Stratigraphy of the 

Mascot-Jefferson City 

Zinc District, Tennessee

GEOLOGICAL SURVEY PROFESSIONAL PAPER 277

Prepared with the cooperation of the 

Tennessee Department of Conservation^ 

Division of Geology
Stratigraphy of the 

Mascot-Jefferson City 

Zinc District, Tennessee

By JOSIAH BRIDGE

With an introduction by JOHN RODGERS

GEOLOGICAL SURVEY PROFESSIONAL PAPER 277

Prepared with the cooperation of the 

Tennessee Department of Conservation^ 

Division of Geology

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1956
UNITED STATES DEPARTMENT OF THE INTERIOR 

Douglas McKay, Secretary

GEOLOGICAL SURVEY 

W. E. Wrather, Director

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

Washington 25, D. C.
CONTENTS

Abstract-...__________________________________

Introduction, by John Rodgers-________—___________

Scope and purpose of the present report_________

Work before 1929_____________________ 

Recent work in the Knox group of East Tennessee __ 

The geologic map and mapping procedures._______

Acknowledgments___ _________________________

Geography_______________________________________

Stratigraphy ____—_____ —— _______________________

Pre-Knox formations__________________________

Summary description______________________

Names and distribution________________

Rome formation____________________

Rutledge limestone____________________

Rogersville shale______________________

Maryville limestone_____________________

Nolichucky shale_________________

Maynardville limestone member of Nolichucky 

shale_______ _____________________________

General features. ___________ ________________

Facies relationships.________________

Topographic expression_______________

Paleontology and correlation _____________

Knox group______________________________

General remarks____________________________

Definition____________________________

History____________________________

Present usage._________________________

Ozarkian and Canadian systems of Ulrich__ 

Copper Ridge dolomite.___________________

Name.______________________________

Distribution ___________________________

Limits and thickness____________________

Bedrock lithology_____________________

Residual products_____________________

Subdivisions. _____'_____________________

Facies relationships__________________

Paleontology and correlation.____________

Chepultepec dolomite.______________________

Name.______-_--______--___-_--_--__

Limits_____--__________---_--_---_-__

Thickness_ ___________________________

Page 

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3 

3 

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6

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8

8

8

10

10

11

17

17

18

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21

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24

25

25

26

26

30

31

33

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37

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Page

Stratigraphy—Continued 

Knox group—Continued

Chepultepec dolomite—Continued

Bedrock lithology__—__________________ 38

Residual products_____________________ 40

Facies relationships___________________ 41

Paleontology and correlation_ ——— _______ 41

Relation to the Longview dolomite______ 45

Longview dolomite.-________________________ 46

Name____ __ _ _______________________ 46

Limits___ ____________________________ 47

Thickness__________________ — __ 47

Bedrock lithology_____________________ 47

Residual products____________________ 48

Paleontology and correlation__________ 48

Kingsport limestone_______________________ 49

Name_______________________________ 49

Limits______________________________ 50

Thickness______________________ 53

Bedrock lithology_____________________ 53

Correlation___ ______-__---____---___- 54

Mascot dolomite___________---___-_-_-_-__ 54

Name_____________________________ 54

Limits and thickness—________________ 54

Bedrock lithology———__________________ 55

Correlation________________________ 55

Topographic expression..____________________ 55

Post-Knox formations.________—____________ 56

The name Chickamauga limestone.________ 56

Unconformity at base of Lenoir limestone____ 57

Lenoir limestone.— — — _____________________ 59

Mosheim member____________________ 59

Lenoir limestone exclusive of Mosheim

member___ _ _______________________ 60

Structure_____________________________________ 61

Appalachian Valley_________________-_--_-____- 61

Mascot belt____________________________ 61

Jefferson City belt____________________________ 62

Shields Ridge belt_______________________ 66

Mechanics of rock structure____________________ 68

Economic generalizations________-_____-__-_--___- 69

Literature cited__________________________________ 72

Index___________________________________________ 75

m
IV CONTENTS

ILLUSTRATIONS

[All plates are in pocket]

PLATE 1. Geologic map and sections of the Mas cot-Jefferson City zinc mining district, Tennessee,

2. Map showing the relation of the Mascot-Jefferson City area to the main structural features of the Appalachian 

Valley.

3. Geologic maps of type areas of formations in the Mascot-Jefferson City zinc district, Tennessee. Page 

FIGURE 1. Index map of part of East Tennessee, showing location of Mascot-Jefferson City district-____-_--___-_---_-_-- 2

2. Generalized columnar section for the Mascot-Jeff erson City district ________________________________________ 7

CHART 1. History of the stratigraphic terminology applied to the Knox group and associated Cambrian and 0"dovician

formations in the southern Appalachians._-_________-._______________-----__----_-__-_------_---_--_ In pocket

TABLES

TABLE 1. Distribution of species from the Chepultepec dolomite._-_-_-_-_--__________

2. Distribution of species from the Longview dolomite and equivalent formations.

Page 

43 

49
STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

By JOSIAH BKIDGE

ABSTRACT

The Mascot-Jefferson City zinc district is underlain by Cambrian and Ordovician sedimentary rocks. Sulfide zinc deposits, 

the only ores now being exploited in the district, occur in limestone and dolomite layers of the Knox group. This group in 

East Tennessee has been divided, on the basis of work begun 

in this district but carried also into other areas, into five formations—in ascending order, the Copper Ridge dolomite, the 

Chepultepec dolomite, the Longview dolomite, the Kingsport 

limestone, and the Mascot dolomite. These units are distinguished and mapped by key beds of sandstone and limestone, 

by minor differences in type of dolomite, and especially by differences in the residuum overlying them. In the Mascot-Jefferson City district, the rocks have been deformed by large folds 

and thrust faults; the pattern of folding and faulting generally 

conforms to but is less regular than that in East Tennessee as 

a whole. The zinc deposits are found in the lower part of the 

Kingsport limestone (and locally in the top of the Longview 

dolomite) where the beds show brecciation or recrystallization 

or most commonly both, especially near the ends of minor thrust 

faults in the vicinity of anticlinal changes in strike.

INTRODUCTION

By John Rodgers

The Mascot-Jefferson City zinc district, one of the 

principal metal mining districts in the southeastern 

United States, is located in Knox and Jefferson Counties, Tenn., eastward from and within 25 miles of the 

city of Knoxville. Its location is shown in figure 1. 

The present report, which includes a geologic map 

(first published in 1945) of the zinc district and immediately surrounding area, emphasizes the stratigraphy of the district in relation to the stratigraphy of 

the whole southern Appalachian region; it is only secondarily concerned with the economic geology of the 

zinc deposits, which are described by Brokaw (1955). 

The manuscript for the present report was left unfinished at the death of its author in April 1953 and has 

been prepared for publication by John Rodgers, who 

has written the abstract and most of the introduction. 

Except for these, no sections were added to the report as 

Bridge left it, though several were expanded from other 

material that he left or in accordance with his instructions on the manuscript. As a result, some parts of the

report are incomplete, notably the descriptions of some 

of the Ordovician formations. Incomplete as it is, 

however, the report summarizes the stratigraphy of the 

zinc-bearing rocks and of the Knox .group in East Tennessee generally as no one but Bridge could have summarized it.

