Borden Formation 

(Mississippian) 

in South- and SoutheastCentral Kentucky

By G. W. WEIR, J. L. GUALTIERI, and S. 0. SCHLANGER

CONTRIBUTIONS TO STRATIGRAPHY

GEOLOGICAL SURVEY BULLETIN 1224-F

ff^ork done in cooperation with the 

Kentucky Geological Survey

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

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY 

William T. Pecora, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington, D.C. 20402 - Price 25 cents (paper coyer)
CONTENTS

Page

Abstract __ _.......__.._.__._.__--...-_______.__.__..___.__-..__ Fl

Introduction and acknowledgments -_------_------.---_-_-----_----_- 1

Previous nomenclature. ____________---_--_--_-_.____-__--___.____._ 2

Borden Group __ _-___---____---___----_-__--__-___-___--_-__ 2

New Providence Formation.. . -_--_-____________.-____--__._ 3

Brodhead Formation _ _ ___________________________________ 3

Floyds Knob Formation _ _----_-__._--________._____--.___ 6

Muldraugh Formation______---___---_____.____. ___._-____. 7

Borden Formation.. - _______________---_-_---_-___-_____-____--____ 8

Nancy Member. ______________________________________________ 11

Cowbell Member.------------------.-------------------------- 14

Nada Member____--_____-____-__-_-___--_--_____-_______--.-- 15

Halls Gap Member. ___.-________-__-.-_-._.._-_--___--_____-__ 15

Wildie Member. ._-_--_----__-------_------.--___---_-__------ 18

Renfro Member. . _____________________________________________ 19

Muldraugh Member_-___-_-__---------_--___--_.__. --____---_- 21

Measured sections .__________-_-__-------_---___.--_____-_-___----_ 23

References.. . _---_________._____.___-____--_-____.____.___.__--_-_ 38

ILLUSTRATIONS

Page 

FIGUBE 1. Index map of south- and southeast-central Kentucky________ F2

2. Graphic sections of the Borden Formation.__--_._______-__- 4

3. Sections showing siltstone units between Brodhead and Bighill, Ky.----_----_-_------_--------..-..--.--_.-----. 6

4. Photograph of basal contact of Borden Formation.________.. 9

5, 6. Photographs of upper contact of Borden Formation_.--...- 10 

7-13. Photographs of membeis of the Borden Formation:

7. Nancy Member_._-.______.._.._._...__._.._._. 12

8. Cowbell Member.--.--_.---.._---_.._--_--.---_- 13

9. Nada Member__________________________________ 14

10. Halls Gap Member.--...____.._.._..._.. 16

11. Wildie Member_____._____________________ 17

12. Renfro Member.------------------------..------ 20

13. Muldraugh Member____________________________ 21

 1 

s

CONTRIBUTIONS TO STRATIGRAPHY

BORDEN FORMATION (MISSISSIPPIAN) IN SOUTH- AND 

SOUTHEAST-CENTRAL KENTUCKY

By G. W. WEIR, J. L. GUALTIERI, and S. 0. SCHLANGER

ABSTRACT

The Borden Formation is a major stratigraphic unit in south- and southeastcentral Kentucky. It includes strata divided by P. B. Stockdale in 1939 into 

the New Providence, Brodhead, Floyds Knob, and Muldraugh Formations of the 

Borden Group and locally also strata previously assigned to the Salem and Warsaw Limestones and to the St. Louis Limestone. The older nomenclature is 

unsuitable because the named stratigraphic units are not mappable.

The Borden Formation in south- and southeast-central Kentucky is composed 

of clayey and silty shale, limy and shaly siltstone and siltstone, and cherty, 

dolomitic, and argillaceous limestone and limestone. These rock types differ 

in proportion from place to place, but characterize mappable units that in this 

report are newly named or redefined as members of the Borden Formation. 

Members of the Borden recognized in this report are the Nancy Member (shale 

and shaly siltstone), the Cowbell and Halls Gap Members (resistant siltstone), 

the Nada and Wildie Members (shale and siltstone), the Renfro Member (argillaceous limestone and dolomite), and the Muldraugh Member (cherty and dolomitic limestone, limestone, and limy and dolomitic siltstone).

The Borden Formation conformably overlies black shale the New Albany 

Shale of Devonian age in south-central and part of southeast-central Kentucky, 

the generally equivalent Chattanooga Shale in part of southeast-central Kentucky, and the Sunbury Shale of Early Mississippian age in northeast Kentucky. 

The Borden is conformably overlain by the Salem and Warsaw Limestones of 

Late Mississippian age in south-central Kentucky and by the Newman Limestone 

of Late Mississippian age in southeast-central Kentucky.

The Borden ranges from about 220 to 450 feet in thickness in south- and southeast-central Kentucky. The Borden Formation is chiefly of Early Mississippian 

age, but it locally includes some beds of Late Mississippian age.

INTRODUCTION AND ACKNOWLEDGMENTS

Current geologic mapping of 7^-minute quadrangles in southeastcentral Kentucky shows that the Borden Formation is divisible into 

mappable members, which do not coincide with previously named divisions of the Borden. This paper describes seven members of the

Fl
F2 CONTRIBUTIONS TO STRATIGRAPHY'

Borden Formation in south- and southeast-central Kentucky (fig. 1). 

These are, in ascending order, the Nancy, Cowbell, Nada, Halls Gap, 

Wildie, Renf ro, and Muldraugh Members (fig. 2).

85' 

38°00'

22'30"

37°30'

37°00'

85° 00' 84°30' 84° 00' 83°30'

1 Phillipsburg

2. Nancy

3. Halls Gap

4.Renfro Valley North

5.Disputanta |

6. Indian Fort Mountain

7. Nada

LEBANON

SPURLINGTON 

QUADRANGLES

BEREA

QUADRANGLE 

CRAB ORCHARD 

OUADRANGLEXBEREA_^J

STANFORD

SLADE 

QUADRANGLE

Brodhead' 

Maretburg

.SOMERSET

DELMER 

QUADRANGLE

INDEX MAP OF KENTUCKY, 

SHOWING AREA OF THIS REPORT

10 10

I

20 MILES 

_I

FIGURE 1. Index map of south- and southeast-central Kentucky showing locations of principal measured sections, towns, and 7%-minute quadrangles mentioned in text.

This report is based in large part on the geological mapping of Kentucky being conducted by the U.S. Geological Survey in cooperation 

with the Kentucky Geological Survey. Areas not currently being 

mapped were studied chiefly in the spring and summer of 1962 by 

the writers, who reviewed exposed sections described by Stockdale 

(1939) and Butts (1922) and measured supplementary sections. Of 

special help was the information and criticism contributed by N. L. 

Hatch, R. C. Kepferle, R. Q. Lewis, Sr., E. G. Sable, and W. L. Peterson of the U.S. Geological Survey and by T. J. Crawford of the Kentucky Geological Survey.

PREVIOUS NOMENCLATURE

BOBDEN GROUP

The name Borden Group, given to rocks of Early Mississippian 

age in Indiana by Cumings (1922), was extended by Stockdale (1931, 

1939) to an equivalent sequence of shale, siltstone, and limestone in
BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY F3

Kentucky. Stockdale (1939) divided the Borden Group 1 of Kentucky into, in ascending order, the New Providence, Brodhead, Floyds 

Knob, and Muldraugh Formations. These formations, subdivided 

into named members and facies, were considered to extend generally 

throughout the outcrop of Lower Mississippian rocks of central Kentucky.

NEW PROVIDENCE FORMATION

The New Providence Formation (Borden 1874; Stockdale, 1931) 

was named for exposures near the village of Borden, formerly New 

Providence, Ind. The New Providence Formation as described by 

Stockdale (1939, p. 85,106) has a vaguely defined top in its type area 

and throughout most of Kentucky. Stockdale (1939, p. 114,117,119, 

153) noted that in many places the top of the New Providence is 

conjectural because there is no contrasting lithology. Restudy of 

many of Stockdale's sections in south- and southeast-central Kentucky 

shows that a major break in lithology a mappable contact commonly lies 50 to more than 100 feet above fche top of the New Providence as described by Stockdale (1939). The meaning of the term 

New Providence in Kentucky is further confused by misunderstanding of relations between "New Providence" and the overlying Brodhead Formation as used by Stockdale (1939). In short, the mappable 

basal unit of the Borden differs so greatly from the interval commonly 

designated as New Providence that the name "New Providence" is 

not useful in south- and southeast-central Kentucky.

BRODHEAD FORMATION

Stockdale (1939, p. 125-136) gave the name Brodhead Formation 

to a generalized unit in Kentucky that overlies his New Providence 

Formation and underlies his Floyds Knob Formation. The type 

section of the formation is near the town of Brodhead in southeastcentral Kentucky. There Stockdale assigned 117 feet of beds to the 

Brodhead, including at the base 65 feet of slightly silty shale, which 

closely resembles the underlying shale that he assigned to the New 

Providence. The mappable part of Stockdale's type Brodhead consists of about 50 feet of fairly resistant siltstone with minor shaly 

siltstone (in this report the Halls Gap Member of the Borden Formation).

A simple two-layer relation of the Brodhead and New Providence 

as inferred by Stockdale (fig. 3, upper section) does not exist. He

1 Recently the Borden In southeast-central Kentucky has been called a formation rather 

than a group (Hatch, 1964).
F4 CONTRIBUTIONS TO STRATIGRAPHY

thought, for example, that the lower siltstone bed near Brodhead (fig. 

3, upper section) was the same as the lower siltstone bed near Con way 

(fig. 3, lower section) and, as shown in the upper section of figure 3, 

called both the Gum Sulphur Siltstone Member of the New ProviEXPLANATION

Argillaceous

limestone and

limy shale

Limestone, argillaceous limestone, or 

siderite lentils

Carbonaceous 

shale

Covered

Limy 

siltstone

Fossils Renfro Valley 

North

Phillipsburg 

-?

FIGURE 2. Graphic sections of the Borden Formation in south- and southeastcentral Kentucky. See figure 1 for location of .sections.
F5

dence Formation. Geologic mapping has demonstrated, however, that 

the siltstone beds at the two localities are not the same and that one 

bed overlies the other, as shown in the lower section of figure 3. Furthermore, the siltstone unit forming the mappable part of the type

rSOFEET

FIGURE 2. Continued.

709-^642 i
F6 CONTRIBUTIONS TO STRATIGRAPHY

New Albany Shale

New Albany Shale

 300 FEET

 200

-100

-0

EXPLANATION

Siltstone

Shale

Location of sections 

5 MILES

FIGURE 3. Sections showing relations of siltstone units of Early Mississippian 

age in the area between Brodhead and Bighill, Ky. Upper section, as inferred by Stockdale (1939, pi. 15, p. 136-137, 164, 172-174). Lower section, as 

determined by detailed mapping. Explanation of lithologic symbols applies 

to lower section only.

