The heads of each 

of the valleys tributary to the master valleys are abruptly terminated. 

Where each of these tributary valleys terminates against the upland, 

a sinkhole is developed. These sinkholes have large vertical shafts 

under them, and it is largely through lateral expansion and coalescing 

of the verticle shafts that the upland is now being dissected (Pohl, 

1955).

The gross drainage pattern of the valleys is dendritic, and is a 

remnant of subsequent drainage developed on the dip-slope surface of 

the Big Clif ty Sandstone Member during Tertiary time (Weller, 1927, 

p. 50). In the large valleys, subsurface solution channels now carry 

all the drainage during periods of normal flow. Ephemeral dendritic 

tributary streams still persist on the surface in some areas adjacent to 

the more extensive upland divides; however, continued solution action 

will decrease the areal extent of the ridges and increase the area that 

is drained exclusively through subsurface solution channels. Surface 

drainage will not predominate in the area again until the floor of the 

valleys has a normal gradient to the local base level, the Green 

River.

Three ridges are dominant on the upland (fig. 2). Flint Ridge, on 

the northeastern edge of the park, is underlain by many large caves 

including Crystal, Colossal, and Great Onyx Caves. Small sinkholes 

are at the heads of most of the valleys that dissect the edges of the 

ridge, but none is on the surface of the upland. Flint Ridge, is about 

2 miles wide and more than 3 miles long, and is bounded on the east 

by a large unnamed valley that lies about 300 feet below the upland 

of Flint Ridge and on the west by Eaton and Houchens Valleys and 

an isolated depression, Strawberry Valley. The bottoms of these 

valleys are about 200 feet below the upland. Southwest of these 

valleys is Mammoth Cave Ridge, under which are the famed caverns 

of Mammoth Cave. Mammoth Cave Ridge trends northwestward and 

is about half a mile wide and more than 3 miles long. Jim Lee Ridge 

is a thumblike projection west from Mammoth Cave Ridge. The 

New Discovery, a large cave found in 1938 by traversing several small 

passageways from one of the lower levels of Mammoth Cave, underlies this ridge. Although the perimeter of these ridges is bounded 

by large sinkholes, there are almost no sinkholes in the upland surface. These two ridges are bounded on the southwest by Doyel Valley.
10 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

The bottom of Doyel Valley is in places nearly 300 feet below the 

upland, but nowhere does it extend deep enough to intersect the level 

of the Green River or the water table that is graded to that level.

West and southwest of Doyel Valley is Joppa Ridge, which also 

trends northwestward. It is as much as 2 miles wide and about 3 miles 

long. Sinkholes are rare on the crest of the ridge, although they are 

abundant on the perimeter. No large caverns have been discovered 

under Joppa Ridge.

On the southwest side of Joppa Ridge is another large valley, 

branches of which are called Cedar Spring, Smith, Woolsey, Owens, 

and Katy Pace Valleys. The lowest part of this valley complex, the 

bottom of Cedar Sink in Cedar Spring Valley, is at an altitude of about 

420 feet, and about 340 feet below Joppa Ridge. Cedar Spring Valley 

has a well-defined connection with the Pennyroyal plain, and the subsurface stream that flows beneath the floor of the valley is probably 

the one that is visible not only in the bottom of Cedar Sink (fig. 5), but

FIGURE 5. Cedar Sink in Cedar Spring Valley intercepts the regional water table 

between the Pennyroyal plain and the Green River. The water level in Cedar 

Sink is slightly higher than the Green River at the Turnhole. The inlet to the 

sink is a partly collapsed cavern to the left of the photograph and is larger than 

the outlet. High flows from the Pennyroyal plain to the river form a large 

temporary lake in the sinkhole, and a whirlpool develops at this site. The 

lake sometimes overflows through the left foreground to a second sinkhole. 

Photograph by W. Ray Scott.
CAVE DEVELOPMENT 11

also in the bottom of Mill Hole, a sinkhole near the edge of the escarpment. A large spring that discharges from a sinkhole adjacent to the 

Green River, known as the Turnhole, is probably the discharge point 

for some, if not all, of the water that flows under the floor of Cedar 

Spring Valley.

West of Cedar Spring Valley, the topography is characterized by 

short dendritic perennial streams which flow generally northward into 

the Green River. South of the headwaters of these streams, drainage 

is into Beaver Dam Creek. Although some of the tributaries to 

Beaver Dam Creek drain into sinkholes, the area as a whole is not 

karst topography. The few sinkholes on the surface are shallow and 

relatively small. The area is underlain by relatively insoluble beds 

of alternating sandstone and limestone of middle Chester age. The 

escarpment west of the Mammoth Cave area is distinctively different. 

Instead of an irregular escarpment indented with sinkholes and extensive valley sinks, it is regular in outline and everywhere very steep. 

Streams as much as a mile in length that are tributary to Beaver Dam 

Creek flow7 northward from the top of the escarpment down the dip 

slope of formations in the middle part of the Chester. BelowT the 

escarpment in this area the karst surface on the Pennyroyal plain is 

particularly well developed in formations of early Chester and late 

Meramec ages.

Northwest of the Green River the topography is markedly different. 

Solution features are principally a few caves along the bluffs on the 

north side of the river and some just north of the river opposite Joppa 

Ridge. None of the caves is more than a few hundred feet in length 

(E. R. Pohl, written commun., 1938). The formations north of the 

river consist of layers of sandstone and limestone of Chester age 

capped by a conglomerate of the Pennsylvanian System. The area is 

drained by short ephemeral streams with steep gradients. The drainage is typically dendritic and is little affected by solution action.

CAVE DEVELOPMENT

Mammoth Cave National Park is world famed for the size and 

length of its passageways. Within the boundaries of the national 

park are many miles of passageways which display every type of cave 

formation. Much has been learned in recent years of the processes 

that create such a labyrinth of underground passages, but much research is still needed to explain details of how the caves were formed.

The major caves underlie ridges. Mammoth Cave underlies Mammoth Cave Ridge; Crystal Cave, Colossal Cave, and Great Onyx Cave 

underlie Flint Ridge; and New Discovery underlies Jim Lee Ridge. 

Caves may have formerly existed in what are now open valleys between the ridges, but the valleys have been so eroded that no evidence
12 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

of caves remains above the water table. Below the water table there 

are reported to be small solution openings in some valleys. A test, hole 

drilled in Eaton Valley to locate new water supplies for the national 

park headquarters area failed <o penetrate any significant openings to 

a depth of o22 feet. Explorations in westward extensions of Crystal 

Cave are reported to have located some caverns that are under Eaton 

Valley, but their extent is not known.

The southern edge of the Dripping Springs escarpment is the southern edge of the cave area. The Dripping Springs escarpment is 

capped with the Big Clifty Sandstone Member of the Golconda 

Formation which, in turn, is underlain by thick deposits of limestone. 

The caves are formed in the limestone, and the Big Clifty protects the 

escarpment from complete erosion. Where the sandstone cap has 

been removed by erosion, or wrhere it is close to the base level of the 

Green River, as in the northwestern part of the park, there is no cave 

development.

At one time the cap of the Big Clifty Sandstone Member extended 

several miles south of the present escarpment. Retreat of the escarpment from its original position toward the Green River was caused by 

solution of the underlying limestone. The present position of the 

escarpment coincides in this area with a iiortlnvard-facing monoclinal 

structure in the underlying Chatanooga Shale of Devonian age. This 

structure probably controlled the movement of subsurface water and 

the extent of erosion by solution. Solution took place most rapidly 

along the escarpment edge. Pohl (1955) ascribes the retreat to the 

development of vertical shafts formed by vertical enlargement of cross 

joints by downward-seeping surface water. Development of these 

shafts can be observed in the dome pits in Mammoth Cave. Remnants 

of former vertical shafts can be seen on the Pennyroyal plain below 

the Dripping Springs escarpment where the numerous sinkholes presumably mark the sites of former shafts.

The major horizontal passageways in the park are developed in the 

Ste. Genevieve Limestone. Higher caves on the plateau are developed 

in part in the Girkin Formation; the few caves on the Pennyroyal 

plain are developed in the St. Louis Limestone. The vertical shafts 

or dome pits extend from the lower Chester sandstone down into the 

Meramec.

All the cavernous area was developed in limestone formations by 

the dissolving action of ground water. Limestone is slightly soluble 

in pure water, but it is about 30 times more soluble in water containing 

a small amount of carbon dioxide. Rainwater contains small amounts 

of carbon dioxide and picks up small amounts of humic acid from 

soils as it moves into the ground. To be effective in dissolving limestone, water must be in motion; water which has become saturated with
CAVE DEVELOPMENT 13

calcium carbonate must leave the area, and unsaturated water must 

be constantly available for replacement.

Water exists in the ground in two environments. These are called 

vadose and phreatic. Vadose water is in the upper zone, or zone of 

aeration, where pore space in rocks is normally filled with air. Vadose 

water flows through fractures in the limestone much as a stream flows 

down a steep hill. Phreatic water is in the lower /one where all pore 

space is saturated. Vadose water moves down to the phreatic zone 

under the influence of gravity. In the phreat ic /one, water moves from 

areas of high head (southeast of the escarpment) to areas of low head 

(Green River). Circulation of phreatic water takes place from the 

water table to below local drainage.

The major passageways of Mammoth Cave were formed initially in 

a phreatic environment. Solution enlargement took place first along 

the joints and bedding planes. Subsequently, these enlarged and 

joined to form major rooms and passageways. The orientation of the 

caverns coincides roughly with the joints or fracture patterns in the 

rocks in the area, t rending northwest and northeast. Solution has 

been so extensive in many areas that the initial orientation of a cavern 

passageway or room is difficult to determine, but. overall, the pattern 

is easily recognized. Caverns in adjoining Crystal Cave are oriented 

along the same joint patterns as are segments of the meanders of the 

Green River. Secondary modification of the passageways took place 

in a vadose environment.

The floors of most of the passageways are developed on bedding 

planes. The numerous levels of cavern development are connected 

by short steep caverns developed where solublity of a bed was greater 

than average. Probably the levels in Mammoth Cave, discussed by 

previous authors, have been overemphasized. In a phreatic environment, solution takes place at all levels at the same time. A substantial 

difference in head between the former recharge area south of the area 

shown in figure 2 and the discharge area along the Green River would 

result in circulation to depths as great as solution openings are known 

to exist, some 40 feet below the present level of the Green River. 

Some authors, following Swinnerton (1932), believe that circulation 

was as much more rapid near the surface of the water table. This is 

certainly the situation at present where flow takes place through River 

Styx and Echo River. It would not be as true if the water table were 

assumed to lie somewhere in the Chester Series during the period 

of cave formation.

The problem of reconstructing the history of cave formation is complicated by the complex glacial history of the region. The deep valley 

of the Green River, about 40 feet below the level of the present valley 

floor, was carved during Yarmouth time (Walker, 1957, p. 6). Dur217-O8S O 66 2
14 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

ing Illinoian and Wisconsin Glaciations the Green River valley was 

alternately aggraded and eroded, and fill in the valley was probably 

many tens of feet. It is probable that most of the caverns were formed 

during pre-Pleistocene time, but they were greatly modified and 

enlarged during the Pleistocene. A sample of guano from Chief City 

on the Historic Entrance has been dated at more than 38,000 B.P. 

(before present) (W. E. Davies, written commun., 1960), indicating 

no major changes in this part of the cave since that time.

A two-cycle origin of the caves (a first cycle of phreatic and later 

vadose conditions) is indicated by numerous features. Most prominent 

among those that indicate a phreatic cycle are the spectacular pendants 

shown in figure 6. These were formed in the zone of saturation by 

water that completely filled the cavern and moved very slowly from 

areas of high head to areas of low head. The beautifully etched patterns are the result of differences in solubility of the limestone. Figure 

7 shows similar etching near the ceiling and also a flat relatively insoluble bed forming the cave ceiling which prevented further vertical 

enlargement of the passageway.

FIGURE 6. Hanging pendants in New Discovery in Mammoth Cave show the uniform solution action of slow-moving waters under phreatic conditions. The 

undisturbed floor is underlain by several feet of silt and clay deposited in 

standing water. Photograph by W. Ray Scott.
CAVE DEVELOPMENT 15

\ '

FIGURE 7. Main Avenue in Mammoth Cave. Hanging pendants are along the 

upper right and left borders. Solution action was ineffectual on bed that 

forms the flat ceiling. Piles of silt are the result of mining the cave for saltpeter. Photograph by W. Ray Scott.

Other features in the caves that Bretz (1956) lists as evidence of 

phreatic origin include joint-determined wall and ceiling cavities, and 

bedding-plane and joint-plane anastomosing. The latter features 

are systems of minor curvilinear tubelike solution cavities lying along 

interconnecting bedding and joint planes.

The Echo River and River Styx are vadose streams which are imposed on the phreatic caverns and show a second set of features that 

are characteristic of normal erosion. These include incised meanders 

and horizontal grooves in cave walls. Some tributaries to these major 

streams also show vadose features. Incised meanders are particularly 

well displayed in Robertson Avenue near Fairy Spring.

Secondary deposition under the vadose conditions in air-filled caves 

has resulted in the formation of many types of evaporite deposits 

including the familiar flowstone, stalactites, and stalagmites. Less 

commonly seen features include evaporite dams, one of which is shown 

in figure 8. This dam, almost 2 feet high, was formed by deposition 

of evaporites at the edge of a pond. Rippling of the surface from 

dripping water caused intermittent overflow of the dam. Evaporation 

of this overflow built the dam higher.
16 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

FIGURE 8. Evaporite dam in New Discovery in Mammoth Cave. The dam is 

near the edge of Jim Lee Ridge. The sandstone capping of the ridge has been 

removed by erosion in the area behind the dam, and seepage enters the cave 

after heavy rains. High moisture conditions near here result in exquisite 

growths of gypsum "flowers." Photograph by W. Ray Scott.

GEOLOGIC FORMATIONS AND THEIR WATER-BEARING

PROPERTIES

The formations exposed in the area are sedimentary and consist of 

limestone and sandstone and some shale. They range in age from Early 

Mississippian through Early Pennsylvania!!. The oldest rocks are 

limestone and shale of the Osage Series of Early Mississippian age. 

Above these is the Meramec Series, which includes the Warsaw, St. 