SCOPE AND PURPOSE OF THE PRESENT REPORT

The present report is the result of a project of long 

standing, begun in 1929 as a pioneer attempt to subdivide stratigraphically the Knox dolomite of East 

Tennessee. For this attempt, the Mascot-Jefferson City 

zinc district was chosen for several reasons: the area includes a belt continuous with the type section of the 

Knox at Knoxville, information was desired on the 

unknown relation of the zinc deposits in the district 

to the surrounding geology, and a large-scale map of 

the vicinity of the Holston River within the are?, had 

recently been issued by the U. S. Army Engineers. 

Three general aims were set for the project: to test how 

far the Knox dolomite could be subdivided, to determine the stratigraphic and structural control, if any, 

of the zinc deposits, and to provide data for a possible 

revision of the State geologic map.

It was hoped from the beginning that this project 

would be only the first in a series of projects directed 

toward these aims; its success in achieving them in 

this area was indeed a major stimulus to the great 

amount of geologic work that has been canned out 

in East Tennessee in the last two decades. The original 

aims have now been almost completely achieved: the 

Knox dolomite is now a group divided into named 

formations in every part of East Tennessee and adjacent areas where detailed work has been done, the 

stratigraphic and structural control of the zinc deposits 

is fairly well understood (Brokaw, 1955), and a new 

geologic map of East Tennessee has been compiled and 

published (Rodgers, 1953). All these developments 

are outgrowths of Bridge's pioneering project.

Bridge was of course in close touch with all thes^ new 

projects—which he aided enormously by his enthu-
VIRGINIA

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MORRISTOWN

36 BRICEVILLE

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BOTT^ ^ \\

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MASCOT ^ JJE FFERSON 

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FIGURE 1.—Index map of part of East Tennessee, showing location of Mascot-Jefferson City district and other areas covered by detail
INTRODUCTION

siastic encouragement and assistance—and, as they developed, his project also changed in scope. At his 

death, then, the aims of his report were to set forth the 

evidence on which his geologic map of the zinc district 

was based, to discuss the regional aspects of the geologic 

control of the zinc deposits, and, abovfc all, to provide a 

definitive description of the subdivisions of the Knox 

to serve as a standard of comparison for other areas in 

the southern Appalachians.

WORK BEFORE 1929 1

In his pioneer work in Tennessee, Safford (1869, p. 

204) named the Knox group and divided it into three 

units which he termed the Knox sandstone, the Knox 

shale, and the Knox dolomite, respectively (chart 1). 

He placed these, together with the underlying Chilhowee sandstone and Ocoee series, in a large group 

which he termed the Potsdam, and he referred the Chilhowee sandstone to the Potsdam proper (that is, the 

Potsdam of New York). The limestones overlying the 

Knox dolomite, which was the youngest member of 

Safford's Potsdam group, were termed the Lebanon, 

Trenton, or Maclurea limestones. The name Knox was 

taken from Knoxville and Knox County (Safford, 1869, 

p. 204), and Safford's original section was measured 

along Second Creek in the city of Knoxville. This 

section lies just west of the area studied for the present 

report, partly in direct prolongation of the Mascot belt 

(p. 7 and pi. 2). Safford extended the term Knox 

dolomite to cover all the dolomitic limestones in this 

portion of the section in East Tennessee, and this classification was used with slight local modifications by 

various writers until about 1890. Smith (1876 and 

later publications) used the term to include supposedly 

equivalent strata in northeastern Alabama.

Between 1890 and 1905, the U. S. Geological Survey 

mapped the greater portion of the southern Appalachian Valley in considerable detail and published a 

series of geologic folios covering most of eastern Tennessee and adjoining States. These folios were the 

work of several men, chiefly C. Willard Hayes, Marius 

R. Campbell, and Arthur Keith. In the folios, the 

Knox sandstone and shale were subdivided into a number of formations and Safford's terms were discarded. 

The name Knox dolomite was retained as a formation 

name with practically the same limits which Safford 

gave it, but the overlying Trenton, or Lebanon, limestone of Safford was called the Chickamauga limestone.

These men realized the composite nature of the Knox 

dolomite; in all their reports the Knox dolomite is

1 This section is taken with little change from one entitled "Previous 

work" In the preliminary report prepared by Bridge after his 1929 

field season.

classed as Cambrian and Silurian 2 or Cambrian and 

Ordovician in age. Moreover, they repeatedly rtated 

that the base of the formation contained Cambrian 

fossils whereas the top contained Silurian (CaHferous) fossils and that it was impossible to drav^ any 

boundary between parts of the formation.

The most significant of these folios, for the present 

report, are the Knoxville folio (no. 16), the Morristown folio (no. 27), the Maynardville folio (no< 75), 

the Greeneville folio (no. 118), and the Roan Mountain 

folio (no. 151), all the work of Keith (fig. 1). The 

first of these folios covers the region immediately to the 

southwest of the area under discussion and contains 

Safford's original section. The second and third include the Mascot-Jefferson City area. In the other 

two, which embrace the area to the east and were published at a later date, there is a much more extended 

discussion of the Knox dolomite, but still no attempt 

to subdivide it.

The first subdivision of the Knox was made by Ulrich (1911, p. 633-640), who divided the Knox in the 

Knoxville area into three units: a lower unnamed limestone, the Copper Ridge chert, and an unnamed "Upper Division of the Knox." Ulrich stated thr.t the 

sequence of units within the Knox is not the same in 

different parts of the Appalachian Valley. He also 

discussed many sections, proposed several new formations (including the Copper Ridge chert), and pointed 

out many of the unsolved problems of correlation.

For many years after this, Butts worked on problems of Appalachian stratigraphy. With the cooperation of Ulrich, he subdivided the Knox in Alrbama 

and Virginia (also later Georgia) into several units, 

and his results appeared on the geologic maps of those 

States. Before 1929, however, no attempt was made to 

map the areal distribution of these units in Tenr^see.

Purdue (1912) and Secrist (1924) described th^ zinc 

deposits of the district, but neither of them attempted 

a subdivision of the Knox, although Secrist published a 

correlation table for East Tennessee compiled by 

Nelson from data supplied by Ulrich.

RECENT WORK IN THE KNOX GROUP OF 

EAST TENNESSEE

In 1929, Captain Walter F. Pond, the State Geologist of Tennessee, employed Bridge, who was then 

teaching at the Missouri School of Mines and had recently completed mapping two 15-minute quadrrngles 

in the Ozarks in formations equivalent to the Knox 

group, to undertake the project of subdividing the 

Knox in East Tennessee. In April, Bridge and Pond,

* The Ordovician period had not been recognized by the U. S. Geological 

Survey at the time the earlier folios were published.
STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

representing the Tennessee Division of Geology, took 

part in a field conference with Ulrich and Butts, of 

the U. S. Geological Survey, making a reconnaissance trip from Bristol to Knoxville by way of Bluff 

City, Johnson City, Greeneville, and Morristown. 