Brodhead pinches out south of Berea and is not continuous with the 

inappable unit near Berea (Cowbell Member of the Borden Formation in this report) that Stockdale assigned to his Brodhead formation. 

The name Brodhead Formation is abandoned because this unit is 

not mappable at its type section and because the name has been previously applied to separate units.

FLOYI>S KNOB FORMATION

Stockdale correlated a thin unit of glauconitic limestone and siltstone in the Lower Mississippian rocks of central Kentucky with his 

Floyds Knob Formation (Stockdale, 1929) in Indiana. The Floyds
BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY F7

Knob Formation as used by Stockdale (1939, p. 191) in Kentucky 

"is a thin nonimpressive feature of varying lithology, generally limestone with one or more associated sheets of greenish-black silt, which 

constitutes an extremely minor part of the rock column." Stockdale 

reported thicknesses of the formation ranging from about 2 feet to 

a fraction of an inch in south- and southeast-central Kentucky.

The Floyds Knob of Stockdale's usage in south-central and eastern 

Kentucky is a very thin bed of glauconitic siltstone or silty limestone 

that is commonly well exposed only in fresh roadcuts. In southeastcentral and south-central Kentucky the identity of the Floyds Knob 

of Stockdale's usage is frequently confused by the presence of more 

than one seam of glauconitic silt, and in some areas as near Stanton 

the glauconitic silt is absent or so sparse as to make recognition of the 

glauconitic marker bed impracticable.

The Floyds Knob Formation is not a stratigraphic unit of formational rank in south- and southeast-central Kentucky because it is 

discontinuous and too thin to map separately. In some areas, however, glauconitic siltstone or glauconitic limestone form marker beds 

that are useful in interrelating dissimilar stratigraphic sections.

The Floyds Knob Formation as used by Stockdale (1939) separated the Brodhead Formation from the Muldraugh Formation. In 

a few places, such as near Brodhead and Phillipsburg (Stockdale, 

1939, p. 136, 201), the glauconitic seam he identified as Floyds Knob 

does separate dissimilar lithologic units. More generally, however, 

the glauconitic silt lies within a lithologic unit a few feet to several 

tens of feet above a major change in rock types.

MULDRAUGH FORMATION

Stockdale (1939, p. 200-201) applied the name Muldraugh Formation in Kentucky to ro'cks of the upper part of the Borden Group 

above the Floyds Knob Formation. The type section (p. F36) is on 

Muldraugh Hill near Phillipsburg in south-central Kentucky.

At the type section the Muldraugh consists chiefly of cherty and 

dolomitic limestone and silty limestone. Eastward it becomes more 

cherty and includes much silty limestone, and minor calcareous siltstone and crinoidal limestone. In southeast-central and east-central 

Kentucky the Muldraugh Formation as used by Stockdale includes 

much siltstone overlain by yellowish silty limestone. The yellowish 

silty limestone was in part assigned to the Muldraugh Formation and 

in part assigned with a query to the Salem Formation and the St. 

Louis Limestone (Stockdale, 1939, p. 173, 212, pi. 6).

In this report the Muldraugh is redefined in terms of its lithology 

at its type section as a member of the Borden Formation.
F8 CONTRIBUTIONS TO STRATIGRAPHY 

BORDBN FORMATION

The Borden Formation in south- and southeast-central Kentucky 

is a heterogeneous unit that ranges from about 220 to 450 feet in thickness. It commonly shows the following general sequence from the base 

upward: (1) a thick unit of grayish-green to gray clayey shale grading upward into (2) medium-gray silty shale with minor gray siltstone, and (3) gray to grayish-yellow limestone commonly dolomitic, 

cherty, or silty and locally crinoidal and crystalline and minor lightgray, grayish-green, grayish-yellow, and grayish-red shale and siltstone. The formation can be divided into mappable members of relatively homogeneous lithologic character. Recognized in this report are 

the Nancy, Cowbell, Nada, Halls Gap, Wildie, Eenfro, and Muldraugh 

Members of the Borden Formation. Three minor units useful in 

understanding the regional stratigraphic relations are named the Gum 

Sulphur Bed of the Nancy Member and the Conway Cut and Roundstone Beds of the Cowbell Member.

The Borden Formation in Kentucky overlies black shale (fig. 2). In 

most of south-central and southeast-central Kentucky the black shale 

is assigned to the New Albany Shale of Devonian age; near Somerset 

the generally equivalent black shale is the Chattanooga Shale. North 

of Irvine, black shale underlying the Borden is the Sunbury Shale of 

Early Mississippian age. The basal greenish-gray to light-gray clayey 

shale of the Borden contrasts strongly with the underlying brittle, 

laminated black shale. Exceptionally, the black shale and clayey shale 

are interlaminated for a few inches. The basal few inches of the 

Borden Formation, as shown in figure 4, are characterized by sporadic, 

grayish-brown to light-gray phosphatic nodules ranging in diameter 

from a fraction of an inch to about 2 inches.

The Borden Formation is overlain by the Salem and Warsaw Limestones 2 in south-central Kentucky (west of Halls Gap) and by the 

St. Louis Limestone Member of the Newman Limestone in southeastcentral Kentucky (east of Halls Gap). Where the Salem and Warsaw 

Limestones are recognized, the upper contact of the Borden Formation, as shown in figure 5, is placed above unfossiliferous silty, finegrained dolomitic limestone and calcareous siltstone of the Borden 

and below the basal shelly medium- to coarse-grained limestone of the 

Salem and Warsaw Limestones.. At many localities a thin but 

conspicuous layer of calcareous shale occurs several feet above the 

base of the Salem and Warsaw Limestones.

2 The Salem and Warsaw Limestones as used in this report locally include the Harrodsburg Limestone as redefined by Sable, Kepferle, and Peterson (1966).
BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY F9

FIGURE 4. Basal contact of the Borden Formation (at pencil point). Greenishgray clayey shale of the Nancy Member of the Borden with basal zone of gray 

phosphatic nodules overlying black shale of the New Albany Shale. West side 

of U.S. Highway 25, 1.6 miles south of Berea, Ky.

In southeast-central Kentucky, where the Salem and Warsaw Limestones are not recognized, the upper contact, shown in figure 6, is 

placed between yellowish-gray argillaceous limestone of the Borden 

Formation and light-gray cherty fine-grained limestone of the St. 

Louis Limestone Member of the Newman Limestone. Where outcrops
no CONTRIBUTIONS TO STRATIGRAPHY

 ' . -?' '»!/' r " - *^ - ~

FIGURE 5. Upper contact of the Borden Formation in south-central Kentucky. 

Grayish-orange silty dolomitic limestone of the Muldraugh Member of the 

Borden Formation (Mbm) overlain by light-gray shelly coarse-grained limestone and gray shale of the Salem and Warsaw Limestones (Msw). East side 

of U.S. Highway 27, Halls Gap, Ky.

are poor, the contact is placed at the base of the dark-red soil which 

forms on the St. Louis Limestone Member and which contrasts with the 

yellowish-brown soil developed on the Borden Formation.

This contact is generally a conspicuous diastem, but locally the 

argillaceous limestone of the Borden Formation interfingers with the
BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY Fll

Aafrk

FIGURE 6. Upper contact of the Borden Formation in southeast-central Kentucky. Yellowish-gray argillaceous limestone of the Renfro Member of the 

Borden Formation (Mbr) is sharply overlain by gray cherty fine-grained limestone of the St. Louis Limestone Member of the Newman Limestone (Mnsl); 

the St. Louis Limestone Member is unconformably overlain by gray oolitic 

limestone of the Ste. Genevieve Limestone Member of the Newman Limestone 

(Mnsg). Contact between the Borden Formation and the Newman Limestone 

is here slightly wavy and marked by a thin seam of greenish-gray claystone. 

West side of U.S. Highway 421, about 1.7 miles south of Bighill, Madison, 

County, Ky.

fine-grained limestone of the Newman Limestone through a thickness 

of a few feet; and between Renfro Valley and Brodhead the upper 

part of the Borden intertongues with the St. Louis Limestone Member of the Newman through a thickness of several tens of feet.

NANCY MEMBER

The Nancy Member of the Borden Formation is here named for the 

typical section of shale and shaly siltstone exposed in Pulaski County 

Park about 2 miles east of Nancy, Ky. (p. F23). The Nancy Member 

includes all of the beds assigned to the New Providence Formation by 

Stockdale (1939) and in places a large part of the beds that he assigned to the Brodhead Formation. : .
F12 CONTRIBUTIONS TO STRATIGRAPHY

The Nancy Member is chiefly nonresistant gray clayey to silty shale 

(fig. 7). Locally it includes much nonresistant shaly siltstone, minor 

resistant thin-bedded siltstone, and thin discontinuous lenses of crinoidal limestone. At many localities iron-rich siliceous and calcareous 

concretions, a few inches to a few feet in diameter, like those shown 

in figure 7, occur sporadically through the member.

Stockdale's (1939, p. 117-119,137) Gum Sulphur Siltstone Member 

of the New Providence Formation is here called the Gum Sulphur Bed 

of the Nancy Member. It consists of ledge-forming spally weathering 

gray siltstone, and is gradational above and below into silty shale of 

the Nancy Member. The Gum Sulphur Bed is as much as 80 feet 

thick, but it feathers out into the Nancy Member in all directions 

within 10 miles of Brodhead (figs. 2; 3, lower section).

FIGURE 7. Characteristic outcrop of the Nancy Member of the Borden Formation. Gray slightly silty shale with layer of iron-rich, siliceous concretions 

about 50 feet below top of member. West side of U.S. Highway 25, about 2.5 

miles south of Berea, Ky.

The Nancy Member, the only member of the Borden Formation that 

extends throughout the area studied, is the basal part of the Borden 

Formation. It ranges in thickness from about 150 to 300 feet and is 

generally poorly exposed on long gentle slopes leading up to more 

resistant members of the Borden. The Nancy Member overlies the

fei
BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY F13

fissile black shales of the New Albany or Chattanooga Shale of Late 

Devonian age or Sunbury Shale of Early Mississippian age (figs. 2, 

4) . It is overlain in most of the area south of Berea by the Halls Gap 

Member (fig. 2) and by the Cowbell Member north of Berea (figs. 2, 

8) . At its type locality (fig. 2, section 2) , it is overlain by cherty and 

dolomitic limestone of the Muldraugh Member. In a small area south 

of Mount Vernon, east of the line of sections shown in figure 2, it is 

overlain by the Renfro Member (N. L. Hatch, Jr., U.S. Geol. Survey, 

oral commun., 1962) .