Louis, and Ste. Genevieve Limestones. The Chester Series in the area 

includes the Girkin Formation, Big Clifty Sandstone and Haney 

Limestone Members of the Golconda Formation, Hardinsburg Sandstone, Glen Dean Limestone, and the Leitchfield Formation. On the 

north side of the Green River, the Oaseyville Formation of Early 

Pennsylvania!! age caps the ridges. All the rocks clip about 25 feet per 

mile to the northwest. Only a few small faults and folds are in the 

area. A generalized section of the geologic formations and their 

water-bearing properties is given in table 1, and the areal extent of the 

major geologic subdivisions is shown in figure 9.
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 17

0
18 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

TABLE 1. Generalized section of the geologic formations exposed in the vicinity of 

Mammoth Cave National Park

Kra System

Quaternary

n

3 

3 

5

3 

3

3

J

a « _. s^s a<5?'S

Mississippian

Scries

Chester

Meramec

Subdivision

Pleistocene and 

Recent deposits

Caseyville Formation

Leitclificld Formation

(Jlcn Dean 

Limestone

Hardinsburg 

Sandstone

Ilaney Limestone Member of Qolconda Formation

Big Clifty 

Sandstone 

Member of 

Qolconda 

Formation

Oirkin Formation

Ste. Qenevieve 

Limestone

St. Louis 

Limestone

Warsaw Limestone

Approximate 

thickness 

(feet)

SO

10

125

00

30

40

f.O

120

180

300

100

Physical character

Silt, mud, sand. Sand 

and fine gravel in 

tributary valleys.

Thick-bedded sandstone with a coarse 

pebble conglomerate at the base.

Shale with limestone 

and sandstone 

members.

Fine- to coarsc-crysstallinc gray limestone. Shale at 

base of formation.

Medium-grained 

crossbcdded white 

to yellow-brown 

sandstone and intcrlaminatcd siltstone and shale.

Fine- to coarse-crystalline light -gray 

limestone. Shale 

at base.

Medium-grained 

crossbedded lightyellow to yellowbrown sandstone 

intcrbedded with 

black shale near 

base.

Coarse- to fine-crystalline oolitic lightgray limestone. 

Shale at base.

Finely crystalline 

oolitic crossbcdded 

white to light-gray 

limestone; contains 

abundant chert.

Medium-crystalline 

to lithographic 

light-gray to black 

limestone. Contains abundant 

chert.

Medium- to coarsecrystalline mediumto dark-gray limestone and interbedded shale.

Water-bearing 

properties

Transmits large quantities of water at low 

velocities. Discharges 

large quantities of 

water to streams from 

seeps.

Unimportant as an aquifer ir this area.

Unimportant as an aquifer ir this area.

Transmits small quantities of water through 

solution channels. 

Sprirgs arc concentrate! at the base of 

the formation in western part of area.

Transmits small quantities of clear water to 

lower formations.

Transnits moderate 

quantities of water to 

sprin?s through solution channels. Springs 

and s"eps arc concentrated at the base of the 

formation.

Transmits small quantities of clear water to 

lower formations. 

Locally discharges 

small quantities of 

wate- to springs.

Transmits small quantities of relatively clear 

water through solution 

channels. Locally 

discharges small quantities of water to 

springs.

Transmits large quantities of water through 

solut: on channels. 

Water is clear during 

low flow but is very 

turbii during high 

flow. Locally discharges large quantities of water to 

springs.

Transrrits small quantities of water through 

small solution channels. Important as a 

relatively insoluble 

base level.
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 19

TABLE 1. Generalized section of the geologic formations exposed in the vicinity of 

Mammoth Cave National Park Continued

Era

a

System

3 Ofc4

O

X!

53 O

a -2 '5,

%

%

Scries

CJ

a

O

Subdivision

Fort Paync 

Formation

Approximate

thickness

(feet)

150

Physical character

Medium-cry stall inc 

light-gray limestone and chert

and calcareous

shale. Grades into

silty limestone.

Water-bearing

properties

Unimportant as an 

aquifer in this region.

Relatively insoluble

base level in surrounding areas.

Records of wells and springs inventoried in the Mammoth Cave area 

are given in tables 2 and 3. The locations of wells, springs, and dye 

tests are shown in figure 10.

The sequence of the geologic formations in the area and the. relation 

of water tables and spring horizons 1o the formations are shown in 

figure 11.

Fluctuations of water levels in wells in different formations and in 

the Green River are shown in figures 12-10. The chemical quality of 

samples of water obtained from the various geologic horizons sampled 

and the Green River is shown in table 4.
20 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

TABLE 2. Records of wells in the

[Type of well: Dr, drilled; DrP, percussion drilled; Du, dug. Depth of well: Reported in feet; measured 

Sandstone Member of Golconda Fm.; Mh, Hardinsburg Sandstone; Mg, Girkin Fo-mation; Msg, Ste. 

H, hand; ,T, jet; Tu, turbine. Use: D, domestic; In, industrial; P, public supply; S, stock]

Well

3-1,879.9-295.0

1, 882. 8-299. 5

1,884.7-280.9

1, 886. 7-268. 3 

1,888.1-302.1

1,891.3-297.9

1,894.1-281.7 

1,900.8-276.6

1,902.8-297.9

1,903.8-293.7

1,904.8-316.3

1,906.4-293.3

1,907.4-289.6

1,908.4-289.6

1,909.0-285.1

1,909.2-267.8

1,909.5-297.6

1,909.6-257.8 

1,910.2-320.1 

1,911.9-298.6

1,912.5-276.7

1,913.4-276.9 

1,914.0-297.7

Owner or name

Joe Blair__._____

Natl. Park

Service. 

Arthur Keith...

M. H. Wheeler.. 

Natl. Park

Service. 

_...do., .........

J. R. Hawkins.. 

J. F. Taylor.....

Natl. Park

Service. 

.. ...do..... ______

--...do.,- _ ___

___._do_.__ ______

_.___do. ...... _

____.do_-__ ______

_____do_-___...___

Ilanson.

Caverns. 

Hazel Grav.___

Natl. Park 

Service.

G. W. Bellamy __

Floyd Collins 

Crystal Cave.

Citv of Park 

City. 

W. L. Gardner. 

L. A. Ferguson.

Driller

Francis Wilson.

Malcolm 

Dillingham.

Dillingham.

Dillingham.

Malcolm 

Dillingham.

Bill Bailey. ____

Malcolm 

Dillingham.

James Hardy _

Taylor and 

Woodson.

Date 

completed

1920

1925

1949 

1925

1925

1941

1925

1953

1900

1925

1928

1925

1850

1938

1900 

1947

1950

1945 

1940

Topographic 

situation

Top of

ridge. 

__._do_...

_.__do_.._

Sinkhole 

plain.

Top of

ridge.

___. do--

Side of 

hill.

plain. 

Side of

valley. 

Top of

ridge. 

..... doSide of

hill. 

Top of

ridge. 

___do______

___do....__

...do......

plain. 

Side of

hill.

Top of 

ridge.

Sinkhole 

plain. 

Top of 

ridge.

valley. 

Sinkhole 

plain, 

do..... 

Top of 

ridge.

Altitude 

above 

sea 

level i 

(feet)

724

722

750

640

782

788

560 

610

670

885

740

885

858

750

700

070

873

765 

780 

890

040

MO 

X80

Typo

Du

Du

DrP

DrP 

Du

Du

DrP 

DrP

Du

Du

Du

DrP

Du

DrP

DrP

Du

DrP

Du,

Dr^. 

Drl'

Du 

DrP 

Du

Dr

DrP 

DrP

Well

Depth

22.8

5.5

55.2

101 

18.5

17.5

180 

200

14.6

21.5

24.4

23.8

90.6

27.8

251

88

500

29.4 

422 

20. 2

250

225 

445

Diameter

26

6.5

6 

22

20

8 

6

36

60

32

6

22

21

6

6

8

18 

0

0

10

S

See footnote at end of labh
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 21

vicinity of Mammoth Cave National Park

in tenths of feet. Character of material: L, limestone; S, sandstone. Geologic horizon: Mgb, Big Clifty 

Genevieve Limestone; Msl, St. Louis Limestone. Type of lift: Bu, Bucket; Cy, cylinder; E, electric;

Principal 

water-bearing 

bed

Character 

of material

S

S 

L 

L

S

S 

L

L 

L

S 

S

S

L 

L

L 

L

L 

L

L 

L

S 

L

L 

L

Geologic horizon

Mgb

Mgb 

Mg 

Msd

Mgb

Mgb 

Msd

Msd 

Mg

Mgb 

Mh

Mgb

Mg 

Msg

Mg 

Msd

Msd 

Msg

Msl 

Msg 

Mgb 

Msl

Msl 

Msg

Depth of casing 

(feet)

89

8

None

None 

None

None

200 

44

40

180

100 

20

Water level

Below 

land 

surface 

(feet)

5.5 

3.6

49.2 

96

2.4 

3.8

150

13.2

2.4

16.0 

303.3

3.2 

81.3

27.3 

225

84 

419.7

8.3 

422 

10.4 

225

159.0 

410

Date of 

measurement

5- 5-53 

...do....

6- 9-53 

1949

4-30-53 

__.do._..

1941

5- 8-53

5- 6-53 

.-.do 6-22-53

4-30-53 

5- 6-53

5- 6-53 

1948

1948 

5-22 -53

6-10-53 

1947 

5-12-53 

1956

8-20-52 

1946

Type of 

lift

Bu, H

None 

Bu,H 

Cy, E

None

Cy, E 

Cy, E

None 

None

Cy,E

None

None 

None

J,E 

Cy, E

J, E 

None

Bu, 11 

Cy, E 

None 

Tu, E

Tu, E 

Cy, E

Capacity 

of 

pump 

(gpm)

50 

60

Reported 

yield 

(gpm)

10

10

92

50

60 

35

Use

D,S

None 

D 

D

None

None 

D

P 

None

None

None 

P

None

None 

None

D 

P

D, S 

None

D 

P 

None 

P

P 

D

Remarks

Temperature 54° F. 

Temperature 59° F. 

Temperature 54°F.

Water flows in at 10 ft 

depth, out at 13.2 ft 

through solution openings.

Temperature 58°F.

Rate of yield measured Jun e 

22, 1956. Emergency public supply for Mammoth 

Cave National Park. 

Temperature 56°F.

Automatic recorder installed 

May 13, 1953.

Do. 

Well used to carry electric 

wires into Marrmoth 

Cave.

Well formed by d'gging a 

hole into a cave and putting the pump in a reservoir constructed in the 

cave. Dug wel' caved in 

1948 and was reirilled. 

Former public suoply for 

Civilian Conservation 

Corps Camp. Automatic 

recorder installed May 

22, 1953. Temperature 

58°F. 

Temperature 58°F.

Believed to obtain water 

from Pike Sprir^.

Temperature 59°F. 

Temperature 59°F.
22 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

TABLE 2. Records of wells in tlic

Well

S-l, 91 5.9- 292.0

1,919.9-288.7

1,922.8-277.1

1,922.9-276.1

1,932.8-281.9

1,938.2-289.9

1,939.2-293.8

1,943.3-295.8

1,945.7-282.9

1,947.0-317.7

1,950.5-302.5

1,951.4-282.2

1,952.3-304.6

1,953.7-307.0

1,953.4-307.4

1,954.6-292.1

1,955.4-283.6

Owner of name

Rock Cabin

Camp.

L. A. Ferguson..

Emit Coomer

. -do__. ........

Ernest Dossey. .

Roscoe Atwell...

Town of Cave

City.

W. O. Proffltt -

Leron Reynolds.

Erwin R. PohL.

V. W. McCoy

H. H. Barlow,

Jr.

Hart County

Creameries.

Town of Horse

Cave.

____.do_.._-___...

D. D. Higgaso

L. M. Wilson. __

Driller

Charley

Downey.

Wilson and

Wilson.

Pall Dean......

Claude Morris

Acme Well

Drillers.

Woods and

Forest .

Henderson

Carpenter.

Malcom

Dillingham.

Francis Wilson.

Tom Walters...

Date

completed

1952

1937

1913

1952

1953

1949

1921

1947

1940

1947

1952

1946

Topographic

situation

...do......

...do......

Sinkhole

plain.

...do......

Side of

hill.

Sinkhole

plain.

...do 

...do..._._

...do......

Side of

valley.

Sinkhole

plain.

-..do......

Sinkhole

plain.

...do......

...do. ._

-_.do,..__.

...do.-_.._

Altitude

above

sea

level i

(feet)

910

770

720

700

750

610

640

620

690

700

630

700

620

680

700

T/pe

DrP

DrP

DrP

Du

DrP

DrP

DrP

DrP

DrP

DrP

DrP

DrP

DrP

Dr

Dr

DrP

DrP

Well

Depth

495

1,350

220

53.4

180

141.0

145

188.8

250

190

128

270

315

265

247

170

Diameter

6

14

6

40

6

6

10

6

8

8

6

6

8

8

8

7

6

1 Altitudes from U.S. Oeol. Survey 7J4-minute topographic quadrangles: Horse Cane, Glasgow North ,
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 23

vicinity of Mammoth Cave National Park Continued

Principal 

water-bearing 

bed

Character of material

L 

L

L

L 

L

L 

L 

L

L 

L

L 

L

L

L 

L 

L 

L

Geologic horizon

Msg 

Msg

Msl

Msl 

Msl

Msl 

Msl 

Msl

Msl 

Msl

Msl 

Msl

Msl

Msl 

Msl 

Msl 

Msl

Depth of casing 

(feet)

20 

None

None 

20

75

114

144

27 

30

Water level

Below 

land 

surface 

(feet)

450 

200

200

50.0 

160

103.6

102.0

220

90

142 

186 

243 

155

Date of measurement

1952

6- 9-53 

1952

6- 4-53

6- 3-53

1941

1940

1947 

1946 

1952 

1946

Type of 

lift

Cy.E

None

Cy.E

None 

Cy, E

None 

Tu, E 

None

Cy, H 

Cy, E

Cy, E

Cy, E 

Tu, E

Tu, E 

Tu, E 

Cy, E 

Cy.E

Capacity 

of 

pump 

(gpm)

12

4.5

35

150 

105

Reported 

yield 

(gpm)

12

300

4.S

35

146

85

H

Use

P

None

D,S

None 

D, S

None 

P 

None

D, S 

P

P 

D,S

In

P 

P 

D, S 

D

Remarks

Oil test well. Plugged at 

200 ft for water well. Caved 

to 160 ft, no water in caved 

hole.