During this trip Ulrich and Butts gave Bridge the 

benefit of their knowledge of the sequence of units then 

recognized in the Knox group of the southern Appalachians, pointed out the criteria used for separating 

these units, and especially introduced him to the two 

principal standard sections of the Knox in East Tennessee—the section along Jockey Creek near Limestone in 

Washington and Greene Counties and the section along 

Forked Deer Creek near Thorn Hill in Grainger 

County. Following this field conference, Bridge spent 

the summer mapping the Mascot-Jefferson City zinc 

district on the maps available: the Holston River Survey of the U. S. Army Engineers, a map of the area 

between New Market and Jefferson City, compiled and 

kindly loaned by the Universal Exploration Co. (now 

part of the Tennessee Coal & Iron Division of the U. S. 

Steel Corp.), and planetable traverses made especially 

for the project by W. B. Brewer and T. G. Andrews, 

of the U. S. Geological Survey. During the school 

year 1929-30, Bridge prepared a report of about 85 

typescript pages which he transmitted to the Tennessee 

Division of Geology in 1930.

In 1930, Bridge became a member of the U. S. Geological Survey, and Pond employed C. R. L. Oder to 

carry forward the Tennessee Division of Geology project on the subdivision of the Knox group. From 1930 

until 1934, when he became geologist with the American 

Zinc Co. of Tennessee, Oder worked on this project, 

mapping subdivisions of the Knox in several parts of 

East Tennessee, notably in the Morristown-Kussellville 

area northeast of the Mascot-Jefferson City district. 

In 1934, he published a preliminary paper on the results 

of this work (Oder, 1934). More recently he has carried forward his detailed mapping in the MorristownRussellville area, but his report on this area has not 

appeared.

In 1932 and 1933, the late Professor George M. Hall 

and Professor H. C. Amick, of the University of Tennessee, made a detailed bed-by-bed measurement of the 

Thorn Hill section. This very useful document was 

published in 1934.

In 1934, the U. S. Geological Survey began a project 

to investigate the zinc deposits of southwest Virginia 

and East Tennessee, under the direction of D. F. Hewett 

and L. W. Currier. Considerable material was assembled and some short articles were published, but no final 

report on the Tennessee phase of the project was completed. Shortly thereafter the Geologic Division of

the Tennessee Valley Authority was organized, and 

since then it has carried on a great deal of geologic 

work in East Tennessee. In the first yearr of the Division, a reconnaissance survey of the Norris Reservoir 

area was made by James S. Cullison am? others, who 

used some of the subdivisions of the Knox group already 

established by Bridge. The report on this survey has 

not been published. Several short papers on other 

projects have appeared, and a more general report on 

the work of the Division has been published by the 

Authority (Moneymaker, Leonard, and others, 1949).

In 1937, the Tennessee Valley Authority began the 

publication of large-scale planimetric maps of East 

Tennessee. As a joint project of the Tennessee Division 

of Geology and the U. S. Geological Survey, Bridge 

spent several months in 1937,1938, and 1939 remapping 

the area on the new base and began a revision of the 

1930 report. At this time, Oder and Bridge agreed 

upon a terminology for the subdivisions of the Knox 

group for their two reports; this terminology has 

been accepted and used in all more recent work in East 

Tennessee. Bridge's revision was interrupted, however, for strategic minerals defense projects in 1941, 

and neither he nor Oder was able to prepare a definitive 

publication of the new terminology.

In 1942, the U. S. Geological Survey, as a part of its 

strategic minerals program, continued its investigations 

of the zinc deposits of East Tennessee, leading to the 

publication beginning in 1943 of several preliminary 

maps and reports, depending for their stratigraphy on 

Bridge's unpublished report and inakirg use of its 

terminology. The final report on this project is in preparation by Brokaw. As a phase of this project, Bridge's 

data were transferred to the new topographic maps 

published jointly by the Tennessee Valhy Authority 

and the U. S. Geological Survey, and the map was 

published without text in 1945 by the Tennessee Division of Geology.

Since 1945, much geologic work has been done in East 

Tennessee, and most of it through 1950 was incorporated into a new geologic map of East Tennessee compiled by Rodgers and published by the Tennessee 

Division of Geology in 1952. Again the terminology of 

the Knox group was taken from the unpublished reports by Bridge and Oder; a fairly detailed though 

not definitive discussion of this terminology was included in the text accompanying the imp (Rodgers, 

1953).

In 1947 and again in 1950, Bridge and Rodgers reviewed the Mascot-Jefferson City repor4: in order to 

begin a final revision, and from 1950 until his death in 

April 1953, Bridge carried forward his work on the 

report along with work on other commitments. At the
INTRODUCTION

time of his death, he had completed in semifinal form 

the descriptions of the rock formations through the 

Chepultepec dolomite and the sections entitled "Structure" and "Economic generalizations" and had prepared less final and less complete material for all other 

parts of the report except the introduction. This material constitutes the present report.

THE GEOLOGIC MAP AND MAPPING PROCEDURES

Bridge intended to prepare a section for the introduction entitled "Accuracy of the map," in which he wished 

particularly to emphasize how the contacts between the 

formations of the Knox group were drawn and how 

uncertain they may be locally. Although the pre-Knox 

and post-Knox formations crop out fairly extensively 

in most areas where they occur, the rocks of the Knox 

group are mostly covered with a thick mantle of cherty 

residual clay. Scattered outcrops occur, and the map 

indicates nearly all by dip and strike symbols. Except 

where the outcrops form nearly continuous sections, 

however, they are of little direct help, for the various 

kinds of dolomite are repeated through most of the 

group and isolated outcrops are rarely critical. In most 

of the area, therefore, the contacts are based on evidence 

from residuum: on fossils in the chert if they can be 

found, on differences in the kinds of chert, or on other 

residual materials like sandstone. In a broad way, a 

first division of the Knox group in this area is made 

by finding the band of sandstone residuum from the 

zone of sandstone layers that straddles the boundary 

between the Copper Ridge and Chepultepec dolomites. 

On the stratigraphically lower side of this band, the 

sandstone blocks are commonly mixed with blocks of 

coarsely oolitic chert; there are also other differences 

in the chert on the two sides. This band, or more exactly the stratigraphically higher edge of the part with 

oolitic chert blocks, is assumed to indicate the-CambrianOrdovician boundary. The part of the Knox group 

below this boundary, the Copper Ridge dolomite, is not 

further divided, except locally by special criteria, but 

the base of the group may also be mapped on the basis 

of residuum, for it is marked by the abrupt lower limit 

of abundant chert.

The Ordovician part of the Knox group can generally 

be further divided into three parts by a band in which 

the residuum is exceptionally cherty—the chert being 

normally in large massive light-colored blocks and containing molds of the gastropod Lecanospiror-r&n<{ over 

which the hills are generally somewhat higher than on 

either side. On the stratigraphically higher side of this 

band, limestone (or recrystallized dolomite, see p. 47,54) 

is commonly found if outcrops are present. This band 

is mapped as the Longview dolomite (which includes

339223—55———2

several thinner limestone beds but excludes at the top 

a thick and fairly distinctive bed that can be found 

wherever exposures are sufficient), and the band between 

it and the contact in the sandstone bancj. is mapped as 

the Chepultepec dolomite. The band stratigraphically 

above the Longview is further divided into the Kingsport limestone below and the Mascot dolomite above 

by finding residual float or outcrops of a characteristic 

sandstone with a chert matrix, which forms a valuable 

key bed in this part of East Tennessee.