The contact with the Muldraugh and Renfro Members commonly is 

sharp, although it is locally gradational through several feet of limy, 

silty shale that contains thin beds of crinoidal limestone. Where overlain by the Cowbell or Halls Gap Members, the contact is gradational 

and is mapped at the base of the lowest relatively continuous ledgeforming siltstone.

t^i'f-

 tt.

FIGURE 8. Characteristic lithology and basal contact of the Cowbell Member of 

the Borden Formation. Resistant grayish-brown siltstone of the Cowbell 

Member (Mbc) grades through a few feet into underlying gray silty shale of 

the Nancy Member of the Borden Formation (Mbn). West side of U.S. Highway 25 about 3 miles south of Berea, Ky.
F14 CONTRIBUTIONS TO STRATIGRAPHY

COWBELL MEMBER

The Cowbell Member of the Borden Formation is here named for 

the typical section of siltstone that crops out near the head of a minor 

tributary of Cowbell Creek about 1.5 miles west of Bighill, Ky. (p. 

F26). The type section is exposed along a forest road on the south 

ridge of Indian Fort Mountain. The member includes most of the 

beds that were assigned to the Brodhead Formation by Stockdale 

(1939, p. 175) near this locality.

The member, as shown in figure 8, is made up chiefly of thick resistant units of gray, brownish-weathering indistinctly bedded siltstone 

separated by thin discontinuous units of less resistant gray shaly siltstone. Molds of brachiopods and bryozoans occur sparsely. In the 

area from near Berea to near Stanton the Cowbell ranges from 0 to 

about 175 feet in thickness.

North of the Disputanta section (fig. 2, section 5) the Cowbell Member conformably overlies the nonresistant Nancy Member (fig. 8).

FIGURE 9. Typical shale and minor siltstone of the Nada Member of the Borden 

Formation (Mbno) overlying resistant siltstone and minor silty shale of the 

Cowbell Member of the Borden Formation (Mbc) and underlying argillaceous 

limestone and minor shale of the Renfro Member of the Borden Formation 

(Mbr). At top of outcrop is cherty sparsely oolitic very fine grained limestone 

of the Newman Limestone (Mn). Type locality of the Nada Member, north 

side of Mountain Parkway 0.1 mile west of Nada (Lombard Post Office), Ky.
BORDEN FORMATION (MISSISSIPPI^) KENTUCKY F15

It is conformably overlain by less resistant silty shale and minor 

siltstone of the Nada Member of the Borden Formation (fig. 9). This 

contact is fairly sharp, but in places it is gradational through a few 

feet.

South of the Disputanta section, as shown in figures 2 and 3 (lower 

part), the Cowbell Member splits into two prominent mappable 

tongues of siltstone that pinch out a few miles southwestward within 

the Nancy Member. The lower of these tongues is here named the 

Roundstone Bed for outcrops along Roundstone Creek about 3 miles 

south of Berea. The upper tongue, the Conway Cut Siltstone Member 

of Stockdale (1939, p. 1YO) of the Brodhead Formation, is here called 

the Conway Cut Bed of the Cowbell Member; the typical outcrops are 

along the Louisville and Nashville Railroad near Conway about 9 

miles south of Berea.

NADA MEMBER

The Nada Member is here named for the typical outcrops, shown 

in figure 9, of shale and siltstone exposed along the Mountain Parkway near Nada (Lombard Post Office) about 10 miles east of Stanton, 

Ky. (p. F31). It includes beds assigned to the Brodhead, Floyds 

Knob, and Muldraugh Formations by Stockdale (1939, p. 189).

The Nada Member is a slope-forming unit that consists of clayey 

and silty shale with minor siltstone (figs. 2, 9). The shale, which is 

mostly olive gray with patches of grayish red and grayish purple, 

locally grades into thin-bedded resistant limy siltstone, which is more 

abundant near the southern edge of the member. Nonresistant glauconitic siltstone is also locally common. The member, ranges from 

about 30 to 65 feet in thickness.

The drab shale and siltstone of the Nada Member contrast strongly 

with the yellowish- and grayish-orange silty limestone of the conformably overlying Renfro Member of the Borden Formation. The 

Nada Member is readily distinguished from the more resistant overlying and underlying units east and northeast of Berea, but south and 

southwest of Berea its upper part grades into the Wildie Member and 

its lower part grades into the Nancy Member. Because of the lateral 

gradation of the members, arbitrary cutoffs for mapping the Nada 

Member are the south and east edges of the Berea quadrangle (lat 

37°30' N., long 84°22'30" W.).

HALLS OAF MEMBER

The Halls Gap Member of the Borden Formation is here named for 

the typical section of siltstone exposed along U.S. Highway 27 on the 

north side of Halls Gap, about 4.5 miles south of Stanford, Ky. (p.
F16 CONTRIBUTIONS TO STRATIGRAPHY

F30). It includes beds previously assigned by Stockdale (1939) to 

the upper part of the Brodhead Formation at this locality.

The Halls Gap Member is made up of resistant limy siltstone with 

minor shaly siltstone and silty limestone (fig. 10). The fresh rock is 

chiefly medium gray to greenish gray; weathered surfaces are commonly brownish gray from limonite stain. The member is generally 

in obscure rough beds about a foot thick; locally south of Halls Gap 

the beds are in broad sweeping lenses 2 to 20 feet thick and several 

hundred feet long. Lenticular concretions of finely crystalline limestone about a foot thick and a few feet long, geodes of white chert 

a fraction of an inch to several inches in diameter, and nodules of 

pyrite less than 1 inch in diameter are sparse to common. Fragments 

of fossils, chiefly crinoid stems but also brachiopods and horn corals, 

are common to abundant in very limy siltstone and silty limestone; 

whole fossils are sparse. The member weathers by spalling to form 

ledges with convex smooth to hackly surfaces.

Mbh

5 feet

FIGURE 10. Characteristic lithology and upper contact of the Halls Gap Member 

of the Borden Formation. Resistant gray and brownish-gray limy siltstone of 

the Halls Gap Member (Mbh) gradationally overlain by dolomitic siltstone 

of the Muldraugh Member of the Borden Formation (Mbm). Type locality of 

the Halls Gap Member, east side of U.S. Highway 27, near Halls Gap, about 

4.5 miles south of Stanford, Ky. (Rule in lower right corner is extended 5 ft.)
BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY FIT

The Halls Gap Member is conformably overlain by the Muldraugh 

Member in much of the area (fig. 2). The contact is sharp where 

persistent beds of limestone of the Muldraugh Member rest on siltstone 

of the Halls Gap Member. In places, as at Halls Gap, the contact is 

fairly sharp although gradational through a few feet where siltstone 

of the Halls Gap Member grades into calcareous, dolomitic, and cherty 

siltstone of the Muldraugh Member, as shown in figure 10. Less commonly the members are transitional where siltstone of the Halls Gap 

Member contains scattered lenses of limestone that become more 

numerous and persistent upward; the contact is placed at the base of 

the relatively persistent zone of lenses of limestone.

Between Halls Gap and Berea the Halls Gap Member is overlain 

by nonresistant shale and shaly siltstone and resistant coarse siltstone

FIGURE 11. Characteristic lithology, shale and siltstone, of the Wildie Member 

of the Borden Formation (Mbw). Lower part of the member here is even-bedded 

coarse siltstone like that making up most of member at type locality near 

Wildie, Rockcastle County, Ky. Beneath these lower siltstone beds is a seam 

of greenish-black glauconitic siltstone (g) at the base of the member; below is 

siltstone and minor shale of the Halls Gap Member of the Borden Formation (Mbh). Projecting ledge near top of photograph is argillaceous limestone 

of the overlying Renfro Member of the Borden Formation (Mbr). Beneath 

this ledge at the top of the Wildie Member is another seam of greenish-black 

glauconitic siltstone (g) like that at the base of the member. West side of 

U.S. Highway 25 about 3 miles north of Renfro Valley, Ky.
F18 CONTRIBUTIONS TO STRATIGRAPHY ^

of the Wildie Member of the Borden Formation (figs. 2, 11). The 

contact commonly is fairly sharp and, as shown in figure 11, is generally conspicuous because of ledges formed by very resistant even- f 

bedded coarse siltstone near the base of the Wildie Member. ,--

The full extent and stratigraphic relations of the Halls Gap Member 

are not precisely known. The member reaches its greatest thickness 

of about 100 feet a few miles southeast of Halls Gap; it thins north- ^ 

eastward and pinches out near Berea within the Nada Member of the 

Borden Formation. It is not a mappable unit north of the south 

boundary of the Berea quadrangle (lat 37°30' N.), Kentucky. The wHalls Gap Member has been traced southward in numerous sections 

to Bobtown, but it is not present near Nancy or in the area south of 

Mount Vernon; and in these areas it apparently grades into non- V 

resistant shaly siltstone and shale of the Nancy Member. The Halls 

Gap Member has been traced in scattered sections westward with some 

uncertainty as far as Phillipsburg, Ky. (p. F37). -<

WILDIE MEMBER

Stockdale (1939, p. 215-216) included the Wildie Sandstone Mem- "" 

ber of the Warsaw Formation (Butts, 1922, p. 89, 102-104) in his * 

Wildie Siltstone Member of the Muldraugh Formation of the Borden 

Group. The Wildie Member is here redefined as a siltstone and shale ^ 

member of the Borden Formation and includes the equivalent Cummins Station Member of Stockdale (1939, p. 213-214), with which ( 

it intergrades. r

Stockdale (1939, p. 216-217) gives excellent descriptions of the y 

member near and a short distance away from the type locality near 

Wildie, Ky. Representative outcrops of the Wildie Member are herein described at the Renfro Valley North section (p. F34). ' <--

Near Wildie the member is made up almost entirely of thick beds 

of resistant brownish-weathering, greenish-gray siltstone and very 

fine grained sandstone with shale in thin seams and partings. Along 

the outcrop a few miles away from the type locality, the siltstone 

beds decrease in thickness and number and the amount of shale increases so that siltstone forms a minor part of the member as shown V^ 

in figure 11 at the Renfro Valley North section. The shale is non- ^ 

resistant, clayey to silty, in places glauconitic, and mostly greenish 

gray but locally 'grayish red and grayish purple. A persistent seam of 

glauconitic siltstone is present at the base of the unit and another ^ 

glauconitic seam is at the top.

The contact between the Wildie Member and the underlying Halls *-- 

Gap Member is sharp and commonly expressed topographically as ^ 

a pronounced change in slope. The Wildie Member is overlain by
BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY F19

the Renfro Member, whose yellowish-gray silty limestone contrasts

strongly with the drab shale 'and siltstone of the Wildie Member.