Temperature 60°F.

Temperature 59°F. 

Temperature 58°F.

Temperature 57°F.

Well yields 30 gal and can 

then be pumped dry with 

a hand pump. 

Gas at 285 ft, drilled to 375 

ft ; well plugged to 270 ft 

40 ft drawdown after 5 

days pumping. Temperature 57° F. 

1.5 ft. drawdown after 24 hr 

pumping reported. 

Temperature 5P°F. 

35 ft drawdown after 10 

days pumping reported. 

Temperature 56°F. 

Well has yielded 2 in. 

stream of water continuously for 12 hr. 

Well pumps dry in a few 

minutes. Gas encountered at 450 ft, and 650 

ft; well plugged back to 

170 ft.

Mammoth Cave, and Rhoda.
24 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

TABLE 3. Records of springs in ihc ricinihi

[Character of material: L, limestone; S, sandstone. Geologic horizon: Mgh, Big Clifty Sandstone Member'

public

Spring

S-1,881. 0-303.2

1.884.0-304.7

1,880.9-287.2

1,893.0-283.3

1,893.2-283.7

1,895.5-308.1

1,895.5-311.0

1,902.9-314.2

1,904.8-310.2

1,911.0-320.9

1,913.8-314.1

1.940.7-291.0

1.94(1.1-330.2

1,954.0-307.9

1, 955. 1-281.0

Owner or name

Natl. 1'ark Service .

.....do.....

._ .do. -- .

Willie Doyle

... .do.. _ Natl. Park Service

... _do_ 

_ .do.... _

._ .do......

Floyd Coll ins Crystal

Cave.

John Buckingham

villo Railroad Co.

Mrs. H. B. Thomas..

Salem Baptist Church.

Type of

spring

. .do .

_do 

___do .

.do ..

_do ...

do.. ..

do.....

...do .

_ .do... ._-

.do - _

-.do .. -

.do.......

. do ...

--.do..... .

Topographic

situation

Base of MutT-. ._._

hole.

do...

Bottom ofsinkliole.

Side of sinkhole _

Sideofvallev ...

do....- .

.do 

. -do... .... -- -

Bascofhlufl.

Side of valley- .. -

Bottom of sinkhole.

Altitude

above

sea

level i

(feet)

430

430

000

450

500

420

425

740

738

430

795

020

Principal waterbearing bed

Cl aracter

of

material

L

L

I,

L

L

L

L

L

L

s

L

S

L

L

L

L

Geologic

horizon

Msg

ATcrr

]VTcpMsg

Msg

Msg

Msg

Mgh

Mgb

Msl

Mgb

Msl

jVTcpr

Msl

Msl

1 Altitudes from U.S. Qcol. Survey 7}i-minutc topographic quadrangles: Horse Cave, Glasgow North,
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 25

of Mammoth Cave National Park

Mgh, Hancy Limestone Member; Msg, Ste. Genevicve Limestone; Msl, St. Louis Limestone. Use: P, 

supply]

Improvements

lecting pond.

None. __ _ 

None. _ _____

Enclosure, reservoir pumps.

_____do.__ ______

None. __ _ _..

Pump, _ _____

Dam, pumps, 

walks.

Dependability

____ do__..___

___ .do . ...

_____do. . _.

Never dry 

.... do_... ..

Never dry. _

Never dry. _

Yield: 

Estimated 

rate of 

flow 

(gpni)

50, 000

25, 000

10, 000

50

100

 400 

300

900 

300

100-30, 000 

1

200-500 

8,000

35,000

Date of 

estimate

5-18-53

4-30-53

5-29-53

5- 7-53

5-2G-53

5-20-53

(i- 1-53 

...do.

4-29-53 

.. do

0-14-59 

5- 6-53

4-26-51 

5-27-53

5-28-53

Use

1' 

P

1'

None 

None

None

Temperature (°F)

58

5G

56

55

59

50

50 

56

55 

55

55 

54

58

58

Remarks

River.

hole was formerly used to 

turn a floating water wheel 

for a mill.

Outlet for Echo River. 

Outlet for Styx River.

Source of public water supply 

for Mammoth Cave National Park. Inadequate 

during dry summers. 

Source of supplemental public

water supply for Mammoth 

Cave National Park during 

dry weather.

No longer used by railroad.

Former source of public water 

supply for Horse Cave. 

Abandoned boca.uso of fecal 

pollution.

Mammoth Cave, and Rhoda.
86°10' 86°00

37°10' -

37-05'h

Observ

equipped 

'Echo \River outlet 

GREEN RIVER FERRY

Base map from Kentucky Dept. of Highways

FIGURE 10. Location of wells, springs, and dye tests in th
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 27

PALEOZOIC ERA 

MISSISSIPPIAN SYSTEM

OSAGE SERIES 

Fort Payne Formation

The Fort Payne Formation, the oldest rock exposed, underlies the 

entire area and is about 150 feet thick. In its outcrop area to the 

south and east, the Fort Payne consists of alternating impur? limestone and shale and extensive beds of chert. The formation ranges 

in color from light to dark gray. The limestone is mostly medium 

crystalline and light gray. In many localities it is silty and grades 

into calcareous shale. The chert is blocky and light bluish gray. 

The formation weathers slowly to a medium gray, and the b°,ds of 

chert, and siltstone form small resistant benches on hill slopes. In the 

area in which it crops out, good exposures are numerous.

In the report area, the Fort Payne is not known to yield water to 

wells. Farther to the south it yields small amounts of water to 

domestic wells and supplies small springs that are suitable for stock 

and domestic use. In general, the resistant beds of shale and siltstone 

prevent rapid downward percolation of water, the limestone b°ds are 

neither thick enough nor soluble enough to have large solution conduits 

formed. The importance of the Fort Payne in the perimeter of the 

Mammoth Cave region is that on the south and west, it and th° overlying Warsaw Limestone of Meramec age form a relatively insoluble 

base level below which the solution action that prevails in the higher 

limestone formations cannot persist. Accordingly, in the areas in 

which the Fort Payne Formation is close to the surface, drainage is 

conducted by normal streams.

MERAMEC SERIES 

Warsaw Limestone

The Warsaw Limestone is about 100 feet thick in this area. It 

consists of medium- to coarse-crystalline medium- to dark-gray limestone and interbeclded shale. In some places the limestone grades into 

siltstone or a silty limestone. Numerous geodes, in many localities 

and at several horizons, are characteristic of the formation. It is 

moderately resistant to weathering and supports steep slopes Exposures are good in many places. The residual soil developed on the 

Warsaw is generally a reddish silty clay. Geodes generally are 

numerous in the soil.

In the southern and eastern part of the Mammoth Cave area where 

it is exposed at the surface, the Warsaw Limestone is not a good source 

of water. Although south of this area it yields domestic supplies to 

wells and springs, no large supplies are obtained from it. No effort 

was made to inventory all the wells in the area, and it is presumed that
28 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

North

Haney Limestone Member

of Golconda Fm 

Mammoth Cave plateau

Spring horizon^/^r^ii 

Perched water table

1 South 

Big Clifty Sandstone Member

of Golcondc Fm 

Spring horizon

FIGURE 11. Diagrammatic section through the Mammoth Cave plateau.

some wells obtain water from the Warsaw. It is important to the 

hydrology of the region because it generally is much less soluble than 

the St. Louis Limestone that overlies it. The surface streams in the 

southern and eastern part of the area flow on the upp°r part of the 

Warsaw. Near the point where they flow onto the St. Louis Limestone, they enter large cavernous passageways and flow underground. 

A few sinkholes are developed in the Warsaw, but the rreas of major 

sinkhole development are those that are underlain by younger 

formations.

St. Louis Limestone

The St. Louis Limestone is about 300 feet thick in the Mammoth 

Cave area. It is composed predominantly of relatively pure limestone. The upper part ranges from lithographic to medium-crystalline light-gray limestone. The lower part is very fine crystalline and 

gray to black. Both parts contain abundant chert and a few thin 

shale layers. The limestone weathers to a bright red clay containing 

numerous blocks of chert. The St. Louis Limestone underlies the
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 29

| 84

406

408 

 410 

412 

414 

416 

418 

420

422

40

lL 3° 

= £20 

¥ = 

^> 10 «H 

CJ

0 

- 20

Union City well

Chaumont well I 

FIGURE 12. Hydrographs of wells at CCC No. 2, Union City, 

Chaumont, and Green River at Mammoth Cave Ferry ; and 

precipitation. Mammoth Cave area, 1953-57.
395.15'DEPTH TO WATER AT PEAK

Green River at Mammoth Cave Ferry

Oblique line shows period 

 »-, /during which the indicated 

/-|H / precipitation accumulated

Li/-1___ I I I L

12 14 16 18 20 22 24 26 28 

FIGURE 13. Relationship between water level in wells at CCC No. 2 and Union C

Spring at outlets, stage of Green River at Mammoth Cave Ferry, and pr

February 18, 1954.
-

-

-

1

Greenburg

Mammoth Cave

 _ 

1 1

X

Oblique line shows period 

during which the indicated 

precipitation accumulated^

1

 1

I I 

River Styx at outletV

reen R

FIO.UKK 14. Relationship between stage of River Styx Spring at outlet, st

Ferry, and precipitation at Greensburg and Mammoth Cave, 
32 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

18 20 22 24 

JANUARY

26 28 

EXPLANATION

30 2 

FEBRUARY

CHLORIDE CONCENTRATION 

River Styx at outlet

A

Echo River at outlet 

Green River at Mammoth Cave Ferry

DIRECTION OF FLOW IN RIO STYX

!

Into Mammoth Cave

I 

Out of Mammoth Cave

No observable flow

FIGURE lo. Relationship between stage of River Styx Spring at outlet and stage 

of Green River at Mammoth Cave Ferry; relationship between chloride concentration and stage in Echo River, River Styx, and Green Fiver; and precipitation at Mammoth Cave, January 18 to February 6, 195").

entire area of investigation, but it crops out only on the Pennyroyal 

plain. Exposures are rare because it is not resistant to weathering. 

The St. Louis Limestone is the main water-bearing formation for 

that, part of the area lying in the Pennyroyal plain south of the Dripping Springs escarpment. The upper part is especially soluble and 

cavernous. All the wells inventoried in the Pennyroyal plain probably derive their water from the St. Louis, and the wells having the 

largest yields are in the St. Louis. A well owned by the city of Horse 

Cave (S-1,953.7-307.0) had a reported yield of 146 gpm (gallons per 

minute), and a Cave City municipal well (S-1,939.1-293.8) had a 

reported yield of 300 gpm. In addition, there are large flows from 

several springs in the St. Louis. The flow of Hidden River Spring
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 33

Mammoth Cave

Greensburg

Oblique line shows period 

during which the indicated 

precipitation accumulated

22 24 25 

DECEMBER 1958

FIGURE 16. Effect of precipitation at Mammoth Cave on stage of River 

Styx and Echo River Springs and of Green River at Mammoth Cave 

Ferry, December 21-27,1958.

(S-1,954.6-307.9) in Hidden River Cave, near Horse Cave, was estimated to be 35,000 gpm when visited, and a spring owned by the L & N 

Railroad (S-1,940.7-291.6) is reported to yield a minimum flow of 200 

gpm. In the southern part of the area, several streams flow northward on the upper part of the Warsaw and the lower part of the St. 

Louis for short distances, but all sink into underground channels before 

reaching the Dripping Springs escarpment. The network of solution 

channels in the St. Louis is so large that, even after heavy rains, all 

water drains underground in a few hours. There is little or no filtering action through these caverns, and the water carries a considerable 

amount of sediment; nearly all the wells in the area were reported to 

yield turbid water after heavy rains. Hidden River Spring, which 

is in the St. Louis, discharges several thousand gallons of water per 

minute after heavy rains (table 3) and at such times is turbid.

The chemical quality of samples of water obtained from the St. Louis 

Limestone is shown in table 4.

Ste. Genevieve Limestone

The Ste. Genevieve Limestone is about 180 feet thick in this area. 

It consists of relatively pure oolitic finely crystalline limestone, occasional shale partings, and abundant chert. Crossbeclding is common 

in the granular and oolitic beds. It ranges in color from nearly white 

or light gray to bluish gray and weathers to form a rusty-brown to
34 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

TABLE 4. Chemical analyses of water from wells, springs and the

[Results by U.S. Geol. Survey

Well or spring

3-1,879.9-295.0 

1,881.0-303.2

1,882.2-297.1

1,884.0-304.7 

1,886.9-287.2 

1,893.0-283.3

1,895.5-308.1 

1,895.5-308.1

1,895.5-311.0

1,895.5-311.0

1,902.9-314.2 

1,909.0-285.1

Owner or name

Natl. Park 

Service.

-_-__do___._____

_____ do. ..._____ 

Willie Doyle. _

Natl. Park 

Service.

._ __do_._-- __

_____do___._____ 

... -_do.-_---.

 do... ._ _._

Diamond 

Caverns.

Depth 

of well 

(feet)

22.8 

Spring

Spring 

Spring

Spring 

Spring

Spring

Spring 

251

Waterbearing 

formation

Big Clifty 

Sandstone 

Member of 

Qolconda 

Fm. 

Ste. Genevieve 

Limestone.

... ..do ..

____. do. _______ 

--.do... ._

_____ do. _______

-___. do.. -.____

_.___do______._

.-..do. ... 

- do_._-_._

Genevieve 

Limestone.

Haney 

Limestone 

Member.

St. Louis 

Limestone.