But residual materials, such as chert or sardstone 

blocks, are very apt to creep downhill or to settle vertically far below the level at which they were originally 

released from the bedrock, and either process could 

introduce serious systematic errors into the mapping. 

Bridge was well aware of this difficulty, and, as far as 

possible, he checked the residuum against all available 

outcrops and against the projected dip and strike of 

any known contacts. Moreover, it should be mentioned 

that at no time during the mapping did Bridge have 

access to any underground information, except for a 

few scattered drill records. Despite these difficulties, 

Bridge's mapping has proved in fact to be remarkably accurate, when checked by later drilling and underground development, and he often took considerable 

pride in these verifications, as, for example, his prediction of not only the surface trace but the subsurface 

position of the Rocky Valley fault under Koppick Knob 

south of Jefferson City.

ACKNOWLEDGMENTS

In a letter dated 1947, Bridge states that "acknowledgments will of necessity be many," but unfortunately 

he was unable to prepare the list. The one below, therefore, reconstructed by Rodgers after Bridge's death, 

runs the risk of injustices, both of omission and of misplaced emphasis.

Acknowledgments for assistance during the life of 

the project and in the preparation of the manuscript 

are due to Walter F. Pond, who originally proposed 

the project; H. A. Buehler, who suggested I Edge's 

assignment to it on the basis of his successful vork in 

Missouri; E. O. Ulrich, Charles Butts, August F. 

Foerste, and the others who helped train him in the 

paleontology and stratigraphy of the Knox group and 

its equivalents; the geologists in charge of the various 

field parties in the southern Appalachians witli whom 

he collaborated—D. F. Hewett, L. W. Currier, E. C. 

Eckel, and C. H. Behre, Jr.; the zinc companies in the 

area—the American Zinc Co. of Tennessee, and the 

Universal Exploration Co., now part of the Tennessee 

Coal & Iron Division of the U. S. Steel Corp.—and 

their officials and geologists—Hiram Mills, Mark H.
6 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

Newman, Charles K. L. Oder, H. A. Coy, Floyd Weed, 

and Johnson Crawford; and many other geologists, including George M. Hall, H. C. Amick, and R. E. Lee 

Collins; Robert A. Laurence, Benjamin Gildersleeve, 

Berlen C. Moneymaker, C. B. MacGavock, James S. 

Cullison, John C. Dunlap, and C. H. Prouty, Jr.; Mrs. 

Christina Lochman Balk, A. R. Palmer, and Arnold 

L. Brokaw, for their help at various stages in the 

project.

GEOGRAPHY

The Mascot-Jefferson City area lies in the Valley of 

East Tennessee, a part of the Appalachian Valley and 

Ridge province. The Valley extends entirely across 

Tennessee from Bristol to Chattanooga between the 

Unaka and Great Smoky Mountains along the North 

Carolina State line on the southeast and the Cumberland Plateau on the northwest. The Mascot-Jefferson 

City area lies about halfway from Bristol to Chattanooga, almost in the center of the Valley, here about 50 

miles wide.

This part of the Valley of East Tennessee is chiefly 

rolling country, marked by several broad ridges trending northeast. The ridges crossing the area mapped 

are less regularly distributed than in most parts of the 

Valley. The most prominent is Shields Ridge (called 

Bays Mountain on the 1945 map, Bridge, 1945 3 ), which 

reaches an altitude of about 1,750 feet above sea level. 

Narrower, sharper ridges with the same northeast 

trend extend along the northwest and southeast edges 

of the mapped area. Just to the north and northeast 

are House and Clinch Mountains, the southwesternmost of the prominent linear mountains that characterize the northwest part of the Valley and Ridge province in northeast Tennessee and Virginia. The total 

relief in the mapped area is about 900 feet, but House 

and Clinch Mountains add another 500 feet. The local 

relief rarely exceeds 600 feet. (See pi. 1.)

The Holston River winds westward across the center of the area, and just south of the southwest corner 

it joins the French Broad River to form the Tennessee.

8 The name Bays Mountain, or Bays Mountains, is indiscriminately 

applied to a series of disconnected ridges between Kingsport and Maryville, Tenn. The principal ridge and the one most universally known 

as Bays Mountain is the synclinal mountain group starting just southwest of Kingsport and extending southwestward past Bulla Gap to the 

Nolichucky River about 7 miles southeast of Morristown. The name is 

also applied to a series of three or four subparallel monoclinal ridges 

starting in the vicinity of Whitesburg, extending southwestward along 

the valley of Dumplin Creek, crossing the French Broad River, and 

finally dying out in the vicinity of Rockford north of Maryville. These 

ridges are not a continuation of the first one mentioned but are about 

3 mile northwest of and in echelon to it. Still a third ridge, sometimes 

known as Bays Mountain, is the short, steep ridge forming the south 

wall of Rocky Valley within the New Market and Jefferson City quadrangles. This ridge lies 2 or 3 miles northwest of the second group 

described above and is entirely distinct from them. It is also known 

locally as Shields Ridge. That name appears on the new Jefferson City 

. quadrangle map and will be used1 in this report.

North of Jefferson City, the Holston is ponded by 

Cherokee Dam to form Cherokee Reservoir, which 

covers several square miles in the northeast corner of 

the area and extends many miles farther eastward. 

Most of the mapped area drains into the Holston, but 

south of Shields Ridge the streams flow generally southward to Dumplin Creek, a tributary of the French 

Broad. Important tributaries of the Houston within 

the area are, on the north side, Buffalo, Richland, Big 

Flat, and Roseberry Creeks, and, on the south side, 

Mossy, Lost, and Beaver Creeks. One of the striking 

hydrographic features of the region is the prominence 

of underground drainage; thus Lost Creek goes underground about a mile from the Holston River and perhaps 40 feet above it, and its waters apparently reappear in a large spring on the east bank of the river 

opposite McBee Island. Many smaller streams likewise 

disappear into sinks, and an area of several square miles 

east of Jefferson City, extending nearly to Morristown, 

14 miles north-northeastward, is entirely without ordinary surface drainage but is pocked with innumerable sinks, large and small.

A very large proportion of the area is cleared, much 

of it for cultivation of tobacco, corn, and rmall grains, 

much of it for pasture. Woodland is sparse on low 

ground, commoner in hilly areas, and widest spread 

on the steeper slopes of the more prominent ridges, 

such as Shields Ridge. The principal towr^ in the area 

are Jefferson City (1950 population, 3,633), New Market (600), Strawberry Plains (400), and Mascot 

(1,800); the city of Knoxville (124,769) lies at the 

southwest corner of the area. Mascot—a companyowned town—Jefferson City, and New Market are 

the main seats of the zinc mining industry, though Jefferson City has also several mills or shop^ and is the 

seat of Carson-Newman College (1950 enrollment, 895). 

A main line of the Southern Railway (here doubletracked) crosses the center of the area from east to 

west, connecting Washington, D. C., and Bristol, Va.- 

Tenn., with Chattanooga, Tenn., Memphir Tenn., and 

Birmingham, Ala.; and Charleston, S. C., and Asheville, N. C., with Cincinnati, Ohio, and Lcnisville, Ky. 