1 The Wildie Member ranges in thickness from a few feet to about

,, 25 feet; in some quadrangles it is too thin to map separately and 

must be combined with the overlying Renfro Member. The Wildie

^ Member feathers out into the Muldraugh Member of the Borden

^ Formation near the west edge of the Crab Orchard quadrangle (long 

84°37'30" W.). On the north it grades into the upper part of the 

Nada Member; for mapping purposes the north edge of the Wildie

~v quadrangle (lat 37°30' N.) is the northern cutoff of the Wildie 

Member.

* RENFRO MEMBER

.;

The Renfro Member of the Borden Formation is here named for

*' exposures near Renfro Valley, Ky. (p. F32). The Renfro Member 

^ is made up dominantly of sparsely cherty unfossiliferous light-greenish-gray, yellow- to orange-weathering aphanitic to finely crystalline 

^ argillaceous and dolomitic limestone. The argillaceous limestone is 

_j commonly in fairly even to wavy beds separated by partings, seams,

and thin units of greenish shale. The beds of argillaceous limestone

**" commonly weather by spalling to form rounded ledges as shown in

M figure 12.

The Renfro Member includes equivalents of the Salem and Warsaw 

Limestones and of the Muldraugh Member of the Borden Formation

j (fig. 2). Limestone beds of both the Muldraugh Member and Salem 

and Warsaw Limestones become more silty and thus more alike east-

^ ward from south-central Kentucky; they cannot be readily distin-

_f guished east of Halls Gap, although crossbedded fossiliferous sandy, 

coarse-grained limestone suggestive of the Salem and Warsaw Lime-

"^ stones and geode-bearing knotty-textured laminated calcareous silt-

^ stone and limestone like those in the Muldraugh Member are recognizable in the Renfro Member about as far east of Maretburg. Near 

Berea the Renfro Member includes some beds of yellowish-gray

_, argillaceous limestone that were assigned to the St. Louis Limestone 

by Butts (1922, p. 123,125-126, chart) and by Stockdale (1939, p. 173,

'-* 212, pi. 6).

>. The basal contact of the Renfro Member, as shown in figures 9 and 

11, is generally a fairly sharp break between the moderately resistant

' yellowish-gray silty limestone of the Renfro Member and the non-

* resistant shale and siltstone of the Wildie or the Nada Members. 

South of Mount Vernon, Ky., both the Wildie and Halls Gap Members pinch out so that the Renfro Member rests on silty shale beds of the

^ Nancy Member (N. L. Hatch, Jr., U.S. Geol. Survey, oral commun., 1962).
F20 CONTRIBUTIONS TO STRATIGRAPHY

FIGURE 12. Characteristic argillaceous limestone and minor limestone and shale 

of the Renfro Member of the Borden Formation. Type locality of the Renfro Member, west side of U.S. Highway 25 about 3 miles north of Renfro 

Valley, Ky. Geologic pick for scale (see arrow).

The upper contact generally is a conspicuous diastem (fig. 6) that 

separates yellowish-gray argillaceous limestone of the Eenfro Member from the light-gray aphanitic to fine-grained limestone of the 

St. Louis Limestone Member of the Newman Limestone. In many 

places the upper part of the Renfro Member contains a few thin beds 

of gray fine-grained limestone similar to beds of the St. Louis Member. 

Most of these beds seem to be discrete lentils, but some are tongues of 

the St. Louis Member. The intertonguing is generally sporadic and 

limited to a thickness of a few feet. Between Brodhead and Renfro 

Valley, however, the upper part of the Renfro Member and the lower 

part of the St. Louis Member intertongue through a thickness of 

several tens of feet. In this area the St. Louis Member thins by intertonguing from a thickness of about 60 feet to 20 feet, and the Renfro 

Member thickens from about 50 feet to 80 feet. : > 

The Renfro Member has been traced in sections from near Halls 

Gap to near Stanton, Ky. The east edge of the Halls Gap quadrangle 

(long 84°37'30" W.) is the arbitrary cutoff of the Renfro Member; 

west of this line the Salem and Warsaw Limestones and the Muldraugh
BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY F21

Member of the Borden Formation can be mapped. The Renfro Member reaches its greatest thickness of about 100 feet a few miles east of 

Halls Gap; through much of east-central Kentucky it ranges from 

about 25 to 50 feet in thickness. ': ;.-' ,./- . ..'-":. 

MULDRAUGH MEMBER ,

The Muldraugh Formation (Stockdale, 1939) is here redefined as 

the Muldraugh Member of the Borden Formation. Its characteristic 

lithology is well displayed at the type section near Phillipsburg, 

Ky. (p.F36).

The Muldraugh Member consists chiefly of cherty and dolomitic 

limestone and cherty, dolomitic, and calcareous siltstone that weather 

to a yellowish-orange rubble. It is generally about 50 feet thick 

between Phillipsburg and Halls Gap but is locally as much as 100 

feet thick. Laminae in the silty units are commonly contorted around 

small (less than an inch in diameter) chert or calcareous concretions, 

which give most of the silty units in the member the characteristic 

swirl or knotty texture shown in figure 13. Shale and shaly siltstone

FIGURE 13. Characteristic texture of dolomitic and calcareous siltstone of the 

Muldraugh Member of the Borden Formation. Irregular knotty texture is an 

effect of very small siliceous and calcareous concretions and irregularities in 

dolomite and calcite content of siltstone. Bast side of U.S. Highway 27 near 

Halls Gap, Ky.
F22 CONTRIBUTIONS TO STRATIGRAPHY Voccur locally as thin beds and partings. The dolomitic limestone is ? 

commonly fine to medium grained and silty and contains few fossils. ^

As redefined the base of the cherty and dolomitic limestone and 

siltstone of the Muldraugh Member lies generally a few feet to several ^ 

tens of feet below glauconitic siltstone that Stockdale (1939) assigned U 

to the Floyds Knob Formation. The glauconitic siltstone is here ( 

regarded as an informal unit, not a formation boundary, but is useful r 

as a marker bed in parts of Kentucky.

The Muldraugh Member lies conformably upon the Hall's Gap 

Member or the Nancy Member (fig. 2). The resistant cherty dolomitic or calcareous siltstone of the Muldraugh Member generally ^ 

forms cliffs or steep slopes above the less resistant siltstone and silty 

shale of the Halls Gap Member (fig. 10) or the shale and silty shale of 

the Nancy Member. lj*

The Muldraugh Member is conformably overlain by the Salem and ^ 

Warsaw Limestones 3 that form a single mappable unit in southcentral Kentucky (Nelson, 1962). The basal unit of the Salem and v 

Warsaw, as shown in figure 5, is commonly cherty fossil-fragmental v 

medium- to coarse-grained limestone that contrasts strongly with the 

sparsely f ossiliferous spally weathering much finer grained, more silty '"* 

and dolomitic limestone o.f the Muldraugh Member. Calcareous shale u . 

generally overlies the basal limestone unit of the Salem and Warsaw 

and forms a deep recess only a few feet above the top of the Muldraugh 

Member. <v

Near Halls Gap the Muldraugh Member of the Borden Formation 

and the overlying Salem and Warsaw Limestones gradually thin and 

grade eastward into argillaceous limestone with minor shale and silt- t, 

stone forming the Kenfro Member of the Borden Formation. For 

mapping purposes the east edge of the Halls Gap quadrangle (long 

84°37'30" W.) is the eastern cutoff of the Muldraugh Member. v

8 See footnote 2, page F8.
-< BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY F23

MEASURED SECTIONS

-*\ Nancy section

[Type section of the Nancy Member of the Borden Formation. Measured about 2 miles east

"~? of village of Nancy, Puiaskl County, Ky. (Delmer quadrangle), in Pulaski County Park,

beginning at point about 500 ft. below park entrance. Described from outcrops on

-; right side of Kentucky Highway 1248 for basal 35 ft. of section ; rest of section described 

from outcrops on left side of road. Uppermost part of section measured up face of

^ steep nose above sharp curve in road. Elevation at top of New Albany Shale about 790 

ft. Measured with barometer and tape by J. L. Gualtierl assisted by J. C. Dills, August 

1962]

Mississippian:

Borden Formation (incomplete):

-y Muldraugh Member (incomplete): Feet 

11. Chert, light-brownish-gray (5FE6/1),1 weathering dark yellowish

-\ orange; beds as thick as 2 ft interbedded with thin undulatory 

clay shale units as thick as 6 in. Top of unit not established; 

basal 10 ft well exposed. Not measured.

10. Shale, silty, medium-gray (N 5), weathering light bluish gray; 

imperfectly fissile; abundant siliceous geodes as much as 4 in.

x long __-______-__-_-_-________----------_----- 11.5

9. Siltstone, dolomitic and limy, greenish-gray (5GY 6/1) and

<{ yellowish-gray (5F 7/2), weathering same and pale yellowish 

orange; weathering of contorted laminae gives surface of

v rock a gnarly or knotty appearance; numerous shale partings. 8 

8. Shale, glauconitic, silty and clayey, medium-light-gray (N 6);

~""< abundant grains of a greenish-black (5G 2/1) mineral, probably glauconite. This unit is probably the Floyds Knob 

Formation as used by Stockdale (1929, 1939) _-----__ .3

V 7. Limestone, medium-gray (N 5), coarse-grained; several shale 

partings as thick as 4 in.; pyrite nodules and irregular chert

V bodies in basal 1 ft; upward the unit is more coarsely grained, 

containing anhedral calcite crystals as much as 5 mm long.