Date of 

collection

5- 5-53

5-18-53

11- 4-58 5-20-59 

5- 1-53 

11- 4-58 1-24-59 

1-29-59 

5-29-53 

5- 7-53 

5-26-53 

11- 4-58 3-28-59 

6- 1-53 

8-29-55 

11-11-55 3- 7-56 

6-12-56 

9-25-56 

5- 7-57 

8-13-57 

11-12-57 2-25-58 

5-27-58 

8-20-58 

11- 3-58 1-22-59 

1-23-59 

1-24-59 

1-25-59 

1-28-59 

1-29-59 

3-20-59 

3 26-59 4- 7-59 

5-20-59 

5-18-53 

6- 1-53 

11- 3-58 1-22-59 

1-23-59 

(12:50 p.m.) 1-23-59 

(4:15 p.m.) 1-24-59 

1-25-59 

1-28-59 

1-29-59 

3-26-59 

4- 7-59 

5-20-59 

6-20-51 

10- 4-57 

2-20-58 

2- 2-59 

4-28-59 

5-13-53

Temperature (°F)

54

58

57 

63 

57

57

52 

56 

55 

59 

57 

55 

56 

57 

61 

56 

55

55 

56

52 

55 

57

56 

54 

54 

47 

48 

51 

51 

54

54 

55 

56 

59 

59 

54 

52

50

4f> 

43

45.5

55 

54 

58

48 

54 

58

Parts per million

Silica )(Si02

12 

6.8

6.9

7.9 

9.5 

8.5

8.0

8.0

6.6 

7.8

9.8

7.6

"a?

fe

ao

kri I <

0.47 

3.4

2.0

.29 

.02 

.40

.01

.22 

.26

.08

.05

.03

.09

.14

.12

.12

.00

.09 

.50

.01

.10

.06

.00

1.8 

.41

.01

.16 

.04

.09

.40

.47

(Mn) Manganese 

0.00 

.00

.00

.00 

.00 

.00

.00

.06

.00 

.06

______

.00

Calcium (Ca)

6.4 

32

56 

42

34

25 

48

43

43

37 

31

42

38 

24

50

See footnotes at end of table.
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 35

Green River in the vicinity of Mammoth Cave National Park 

unless otherwise specified]

Parts per million Continued

(Mg) Magnesium 

3.9 

3.9

13 

4.9

3.4 

1.5 

8.3

3.9

3.4

3.8 

2.9 

4.4

3.7 

1.9

15

'c?

£

|

3co

39 

1.4

100 

3.5

.8 

1.2 

5.0

1.2

1.2

1.2 

1.2 

1.7

1.8 

1.5

1.5

g

6 

.3

1 

o

PH

2.2 

1.1

1.2

.5 

.5 

.6

1.0

.5

"i.~2~

.7

~i.T

.8

0

a W

<U "o

§1o 

«

8

104

238 

130 

140 

246 

136 

151 

112 

78 

170 

273 

180 

140 

174 

150 

126 

139 

124 

127 

144 

148 

137 

139 

156 

154 

118 

130 

84 

91 

122 

133 

126 

122 

118 

125 

102 

140 

134 

116 

115

110

93 

82 

110 

114 

140 

106 

125 

84 

126 

55 

48 

44 

222

6 

o

<U

as

§ & 

% 

O

0

0

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

o

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0

0

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0

6 

£

 S"3

co

12

11

14 

16 

8.4 

12 

6.0 

7.2 

8.1 

8.2 

8.9 

20 

10 

8.2 

10 

11 

7.2 

16 

6.0 

6.8 

9.6 

13 

7.2 

7.0 

7.2 

7.2 

5.2 

6.0 

10 

11 

8.0 

7.6 

7.8 

8.4 

10 

7.6 

4.9 

10 

11 

6.6 

7.2

7.2

11 

12 

11 

14 

13 

16 

3.2 

1.6 

4.6 

1.4 

2.0 

2.6 

3.6

3

5 12 

a

65

1.9

61 

215 

5.8 

22 

1.6 

5.0 

1.0 

1.2 

9.0 

48 

19 

1.5 

4.0 

1.5 

2.2 

2.0 

3.0 

1.5 

3.0 

5.0 

2.0 

2.0 

1.0 

2.5 

3.0 

5.4 

15 

14 

25 

33 

12 

7.0 

44 

1.0 

1.1 

2.0 

25 

5.0 

8.0

9.6

15 

22 

82 

98 

73 

142 

3.5 

1.2 

3.0 

4.0 

1.0 

.0 

1.1

£

5 ga

s

0.0 

.0

.1

.0.1

.1

.0.1 .1 .1

.0 

.2.1 .1

.0 

.2 

.1 

.1 

.1 

.1 

.1 

.1 

.1

.1 

.1 

.1

.1 

.1 

.2

.1 

.1

.0 

.1 

.2 

.0 

.0 

.0

6 fc

<o "o 

£

g

8.6

3.7 

4.4

4.0 

5.9

1.5 

.5 

6.6 

5.4 

5.6 

3.6 

4.4 

4.2 

2.5 

1.0 

1.7 

1.2 

2.4 

3.6 

2.4 

2.3 

2.6 

1.8

2.2 

1.7 

.9

2.8 

3.3 

1.8

2.1 

1.6

.8 

.5 

.4 

.1 

.3 

2.4

ao 

a 

eg c5 

« Q, 

3£"5 (o

9 a *!? t> So 322

1 S« a £ o

Q

171 

124

155

111

85 

177

137

136

117 

139

-- 

83

"i9l"

Hardness as 

CaCOs

0 

.3'55

d a> la IB

a

32

96

231 

193 

126 

224 

123 

138 

98 

68 

154 

264 

166 

124 

153 

134 

106 

121 

110 

115 

133 

136 

118 

121 

134 

130 

109 

114 

86 

88 

127 

131 

114 

108 

119 

108 

90 

122 

125 

105 

109

104

100 

89 

136 

151 

153 

149 

110 

68 

99 

37 

40 

35 

186

"5 

a

o &%

1

fc

36

86

"22" 

12 

14

16" 

18

"16" 

11 

3 

7 

8 

11 

15 

12 

6 

7 

6 

4 

12 

8 

17 

14 

27 

22 

11 

8 

22 

6

"is"

10 

15

14

24 

22 

46 

58 

38 

62 

8

"6"

0

i

0

Specific conductance 

(micromhos 25° C) at

282

194

575 

924 

264 

465 

238 

276 

196 

146 

316 

598 

363 

248 

301 

263 

214 

236 

215 

220 

258 

280 

236 

235 

261 

257 

211 

230 

206 

210 

296 

340 

251 

230 

351 

209 

187 

248 

277 

208 

228

226

218 

235 

476 

534 

481 

665 

219 

145 

201 

93 

87 

81 

346

M 

c.

6.2

6.9

7.2 

7.9 

7.2 

7.1 

7.1 

7.2 

7.3 

7.6 

7.4 

7.0 

7.3 

7.5 

7.4 

7.3 

7.5 

8.2 

6.8 

7.3 

7.4 

8.3 

8.0 

7.4 

7.8 

7.4 

7.0 

6.9 

7.0 

7.0 

7.3 

7.6 

7.8 

7.5 

7.7 

7.9 

7.4 

7.6 

7.5 

6.9 

7.0

7.1

7.0 

6.9 

7.1 

7.6 

7.4 

7.5 

7.9 

7.8 

7.5 

8.2 

7.1 

6.3 

7.7

Color i

16? 

45

""is"

5 

3 

5

"~4~

-----

...-.

3

 -

 --

"l7" 

5

.....

2 

-...-

Remarks

Sample affected 

by local rains.

To. 

To. 

Io.

Sample affected 

by local rains.
36 HYDROLOGY, CAVERNOUS LIMESTONES. MAMMOTH C/VE AREA, KY. 

TABLE 4. Chemical analyses of water from wells, springs, and the

Well or spring

3-1,909.5-297.6

1,910.2-320.1

1,913.4-270.9

1,939.2-293.8

1,940.7-291.6

1, 946.1-330.2

1,947.0-317.7

1,953.4-307.4 

1,953.7-307.0

1,954.6-307.9

Owner or name

Natl. Park

Service.

Floyd Collins

Crystal

Cave.

W. L.

Gardner.

Town of Cave

City.

Louisville <fr

Nashville

Railroad

Co.

J. L. Garvin.,

E. R. Pohl -

IHorse Cave 

I Water Co.

Mrs. II. B.

Thomas.

Green River

at Munfordville.

Depth

of well

(feet)

500

422

225

240

Spring

Spring

250

1 265 

\ 315

Spring

River

Waterbearing

formation

Ste.

Genevieve

Limestone.

do

St. Louis

Limestone.

- do --

.-- .do ---

Ste. Genevieve limestone.

St. Louis

limestone.

}_ do -----

.--.-do -----

Date of

collection

5-21-53

4- 7-59

5-12-53

6-14-51

4-20-51

10- 8-57

4-26-51

5 -27-53

11- 5-58

5-28-53

6-14-51

5-28-53

May 11-20,

1953 2

Sept. 21-30,

19532

10- 8-57 3

5-19-59 2

°^

<L>

3

ta t-.

C,

c

H

58

59

60

59

58

58

52

58

56

58

62

62

Parts per million

O

5

a

ix

9.5

9.0

9.5

12

9.1

8.9

8.4

9.9

9.1

12

8.8

fe^

o

^

0.68

1.0

.28

.20

1.7

.00

.17

.41

.40

.27

.24

.03

.04

.10

"3

2.

0

a

a

^

0.02

.00

.00

.00

.00

'c?

o

6

3

"3

O

42

34

72

86

50

51

41

55

51

30

50

67

1 Color units based on platinum-colbalt scale of Hazen (1892, p. 427-428).

2 Collected at gaging station at bridge on U.S. Highway 31W.

3 Collected 3,000 ft downstream from intake.
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 37

Green River in the vicinity of Mammoth Cave National Park Continued

Parts per million Continued

"So

"i3

a 

1

22

14

16

27

6.8

6.8

25

16

8.3

5.3

8.8

18

*a

e3

 3

o 

co

8.0

1.6

1.9

8.1

1.2

4.3

.9

10

2.2

2.9

8.1

192

_3

1

o

.9

.7

.9

.4

1.1

.8

.5

2.6

.6

1.2

1.4

 --

6

o

bonate (

1

5

168

156

130

194

232

243

182

172

260

244

210

176

105

174

154

116

6

o

03 

§

 e

3

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

6

co

o

"3

CO

54

44

32

85

139

166

4.4

12

14

4.4

31

10

12

16

14

19

O 

I

o

6

12

2.0

1.1

3.0

8.0

">.

7.0

14

.8

10

3.2

2.5

12

12

380

£

"3

o 

j3

1.3

1.4

.6

.4

1.0

.9

.1

.1

.2

.4

.8

.1

.0

.1

.1

0

0

'03

.0

.1

2.2

2.9

.1

.1

9.7

8.3

5.8

.6

4.1

10

3.2

1.5

.9

§

s co o

W 03 a >

Ived solidue one

.80° C

°'g« 

X ^

256

179

295

421

167

183

190

246

182

119

194

Hardness as

CaCOs

um 

*nesium

11 

O

196

166

140

246

326

365

154

156

229

204

202

162

96

161

140

241

arbonatc

1

....

00

86

135

166

4

16

....

31

 .

__

14

146

O

ftCO 

"o 03

fie condu :cromhos

gs 

ST

407

329

277

464

614

688

295

325

458

370

422

329

200

337

303

1,470

hH

C,

7.3

7.3

7.7

7.7

7.0

7.5

7.2

7.5

7.6

7.8

7.9

7.4

7.3

7.6

8.2

7.7

fe "3

O

13

3

1

1

0

4

2

2

Remarks

Sample affected 

by local rains.

Phosphate

0.02.

f Composite 

\ sample 4 '

2

1

.....

10-day composite sample.

353 ppm suspended matter.

10-day composite sample.

ppm suspended matter.
38 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

bright-red clay. The oolites are abundant, and their presence is one 

of the means of distinguishing the formation from the underlying St. 

Louis Limestone. The Ste. Genevieve Limestone underlies the entire 

Mammoth Cave plateau in the area. It crops out on the sides of sinkholes on the plateau and along the edge of the Dripping Springs 

escarpment (fig. 17).

The Ste. Genevieve Limestone is the major aquifer underlying the 

Mammoth Cave plateau. The greater parts of Mammoth, Crystal, 

and Great Onyx Caves are developed in the Ste. Genevieve and in the

FIGURE 17. Ste. Genevieve Limestone exposed on south side of Cedar Sink, Mammoth Cave National Park. Contact with the overlying Girkin Formation is 

at top of upper right corner. Photograph by W. Ray Scott.
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 39

overlying Girkin Formation which is lithologically similar. The 

large cavernous openings and connected smaller openings serve as conduits for ground-water movement in the area. Six wells in this formation encountered fairly large quantities of water in solution 

openings. The water level in these openings fluctuates rapidly. 

During dry weather and after light summer rains, almost no change in 

the water level occurred; however, during a heavy spring rain, the 

water level rose nearly 20 feet in a day. These variations aro shown 

by the hydrograph of the well at CCC No. 2 (figs. 12,13).

The fe\v wells on the Mammoth Cave plateau that are known to 

have been drilled into the Ste. Genevieve all yielded water, rJthough 

the depth to water was generally 400 feet or more. It is probable that 

wells this deep also penetrate the top of the St. Louis (table 1). A 

short pumping test on Bransford well 1 (S-1,904.8-316.3) showed 18 

feet of drawdown after pumping about 90 minutes at 10 gpm (fig. 18). 

The log of this well is given on following page.

The owners of wells in the Ste. Genevieve reported that the water in 

these wells became turbid after heavy rains. Springs in the area that 

discharge from the same horizon also yielded turbid water after heavy 

rains. No samples of the sediment in the water were taken during the 

investigation.

The chemical quality of samples of water obtained from the Ste. 

Genevieve Limestone is shown in table 4.

0

5

10

15

20

30 

35

 

Rate >f DUmpir g=10gp m

"*.

 .

» 

" .