The railway maintains a large freight classification 

yard at John Sevier, near the west end of the area. 

U. S. Highway 11-E roughly parallels the railway 

across the area, U. S. Highway 11-W crosses the northwest part of the area, and U. S. Highways 25-W and 

70 (here following the same route) skirt the southern 

edge; the highways and the railroad converge at Knoxville at the southwest corner of the area. State Highway 92 passes north and south through Jefferson City, 

connecting it with U. S. Highway 11-W at Rutledge 

and U. S. Highway 70 at Dandridge, both a little be-
STRATIGRAPHY

yond the limits of the map. U. S. Highway 25-E 

passes north and south through Morristown, about 10 

miles to the east of the area.

A network of county roads, some paved, the others 

mostly macadamized, gives ready access to all parts of 

the area. The Holston River forms the most significant 

barrier to movement, and it is bridged at three points: 

just north of Jefferson City (State Highway 92), between Strawberry Plains and Mascot, and south of 

John Sevier (U. S. Highways 11-E, 25-W and TO).

STRATIGRAPHY

The rocks of the Appalachian Valley are almost entirely of sedimentary origin and consist of conglomerates, sandstones, shales, limestones, and dolomites. 

They range in age from Early Cambrian to Carboniferous. In the Mascot-Jefferson City district limestones 

and dolomites are by far the most abundant lithologic 

types, and no consolidated rocks younger than Middle 

Ordovician are present.

The stratigraphic column for the district is shown 011 

chart 1 and in the columnar section, figure 2.

The Mascot-Jefferson City district may be divided 

into three distinct narrow subparallel structural belts, 

which strike approximately northeast, and which are 

separated from one another by thrust faults (pi. 2). 

Each belt is a portion of a great fault block which has 

been thrust over a part of the block lying to the northwest of it, and in each block the sequence of formations 

is repeated. In this report the following names will be 

used for these major thrust faults and belts, beginning 

at the northwest: Saltville thrust fault,4 Mascot belt, 

Mill Spring thrust fault, Jefferson City belt, Rocky 

Valley thrust fault,4 Shields Ridge belt, and Dumplin 

Valley thrust fault.

PBE-KNOX FORMATIONS 

SUMMARY DESCRIPTION

NAMES AND DISTRIBUTION

The pre-Knox formations range from Early to Late 

Cambrian in age and consist of five easily differentiated 

formations. These, in ascending order, are the Rome 

formation (Lower Cambrian), the Rutledge limestone, 

Rogersville shale, and Maryville limestone (Middle 

Cambrian), and the Nolichucky shale (Upper Cambrian) . The Rogersville shale is further divided into 

a lower and upper shale member separated by the Craig

*On the geologic map issued in 1945 (Bridge, 1945), the Saltville 

fault was called the Bichland fault, but the name Saltville is older and 

has been widely used for this fault. Likewise, the Rocky Valley fault 

was called the Bays Mountain fault, but that name had previously been 

used by Gordon (1918, p. 54) for an entirely different fault south of 

Knoxville, and it is therefore abandoned in this report. For a discussion 

of the various Bays Mountains of East Tennessee, see Safford (1869, 

p. 43) and the footnote on page 6 of this report.

^OK

-Omaas>feaa/<ss>/

\~\

-€rf- I~T

I..-, i . i

0-50'

500- 

600'

400'

250- 

500'

500'

1050- 

1200'

250'?

350'

450- 

500'

250

200- 

500'

1000'd

1200'

200'

520'

650'

150'"

0-100

400'

1050- 1050-

1200'

300- 

320'

520'

20Oi

350'+

Ottosee and Tellico formations, 

undifferentiated, Oto, with b«ds 

of red and gray marble, Otm

Holston marble, Oh

Lenoir limestone, 01, with Mosheim 

member, Om, at base

Mascot dolomite

Kingsport limestone

Longview dolomite

Chepultepec dolomite

Copper Ridge dolomite

Nolichucky shale, €n, with Ma:'nardville limestone member, €nm, at top

Maryville limestone

Rogersville shale, €rg, with Craig 

limestone member, Crgc, near top

Rutledge limestone

Rome formation; includes Purrrckin 

Valley shale of early Middle Cambrian age at top

FIGURE 2.—Generalized columnar section for the Mascot-Jefferson City

district.
8 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

limestone member; the Nolichucky shale is divided into 

a lower shale member and an upper limestone and shale 

member, the Maynardville limestone member. All five 

formations were named and described in the early Appalachian Valley folios, and their distribution was well 

shown on the accompanying maps. More recently, their 

faunas have been figured and described (Resser, 1938). 

All five formations crop out within the mapped area; 

but, inasmuch as they have been well described in other 

reports, do not carry any of the zinc deposits in the 

area, and, with the exception of the Maynardville limestone member of the Nolichucky shale, are not connected 

with the problem of subdividing the Knox group—the 

original aim of this report (see p. 1)—only a generalized description will be given. They have been mapped 

throughout the Mascot-Jefferson City area partly for 

the sake of completeness but mostly because of their 

importance in interpreting structure.

ROME FORMATION

The Eome formation, named by Hayes (1891, p. 143- 

146) from exposures in the city of Eome, Ga., forms 

the base of the section in the Mascot-Jefferson City 

district. Along the eastern edge of the Appalachian 

Valley, where complete sections of the formation are 

exposed, the Rome formation rests upon the Shady 

dolomite, also of Early Cambrian age. Throughout the 

central and western portions of the Valley, however, it 

is the oldest formation exposed in any section and either 

occupies the center of an anticline or is cut off below 

by a thrust fault. In the Mascot-Jefferson City district 

the Rome formation averages about 1,000 feet in thickness and consists largely of thick rusty sandstones below and of arenaceous varicolored shales above. Yellow, orange, and maroon tones are prominent in the 

shale, but the highest beds are mostly greenish; these 

greenish beds appear to correspond to the Pumpkin 

Valley shale as described by Rodgers and Kent (1948, 

p. 7-9) at Lee Valley, Hawkins County, Tenn. Thin 

beds and lenses of limestone and dolomite, some of 

which are fossiliferous, occur locally in the Home 

formation.

Within the district the Home formation crops out in 

three areas: in Legg, Rogers, and McAnnally Ridges 

along the northwestern edge of the Mascot belt in the 

John Sevier quadrangle; in the center of the Rocky 

Valley anticline in the New Market quadrangle; and 

in the high unnamed ridge between Piedmont in the 

New Market quadrangle and Oakland in the Jefferson 

City quadrangle along the southeastern border of the 

area. The material in the crest of the Rocky Valley 

anticline would now be classed as Pumpkin Valley 

shale; the other areas contain strata belonging to the

underlying part of the Rome formation as well. Good 

exposures may be found in the gap north cf Bethlehem 

Church (John Sevier quadrangle) and along State 

Highway 92 in the gap southeast of Flat Gr.p (Jefferson 

City quadrangle).