'"* Fossil debris, especially crinoid stems, very abundant--..__ 10

Measured Muldraugh Member (incomplete)-.----.------ 30

Nancy Member:

6. Shale, silty, clayey, medium-gray (N 5), well developed to 

poorly developed shale partings; forms resistant ledge; base 

indistinct __ __________________________________________ 16

5. Shale, silty, clayey, medium-gray (N 5) to medium-dark-gray 

(N 4) ; shale partings poorly developed in basal part, better 

developed upward where unit is less silty; resistant, forms 

prominent overhanging ledge at base. Common brachiopods, 

crinoids, and fernlike bryozoans.. _ ____._____-__-_____---_ 26

4. Shale, silty, clayey; silty shale and siltstone; medium light gray 

(N 6) and medium gray (N 7); obscurely and crudely laminated; weathered outcrop yields chips and small plates and 

blocks; upper part of unit not well exposed but appears more 

shaly than base; forms prominent ledge at base. Abundant 

brachiopods, very sparse trilobites; worm(?) trails in clayey

---_-___._.__. ....___-_--..----.._-_..__...._.. 37

Color name with numbers based on color chart by Ooddard and others (1948).
F24 CONTRIBUTIONS TO STRATIGRAPHY y

Nancy section Continued vf

Mississippian Continued ^ 

Borden Formation (incomplete) Continued 

Nancy Member Continued Feet <^~

3. Shale, clayey, very slightly silty, dark-greenish-gray (5GY 4/1), 

fairly well developed shale partings; fracture surfaces limonite 

stained; forms prominent ledge...---_____-___---------_- 11 ,

2. Shale, clayey, very slightly silty to slightly silty, grayish-yellow- r 

green (5GY 7/2), mottled moderate red (5R 4/6) at base, 

changing upward to medium gray (N 5), dark greenish gray 

(5GY 4/1), dusky yellow green (5GY 5/2) and medium bluish rgray (5B 5/1); well developed shale partings; limonite stains 

fracture surfaces where unit is more silty. Basal 7 ft mostly ~^ 

covered but yields small phosphatic nodules. Top 15 ft 

consists of slightly more resistant rock, forming irregular and * 

discontinuous ledges. A single continuous ledge, 3 to 4 ft 

thick but otherwise similar to those below it, occurs near top 

of unit--__----_-_--_---_____.-____.-_._-_-_---__--_--- 60 ..,

Total Nancy Member._________________________________ 150

Measured Borden Formation (incomplete)-----.---------- 180

Devonian:

Chattanooga Shale:

1. Shale, carbonaceous, black (N 1), laminated, weathering to plates 

and chips. Contact with overlying clayey shale very poorly 

exposed. Not measured.

Indian Fort Mountain section

[Type section of the Cowbell Member of the Borden Formation. Units 1 and 2 measured 

along road to reservoirs In Cowbell Creek joining Kentucky Highway 21 about 0.9 mile, 

west of village of Blghill, Madison County, Ky. (Bighill quadrangle) ; units 3 and 4 

measured westward along Kentucky Highway 21 to top of hill; units 5 through 8 measured along forest road up south point of Indian Fort Mountain, beginning about 300 ft. 

west of high point on highway; units 9 through 19 measured along abandoned road 

branching off newer forest road; section then offset to foot trail up southwest spur of 

south point of Indian Fort Mountain, units 20 through 22 measured along this trail; 

units 23 and 24 measured over cliff on northwest side of this trail. Measured with 

barometer, Jacob staff, and tape by G. W. Weir and J. L. Gualtieri assisted by D. R. Siegle, 

June 1963]

Mississippian:

Newman Limestone (incomplete): Feet 

St. Louis Limestone Member:

24. Limestone, cherty, very light brownish gray (5YR 7/1) and 

olive-gray (5Y 5/1) to yellowish-gray (5Y 8/1), chiefly micrograined, in part fine- to medium-grained. Common to 

abundant grayish-orange chert in irregular masses commonly 

about 1 ft long and 2 in. thick and as replacement of abundant colonial corals.___.___-_______._.________-._._._- 7. 7
BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY F25

Indian Fort Mountain section Continued

Mississippian Continued 

Newman Limestone (incomplete) Continued

St. Louis Limestone Member Continued Feet 

23. Limestone, very light greenish gray (5GY 7/1), fine- to mediumgrained; sparse medium to coarse grains of orange chert; in 

beds 1 to 8 in. thick; sparse small brachiopods. Some argillaceous layers 1 to 4 in. thick interbedded with thin seams 

of grayish-yellow-green (5GY 7/2) clay stone; common crinoids, bryozoans in argillaceous limestone and as impressions 

in the claystone. Base undulatory, thickness ranges from 

2 to 2.5 ft..._. .._.._....._. .._....._............ 2.3

Total St. Louis Limestone Member of Newman Limestone. 10

Borden Formation:

** Renfro Member:

22. Limestone, argillaceous, dark-yellowish-orange (1QYR 6/6), very 

fine grained, silty and clayey; in uneven beds 1 to 4 in. thick; 

fairly resistant except in top 5 ft.____--____-__-___-______ 17

21. Poorly exposed, probably most is yellowish argillaceous limej stone similar to overlying and underlying units. About 1 ft

above base is argillaceous limestone, pale greenish yellow

N- (lOF 3/2), and very fine grained; contains abundant discoidal 

nodules of chert as much as 3 in. across and H in. thick.

--' About 4 ft above base is limestone, light olive gray (5Y 6/1);

micrograined to very fine grained; a resistant bed about 0.2

ft thick._._..___._.___._____.._.______-_.. 5.5

i 20. Limestone, argillaceous, generally similar to limestone of unit

22 but nonresistant, mostly punky weathering. Scattered

y irregular patches of light-gray chert about 1 in. thick and as 

much as 12 in. long at 12 to 15 ft above base. On original 

line of section basal layer of argillaceous limestone, 0.1 to 

0.3 ft thick, is silicified to pinkish-gray (5YR 8/1) chert_-_-_ 27. 5

Total Renfro Member______---.______.________------- 50

Nada Member:

19. Claystone, glauconitic silty, grayish-yellow-green (5GT 7/2); 

disseminated grains and streaks of grayish-olive-green (5GY 

3/2) grains of glauconite; nonresistant________-__-_____--_ .3

18. Siltstone, pale-olive (10F 6/2), weathering light olive gray 

(5Y 5/2) with surface blotches of grayish orange or grayish 

yellow; coarse silt; internal layering obscure; nonfissile, a 

"freestone;" contains a few worm(?) markings; forms prominent ledge. Abundant small concretionary nodules imbedded 

in upper surface; dark gray (N 3), weathering lighter gray; 

silicified, possibly phosphatic in part, in part very fine 

grained; irregularly rounded; mostly % to % in. in diameter. 

Unit thickens to 0.8 ft thick 10 ft east of line of section__. . 4

17. Siltstone, clayey, yellowish-gray (5Y 7/4), very thinly bedded;

splits along irregular planes about % in. apart; forms slope 2. 4
F26 CONTRIBUTIONS TO STRATIGRAPHY

Indian Fort Mountain sections-Continued ^-

Mississippaan Continued 

Borden Formation Continued

Nada Member Continued Feet >_ 

16. Siltstone, similar to unit 18-__--__-_-_--__________________ 0.5

15. Siltstone, clayey, similar to unit 17_______________________ 9.3 <- 

14. Siltstone, similar to unit 18______________________________ . 2

13. Siltstone, clayey, similar to unit 17_______________________ .8 /-

12. Siltstone, similar to unit 18______________________________ . 8

11. Siltstone, similar to unit 17 but less clayey___-_-_-_____--_-- 7.7 

10. Mudstone, silty (60 percent), leached limestone (30 percent), 

and siltstone (10 percent). From base upward: siltstone 

with abundant silt-sized to medium grains of greenish-black 

glauconite, mostly dusky green (5G 3/2), in less glauconitic 

portions pale yellowish brown (1QYR 6/2); about 2 in. thick. V, 

Mudstone, silty, glauconitic, poorly exposed; about 20 in. 

thick. Leached limestone, weathered to dark yellowish -** 

orange (10 YR 6/6). Unit is Ployds Knob Formation as used 

by Stockdale (1929, 1939, p. 175)__-----_-_----__-_---__- 2.6 ^ 

9. Shale, clayey; base dark greenish gray (5GY 4/1) mottled 

brownish black (SYR 2/1), upper hah* moderate olive brown 

(5Y 4/4) and grayish red (10R 4/2) to moderate brown (5Y ^ 

4/4); very slightly silty; laminated; outcrop yields thin chips 

less than % in. across. Phosphatic nodules, greenish gray -* 

(5GY 6/1), ovoid, commonly about % in. in diameter and 1 

in. long; abundant on weathered slope in basal few feet of >- 

unit. Well to poorly exposed; nonresistant; forms narrow 

bench at base, moderate slope above.____________________ 22

Total Nada Member___--------_---------------_----- 47

Cowbell Member:

8. Siltstone, mostly pale olive (10F 6/2) and light-olive-gray 

(5Y 6/1), grading at top to grayish olive (10F 4/2) with common dark-brown limonite stain on bedding planes and wr 

fracture surf aces; bedding partly obscure, mostly in slightly 

uneven beds }i to 2 in. thick; splits along bedding and along ^ 

irregular fracture surfaces % in. to 3 in. apart; outcrop yields 

plates and irregular blocks commonly % to % in. thick and 1 

to 3 in. across; moderately resistant, forms steep slope. y.. 

Fossils common near base and abundant near top, chiefly 

small brachiopods less than 1 in. wide, crinoid columnals, and >^ 

sparse small tubular bryozoans a few millimeters wide; 

mostly preserved as molds. Top of unit marked by pro- -< 

nounced flattening of slope._______--______------_-_----- 43

7. Siltstone, clayey, moderate-yellowish-brown (10F 5/4) to pale- *' 

olive (10F 6/2), very fine micaceous flakes in basal 10 ft; 

less resistant thar underlying or overlying units but otherwise generally similar to them; poorly exposed in eroded ^._ 

roadbed. Dark-brown ovoid limonite concretions, with pronounced layered structure, about 3 to 4 in. thick and 10 to 12 y 

in. long; occur about 35 ft above base. Unfossiliferous.---- 47
BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY F27

Indian Fort Mountain section Continued

Mississippian Continued 

Borden Formation Continued

Cowbell Member Continued Feet 

6. Siltstone (85 percent) and clayey siltstone (15 percent); at base 

moderate olive brown (5Y 4/4), mostly yellowish gray 

(5.F 7/2) to greenish gray (5GY 6/1) or pale olive (10F 6/2); 

dark-brown limonite stain common on bedding planes and 

fracture surfaces; clayey in basal 7 ft; mostly in very thin 

beds % to }i in. thick; splits along bedding planes and irregular 

surfaces about \}'i in. apart; outcrop yields chips and plates 

1 to 3 in. across; fairly well exposed along forest road; moderately resistant, forms steep slope. Limonite concretions, 

yellowish gray and dark brown, in solid spindly bodies as 

much as 1J4 in. in diameter and 3 in. long occur sparsely about 

37 ft above base; in part sideritic; some have casts of small 

gastropods at centers. Concretionary bodies of very limy 

siltstone, greenish gray (5GY 6/1), as much as 1 ft thick, 1.5 ft 

long; weather to rounded surfaces at 51 ft above base. 