4

0.1 1 10 100 1000

TIME SINCE PUMPING BEGAN, IN MINUTES 

FIGURE 18. Effect of pumping on water level in Bransford well 1.
40 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

Sample log of Bransford well 1 drilled for National Park Service by Malcolm 

Dillingham, June 1953

[Samples examined and described by author]

Material

Dirt, composed of weathered sandstone, fine to coarse, and

some fine to medium gravel; yellow-brown_______________ 10

Sandstone, fine to coarse, and fine gravel; yellow-brown.____ 5

Sandstone, fine to coarse, and fine gravel; light-gray ________ 7

Sandstone, very fine to medium, light-gray_ _______________ 23

Sandstone, very fine to medium, light-gray; limestone layer

at 45 ft, medium-grained, gray__ _______________________ 3

Limestone, fine- to medium-grained, med um-gray__________ 16

Limestone, fine- to medium-grained, oolitic, light-gray_--_-_- 36 

Limestone, fine- to medium-grained, oolitic, light-gray;

contains pyrite___________________________________ 5

Limestone, medium-grained, medium-gray _________________ 20

Limestone, fine-grained, oolitic, medium-gray. __ ___________ 27

Limestone, fine-grained, medium-gray-____________________ 5

Limestone, fine-grained, oolitic, medium-gray. _____________ 23

Limestone, fine-grained, medium-gray-____________________ 5

Limestone, fine-grained, very oolitic, medium-gray--________ 15

Limestone, fine-grained, medium-gray-____________________ 20

Limestone, fine-grained, very oolitic, medium-gray_______ ___ 20

Limestone, fine-grained, medium-gray. ____________________ 5

Limestone, fine-grained, very oolitic, medium-gray-.________ 5

Limestone, fine-grained, dolomitic, medium-gray______-____- 11

Limestone, very fine-grained, oolitic, medium-gray. Oolites

separate in sample.___________________________________ 78

Limestone, fine-grained, light-gray. ___ ____________________ 6

Limestone, very fine grained to fine-grained, oolitic, mediumirmy. .. _________________________ _ ______________ 5

Sand, unrep'-olidated, very fine to medium, angular, clear,

iruu-oiained, yellow-tan________________________________ 6

Sand, uneonsolidated, very fine to coarse, angular, clear, ironbtained, yello\v-tan____---____-_____-----_______-__-_-_ 6

L mestone, fine-grained, oolitic, medium-gray_______________ 11

Sand, very fine grained to fine-grained, angular, clear, ironstained- _____________________________________________ 5

Limestone, fine-grained, light- to medium-gray. ____________ 22

No samples____________________________________________ 12

Limestone, very fine grained to fine-grained, oolitic, light-gray_ 6 

Sand, very fine to medium, angular to subaiigular, clear,

iron-stained, yellow-tan________________________________ 6

Water encountered in crevices at 60, 317, and 419 ft.

i

Thickness 

(fe.t)

Depth
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 41

CHESTER SERIES 

Girkin Formation

In the report area the Girkin Formation is about 120 feet thick. 

Lithologically, it is very similar to the underlying Ste. Genevieve Limestone. It consists of light-gray limestone ranging in texture from 

coarse to fine crystalline. The lower part of the formation is characterized by oolitic zones and some shale beds. A shale layer is also present 

at the top of the formation in most places (E. R. Pohl, written commun., 1938). It does not contain significant quantities of chert, but it 

does contain spherical clusters of quartz crystals, which are characteristic of the Girkin residuum. The Girkin underlies the Mammoth 

Cave plateau and crops out in the sides of sinkholes and along the face 

of the Dripping Springs escarpment.

Ground water occurs in solution openings in the Girkin Formation. 

In some places this water is perched in small solution depressions 

within the formation, and the water in a given well may remain at 

about, the same depth during most of the year. Many of these 

"perched" bodies have inlet and outlet channels that transmit flow after 

precipitation, but they are dry at other times. In some wells the water 

supply may be only 1 or 2 gallons per day; in others, it may, with 

normal precipitation, be adequate for a domestic supply, although it 

likely will go dry during dry summers. Commonly, none of these 

perched water bodies are adequate for domestic supplies with pressure 

systems installed.

Some wells intercept water that is in a state of transition from one 

level to another. Water entering the upper part of the Girkin, generally from the overlying Big Clifty Sandstone Member of the Golconda 

flows downward toward the water table through solution channels of 

different sizes and shapes. Some of these openings are adequate to 

transmit large quantities of water, but others are so small that the water 

must trickle or drip through. Clogging and opening of these channels 

through changes in the position of rock debris may rapidly affect the 

rate of flow. In addition, siphon tubes at different levels may int ersect 

vertical or gently sloping channels at numerous points. Water levels 

then may fluctuate in the manner shown by the hydrograph of the 

Chaumont well (fig. 12). During the summer, when recharge is negligible, water levels rise gradually. The highest water levels are after 

heavy spring rains, and the lowest, immediately after the sharp rises. 

The more abrupt and the greater the rise, the greater the following 

decline. However, the water level will not fall below a certain limit 

regardless of the rapidity of water-level changes.

Drillers report that water in noticeable quantities may be found at 

numerous levels in the Girkin. In most wells, however, these waterbearing bodies are drilled through in order to reach the larger and more 

dependable supplies available at the Green River level. Little data are
42 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

available concerning yields from these perched water bodies. Most 

domestic wells in the area obtain water from dug wells in the overlying 

Big Clifty, and most commercial wells have been drilled through to 

the Ste. Genevieve. The few domestic wells that may obtain water exclusively from the Girkin are reported adequate for use with a bailer, 

but they are generally inadequate for use with a pressure system. No 

samples of water were taken from wells obtaining water exclusively 

from the Girkin Formation.

Big Clifty Sandstone Member of the Golconda Formation

The Big Clifty Sandstone Member is about 60 feet thick where it 

caps the edge of the Dripping Springs escarpment. It consists of wellindurated medium-grained quartz sand. The surface is iron stained, 

and this color penetrates the rock to some degree. Crossbedding is 

common. The formation is resistant to weathering, and large talus 

blocks are common in the bottoms and along the sides of sinkholes. In 

some places these blocks are so large and apparently ur disturbed that 

they may be mistaken for rocks that are in place. The Big Clifty 

Sandstone Member caps a major part of the Mammoth Cave plateau. 

It crops out in many places on the plateau uplands and along the sides 

of many of the valleys; it also forms the cap of the Dripping Springs 

escarpment.

Most wells on the Mammoth Cave plateau obtain wate^ from the Big 

Clifty. A perched body of water in the formation is supported by a 

relatively impermeable layer of shale at the top of the underlying 

Girkin Formation. The depth from the surface to the water table in 

this perched body of water ranges from about 2 to 20 feet. Yields of 

wells are not large, but dug wells 2-3 feet in diameter yi Q.ld amounts of 

water that are adequate for domestic and stock use. The layer of 

shale is present locally in the underlying Girkin, but it is not continuous at the contact. Where it is absent, water from the Big Clifty 

drains out and recharges the underlying Girkin Formation and Ste. 

Genevieve Limestone. Water also drains near the perimeter of the 

area of outcrop where the water can discharge laterally from the Big 

Clifty on top of^ the Girkin. This drainage toward the perimeter of 

the formation is responsible for the numerous springs that give the 

escarpment its name.

The gradual loss of water from the Big Clifty Sandstone Member 

to the underlying formations is shown in the hydrograph of the 

Union City well (S-l, 906.4-293.3) (figs. 12, 13). When the water 

level in the formation is high, the hydrostatic head forcing the water 

out of the formation is high, and the water drains comparatively 

rapidly into the underlying formations. As the water level drops, the 

hydrostatic head decreases, and the rate of discharge from the Big 

Clifty into the underlying formations decreases proportionally.
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES' 43

Although the quantity of water released to the lower formations is 

relatively insignificant during periods of heavy precipitation, it is 

probably a major source of water during extended dry periods. 

Analyses of water from the Big Clifty Sandstone Member are rliown 

in table 4.

Haney Limestone Member of tlie Golconda Formation

111 the report area the Haney Limestone Member is about 40 feet 

thick. A shale is *it the base of the Haney almost everywhere. Above 

this, the formation is relatively pure limestone, fine to coarse crystalline, and light gray. The limestone is very soluble in ground water 

and is honeycombed with solution channels, but the solution chr.nnels 

in this limestone are much smaller in size than the large caves in the 

lower limestones. The channels, especially well developed in the 

upper part of the formation, continue down to the basal shale. The 

Haney Limestone Member crops out along the south edge of the Green 

River bluffs as far east as Turnhole Bend (Weller, 1927, p. 119) and 

caps several hills on the Mammoth Cave plateau.

No wells that obtained water from the Haney Limestone Member 

were inventoried. Three Springs (S-l, 902.9-314.2), Mammoth Cave 

National Park public water supply, was the only spring inventoried 

that yielded water from this formation; however, there are many seeps 

and springs 011 the basal shale in the formation (Weller, 1927, p. 121). 

Precipitation on the overlying Hardinsburg Sandstone percolates 

downward into the Haney where it enters an extensive network of 

solution channels. When the water reaches the basal shale in the 

Haney, it flows above the shale until it emerges as seeps and springs or 

is lost by evapotranspiration. After heavy rains, Three Springs 

probably discharges as much as 1,000 gpm.

The chemical quality of the water is shown in the analysis of Union 

City well in table 4.

HardinsTaurg1 Sandstone

The Hardinsburg Sandstone has a maximum thickness in the area 

of about 30 feet. It is composed of medium-grained white sandstone 

beds ranging in thickness from 1 inch to 2 feet. They are considerably 

ripple marked, and the surface is stained dark brown by iron oxide. 

The upper and lower parts of the formation are shaly and in places 

relatively impervious to wr ater.

The Hardinsburg crops out only on the tops of a few hills in the 

area and in a narrow strip along the south side of the Green River 

westward from the vicinity of Turnhole Bend (Weller, 1927, p. 125).

The water body in the formation is perched, being supported by 

the shale zones at the base. Depths to water are shallow, and wells 

in the formation are dug wells, of large diameter, used for domestic 

and stock supplies. Inasmuch as the Hardinsburg Sandstone and Big
44 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

Clifty Sandstone Member of the Golconda Formation are lithologically similar, water in the Hardinsburg probably fluctuates in much 

the same way as it does in the Big Clifty. Vertical drainage from 

the Hardinsburg furnishes water to the underlying Haney Limestone 

Member.

Glen Dean Limestone

The Glen Dean Limestone has a maximum thickness of about 60 

feet. In the central part of the national park area pre-Pennsylvanian 

erosion has removed the formation in many places. The Glen Dean 

is predominantly evenly bedded limestone, fine to corrse crystalline, 

and uniformly gray. A discontinuous layer of shale is at the base of 

the formation. The Glen Dean crops out on the top of Flint Ridge 

in two small areas, and is exposed west from Turnhole Bend on the top 

of the bluffs along the Green River.

Some springs are reported to issue from the base of the formation in 

the western part of the area where it attains its full thickness; however, 

in the eastern part of the area it is thin, discontinuous, and unimportant 

as an aquifer.

No wells that obtained water from the Glen Dean Limestone were 

inventoried.

Leitcnfield Formation

The uppermost unit of the Chester Group is the Leitchfield Formation. In this area it consists predominantly of shale but contains some 

limestone and sandstone members. It has been eroded from most of 

the area south of the Green River in the national parV, and its thickness here was not determined. Weller (1927, p. 140) assigns a maximum thickness of 125 feet to the formation near the Grayson County 

line. It is progressively thinner southward and was removed by 

pre-Pennsylvanian erosion throughout most of the park.

The Leitchfield Formation is relatively impermeable. It probably yields only small quantities of water to wells in its areas of maximum thickness, and in the park area no wells are known to penetrate 

the formation.

PENNSYLVANIAN SYSTEM

Caseyville Formation

The Caseyville Formation of the Pennsylvania!! Sye^ein overlies the 

Leitchfield Formation in the national park. It consists of thickbedded sandstone and has a coarse pebble conglomerate at the base. 

Sandy shale is interbedded with the sandstone at some localities. The 

formation is thin and discontinuous on the south side of the Green 

River. It is, therefore, not important as a source of water or of 

recharge or discharge.

Rocks of Pennsylvania!! age are the youngest consolidated rocks 

exposed in the Mammoth Cave area.
GEOLOGIC FORMATIONS AND THEIR WATER-BEARING PROPERTIES 45

CENOZOIC ERA 

QUATEKNARY SYSTEM

PLEISTOCENE AND RECENT DEPOSITS

Iii the Green River valley, deposits of sand and gravel of Pleistocene 

and Recent ages have a maximum reported thickness of 80 feet (unpub. 

rept, on Mining City Dam Site, U.S. Corps of Engineers). Weller 

(1927, p. 170) reports river terraces 6-8 feet above the level of the 

present flood plain and gravel in Warren County to the west that is 

60 feet above the present river level. According to Weller (1927, 

p. 171)

Some alluvial material is present along the courses of all of the small streams 

in Edmondson County, but flood plains or valley flats are absent except along 

Green and Nolin Rivers and Bear and Reedy Creeks where typical flood plains 

are develoi>ed. Due to the steep V-shape of the valley they are in most places 

quite narrow and are not uncommonly present upon only one side of the stream. 

These deposits are composed of silts and muds with the admixture of a considerable amount of sand. In contrast to this, the alluvium of the smaller 

tributaries is more sandy and contains both angular and rounded pebbles derived 

from the immediately adjacent formations.

In addition, there are extensive deposits of sand and silt and some 

gravel in the cave passageways. The maximum thickness of this fill 

is not known, but thicknesses of more than 30 feet have been reported 

(E. R. Pohl, written commim., 1938). In some places the material is 

predominantly sand derived from the overlying Big Clifty Sandstone 

Member. In other places there are considerable thicknesses of gravel 

derived from weathering of the Caseyville Formation of the Pennsylvanian System and from the high-level gravel deposits of Pleistocene 

age. The predominating deposits are composed of silt and clay that 

was left as insoluble residue from the solution of limestone. Most of 

the deposits have been reworked many times, and in some places they 

show evidence of deposition from rapidly moving water. During 

floods much of the material in the lower passages is reworked and 

recleposited; thus, some of the material is residual, some is from the 

Green River, and some is derived from the surfaces of the Mammoth 

Cave plateau and the Pennyroyal plain.

The deposits of Pleistocene and Recent ages are an important key 

to understanding the physiographic history of the region. Terrace 

deposits on the streams indicate different stream levels during Pleistocene time, and accurate elating of these and of the silt deposits in the 

cave may lead to further refinement of the knowledge of physiographic 

processes during Pleistocene time.

The deposits of Pleistocene and Recent ages in the smaller tributary 

streams cover small areas, and are so thin as to be relatively unimportant as a source of water. The deposits in the flood plains of the Green 

and Nolin Rivers, are relatively thick, but they are composed chiefly 

of fine-grained material that will yield little or no water to wells.
46 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

However, it is possible that lenses of sand and gravel locally may yield 

moderate to large amounts of water. A well in alluvium near the 

Green River at Brownsville, about 5 miles downstream from the 

Mammoth Cave area, is reported to yield 77 gpm; this wrter is used for 

the public supply.