RUTLEDGE LIMESTONE

The remaining four formations were named by Keith 

for exposures in the Maynardville, Morris town, Knoxville, and Greeneville quadrangles, respectively (Keith, 

1901, 1896, 1895, 1905), but the first description of all 

four was given by Campbell (1894, p. 2). The descriptions of the formations in their type areas followed at 

intervals over a period of several years.

The Rutledge limestone was named for exposures 

"in the valley of Rutledge, Grainger County," Tenn. 

(Keith, 1901, p. 2). No type section has ever been 

designated, but there are good exposures of the formation in the valley of the unnamed tributary of Richland Creek about 1 mile, west of Rutledge (Dutch Valley quadrangle), and with further study a type section might be established here. Good exposures have 

also been made nearby along the new location of U. S. 

Highway 11-W west of Rutledge. Most of the formation is massive dark-blue to black limestone exhibiting 

banding, especially on weathered surfaces, and closely resembling much of the limestone in the overlying 

Cambrian formations, but according to Keith the lower 

part of the formation includes shale bed^1 and grades 

imperceptibly into the underlying shales of the Rome 

formation. Resser (1938, p. 11), on the basis of Middle 

Cambrian fossils in these shales, considered them to 

be part of the Rutledge. Actually they were originally 

included in the Rome formation, and they are now 

placed in the Pumpkin Valley shale of Rodgers and 

Kent (1948).

Within the Mascot-Jefferson City area the Rutledge 

limestone is exposed near the northwest edge of the 

Mascot belt in the John Sevier quadrangle and in Rocky 

Valley in the Shields Ridge belt in the Nev Market and 

Jefferson City quadrangles. The limestores are highly 

soluble, and good exposures are rare; the best are in 

Rocky Valley about 3 miles south of New Market.

The Rutledge limestone is about 500 feet thick in 

the type area near Rutledge, but the limestone beds are 

replaced by shales toward the southwest. In the section along Loves Creek near the westerr edge of the 

Mascot belt (John Sevier quadrangle) the formation 

is difficult to recognize, for it is composed largely of 

shale.

ROGERSVILLE SHALE

The Rogersville shale was named from exposures 

near Rogersville, Tenn. (Keith, 1896, p, 2), but the
STRATIGRAPHY 9

exact type locality was never specified. It is a gray 

argillaceous shale that weathers to a fairly distinctive 

light-greenish color (5 GY 6/1, light greenish gray, 

to 10 Y 6/2, pale olive, according to color measurement 

by Robert A. Laurence, personal communication, 1953). 

It is remarkably persistent in this part of the Appalachian Valley in East Tennessee and, because of its 

color and persistence, is an excellent key bed. In the 

Mascot-Jefferson City district and in much of the surrounding region the shale is divided into upper and 

lower members by a thick bed of limestone, here termed 

the Craig limestone member (name first used by Rodgers 

and Kent, 1948, p. 10). The name is taken from the 

Craig quarry (pi. 3(7) in the southern edge of the 

village of Rutledge, where the entire member is well 

exposed.

Type section of the Craig limestone member of the Roger%- 

viUe shale, measured in the quarry 0.14 mile south of the 

junction of U. 8.11-W and Tennessee 92 at Rutledge, Tenn.t 

in oluff south of Richland Creek and just east of sharp turn 

in Highway 92 (pi. SC)

[Measured by Josiah Bridge, 1940]

Maryville limestone: Base, exposed in field about 100 ft south

of the quarry.

Eogersville shale: Feet inches 

Upper shale member: Exposed on flat at top 

of bluff. Shale, light-green, well-bedded, 

soft, calcareous, weathering to small, splintery chips. Strike N. 70° E., dip 20° S. 

Calculated thickness______—_—————— 17 0 

Craig limestone member:

13. Limestone, rather poorly exposed on 

flat south of the quarry, similar to 

the main mass described below. 

Calculated thickness ———————— 8 0 

12. Limestone, dark-blue, finely crystalline 

to aphanitic; massively bedded with 

irregular, wavy partings of black 

glistening carbonaceous material, 

also with irregular mottlings of gray 

finely crystalline dolomitic material, 

which weather into low relief and 

resemble fucoidal markings, especially when seen on bedding planes— 2 0 

11. Dolomite, gray, crystalline; weathers

to a sugary surface————————— 3 0 

10. Limestone, similar to bed 12_—_— 4 6 

9. Limestone, similar to bed 12_——— 2 0 

8. Limestone, similar to bed 12; dolomitic portions weathered into high 

relief and closely resembling 

fucoids ———————————————— 5 0 

7. Limestone, similar to bed 12_____ 11 6 

6. Limestone, similar to bed 12__—— 7 0 

5. Limestone, similar to bed 12__——__ 7 0 

4. Limestone, similar to bed 12, forms 

the floor of the upper half of the 

quarry. Strike N. 70° E., dip 25° 

SE ___________________ 17 0

Rogersville shale—Continued

Craig limestone member—Continued Feet inches 

3. Limestone, similar to bed 12————— 13 0 

2. Limestone, similar to bed 12————— 5 0 

1. Limestone, similar to bed 12; top of 

this bed is the floor of the lower half 

of the quarry———————————— 1 0

Total Craig member. 0

Lower shale member: Poorly exposed below quarry but 

contact well shown in road cuts 100 yd west. About 30 

ft exposed to creek.

The limestone of the Craig member was quarried for 

dimension stone and interior trim. It takes a hig'h. polish and is said to furnish a superior grade of black 

marble, though somewhat mottled. In the section 

above, the units are purely arbitrary and were selected 

with reference to the prominent bedding planes at this 

locality. Except for the nonpersistent bed of do^mite 

(unit 11), the limestones are remarkably unifonr from 

top to bottom; such differences 'as appear to exist are 

merely due to differences in the amount of weathering 

of the particular surface studied.

The Craig limestone member is indistinguishable 

lithologically from the Rutledge limestone beneath and 

the Maryville limestone and some of the limestone in 

the Maynardville limestone member above, but, occurring as it does between two bands of light-green shale, 

it is an extremely valuable key bed.

The Rogersville shale crops out in the Mascot belt 

across the John Sevier, Mascot, and Luttrell qurdrangles; it is well exposed in the center of the Rodrr Valley anticline in the New Market and Jeffersor City 

quadrangles. Formerly there were poor exposures of 

the shale in the center of the Cherokee anticline oast of 

Cherokee Dam in the Talbott quadrangle, but these 

were submerged by the filling of Cherokee Lake.

The Rogersville shale (including the Craig limestone 

member) reaches a maximum thickness of 250 feet in 

this area, but northeastward and southeastward it thins 

and finally is completely replaced by limestone. To the 

southwest it becomes indistinguishable because of the 

replacement of the overlying and underlying limestones 

by shale, and it has not been recognized as a mappable 

unit much west of the longitude of Maryville, Plount 

County (see p. 18). The Craig limestone member is 86 

feet thick in the type section and thins to the south and 

southwest, but it is present in all exposures of the Rogersville in the Mascot-Jefferson City district. It is 

about 50 feet thick in Rocky Valley where it commonly 

has a thin band of shale near the top. It coir prises 

units 63 to 70, inclusive, of the Thorn Hill section (Hall 

and Amick, 1934) where it has a thickness of 36 feet,
10 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

11 inches,5 and it forms unit 52 (47 feet thick) of the 

Lee Valley section (Rodgers and Kent, 1948, p. 11).