Fossils sparse, consisting of gastropods, curly worm(?) 

marks, and TaonurusC?) ("rooster tail" marking) in upper 

part of unit.__________________________________________ 55

Total Cowbell Member.___..__._._____._.___..... 145

 -^ Nancy Member:

5. Shale, clayey, grading upward to silty clay shale; mostly dark 

greenish gray (5GY 4/1) to brownish gray (SYR 4/1) with

^i sporadic reddish streaks, near top chiefly pale yellowish

' brown (WYR 6/2) to dark yellowish brown (IQYR 4/2);

, very slightly silty grading to silty at top; in laminae 3 to 5 mm

thick; splits along laminae or irregular surfaces \i to 1 in.

.-- apart; outcrop yields small platy fragments /4e to 1 in. across 

and irregular blocks commonly about 1 in. thick and 3 in.

:K, long; mostly weathers to yellowish-gray soil with minute 

shale fragments; poorly exposed; nonresistant, forms gentle

 slope. Upper contact broadly gradational through about 30 

, ft as clay shale grades upward to siltstone; contact arbitrarily

placed at base of lowest relatively persistent siltstone.---.. 28 

4. Shale, greenish-gray (5GY 6/1) and pale-olive (10F 6/2),

weathering same; very slightly silty; more fissile than under-

 u-: lying shale, yields chips a few millimeters thick and a few 

inches across. Iron concretions common, sporadically dis-

 * tributed, interiors olive gray (5Y 5/1), surfaces shades of red 

and brown; ovoidal, commonly 3 to 6 in. diameter, 6 to 12 in.

^ long. Well exposed in roadcut at top of hill on highway. 

Sparse to common curly worm(?) marks in upper part of 

unit.._______..._________..__._.__________________._._ 38

_± 3. Shale, clayey, pale-olive (10F 6/2) and near top olive-gray 

(5F 5/1), weathering chiefly yellowish gray (5F 7/2). Mostly

 y covered, about 25 percent outcrop; seems similar to underlying unit.____________________________________________ 122
F28 CONTRIBUTIONS TO STRATIGRAPHY

Indian Fort Mountain section Continued v

/

Mississippian Continued

Borden Formation Continued 

Nancy Member Continued Feet

2. Shale, clayey, chiefly pale olive (10F 6/2), dusky yellow at base; c 

mostly clayey but slightly silty at base; in rough laminae i, 

/\Q I to % in. thick; yields small chips a few millimeters thick 

and 5 to 15 mm across. Sparse phosphatic nodules at base; lr 

moderate-yellowish-brown (10F/2 5/2) interior, light-gray 

(N 4) surface; fine silt; ovoidal, about 1 in. maximum 

diameter._____________________________________________ 12

Total Nancy Member.. ..__..___._._..__...... ___ .. 200

Total Borden Formation. _____________________________ 442 ^

Devonian:

New Albany Shale (incomplete) : ~t_| 

1. Shale, dark-gray (N 3), weathering lighter gray and brownish

gray (5YR 4/1) ; laminated; brittle, yielding small plates a few v~ 

millimeters thick and as much as 3 in. across on weathered 

outcrops. Not measured; about 20 ft exposed locally.

Halls Gap section

[Type section of the Halls Gap Member of the Borden Formation. Measured up hill along ^~+ 

U.S. Highway 27 at Halls Gap, Lincoln County, Ky. (Halls Gap quadrangle). Measured with barometer, Jacob staff, and tape by G. W. Weir and J. L. Gualtieri assisted j_ 

by J. C. Dills, July 1962],

Mississippian:

Salem and Warsaw Limestones (incomplete) : ^

38. Residuum, ferruginous and clayey. Not measured. Feet ;

37. Sandstone, grayish-orange (10FZ2 7/4) and pale-orange, fine- \. 

to medium-grained, poorly sorted, platy (probably originally 

limy but now completely leached). Petroliferous residue voccurs as scattered small blebs and as local concentrations 

permeating whole stratum. Ranges from about 2 to 4 ft in ^ 

thickness. _ __________________________________________ 3. 6 ,

36. Claystone, silty, medium-light-gray (N &}, limonitic. In part

may be a residuum from weathering of limestone_____---___ 1. 3 v

35. Clayey residuum from leached limestone, grayish-orange

(10F/2 7/4); abundant spherical to discoidal siliceous geodes >_. 

as much as 1 ft long _ _________________________________ 1. 8

34. Shale, clayey and silty, medium-bluish-gray (55 5/l)_ -------- 1.6 ^

33. Limestone, light-gray (2V 7), mostly weathered to moderate

olive brown (5F4/4) and dusky yellow (5Y 6/4) residuum; * 

fine grained; numerous lentils of fine-grained sandstone as 

thick as 4 in.; abundant siliceous geodes with ferruginous 

cores as much as 1.5 ft in diameter_-__-_-______-___------ 1.8

32. Shale, clayey and silty, medium-bluish-gray (5B 5/1) and

dusky-yellow-green (5GF5/2)____. ---------------------- 1.7 ^..

31. Clayey residuum from leached limestone, dark-yellowish-orange

(10F-? 6/6), grayish-orange (1QYR 7/4), and moderate-yellow V 

(5 YR 7/6) ; intertongues laterally with silty shale _ .___-_-_ 5. 8
F29

Halls Gap section Continued

Mississippian Continued

Salem and Warsaw Limestones (incomplete) Continued Feet 

30. Limestone, medium-light-gray, coarse-grained; abundant large

brachiopods. Unit ranges in thickness from 2.2 to 2.6 ft__ 2. 4

Measured Salem and Warsaw Limestones (incomplete).. _ 20

Borden Formation: 

Muldraugh Member:

29. Limestone, dolomitic, silty, bluish-white (55 9/1), weathering 

very pale orange; irregular diagonal partings; rubbly weathering; sparse siliceous geodes with calcite centers, very sparse 

pyrite nodules_____--_-__-_-_--_____--_____-----._--___ 4. 8

28. Limestone, medium-light-gray (NQ), coarse-grained, contains 

sparse irregular lentils of dolomitic siltstone. Sparse brachiopods and horn corals. As much as 2 ft thick, pinches 

laterally to thin shale parting___________--_---_________ 1

27. Limestone, dolomitic, silty, light-gray (N 7) and very light gray, 

(N 8) weathering grayish orange to dark yellowish orange; 

rubbly weathering; very abundant pyrite as sparse nodules 

and as disseminated grains and concentrations of grains in 

irregular bodies and lentils. Siliceous pyritic geodes, sparse 

to abundant, as much as 4 in. in diameter. A few silty shale 

partings in upper part.____._______._____.._----_--_----_ 26. 7

26. Siltstone, light-bluish-gray (5B 7/1), weathering same and 

yellowish gray; very fine wavy laminae. Contains pyrite 

nodules, siliceous geodes, and pyritic siliceous geodes. Very 

abundant glauconite in basal 0.5 ft__-_--__--------_------ 4. 8

25. Shale, glauconitic, silty, dark-greenish-gray (5G 4/1). A conspicuous seam, 0.1 to 0.2 ft thick_________----___--____ . 2

24. Siltstone, dark-greenish-gray (5(? 4/1), limonitic at top. Abundant glauconite. _______________________________________ .8

23. Siltstone, greenish-gray (5G 6/1), structureless to finely laminated. Very abundant glauconite-________------_______- .4. 6

22. Shale, glauconitic, silty, similar to unit 25. Unit is probably 

Floyds Knob Formation as used by Stockdale (1929, 1939, 

p. 163)--_. _--__-_-_-_-_ _ -- _- .2

21. Shale, silty, medium-bluish-gray (5B 5/1)------------------- .4

20. Limestone, dolomitic, silty, light-gray (N 7), weathering grayish orange; structureless. Contains abundant films and 

grains of bright-green glauconite; lenses, 1.5 to 2 ft thick; 

interfingers with shale at top___-________-_--_-_-__-_---_ 1.8

19. Shale, similar to unit 21_.________________________________ .8

18. Limestone, dolomitic, light-bluish-gray (5B 7/1), weathering; 

gray to very pale orange. Contains abundant grains of 

bright-green glauconite and a few siliceous geodes._________ .7

17. Limestone, silty, dolomitic, light-bluish-gray (5B 7/1); abundant light-olive-gray (5Y 6/1) to brownish-gray (5YR 4/1) 

phosphatic(?) nodules. Abundant grains of bright-green 

glauconite; sparse siliceous and calcitic geodes.-__-___-_.__ .2
F30 CONTRIBUTIONS TO STRATIGRAPHY

Halls Gap section Continued

Mississippian Continued 

Borden Formation Continued

Muldraugh Member Continued Feet 

16. Siltstone, dolomitic and siliceous, and sijlty clayey shale; lightgreenish-gray (5GY 8/1) and grayish orange (10YR 7/4), 

weathering grayish orange; beds lenticular, interfingering. 

Geodes, 1 to 3 in. across, in upper part.__-____----__-____ 8.3

Total Muldraugh Member...____-_----____-_.._.___._ 55. 3

Halls Gap Member:

15. Siltstone, very pale orange (10 YR 8/2) to grayish-orange 

(1QYR 7/4), limonite-stained, crudely laminated to thinbedded, imperfectly fissile. Base of unit marked by 5-ft-thick 

zone of concretions of finely crystalline limestone; blunt 

lentils as much as 3 ft long and 18 in. thick. Sparse siliceous 

geodes; pyrite nodules common near top__________________ 74. 5

Total Halls Gap Member.___-______.___-__ _-______._ 74. 5

Nancy Member:

14. Siltstone, greenish-gray (5GY 6/1) and medium-light-gray (N 6); 

limonite-stained partings. More resistant Siltstone ribs 

prominent in lower part of unit, less distinct upwards. Base 

marked by zone of concretions of limy siltstone, as thick as 

2 ft and as long as 8 ft_______________________________ 14. 5

13. Shale, clayey, dark-greenish-gray (5GY 4/1), weathering light

olive gray; limonite-stained partings; imperfectly fissile.____ 12

12. Covered..._-__-_--_..._-__-___-._...-__-...._---..____. 8

11. Shale, similar to unit 13_.________________________________ 25.7

10. Siltstone, limonitic (may have been limy), yellowish-gray (5F

7/2) to dark-yellowish-orange (10 YR 6/6)_. .___________ .2

9. Shale, similar to unit 13 but more silty. About 3 ft above base

more resistant silty beds form ledee about 2 ft thick._______ 11. 4

8. Siltstone, limy, light-olive-gray (5F6/1); forms ledge...______ . 2

7. Shale, similar to unit 9.--_------_--------------------.--- 3.9

6. Siltstone, sideritic, light-olive-gray (5Y 6/1), weathering to

limonite; 0.1 to 0.3 ft thick__.._________._____-..___-__ . 2

5. Shale, similar to unit 9.-__------------------------------- 4.8

4. Siltstone, limy, light-olive-gray (5F 6/1), weathering light

brownish gray; 0.3 to 0.5 ft thick. _______________________ . 4

3. Shale, similar to unit 9. Sparse small calcite nodules ip. upper 

part; siderite lentils in lower part, as long as 10 ft and as thick 

as 1 ft, weathering to limonite-___________-____--_-___--- 7. 7

2. Mostly covered, probably similar to unit 3__-------.--------- 67. 5

Total Nancy Member.-------------.--.--------------- 156. 5

Total Borden Formation.....___.__.._..___________.__ 286. 3
^ BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY F31

; Halls Gap section Continued

Devonian:

New Albany Shale (incomplete) :

 . 1. Shale, carbonaceous, black (N 1), laminated, brittle, weathering to plates and chips. Not measured.