The greatest hydrologic significance of the Pleistocene and Recent 

deposits is the control that they have on the movement and storage of 

water in the area. During periods of flood, large quantities of water 

are stored in the alluvial deposits along the banks of the streams and 

in the silt and sand deposits in the caves. This water is discharged 

slowly over many weeks and helps to maintain a more constant discharge of ground water. In addition, silt barriers in the solution 

channels in the caves impede the movement of water through the 

caverns and particularly impede the flow through minute crevices and 

fractures in the limestone. Some of the silt barriers in the large caverns of the cave are tens of feet across. These barriers form ponds 

containing large quantities of water during the summer and fall, when 

recharge into the cave passageways is relatively small.

GENERAL HYDROLOGIC CONDITIONS

The average annual runoff in the Green River basin above the gage 

at the Mammoth Cave Ferry is about 19 inches; the average annual 

precipitation is 48 inches. The average annual loss by evaporation 

and transpiration is about 29 inches. Drainage divides in a cavernous 

limestone area may not be coincident with topographic divides, and, 

therefore, the above figures, based on topographic drrinage divides, 

may be in error. In general, within the park area, water north of the 

Green River flows in surface streams, and water south of the Green 

River follows subsurface drainage patterns.

South of the river, ground water moves from the Pennyroyal plain 

northwestward to the Green River. Streams flow in tHs direction to 

within li/o miles of the Dripping Springs escarpment, then disappear 

under the surface and flow from that point to the Green River as subsurface streams. A piezometric surface, continuous with the level of 

the Green River and intersecting the surface of such underground 

streams as the Echo River and River Styx, probably exists throughout 

the area investigated. The surface of the water observed in the deeper 

sinks, such as Mill Hole and Cedar Sink, may be continuous with this 

piezometric surface. Below this surface all openings in the rocks are 

saturated. Because soluble limestone underlies this surface throughout 

the area, the openings are connected solution cavities through which 

considerable ground water can move at relatively high velocities.

Recharge to the lower ground-water body probably comes from 

several sources: (1) the sinking streams that flowT towards the Dripping Springs escarpment on the surface of the Pennyroyal plain and 

disappear into sinkholes before they reach the escarpment; (2) local
GENERAL HYDROLOGIC CONDITIONS 47

precipitation on the Mammoth Cave plateau, which goes rapidly underground through sinkholes or percolates slowly downward through the 

overlying formations; and (3) recharge from the Green River, especially in time of flood, through solution cavities, such as River Styx, 

that are connected to the river.

Lying above this main ground-water body are several perched water 

bodies. Each of these is recharged by local precipitation in outcrop 

areas and by downward percolation from overlying formations. In 

the sandstone formations the water bodieb are nearly continuous 

through the formation; in the limestone formations they are probably 

discontinuous.

Discharge from the lower ground-water body is generally through 

springs that discharge into the Green River. There may be many 

springs in the bottom of the Green River that discharge large quantities of water. Six springs that discharge near the level of the Green 

River probably are the main source of discharge from the area. From 

southwest to northeast these springs are: Tumhole (S-1,881.0-303.2), 

Sand Cave (S-1,884.<)-30-L7), Echo River (S-1,895.5-308.1) (fig. 19),

FIGURE 19. Outlet of Echo River. The spring discharge, generally more than 

100 gpm. appears small because the flow issues from a cavern about 3 feet 

below the water surface. Increased discharge following heavy rain causes 

rolling boils. Photograph by W. Ray Scott.
48 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

River Styx (8-1,895.5-311.0) (tig. 20), Pike (S-1,911.0-320.9), and 

Garvin (S-1,946.1-330.2).

The exact area that these springs drain is not known. Cedar Spring 

Valley, Woolsey Valley, and most of the streams on the western part 

of the Pennyroyal plain may discharge through the Turnliole and, to 

a lesser extent, through Sand dive Spring. Probably most of the 

water from Doyel Valley, some of Honchens Valley, and Bruce Hollow, 

as well as some of the precipitation on Mammoth Cave Ridge, discharges from the Echo River and River Styx. These streams have 

been observed underground in Mammoth Cave and the New Discovery, 

which underlies Jim Lee Ridge. Dye tests made by the Louisville 

Gas & Electric Co. in L!)^l and 15)25 provide additional information 

on underground flow. The tests are described by R. B. Anderson 

(uiipub. rept., 1925). During the tests, dye was introduced at several 

points to determine the direction of underground drainage. Dye 

introduced at Three Springs ((> on Hg. 10), the present (1959) source 

of water for Mammoth Cave Hotel and the national park installations,

Fir.ruK :_'<). Out Id of River Styx. Shift" gage shown at lower left. Exposed 

nick is lower part of Ste. (Jcnevieve Limestone. During periods of very high 

tlmv the cavern is completely tilled with water. High stage in the Green 

Iliver combined with a low stage in River Styx causes a reversal in flow from 

the (Jreen River into Mammoth Cave. Presumably, this water discharges 

downstream at Echo River Spring or possibly at Turnliole Keiid. Photograph 

by W. Rav Scott.
GENERAL HTDROLOGIC CONDITIONS 49

discharged from the Echo River 15 hours after it was introduced. 

According to the report, the dye was ''pushed through rapidly by rain. 

River Styx [was] flowing in [backward from the Green River into 

Mammoth Cave] at time dye came out; otherwise it would, no doubt, 

have come out there.' 1

Water flowing under Flint Ridge and probably under part of Hamilton and Houchens Valleys discharges from Pike Spring. The solution channels underlying Flint Ridge, including large water-filed 

channels that connect with Pike Spring, are being mapped by the Cave 

Research Foundation. The extent of this system is as yet not known, 

but more than 35 miles of passage have been mapped. The Louisville 

Gas & Electric Co. dye tests provide some information on the areas 

of recharge contributing to some of the springs. The approximate 

area included in these tests, the locations of the points where dye was 

introduced, and the discharge points are shown in figure 10. Dye 

introduced at Bransford Spring (4) discharged from Pike Spring in 

48 hours; dye introduced in the river in Colossal Cave (1) discharged 

from Pike Spring in 192 hours; dye introduced in Upper Branch, 

Colossal Cave (5), discharged from Pike Spring in 168 hours; dye 

introduced in Vaughns Dome (7) and Colossal Dome (8) of Colossal 

Cave discharged from Pike Spring in 60 and -15 hours, respectively. 

The lowest altitude at. which dye was introduced was 640 feet.

Sand Cave and Garvin Springs and numerous small springs along 

the south side of the Green River have not been examined in as much 

detail. Except that many of the springs discharge tremendous quantities of water, almost nothing is known about them. Some may be 

outlets for part of the water that flows from the Green River into 

River Styx; others are almost certainly outlets for drainage from large 

areas of the Pennyroyal plain and Mammoth Cave plateau.

FLUCTUATIONS OF WATER LEVELS AND UNDERGROUND-FLOW

RELATIONSHIPS

Fluctuations of water levels under the Mammoth Cave plateau were 

determined by measuring depths to water in selected wells and reading 

gage heights of water levels in streams inside the cave. Continuous 

recording gages were installed on Union City, Chaumont, and CCC 

No. 2 wells during May 1953. Continuous records of water-level 

fluctuations in the wells have been kept since that time. Staff gages 

were installed at River Hall (sometimes called River Styx) and Roaring River inside the cave and at the outlets of River Styx and Echo 

River in May 1953 by the Surface Water Branch, U.S. Geological 

Survey. (See fig. '21.)

The two staff gages inside the cave were read once daily by the 

National Park Service personnel from July 1953 to January 1954. 

Otherwise, only an occasional reading was made. However, a record-
50 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

ing bubble gage was installed on February 20, 1958, to obtain a continuous stage record of Echo River in the cave. The recording point 

(gage orifice) is located in Dead Sea, and above a stage of about 20 

feet the sea is known to be connected with the Echo River through 

River Styx. No discharge measurements are available at gages in the 

cave.

Gage-height readings of the two outlet gages, River Styx and Echo 

River, are generally complete since installation. The Ground Water 

Branch installed a recording gage on Echo River outlet in September 

1959 and on River Styx outlet in October 1959. Discharge measurements made by both branches are available in most years beginning in 

1953. Those made by the Surface Water Branch ?,re published as 

miscellaneous measurements in the annual water-supply paper. No 

records of stage or daily discharge of the two outlets is published.

Twice-daily readings of the staff gage on the Green River at Mammoth Cave Ferry, about 400 feet downstream from the outlet of the 

Echo River and about 2,800 feet downstream from the outlet of River 

Styx (fig. 21) were made available by the Surface Water Branch. 

This stage record is complete since July 1938. Discharge records were 

published during the period July 1938 to September 1950. A recorder 

of the bubble-gage type was installed at the ferry on January 28,1960. 

Readings of the staff gage at the ferry since 1950, and once-daily readings of the two outlet gages since 1953, were made by the National Park 

Service personnel. The gradient of the Green River from a point opposite River Styx outlet to the gage at the ferry generally is about 0.2 

foot. The gradient from the Echo River outlet is about 0.01 foot. 

All gage readings have been adjusted to the same zero datum, 420.22 

feet above sea level.

Fluctuation of water levels in the wells, the stage of the Green River, 

and precipitation for the period 1953-57 are shown in figure 12. The 

diagrammatic section through the Dripping Springs escarpment (fig. 

11) shows the relationship of the several water bodies, the Green 

River, and the wells.

The hydrograph of Union City well (fig. 12) shows fluctuations of 

water level in a well in the Big Clifty Sandstone Member. The graph 

shows that rapid recharge occurs during the winter and that the rate 

of discharge decreases gradually from about May to November. Rapid 

recharge starts when the deficiency of moisture in the soil has been replaced and continues until the growing season begins in May.

Discharge from the Big Clifty is predominantly through interformational leakage, lateral migration of water to springs on the perimeter of the area, and evapotranspiration. Probably the greatest 

quantity of water is discharged through evapotrarspiration. The 

water table is relatively close to the surface, especially during the 

spring, and conditions are ideal for large losses through evapotran-
GENERAL HYDROLOGIC CONDITIONS 51

Historic 

Entrance Mammoth Cave 

P.O

(Limits of explored water) 

River Styx

(Limits of 

explored water)

MAMMOTH CAVE 

FERRY

(Limits of 

explored water)

Violet City Entrance 

Carmichael Entrance

EXPLANATION 

Gaging station

800

I i

0 800 1600 FEET

I____|

FIGURE 21. Cave passages, major subsurface streams, and gaging stations in 

the Mammoth Cave area.

spiration. During the fall, when the depth to water is greater, the 

quantity of water discharged by evapotranspiratioii is much less.

Where shale is not present at the top of the Girkin Formation, some 

Avater may percolate downward from the Big Clifty into the Girkin. 

In those areas where the shale is continuous, the water moves laterally 

through the Big Clifty and discharges as springs and seeps or is lost 

by evapotranspiratioii at the edge of the escarpment and along the sides 

of the narrow, elongated ridges that are capped by the Big Clifty.
52 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

These springs give the Dripping Springs escarpment its name and 

constitute a major source of discharge from the formation. Much of 

the water discharged by these springs flows back into the ground 

through fractures and solution cavities in the Girkin.

The hydrograph of the Chaumont well (fig. 12) in the 'Girkin shows 

the effects of this continuous recharge during the dry period of the 

year. The highest water levels are recorded during th°, winter just 

as in the Big Clifty Sandstone Member; however, the high peaks are 

as quickly followed by extreme lows because of the siphon action in 

solution openings intersecting the well. During the periods of little 

recharge, when the water level in the well in the Big Clifty declines at 

a nearly constant rate for extended periods of time, the water level in 

the well in the Girkin gradually rises. This is probably caused by 

recharge from water seeping down from the overlying Big Clifty, 

either from the edge of the escarpment or from areas where the shale 

in the Girkin is absent.

Wells drilled in this area may intercept five or more "streams" of 

water in the Girkin. Each of these is connected to the water in the 

Big Clifty Sandstone Member above and the water in the Ste. Genevieve Limestone below by innumerable conduits of different sizes, 

ranging from hairline cracks to large caverns similar to those that 

constitute Mammoth Cave. Many of these passageway? are plugged 

with silt; some are complicated networks of passageways that create 

siphons at different levels, overflow releases, constrictions, and vertical 

drains. The effect of this network of passageways is to cause a nearly 

infinite number of patterns of fluctuations of water level? in wells that 

penetrate one or more of these passageways. The behavior of the water 

level in a well is affected by the height of the water tablQ,, intensity of 

rainfall, location of rainfall, quantity of water recharging from the 

overlying Big Clifty Sandstone Member, and the quantity discharging 

horizontally as springs and vertically into the underlying Ste. Genevieve Limestone. The hydrograph of the Chaumont well, therefore, 

is not considered to be typical of the water-level fluctuations in the 

Girkin; rather, itis an example of only one type of fluctuation.

The hydrograph of the well at CCC No. 2 shows fluctuations of the 

water surface that are more or less contiguous with the Green River. 

The well is about 500 feet deep, and the water level is in the horizon of 

the Ste. Genevieve Limestone. The water level fluctuates rapidly as 

much as 25 feet in less than a day. Some of the rises are followed by a 

siphon action that lowers the water level in the well below that maintained before the rise. In general, the rises correspond to similar 

rises in the Green River, but they precede them and are much more 

rapid. The hydrograph indicates that the well at CCC No. 2 intersects an opening of moderate size that is connected by a riphon tube to 

one of the larger passageways in Mammoth Cave. Below the 420-
GENERAL HYDRGLOGIC CONDITIONS 53

foot level this passageway probably acts as a lake that is emptied by 

a siphon and then is gradually refilled over a period of several weeks 

by water filtering downward from the overlying Girkin Formation.

The relationship between the water level in wells, stage of the 

springs, Echo River and River Styx, stage of the Green River, and 

precipitation at Mammoth Cave are shown in figure 13. In considering this and subsequent illustrations, it should be kept in mind that 

Mie normal gradient of the Green River is about 0.2 foot from the 

point opposite River Styx to the Mammoth Cave Ferry. Precipitation on January 10, 1954, apparently was enough to saturate the soil. 