The shales of the Rogersville are quite fossiliferous, 

and the fauna from them has been described and figured 

byKesser (1938).

MAKYVILLE LIMESTONE

The Maryville limestone was named for exposures 

near Maryville, Term. (Keith, 1895, p. 3). The exact 

location of the type area was not stated, but it is presumably in the belt of Cambrian rocks cropping out 

northwest of the town. This belt extends northeastward and occupies the valley of Dumplin Creek south 

of Jefferson City and just south of the area mapped. 

The Maryville limestone is composed of massive darkblue or bluish-black limestones, similar to the Rutledge 

limestone and the Craig limestone member of the Rogersville shale below and also to some phases of the Maynardville limestone member of the Nolichucky shale 

above. The formation is between 300 and 400 feet thick 

in the type area and apparently reaches a maximum 

of between 600 and 700 feet on the Richland Knobs 

escarpment south of Rutledge. Like the Rutledge, its 

limestones thin out rapidly to the southwest, and in the 

section along Loves Creek at the western end of the area 

it is largely replaced by shale. It has not been mapped 

as a distinct unit more than a short distance southwest 

of Madisonville, Monroe County.

The Maryville limestone crops out near the northern 

edge of the Mascot belt, in the John Sevier quadrangle, 

and also in Rocky Valley in the New Market and Jefferson City quadrangles. As with the Rogersville, there 

were once exposures of this formation in the center of 

the Cherokee anticline as shown on the Joppa and Talbott quadrangles, but these are now almost entirely submerged except at low stages of Cherokee Lake. There 

are good exposures in the abandoned quarry on the old 

route of U. S. Highway 11-W where it crosses Big Flat 

Creek at Brice Bridge (Mascot quadrangle), on State 

Highway 92 south of Rutledge, and on the road on the 

north face of Shields Ridge 3 miles south of Jefferson 

City.

For many years the Maryville limestone had been 

considered to be unfossiliferous, and its stratigraphic 

age was inferred from its position between the fossiliferous Rogersville and Nolichucky shales. Walcott 

(1916, p. 391-392, 396-401, 404) described species of 

Asaphiscus,Blountia,Haryvillia, and Lisania(l) from 

limestones classed as Maryville limestone at several 

localities, and on the basis of these placed the Mary6 A few errors in addition in the section of Hall and Amick have been 

corrected in the thicknesses from the Thorn Hill section given in this 

report. See Rodgers and Kent, 1948, p. 3.

ville limestone in East Tennessee in the Upper Cambrian, but these fossils are now known to have come 

from the Maynardville limestone member of the Nolichucky shale (Resser 1938, p. 12,15; 1942, p. 3). About 

1935 or 1936, fossils were found in a thin shale layer, 

unit 103 of the Thorn Hill section. The fauna from 

this layer was described and figured by Fesser (1938, 

p. 27, 74, 94, 48) and consists of the following: Deltophthalmus hdlli Resser, Proagnostu.8 waryviUensis 

Resser, Perioura masoni Resser, and Obolit* sp. Resser 

(1938, p. 13) also mentions the occurrence of oboloid 

brachiopods in a thin shale on U. S. Highway 25-E 

"a little more than 6 miles north of Morristown." 

Later, Resser (1942) listed a number of faunas from 

the'"Maryville formation" at various localities in Tennessee, Alabama, and Georgia. He was us;ng the term 

"formation" in a faunal rather than a lithologic sense, 

and in most of the localities listed the formation has 

either lost or nearly lost its distinctive litl ologic character and has been replaced by shale. All the faunas 

listed by him have been found either in shale or in 

limestone nodules in shale commonly mapped as 

Conasauga.

In 1943, P. E. Cloud, Jr., found a single trilobite in 

limestone at the base of unit 124, in the Thorn Hill 

section, and this was identified by N. M. Denson as 

Alokistocare cf. A. georgense Resser, a typical Middle 

Cambrian form (personal communication to Cloud, 

1943). The specimen came from a bed 23 feet below 

the Nolichucky contact and was the first known occurrence of fossils in limestone in the formation in Tennessee ; the present statement is probably the first published notice of the find. According to Denson, this 

fossil indicates a horizon very near the top of the Middle Cambrian in the Cordilleran trough, rnd its presence in the Appalachian Valley lends strong support to 

the current practice of drawing the top of the Middle 

Cambrian at the top of the Maryville limestone in East 

Tennessee. Early in 1953, the writer and /. R. Palmer 

found additional fossils in the Maryville limestone that 

confirm this age assignment.

NOLICHUCKY SHALE

The Nolichucky shale was named by Jreith (1905, 

p. 5) from exposures along the Nolichucky River in the 

Greeneville region, but the name was first used by 

Campbell (1894, p. 2) for strata in the Estillville quadrangle, which he correlated with those afterward described by Keith. No type section was designated, but 

the type area is certainly the long, narrow anticline 

crossed and recrossed by the Nolichucky River a few 

miles southeast of Greeneville. This is in the area cov-
STRATIGRAPHY 11

ered by the Greeneville folio, not by the Morristown 

folio as stated by Wilmarth (1938, p. 1505).

The bulk of the Nolichucky consists of soft wellbedded yellowish to olive-green calcareous shale. The 

slightly darker and browner color of the weathered 

shale (5 Y 5/2, light olive green, to 10 YR 5/4, moderate yellowish brown, according to color measurements 

by Robert A. Laurence, personal communication, 1953) 

and the much greater thickness of the unit serve to distinguish it from the Eogersville shale. Locally, some 

of the shales near the base are maroon and in this respect resemble the thick shales of the Rome formation. 

Thin beds of limestone from a fraction of an inch to a 

few inches thick commonly occur at irregular intervals 

throughout the formation—another distinction from 

the Kogersville shale. Some of these limestones are fine 

grained, others coarser. Beds of edgewise conglomerate 

as much as 18 inches thick occur at various levels, but 

the number of these beds varies from place to place and 

some sections reveal none. Toward the top of the formation the limestone beds become much thicker and 

much more abundant; therefore in this report this limestone unit is separated from the lower shale unit as the 

Maynardville limestone member. Because these beds 

have been included in the Knox group by some authors, 

the Maynardville member is more fully discussed in 

this report than the formations underlying it.

MAYNABDVILLE LIMESTONE MEMBER OF NOLICHUCKY

SHALE

Keith and other early workers noted the thick limestone beds in the upper part of the Nolichucky shale. 

Where these beds were separated from the overlying 

Knox by a distinct bed of shale they were considered 

to be a portion of the Nolichucky, but, where the shale 

bed was missing, the uppermost limestones, especially 

the fine-grained magnesian varieties, were included in 

the Knox.