Nada section

~N [Type section of the Nada Member of the Borden Formation. Measured up roadcut on 

north side of Mountain Parkway 0.4 mile northwest of Nada (Lombard Post Office) 

Powell County, Ky. (Slade quadrangle). Measured with Jacob staff and tape by J. L. 

Gualtieri assisted by J. C. Dills, August 1962] 

*>

Mississippian: 

r Newman Limestone (incomplete) : Feet

18. Limestone, medium-light-gray (N 6), weathering very light 

1 gray (N 8); very fine grained; oolitic in part; sparse pink

chert. Not measured. {^ Borden Formation (incomplete) : 

_^, Renfro Member:

17. Covered by talus from Newman Limestone _ _______________ 22

v 16. Limestone, argillaceous, leached, grayish-orange (1QYR 7/4)

and dark-yellowish-orange (1QYR 6/6), rubbly-weathering___ 6. 1 

K 15. Shale, clayey, slightly silty, dusky-yellow (5 Y 6/4) ._._.___... 1.2

14. Limestone, argillaceous, leached, dark-yellowish-orange (10YR 

'*"' 6/6) and pale-yellowish-orange, thick-bedded, rubbly-weathering -_----__-_-_---------_------------------______- 3.9

^ 13. Shale, clayey, slightly silty, dusky-yellow-green (5GY 5/2). _ _ 1 

12. Limestone, argillaceous, similar to unit 14; film of glauconite

at base- _..___.____-__-_____----_.-.__________.______. 6. 3

j ____

Total Renfro Member. .._.____.__..___.._____. _ .... 40. 5

Nada Member:

"^ 11. Shale, clayey, slightly silty, dusky-yellow-green (5GY 5/2), 

laminated, fissile. Several limy siltstone beds, which pinch 

" ^ and swell, averaging about 4 in. in thickness _ __._._____._ 3. 7

>> 10. Shale, clayey, slightly silty, grayish-red (10 YR 4/2), grades

laterally to yellow-green shale; laminated; fissile___-______ . 4

^ 9. Shale, similar to unit 11. ----------_-_--------------_----. 1

8. Shale, clayey, slightly silty, very dusky red purple (5RP 2/2),

 H- weathering pale red purple; similar to unit 10_ _____________ 2. 3

7. Shale, similar to unit 11. -__--_-----_---___--_-_----_---__ 1.5

* y 6. Shale, similar to unit 11 but with glauconite(?) grains on party ings-.-.-------------------------------.-------------- .2

5. Shale, similar to unit 11 but contains brachiopod impressions.-- 1. 8 

^ 4. Shale, silty, dusky-yellow-green (5GY 5/2), at base dark 

greenish gray (5(7 4/1); contains brachiopod- and crinoid- 

_\ bearing limy lentils that are limonite stained on fracture

surfaces _ _______-_-----_______._________.___-..______ 8. 8

 >-, 3. Siltstone, slightly limy, greenish-gray (5G 6/1); limonite stain

on fracture surfaces ; forms distinct ledge. ___----__._____-_ .8
F32 CONTRIBUTIONS TO STRATIGRAPHY

Nada section Continued

Mississippian Continued 

Borden Formation (incomplete) Continued

Nada Member Continued Feet 

2. Shale, silty, greenish-gray (5G 6/1); imperfectly fissile; brachiopods, Taonurus(l) ("rooster-tail" markings)--------------- 10. 0

Total Nada Member...________---....._______.___.__ 30. 5

Cowbell Member (incomplete):

1. Siltstone, yellowish-gray (5Y 7/2); limonite stain on fracture 

surfaces; in beds as much as 10 ft thick. Interbedded silty 

shale, medium bluish gray (5B 5/1), in sets, as much as 5 ft 

thick, of crude laminae. Not measured-__________________

Measured Borden Formation (incomplete)_.__-__-______ 71

Renfro Valley North section

[Type section of the Renfro Member of the Borden Formation; reference section of the 

Wildie Member of the Borden Formation. Measured along U.S. Highway 25 beginning 

about 0.2 mile southwest of the village of Roundstone, about 3 miles north of Renfro 

Valley, Rockcastle County, Ky. Wildie quadrangle). Renfro and Wildie Members measured with hand level and tape by S. O. Schlanger and J. L. Gualtieri, March 1962 ; Halls 

Gap and Nancy Members measured by J. I*. Gualtieri assisted by J. C. Dills, August 1&62]

Mississippian: 

Newman Limestone (incomplete):

St. Louis Limestone Member: Feet 

49. Limestone, dark-gray (N 3), aphanitic to micrograined; 

abundant nodules of black chert and silicified heads of 

coral resembling Lithostrotion. Sparse endothyrid foraminifera about 10 ft above base..________-__-_----__--_______ 14

48. Limestone, very light gray (N 8) and light gray (N 7), coarsegrained, clastic; abundant moderately sorted crinoid, brachiopod, and bryozoan debris.__________________-_---____-_- 5

Measured St. Louis Member of Newman Limestone (incomplete).._-_-..___-_-_-__...__---_--_-__-_---_.-_- 19

Borden Formation (incomplete): 

Renfro Member:

47. Limestone, argillaceous, light-olive-gray (5GY 6/1), fine-grained. 

Weathers to punky yellowish-orange silt. Base poorly exposed__-_-..-----_.-____-_-------___---------_------ 4

46. Shale, pale-olive (10 Y 6/2); plastic when wet; poorly exposed. _ 1. 5

45. Limestone, argillaceous and silty, grayish-yellow (5F 8/4), 

aphanitic; weathers to dark-yellowish-orange (lOYTi! 6/6) 

punky silty claystone-_____________--__----------------- 4

44. Limestone, light-gray (N 7), weathering yellowish gray (57 7/2); 

medium to coarse grained, clastic; fragments of brachiopod 

shells and crinoids common. Probably grades southward into 

argillaceous limestone like that in unit 43.--------------- 2. 4
BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY F33

R&nfro Valley North section Continued

Mississippian Continued 

Borden Formation (incomplete) Continued 

Renfro Member Continued Feet

43. Limestone, argillaceous, yellowish-gray (57 7/2), aphanitic; cut 

by many irregular veins of clear calcite; 0.1 ft green shale at 

base. Probably thickens southward-------._____-____-___ 3. 5

42. Limestone, argillaceous and silty, yellowish-gray (57 7/2) and 

light-olive-gray (576/1) to pale-yellowish-orange (10 YR 8/6), 

very fine grained to aphanitic; bedding irregular and lensing; 

spalls parallel to exposed face; weathers to punky yellow silty 

clay. Contains many large masses of clear light-brown calcite. Upper 2.5 ft is contorted and contains twisted thin 

beds of green shale. Top uneven________________________ 13

41. Shale, dusky-yellow-green (5GY 5/2)......._______._... .3

40. Limestone, argillaceous, light-olive-gray (576/1) and yellowishgray (577/2), similar to unit 42. Base irregular, marked by 

0.1 to 0.2 ft of green-stained limestone containing irregular 

patches and veinlets of quartz.__________________________ 4. 8

39. Limestone, greenish-gray (5GY 6/1), very fine grained to

aphanitic; a single bed; base gradational___ _______________ 1

38. Limestone, medium-light-gray (N 6), poorly sorted, mediumgrained, clastic. Interbedded greenish-gray (5(? 6/1) shale. 

Sparse endothyrid foraminifera about 3 ft below top.--__-__ 4. 2

37. Limestone, argillaceous, yellowish-gray (57 7/2)............ 3. 2

36. Siltstone, calcareous and dolomitic, dusky-yellow-green (5GY 

4/2), thin-bedded; yields platy fragments. Poorly exposed; 

thickness approximate._________________________________ 5. 5

35. Limestone, olive-gray (57 3/2); poorly sorted calcarenite___- . 9

34. Limestone, very argillaceous, yellowish-gray (5 Y 7/2) and paleyellowish-orange (1QYR 8/6); similar to unit 42. Basal 1.0 

ft contains calcite- and quartz-filled geodes._______________ 3. 7

33. Shale, dusky-yellow-green (5G7 5/2); pinches out laterally...- .6

32. Limestone, argillaceous, light-olive-gray (5Y 5/2) and duskyyellow (5Y Q/4)........................................ .5

31. Shale, silty, grayish-yellow (5Y 8/4) to light-olive (107 5/4).. 1.6

30. Siltstone, calcareous, yellowish-gray (57 7/2) and dark-yellowishorange (107ft 6/6); forms single bed______________________ 1. 3

29. Shale, dusky-yellowish-green (5GY 5/2) and grayish-olive 

(107 4/2), nonresistant; plastic when wet. Upper 0.2 ft 

glauconitic. Single siltstone bed 0.5 ft thick, 0.5 ft above 

base._______-__-_--__-________--_-_-___-_____-__-____- 3.7

28. Limestone, dolomitic, argillaceous, dark-yellowish-orange (107/2 

6/6) to moderate-yellowish-brown (107ft 6/2), finely crystalline; scattered fragments of bryozoans and brachiopods. 