A slight rise occurred in River Styx and the Echo and Green Rivers, 

")ut the CCC No. 2 and Union City wells were not affected; in f?,ct, 

the water level in the well at OCC No. 2 declined at a fairly uniform 

rate from January 10 to 13, 1954. Heavy precipitation on January 

14-16 caused a sharp rise in all water levels. The precipitation was 

general throughout the State and caused a rise in the Green River that 

reached a peak on January 18. River Styx rose before the Green or 

Echo Rivers and was at a higher stage than either of them until January 16; but shortly after that, the surge, of water from the cave area 

became relatively smaller, and the rapid rise in the Green River apparently created a reversal in gradients, so that the Green River flovT ed 

into River Styx and into the various cave passages. The Echo River 

rose rapidly from the effects of local precipitation, but the stage was 

nearly identical with that of the Green River by January 16,1954, and 

remained so throughout this rise.

During the night of January 19-20, 1954, heavy precipitation began 

again and continued through January 22. The effect on water levels 

in the well at CCC No. 2 was almost instantaneous. The water level 

in the well rose 24 feet in slightly more than 6 hours and declined the 

same amount in about 12 hours. The hydrograph of the water level 

in the well at CCC No. 2 shows clearly the type of fluctuation common 

in many places in the limestone areas of Kentucky. During low-flow 

periods the water in subsurface conduits behaves in much the same 

manner as a stream. Moderate amounts of precipitation on January 

14-16, as showrn in the first part of the graph, cause a rise that plots 

*:o a shape roughly similar to a rise on a small river; however, wl~^n 

precipitation is large in quantity, and particularly when it is intense 

in a small area, these subsurface streams in conduits can be compared 

with water flowing through a large tube having several vertical tubes 

of different sizes connected to the large tube. When large quantities 

of water are forced into the large tube, the water in the smaller tubes 

rises suddenly, the rate of rise depending on the diameter of the tube, 

the number and diameter of other tubes connected to the large tube, 

and the pressure under which water is being forced into the large tube. 

Such a hydraulic system will result in rapid rises in water level in some
54 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

of the vertical tubes if water is introduced into one end of the large 

tube under considerable pressure; the decline is equally rapid when the 

pressure is reduced.

Just such a system is underneath Mammoth Cave plateau. Several 

large conduits trend generally northwestward toward the river. Adjoining these are numerous cross conduits and vertical shafts of many 

diameters and shapes. Although conduits may be of large size, restrictions may prevent a rapid flow of water. Some of the restrictions 

may be so great that several days, weeks, or even months are required 

for the water from heavy rains to seep out into main channels.

The different hydrologic characteristics of cavernous limestone 

aquifers and sandstone aquifers are strikingly shown by comparing 

the graph of the well at CCC No. 2 with the Union City well (fig. 

13). Union City well shows typical water-table fluctuations in a 

sandstone bed of fairly uniform porosity and permeability; the well 

at CCC No. 2 shows water-level fluctuations that illustrate the behavior of water in an extremely cavernous limestone formation. The 

precipitation on January 19-20 caused a rise of about 9 feet in the 

Union City well. The well continued to rise slowly until the afternoon of January 21 and then began to decline. The rate of decline 

was about one-twentieth the maximum rate of rise.

The precipitation of January 19-22, 1954, caused a sharp rise in 

water levels in the Green and Echo Eivers and Eiver Styx. For about 

20 hours, the stage of all three rivers rose at about the same rate, and 

during most of this time the Green Eiver probably flowed into Eiver 

Styx. About 6:00 a.m., January 21, the surge of water from precipitation on the Pennyroyal plain and Mammoth Cave plateau reached 

the outlet of Eiver Styx, and discharge was intermittent until January 

25. A similar rise probably occurred at the Echo E : ver, but as there 

was no gage above 16 feet, no record of stage could be obtained. On 

January 26-27, 1954, almost 1 more inch of rain fell. The rise in 

stage of the various water bodies was similar to the previous rise, 

except that the volume of water flowing from Mammoth Cave into 

Eiver Styx was not adequate to maintain outflow, and, seemingly, the 

inflow from the Green Eiver to Eiver Styx should have been strong. 

The great head difference suggests an error in gage-height reading; 

however, this cannot be determined. As flow again declined, Eiver 

Styx, which is partly dammed by a low rock barrier at the outlet, was 

at progressively higher stages above the Green and Echo Eivers.

The relationship between the ground-water reservoir under Mammoth Cave and the Green Eiver is one that cannot now be adequately 

explained. Final conclusions will have to await results of tracer tests, 

collection of additional samples for chloride analysis the installation 

of a higher gage on the Echo Eiver outlet, recorders on springs and 

subsurface streams upstream and downstream from the park area, and
GENERAL HYDROLOGIC CONDITIONS 55

many readings on gages inside the cave. However, some significant 

conclusions can be drawn from the data already collected. Water 

from precipitation on the Pennyroyal plain and Mammoth Cave 

plateau flows through to the exit points, including River Styx and the 

Echo River, rapidly and creates a head differential sufficient to maintain normal flow from the springs into the Green River for as long 

as 2 days. After the initial surge of water, the height differential 

between River Styx outlet and the Green River decreases. At some 

stage, dependent on the rate of rise or fall of the Green River and the 

rate, amount, and distribution of precipitation on the Pennyroyal 

plain and the Mammoth Cave plateau, River Styx ceases to discharge 

into the Green River, and the turbid and sometimes saline high chloride water of the Green River flows into Mammoth Cave through the 

normal spring outlet. This reversed flow may last many days. Figure 13 shows reverse gradients several times on January 16-31, 1954.

Figures 14 16 show the relationship between the stages of River 

Styx and the Green River during three rises. Figure 14 shows the 

relative stages during a rise when base flow of the river was relatively 

high, April 30-May 19, 1954. The heavy local rains probably resulted in intermittent discharge from River Styx, May 6-10, but except 

for the period of most rapid rise immediately after precipitation, the 

Green River stayed higher than River Styx and flowed into River 

Styx during the period April 30-May 16. This segment, of record 

indicates that water flows from the Green River to River Styx moet of 

the time during winter and early spring, except when heavy local 

rainfall causes a temporary surge of water to discharge from River 

Styx.

Figure 16 shows a rise which is probably typical of the period from 

late summer to early winter, when ground-water storage is low and the 

Green River is at a low stage. The precipitation at Mammoth Cave, 

December 22-23, 1958, was the first for about 20 days and the first 

heavy rainfall since early August. Although the river at no time was 

close to the stage of River Styx, stage and discharge from River f?tyx 

increased significantly for about 72 hours. At the same time, the 

stage of the Echo River rose and discharge increased. Thus, when 

ground-water storage is small and the Green River stage is low, heavy 

local rains generally result in discharge from both River Styx and the 

Echo River as well as from other springs in the area, and flow at River 

Styx is not reversed.

If reversals of flow occur in the Echo River, they probably are of 

short duration. All plottings of stage of the Green River and Echo 

River indicate a gradient from the Echo River to the Green River, 

although the gradient is not constant. Figure 15 shows the relationship between the stage of River Styx and the Green River during a 

rise on January 20-23, 1959, and the following decline. A separate
56 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOT'I CAVE AREA, KY. 

100 r

40

=: 20

JAN. 22 24 26 28 30

GREEN RIVER 50 FEET

UPSTREAM FROM RIVER

STYX OUTLET

'

 -) J

-f

2 24 26 28 30

GREEN RIVER AT 

AM MOTH CAVE FERRY

, _

J\\ ---

\ 

-t

-4

\

-1_

r, 

2 24 26 28 30 22 

M

24 26 28 

1

3 

VER STYX AT OUTLET ECHO RIVER AT OUTL

100

60

--

 L

2 24 26 28 3 

CHO RIVER AND RIVE 

FYX AT PLUTOS DOM

2 2

RIVER 

AT

4 2 

STY 

BOA

6 2 

X IN 

RDWA

5 3 

CAVE 

LK

2 2 

C

4 2 

EDAF

6 2 

SIN

I

8 31 

K

JAN. 22 24 26 28 30

ECHO RIVER AND RIVER 

STYX AT DEAD SEA

FIGUKE 22. Relation of chloride concentrations in water sanples from groundwater to surface-water sources, January 22-29,1050.

plotting on figure 15 shows concentration of chlor; de in parts per 

million for River Styx and the Echo and Green Rivers. Figure 22 

shows chloride concentrations plotted as bar diagrams for the same 

period and includes chloride for several water bodies inside Mammoth 

Cave and Cedar Sink. Figure 15 includes chloride concentrations 

determined in the field by approximate methods; figure 22 includes 

only laboratory analyses and, thus, is more accurate but less comprehensive.

As shown by the arrows (fig. 15), River Styx alternately flowed in 

and out on January 23, 1959, when the stage of River Styx at the outlet 

was about 0.2 foot above the stage of the Green River at Mammoth 

Cave Ferry. This is probably the critical stage between flow from 

the cave passages to the Green River and reverse flow of the Green 

River into the cave passages. When the gage-heigl t differential is
GENERAL HYDROLOGIC CONDITIONS 57

less than this, the Green Kiver generally flows into the cave passages; 

when it is greater, River Styx generally discharges water to the Green 

River. However, because of siphon action and restrictions in the solution channels under Mammoth Cave plateau as well as surges in the 

flow of the Green River, the inflow-outflow relationship may not always 

depend on this exact stage differential. During any given half-hour 

period, the stage of River Styx may fluctuate several times through a 

range of 0.2 to 0.3 foot, resulting in alternate inflow and outflow. 

Thus, flow relationships illustrated in these hydrographs are only 

general. Note that discharge from River Styx to the Green River was 

principally during the period of rapidly rising and falling stages of 

the Green River (figs. 14,15).

The chloride concentration in the Green River was about 20 ppm 

(parts per million) at the peak of the rise and 5-10 ppm in the Echo 

River and River Styx during the same period (fig. 15). As the peak 

of the rise passed, the chloride concentration in each of the bodies of 

water generally increased. L»ocal rainfall was heavy on January 20- 

21, 1959, and River Styx, the Echo River, and other springs in the area 

probably discharged until noon January 22. At noon on January 23, 

a reverse flow was observed from the Green River into River Styx, 

and a sample of water from River Styx at the gaging station contained 

15 ppm chloride. By January 25, samples from River Styx contained 

30 ppm chloride, and the chloride content increased erratically until 

January 29, when a sample contained 150 ppm chloride.

During this period the Echo River was discharging into the Green. 

Although the rate of discharge is not known, the stage remained 

slightly above that of the Green River throughout the period shown. 

The concentration of chloride in the water discharging from the Echo 

River increased from about 5 ppm, during the period of maximum 

stage, to about 45 ppm on January 29, when the chloride content in 

River Styx was 150 ppm. Chloride concentrations in the sections of 

the Echo River inside Mammoth Cave show a similar increase (fig. 22). 

The only possible source of the high chloride water in the Echo River 

is water from the Green River. Further, the close correlation of the 

change of concentration of chlorides in River Styx and the Echo and 

Green Rivers indicate that water from the Green River flows rapidly 

into the Echo River from River Styx or other upstream areas at high 

stages.

The water that discharges from the Echo River at high stages probably is a mixture of water from the Green River that flows into the 

cave through River Styx and water from precipitation on the Pennyroyal plain and Mammoth Cave plateau that flows through solution 

channels under Mammoth Cave Ridge and adjoining valleys. River 

Styx contains a high concentration of chloride even after long periods 

of continuous discharge; the source of the chloride is apparently water
58 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

from the Green River that enters solution channels upstream from 

River Styx. A sample of water collected from River Styx on November 3, 1958, contained 25 ppm of chloride, about 10 times the concentration of chloride in samples from this spring before contamination 

of the Green River by chloride in 1958. Gage-height records 

show that outflow from River Styx was constant for more than a month 

before this sample was collected.

II an upstream intake is the source of the high chloride in River Styx 

at low flow, some water probably comes in the same intake at high 

stages, mixes with water coming in through River Styx, and discharges 

from the Echo River. These rivers connect in the cave at high stages 

of flow, and the chloride concentration is high at some stages.

Figure 23 shows the relation of concentrations of chloride to discharge and time. Before 1959 the highest concentration of chloride 

determined was about 3 ppm, and it was relatively less during periods 

of high discharge than during periods of low discharge. In 1959, 

chloride concentration was more than 100 ppm at some discharge rates 

and was generally higher at high discharge than at low discharge. 

This is probably water from River Styx that contains water high in 

chloride from the Green River crossing over at high stage and discharging into the Echo River. Thus, the reason that the Echo River 

does not reverse flow, even during the periods of rapid ris^ of the Green 

River, must be that gradients in the complex system of solution channels in the cave are such that part of the Green River flows into the 

solution channels under the Mammoth Cave plateau anc1 , during high 

stages, discharges from the Echo River outlet. The Echo River, apparently, is not included in this system of flow at low stages.

A sample collected at the Echo River outlet on November 3, 1958, 

contained 2.5 ppm chloride. A sample taken inside the cs.ve on November 4 (fig. 24) from the river contained 3 ppm chloride, whereas a 

sample from River Styx inside the cave on the same date contained 36 

ppm chloride. Water from the Pennyroyal plain and Mammoth Cave 

plateau has a concentration of chloride of about 5 ppm.

Much of the water that enters the solution channels from the Green 

River may 'be discharged at some point downstream f^m the Echo 

River at high stages. If River Styx outlet is ever significantly lower 

in stage than the Echo and Green Rivers, it is obviously impossible for 

the inflow from the Green River to River Styx to discharge from the 

Echo River. Thus, if this stage relationship ever occurs, the reverse 

flow in River Styx must discharge at some point downstream from the 

Echo River. Figure 13 shows such a relationship on Jar uary 27,1954. 

These readings may represent an error by the observer. If they are 

correct, however, they indicate a discharge point downstream from 

the Echo River.
3000

t; 2500

z

s

£ 2000

V)

I 1500

ZD

£ 1000

oe

1 500

EXPLANATION

rO 

L 10

-50

-100 

Scale of diameters

F° 

F-10

^50 

L 100 

Scale of radii

Chloride, in parts per million

» - -

6

1955

12 3 6 9

1956

12 3 6

1957 

TIME, IN MONTHS

9 

FIGURE 23. Relation of discharge and time to concentration of chlori
60 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

JJU 

320 

310 

110 

100 

S 90

QC 

UJ

| 80

| 70

<c

Q£

s0 

1 6°

1 50

40 

30

20 

10 

0

LU 

"" O

. Q£ z £5 > Lut Q- _ 

UJ => OS

Q ^ 

Z O

03 u1 CO

1 

LUS 

O <;

Z ,_

o- «c

UJ uj

^ X 1 

> HQ£ <C I

LU ^j LU ^ 

Q <£ Q 5

li III is

is ii ij

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 1 LU

o 

o

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Of 03 

Q °2 +-

343443444

NOVEMBER 1958

FIGURE 24. Chloride concentrations in water samples taken from groundwater and surface-water sources, November 3-4,1958.