Contains nodules, a few inches in diameter, of gray chert 

with included fossil debris. Unit irregular in thickness. ___ 2.8

27. Siltstone, grayish-yellow (57 8/4) and yellowish-gray (57 

7/2), brittle. Contains conspicuous subspherical quartzfilled geodes as much as 1 ft in diameter.._________.___. 9
F34 CONTRIBUTIONS TO STRATIGRAPHY

Renfro Valley North section Continued

Mississippian Continued 

Borden Formation (incomplete) Continued

Renfro Member Continued Feet 

26. Limestone, dark-yellowish-orange (IQYR 6/6), punky; scattered fragments of crinoids and brachiopods; pinches and 

swells._______----_________----__-__-_______-__-_._-__ 1

25. Shale, grayish-green (10GT 5/2), irregular, probably discontinuous. _-_-__-_-______-_--_-__-_______-_________-_ .3

24. Limestone, dolomitic, pale-yellowish-orange (IQYR 8/6); fossil 

debris in streaks. Thin partings of pale-olive (10F 6/2) 

clay shale. Contains platy to nodular masses of partly 

iron-stained gray chert oriented parallel to bedding________ 9.7

Total Renfro Member___-__--___-__.-_-____._-___-- 82.5

Wildie Member:

23. Limestone, very silty, yellowish-gray (5F 8/1) to dark-yellowishorange (IQYR 6/6); glauconite-streaked, a single bed___-__ 1.5

22. Siltstone, glauconitic, dusky-green (5G 3/2) to greenishblack (5GY 2/1), grading downward into glauconite-streaked 

gray siltstone__--__-_______--__________________________ . 5

21. Claystone, dusky-yellow-green (5GY 5/2) and pale-olive

(107 6/2)......_._.__......_.....___._._.__. .._..__ 4.7

20. Siltstone, light-greenish-gray (5G 8/1), laminated, interbedded

with greenish-gray shale._.__-_-_-____-_--____-___--__._ .7

19. Shale, silty; at top, dark greenish gray (5G 4/1) mottled grayish 

red purple (5RP 6/2); grades downward into dark greenish 

gray (5(? 4/1). Small discoidal phosphatic nodules about 3 ft 

above base____________________________________________ 8. 9

18. Siltstone, locally slightly calcareous, light-olive-gray (5Y 5/2), 

dense; in thin, even beds; breaks into small blocks. Contains 

partings and irregularly lensing thin beds as much as 7 in.

thick of greenish-gray silty shale, mostly in upper one-third 

of unit. Base of unit is discordant owing to northward 

thinning of beds of shale in units 12 through 17_-_______--__ 5. 2

17. Siltstone, glauconitic, greenish-black (5G 2/1)__._______-__-_- .5

16. Shale, light-olive-brown (5F 5/6)-_____..__________________ .6

15. Siltstone, siliceous, dark-greenish-gray (5G 4/l)-_____________ .6

14. Claystone, silty, glauconitic, greenish-black (5G 2/1)__________ . 2

13. Limestone, glauconitic, dark-yellowish-orange (10 YR 6/6) 

streaked with dark-greenish-gray (5(?F 4/1). At base is a 

concentration of round to subangular shiny dark-brown to 

black phosphatic nodules____-___________________________ . 6

Total Wildie Member_____--____-_____-_-_---___--__- 24
BORDEN FORMATION (MISSISSIPPIAN) KENTUCKY F35

Renfro Valley North section Continued

Mississippian Continued 

Borden Formation (incomplete) Continued

Halls Gap Member: feet 

12. Siltstone and silty shale, micaceous, partly limy, light-bluishgray (5B 7/1), weathering same or greenish gray; finely 

laminated; breaks into platy fragments. Worm(?) trails 

common; shale units thin northward_______-_---_------_-_ 16. 5

Total Halls Gap Member............................. 16. 5

Nancy Member (incomplete):

11. Shale, silty to clayey, dark-greenish-gray (5GY 4/1), imperfectly

fissile; abundant bryozoans; as much as 4 ft thick..._--.... 2. 5 

10. Siltstone, greenish-gray (5(7 6/1), finely laminated; breaks into

small blocks. Limonite-stained joint surfaces.____________ 1. 2

9. Shale, similar to unit 11____.__.__________________________ 3. 9

8. Siltstone, micaceous; similar to unit 10. Taonurus(T) markings

common._____________________________________________ 1. 3

7. Shale, similar to unit 11. Abundant lentils, as thick as 1 ft, of 

very fine grained limestone, light-olive-gray (5Y 6/1), limonitic; bryozoans very abundant, crinoid stems common..... 21. 2

6. Covered, probably shale.__________________________________ 23

5. Gum Sulphur Bed. Siltstone, greenish-gray (5GY Q/l); limo- x 

nite-stained joint surfaces; imperfectly fissile; fossiliferous, 

mainly brachiopods. At base are lentils, as thick as 1 ft, of 

grayish-olive (10 Y 4/2) fossiliferous very fine grained limestone. Common siliceous nodules as much as 2 in. in diameter. 12

4. Shale, silty, greenish-gray (5GY 6/1) and dark-greenish-gray 

(5(7 4/1); breaks into rough plates and small blocks; limonitestained joints; less resistant than above but more resistant 

than below.___________________________________________ 7. 4

3. Shale, silty, medium-bluish-gray (5B 5/1), weathering about

same and pale olive; imperfectly fissile....________-_----.- 2. 9

2. Shale, silty; similar to unit 4; abundant limonite spots; common

Taonurus(t) markings; forms conspicuous resistant bed-... 1. 8

1. Shale, silty, medium-bluish-gray (55 5/1) to dark-greenishgray (5GY 4/1), weathering same or lighter; imperfectly fissile; spalls along curved surfaces; abundant limonite spots. 

About 6 ft above base is resistant rib of clayey shale about 

1 ft thick. Base of local exposure, not base of member._-.__ 12. 8

Measured Nancy Member (incomplete)...-------------- 90

Measured Borden Formation (incomplete)________----._ 213
F36 CONTRIBUTIONS TO STRATIGRAPHY

VPhillipsburg section ^_

[Type section of the Muldraugh Member of the Borden Formation. Measured along Kentucky Highway 208 about 0.2 mile south of Phillipsburg, Marion County, Ky. (Spurting- ;<~ 

ton quadrangle), beginning immediately south of creek near Our Lady of Fatima Church 

and continuing about 0.5 mile up hill. Section at base taken from exposures in ditch (__ 

at east side of road ; section above covered interval taken from west side of road and along 

old abandoned road. Measured with barometer, hand level, and tape by J. L. Gualtieri ^ 

assisted by J. C. Dills, July 1962]

Mississippian: "~ 

Salem and Warsaw Limestones (incomplete): Feet ^_

17. Limestone, light-gray (N 7), mostly weathered to yellowishorange punky material; fine to coarse grained; very fossilifer- ^ 

ous; large whole brachiopods and f ragments of crinoid; abundant grayish-white chert. Not measured. Top of section, 

not top of exposure. 

Borden Formation: 

Muldraugh Member:

16. Siltstone, dolomitic or limy, interbedded with lesser amounts of 

cherty siltstone and limestone. Siltstone, very light gray 

(N 8) to medium light gray (N 6), weathering light gray, buff, 

and pale yellowish orange; abundant knotlike contortions of 

laminae about minute blebs of chert; common pyrite nodules; 

sparse fossils. Chert, medium gray (N 5) and medium dark 

gray (A/" 4), weathering light gray. Abundant quartz geodes 

as large as 6 in. in diameter.____________________________ 12.8 ""* 

15. Shale, silty, greenish-gray (5GY 6/1)______________________ .3

14. Limestone, medium-gray (N 5), medium-grained, resistant; con- ^" 

tains sparse brachiopods; gradational with overlying unit.__ _ .8

13. Siltstone, dolomitic and limy, interbedded with chert; similar to

unit 16_________________-____________-_---___-_-__-_-- 24.5 C

12. Chert intermixed with limy and dolomitic siltstone, mediumgray (N 5) and medium-dark-gray (N 4), weathering light '"> 

gray and yellowish orange. Unit made up of lenticular 

cherty bodies surrounded by limy siltstone; abundant quartz 

geodes less than 2 in. in diameter._______________________ 2

11. Siltstone, light-greenish-gray (5G 8/1); abundant glauconite in

basal part; grades upward to more siliceous rock; sparse geodes \ 

similar to geodes in unit 12_____________________________ 2

10. Siltstone, medium-light-gray (N 6), laminated; contains very ^ 

abundant glauconite grains, especially at top. (Units 10 

through 8 constitute the Floyds Knob Formation as used by v*»- 

Stockdale, 1929, 1939, p. 201)..._.__.____ ____-_ _._- . 8

9. Limestone, medium-light-gray (N 6), fine-grained; abundant V 

glauconite grains; resistant-_____________________________ .8

8. Siltstone, greenish-gray (5GY 6/1); contains very abundant

grains of glauconite which gives the rock a greenish cast; , 

laminated--__-----__-__-----__-_-_--_--_-_----_-_--_-- 2

Total Muldraugh Member____-__-__--_-_-------_-_-_- 46

v
F37

Phillipslnwff section Continued

Mississippian Continued

Borden Formation Continued 

Halls Gap(?) Member: Feet

7. Limestone and silty to limy siltstone with minor silty shale; 

medium-light-gray (N 7); in wavy discontinuous laminae; 

shale partings at 26 ft and 28.5 ft above base. Abundant 

pyrite nodules, less than J^ in. in diameter. Glauconite in 

films, seams, and disseminated grains in top 7 ft___________ 45. 3

6. Siltstone, very limy, light-gray (N 7), weathering yellowish 

orange; fossil debris in irregular lentils as much as 6 in. long 

and 3 in. thick_______________________________________ 1. 5

5. Limestone, argillaceous and silty; limy siltstone and chert; 

light-gray (N 7); weathering same and yellowish orange. 

Chert occurs in more limy beds. Crinoid stems, horn corals, 

and brachiopods common in more limy beds. Small pyrite 

nodules common._______-_____-_--__---_--__-_-_..-__-_- 1.2

Total Halls Gap (?) Member....__-_________... 48

Nancy Member:

4. Shale, clayey, and silty shale; dark greenish gray (5GY 4/1), 

grayish olive (10V 4/2), and medium dark gray (N 4); imperfectly fissile; limonite stain on partings and fractures. 

Ferruginous concretions from 6 to 12 in. in diameter occur 

sparsely about 5 ft and 11 ft, and abundantly about 14 ft and 

21 ft above base. About 63 ft above the base, beds are more 

silty and form irregular, ill-defined ledges. Spares brachiopods occur 80 to 85 ft above base of unit________________ 97

3. Covered; probably yellowish-green clay shale. Thickness

determined by barometer._______-______-_____-_-___-_-_ 69

2. Shale, clayey, dusky-yellow-green (5GY 5/2), weathering same 

and forming buff soil; fissile. Phosphatic nodules in basal 

few inches__________________________________________ 5

Total Nancy Member.___-___-__-__-_----______-__-__ 171

Total Borden Formation.-___-_-___-__-_-_-____-___-__ 265

Devonian:

New Albany Shale (incomplete):

1. Shale, black (N I), laminated, brittle, weathering to thin plates 

and chips. Not measured.
F38 CONTRIBUTIONS TO STRATIGRAPHY

REFERENCES

Borden, W. W., 1874, Report of a geological survey of Clarke and Floyd Counties, 

Indiana : Indiana Geol. Survey, 5th Ann. Rept., p. 134-189.

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U.S. GOVERNMENT PRINTING OFFICE: 1966 O 799-642