Possibly, one or more major channels served as a bypass during 

normal water stages before the erection of the U.S. Corps of Engineers 

lock and dam 6 near Brownsville, and water now flow? in these channels only when a gradient is established on the river during times of 

high water. Such channels might have innumerable obstructions, 

siphons, dead ends, and similar shapes and structures that could affect 

the rate of flow at different river stages. They might conduct water 

for several miles before it discharges into the Greer River. Such
SUMMARY 61

subterranean water courses are not uncommon in this part of Kentucky. 

A few miles upstream from the national park boundary, many thousands of gallons per minute flow under the narrow ridge that divides 

two loops of a meander curve in the Green Kiver instead of flowing 

around the ridge in the normal river channel. The discharge 

of water is visible for several hundred feet at river level, ard it 

is likely that many thousands of gallons more discharge from the side 

and bottom of the river channel. The rate of flow is so rapid that the 

temperature of the water declines during the summer by only about 

5° after passage through the ground. Normally, the temperature of 

water discharging from a spring would be about 20° below the summer temperature of the Green River.

SUMMARY

The Mammoth Cave plateau is underlain by limestone of Meramec 

age and alternating limestone, sandstone, and shale formatiors of 

Chester age. The youngest bedrock formation in the area is the CT seyville Formation of Pennsylvanian age.

Precipitation on the Pennyroyal plain or Mammoth Cave plateau is 

either dissipated by evapotranspiration or enters the ground-water 

body. Surface runoff in the areas south of the Green Kiver is negligible. Ground water may be delayed in its passage to the Green Elver 

level by relatively impermeable shale layers and intricately channeled 

limestone, but it ultimately reaches that level and is discharged into the 

Green River. Water levels in wells that intercept the water table 

coincident to the Green River fluctuate in much the same way as sprf ngs 

that discharge into the Green River. The stage of the Green River is 

for the most part, independent of the discharge of local springs and 

water levels in wells. Possibly for this reason, water from the Green 

River at some stages flows backward into the cave passageways under 

Mammoth Cave plateau through the mouth of River Styx.

Contamination of the Green River by salt water high in chloride has 

made it possible to trace the movement of water from the Green River. 

This water flows into the so'lution channels in the Mammoth Cave area 

through River Styx and probably through openings in solution channels upstream from River Styx. Inside Mammoth Cave it mixes with 

water from the Mammoth Cave plateau and Pennyroyal plain and 

discharges through the Echo River and possibly through solution channels that connect with the Green River at some point downstream from 

the Echo River.

The Echo River almost always discharges into the Green River, but 

River Styx apparently discharges into the Green River principally at 

low stage and during rapid rises in stage.
62 HYDROLOGY, CAVERNOUS LIMESTONES, MAMMOTH CAVE AREA, KY.

SELECTED REFERENCES

Bretz, J Harlen, 1942, Vadose and phreatic features of limestone caverns: Jour. 

Geology, v. 50, no. 6, p. 675-811.

Cushman, R. V., Krieger, R. A., and MeCabe, John A., 1965, Present and future 

water supply for Mammoth Cave National Park, Kentucky: U.S. Geol. Survey Water-Supply Paper 1475-Q, p. 601-647, 11 figs.

Davis, W. M., 1930, Origin of limestone caverns: Geol. Soc. America Bull., v. 41, 

p. 475-628.

Dicken, S. N., 1935, A Kentucky solution cuesta: Jour. Geology, v. 43, no. 5, p. 

539-544.

Gardner, J. H., 1935, Origin and development of limestone caverns: Geol. Soc. 

America Bull., v. 46, p. 1, 255-1, 274.

Haynes, Donald D., 1962, Geology of the Park City quadrangle, Kentucky: U.S. 

Geol. Survey Geol. Quad. Map GQ-183.

 1964, Geology of the Mammoth Cave quadrangle, Kertucky: U.S. Geol. 

Survey Geol. Quad. Map GQ-351.

Jillson, W. R., 1929, Geologic map of Kentucky: Kentucky Geol. Survey, ser. 6, 

scale 1: 500,000.

Klemic, Harry, 1963, Geology of the Rhoda quadrangle, Kentucky: U.S. Geol. 

Survey Geol. Quad. Map GQ-219.

Livesay, Ann, 1953, Geology of the Mammoth Cave National Park area: Kentucky Geol. Survey, ser. 9, Spec. Pub. 2, 40 p.

Lobeck, A. K., 1928, The geology and physiography of the Mammoth Cave National Park: Kentucky Geol. Survey, ser. 6, v. 31, pt. 5, p. 331-339.

McFarlan, A. C., Swann, D. H., Walker, F. H., and Nosow, Edmund, 1955, Some 

old Chester problems correlations of lower and middle Chester formations 

of Western Kentucky: Kentucky Geol. Survey, Bull. 16, ser. 9, 37 p.

Pohl, E. R., 1955, Vertical shafts in limestone caves: Natl. Speleol. Soc. Occasional Papers 2, 23 p.

Richards, Paul W., 1964, Geology of the Smiths Grove quadrangle, Kentucky: 

U.S. Geol. Survey Geol. Quad. Map GQ-357.

Swinnerton, A. C., 1932, Origin of limestone caverns: Geol. Poc. America Bull., 

v. 43, p. 663-694.

Weller, J. Marvin, 1927, Geology of Edmonson County: Kentucky Geol. Survey, 

ser. 6, v. 28, 246 p.

Weller, J. Marvin, and Sutton, A. H., 1940, Mississippian border of Eastern 

Interior basin: Am. Assoc. Petroleum Geologists Bull., v. 24, no. 5, p. 765- 

858.
INDEX

[Italic numbers indicate major references]

Acknowledgments __. 

Anderson, R. B., cited.

Page

______ 4 

____ 48

Beaver Dam Creek__________ 11 

Big Clifty Sandstone Member of Golconda Formation___ 6,

8, 12, 41, 43, 45, 50, 52

hydrologic significance.______ 42

Bransford Spring____________ 49

Bransford well 1___________ 39

Bruce Hollow_____________ 48

Caseyville Formation__________ 44, 45

hydrologic significance____ 44 

Cave Research Foundation.______ 49 

Caves, geologic history________ 13

geologic horizon__________ 12 

levels of cavern development__ 13 

location _____________ 11

two-cycle origin__________ l)t 

CCC No. 2, fluctuations of water level

in well________ 52

hydrograph of well______39, 52, 54

Cedar Sink_____________9, 10, 46, 56

Cedar Spring Valley__________ 10, 48

Chaumont well____________ 8

hydrograph __________ 41, 52

Chester Series______________ 6, 41 

Chloride concentration, relation to discharge and time___ 58 

water from Mammoth Cave

plateau _________ 58

water from Pennyroyal plain_ 58 

Chloride in Green River,________ 55, 56 

Colossal cave_______________9, 11, 49

Colossal Dome____________ 49

Crystal cave____________9, 11, 12, 38

Davies, W. E., quoted________ 14 

Dams, evaporite____________ 15 

Dome pits________________ 12 

Doyel Valley_______________ 10, 48 

Discharge from lower ground-water

body through springs._ //7 

Drainage, dendritic________ 6, 9, 11

underground ____________ G, 1

Dripping Springs escarpment_______ 2, 7,

12, 38, 41, 42, 46, 50, 52 

Dye tests, Louisville Gas & Electric

Co _____________ 49

Eaton Valley_______________ 12

Echo River_____________13, 15, 49, 61

chloride concentration _ __ 57

rise in water level 54

Page

Echo River spring ____ 47, 49, 50, 53, 58 

gradient __ . _ _ ___ _____ 50 

Escarpment west of Mammoth Cave

area ___ __ __ ___ 11 

Evaporite deposits __________ __ 15 

Evapotranspiration, water discharged

through _______ _ ____ SO

Fairy Spring_____ _ __ _ _ _ ___ _ _ 15

Flint Ridge _________________ .1, 44

solution channels underlying __ 49

Fluctuations of water levels _ _____ .'/9

Fort Payne Formation. __ _ __ _ __ 27

hydrologic importance _ __ __ 27

Garvin spi-ing_____________________ 48, 49

Geologic formations, sequence _ ____ 4, C

water bearing properties _ _____ 16

Girkin Formation _ __ ___ 39, .'/I, 51, 52

hydrologic significance __ ____ 41 

Glen Dean Limestone _ _ __ _ _ __ 44

hydrologic significance----- 44

Goedes, Warsaw Limestone.- _ _ __ _ 27

Golconda Formation, Big Clifty Sandstone Member- _ _ __ _ C, 8,

12, 41, 42,45, 50, 52 

Haney Limestone Member____ 43

Great Onyx cave ___________ 9, 11, 38

Green River ______ IS, 45, 46, 4? 52, 53

chloride concentration _ __ _ _ 57, 61

deposits of Pleistocene and Recent ages in flood plains. 45 

gradient _________ _ _ ______ 50

relationship between groundwater reservoir under 

Mammoth Cave_ __ _ _ 54

Tise in water level---- -__ _ 54

stage ____ _ __- ___ _ _ 6^

Green River basin, runoff- _ ___ _ __ 46

Ground water, in solution openings in

Girkin Formation _ ___ !t l

movement _ _ _ __ _ _ __

Ground-water storage 

46, 61

55

Hamilton Valley 49

Haney Limestone Member of the Golconda Formation __ ___ 43

hydrologic significance- ___ 43 

Hardinshurg Sandstone----- __ - 43

hydrologic significance __ ,43 

Hidden River Spring, flow_-_- 32 

Historic Entrance _ _ __ _ 13 

Houchens Valley _____________ 48, 49 

Hydrograph, Chaumont well 41, 52

Union City well ______ - //2, 50, 54

well at CCC No. 2 ______ _ 39, 52, 54

63
64 INDEX

Introduction

Jim Lee Ridge. 

Joppa Ridge_-

Leitchfleld Formation 

hydrologic significance _ __

Location and extent of area 

Louisville Gas & Electric Co.

tests __ _ _ __ _-_

dye

Page 

1

9

10

44

1,9

Mammoth Cave, precipitation___ 47, 53,

54, 55, 61

relationship between groundwater reservoir and 

Green River _ 54 

Mammoth Cave plateau-_______ 2, 6, 8,

38, 41,42, 45, 54, 61 

Mammoth Cave Ridge_______ 9

solution channels under______ 57

Meramec Series__________ 6, 27

Mill Hole_____________ 7, 8, 11, 46 

Mississippian System________ __ 27

Monroe Sink _ ___ __ ____ 7

New Discovery cave_ ___ 9, 11 

Nolin River, deposits of Pleistocene 

and Recent ages in flood 

plains _________ _ 45

Oolites, Ste. Genevie Limestone__ 38 

Osage Series_______________ 6, 27

Pennsylvanian System________ 44

Pennyroyal plain__2, C, 10, 11, 12, 32, 46, 61

concentration of chloride in

water __________ 58 

Phreatic water______________ 13 

Physiography ______________ 4 

Piezometric surface ________..__ 46

Pike spring_______________ 48, 49

Pleistocene deposits, hydrologic significance ________ 46

sand and gravel_________ 45 

Precipitation _________ J,6, 54, 55, 61 

Previous investigations________ 2

Quaternary System. 45

Recent deposits, hydrologic significance __________ 46

sand and gravel__________ 45 

Recharge from Green River______ 47

Recharge to lower ground-water body,

sources _______ 46

River Hall. See River Styx. 

River Styx______13, 15, 46, 47, 49, 61 

chloride concentration______ 57

rise in water level________ 54

River Styx spring_______48, 49, 50, 53 

Roaring River_______________ 49

Runoff, Green River basin______ 46

Sand Cave spring____________ 47, 48

St. Louis Limestone______ 7, 12, 28, 52 

hydrologic significance______ 32

Ste. Genevieve Limestone 12,

hydrologic significance _

oolites _ __ _ 

Scope and purpose of report________

Silt barriers in solution channels in 

caves _ ____

Sinkholes _________ 6, 7, 9, 10, 

Solution channels - 

Girkin Formation_____________

Hanney Limestone member of

Golonda Formation 

in caves, silt barriers ____

an St. Louis Limestone- ____

under Mammoth Cave plateau__ 

under Mammoth Cave Ridge____

underlying Flint Ridge________

Springs, Glen Dean Limestone______

main source of discharge from 

area ________________

Streams, ephemeral _____

perennial _ __ _ 

underground ___

Summary ___ ___ -

Surface runoff _ ______

Page 

33, 42

46

11, 28

9, 61

43

46

33

57, 58

57

49

44

47

9, 11

7, 11

46

61

61

61 

45

43, 48 

4

11 

Turnhole spring ____ __ 11, 47, 48

Union City well, fluctuations of

water level _____ __ 50, 53 

hydrograph ___ _____ 42, 50, 54

Temperature of water __ 

Terrace deposits on streamsThree Springs_____________

Topography _____ _ 

karst __ -

Vadose water, definedValleys, subsequent___ 

Vaughns Dome_____-

Warsaw Limestone _ 

hydrologic importance- _

Water-bearing properties of geologic 

formations __________

Hardinsburg Sandstone______

St. Louis Limestone___________

Ste. Genevieve Limestone--____

Warsaw Limestone____________

Water-level fluctuation in wells____ 

records __ ___________

Weller, J. M., quoted______________

Well-numbering system___-_____

Wells, alluvium ____________

Big Clifty Sandstone Member of

Golconda Formation__

Rransford 1_________________

Girkin Formation__________

Hardinsburg Sandstone _ _ 

St. Louis Limestone-_ ___ 

Ste. Genevieve Limestone___ 

Union City _ _____ _ 

water-level fluctuations____

Woolsey Valley___-________

IS

8

49

27

28

16

43

32

39

27

61

49

45

3

45

39

41

43

32

39

42

49, 50

48

o

U.S. GOVERNMENT PRINTING OFFICE: 1991-0-292-923