Ulrich recognized these beds as a stratigraphic unit 

and, in his first subdivision of the Knox dolomite, called 

it the "Basal division of the Knox dolomite (s. st.)" 

and described it as "grayish dolomite and limestone, 

practically free of chert" (Ulrich, 1911, p. 635). He 

noted that it "varies considerably in thickness, possibly 

being absent altogether locally," and stated that it had 

been recognized at Knoxville and therefore was a part 

of the original Knox dolomite of Safford. He did not 

discuss the contact with the Nolichucky, although elsewhere in the same paper he states that "gradual transition is suggested either by increasing development of 

limestone upward in the Nolichucky or by interbedding 

of thin layers of shale with relatively pure and more 

highly magnesian limestone in the basal part of the 

Knox" (Ulrich, 1911, p. 627). At the same time he

carefully excluded all strata carrying identifiable 

Nolichucky fossils from his "Basal division." Despite 

the evidence cited above, he believed the contact between 

this basal division of the Knox and the Nolichiicky to 

be unconformable and placed the "Six Mile series" of 

Alabama in this hiatus (see p. 26).

In 1933, in fieldwork around Norris Dam for the 

Tennessee Valley Authority, Arthur Keith recognized 

two mappable units—the limestone and the chert-free 

dolomite—between the shale of the Nolichucky r.nd the 

cherty dolomites of the Knox group, but the results 

of this work have not been published.

The name Maynardville was proposed by Oder (1934, 

p. 475-476) for essentially the same limestones that 

were included in Ulrich's "Basal division of the Knox." 

Like Ulrich, he regarded it as a distinct formation and 

considered it the basal unit of the Knox group, although 

he realized that the rocks contained in it had at times 

been considered wholly or in part a portion of th<^ Nolichucky. Oder's type section (unpublished) war measured along old Tennessee State Highway 33, at the 

mouth of Fall Creek on the northwest slope of Chestnut Ridge, &y2 miles north of Maynardville and just 

southwest of Ousley Bridge (Oder, 1934, p. 475; Keith, 

1901, map). Inasmuch as this section is now covered 

by Norris Lake and is no longer accessible ever at extreme low lake stages, a new section has been selected 

on the present State Highway 33, at a point 7 miles 

northeast of Maynardville between the bridge crossing Cox Branch and the south end of the Clinch River 

bridge crossing Norris Lake (pi. 35). This is in the 

vicinity of Needham Ford on the MaynardvilJe folio 

map. The old and new sections are only abcnt 3*4 

miles apart and are located on the same belt of ontcrop, 

so that the transferring of the type section to tl is new 

locality does not raise any serious question of miscorrelation.

Oder's original locality is well shown on the new 

7%' Maynardville quadrangle and the new locality is 

shown on the adjoining Powder Springs quadrangle.

Oder, like Ulrich, excluded all beds carrying Nolichucky trilobites from the Maynardville and limited 

his formation to the aphanitic to fine-grained laminated slightly magnesian unfossiliferous limestones 

that occur in the top of the member in the sections 

north of Clinch Mountain. This in part accounts for 

some of the astonishing variations in the thickness of 

the Maynardville as given by Oder, for in some sections thin beds of coarsely crystalline limestone carrying trilobites occur high in the section above tl ^ finer 

grained unfossiliferous limestones which he thought 

characteristic of the member.
12 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

The Maynardville, as interpreted by the writer, is 

different from Ulrich's and Oder's concepts; he considers it the upper member of the Nolichucky shale 

and includes in it the bulk of the limestones and magnesian limestones occurring between the shale of the 

lower Nolichucky and the cherty dolomite of the Knox 

group.

The Maynardville is a highly variable unit and exhibits regional f acies changes that throw much light on 

the sedimentary history of the Appalachian Valley and 

are in harmony with f acies relationships observed in 

older and younger strata. In the sections northwest of 

Clinch Mountain along Chestnut and Copper Ridges, 

the lower portion commonly consists of thin- to thickbedded fine to coarsely crystalline dark-blue limestone. 

Some layers contain beds of edgewise conglomerate, 

some are oolitic, and many are highly fossiliferous. 

Bedding surfaces are commonly rough and uneven, and 

the limestone units are separated -by various amounts 

of shale of the Nolichucky type. One conspicuous bed 

of black oolitic chert in the Maynardville limestone 

member is represented by unit 167 of the Thorn Hill 

section (Hall and Amick, 1934, p. 167) and by unit 76 

of the Lee Valley section (Rodgers and Kent, 1948, 

p. 13). What appears to be this same bed has also been 

recognized at many other localities, and it is the lowest 

conspicuous bed of oolitic chert observed in the stratigraphic column in this part of the Valley. The individual ooids are large, ranging from 1 to 2 millimeters 

in diameter.

In the upper part of the member, the limestones are 

fine grained to aphanitic, subcrystalline, light colored, 

laminated, and somewhat magnesian. Shale partings 

are fewer and much thinner and more highly calcareous 

than those lower in the section. In places a thin shale 

parting marks the contact with the overlying Copper 

Ridge, but more commonly the contact is drawn at the 

base of the massive, more coarsely crystalline dark dolomites. The dolomite beds in the Maynardville weather 

light gray, almost white, and the fine laminations stand 

out in low relief on most weathered surfaces. These 

beds are magnesian limestones rather than true dolomites and are almost totally devoid of chert. They are 

included in units 159 to 202 of the Thorn Hill section.

In the Mascot belt in the vicinity of Rutledge, the 

crystalline fossiliferous limestones in the lower part of 

the member are overlain by a great thickness of massive, 

compact sublithographic light-gray unfossiliferous 

limestone, which is well exposed in the quarry at the 

top of the hill on State Highway 92, about 2 miles south 

of Rutledge (Dutch Valley quadrangle, see section, 

p. 15). The contact with the Copper Ridge is concealed, 

but its approximate position is readily ascertained by

the abrupt appearance of abundant residral chert in 

the soil. The member thins in a short distance to the 

southwest, along the strike, and is barely present in 

the area between Millertown and Loves Creek (John 

Sevier quadrangle).

In the southeastern part of the area, along Shields 

Ridge in the New Market and Jefferson City quadrangles, the Maynardville member consists of two units 

composed mainly of medium to coarsely crystalline 

dark-blue somewhat fossiliferous limestone, separated 

by a thick unit of shale—similar in all respects to that 

of the underlying mass of the Nolichuck^^—and also 

separated from the overlying Copper Ridge dolomite 

by a similar but thinner shale unit.

The limestones in this section are more heterogeneous in color and texture than in the sect'ons farther 

north. It is especially noteworthy that magnesian limestones are almost wanting, and that beds of coarsegrained fossiliferous limestones overlie beds of lightcolored fine-grained to lithographic limertones. The 

percentage of shale in these sections is also much greater 

than in those farther north. It seems that from north 

to south there is a gradual increase in the amount of 

pure limestone, as contrasted with magnesian limestone; 

an increase in the proportionate amount of coarsely 

crystalline limestone present in the section and a decrease in the amount of fine-grained apranitic limestone; and an increase in the proportion of shale 

present.

Very little chert is produced by the weatl °-ring of the 

Maynardville member or by any of the pre-Knox formations, but chert is abundant in the residua] soil over all 

the formations of the Knox group. At some places, 

the upper part of the Maynardville, consisting of very 

pure chert-free fine-grained to aphanitic dolomitic 

limestone, leaches to a banded chert-free clay, the banding being interpreted as traces of the original bedding. 

Such clay has been observed at many places within the 

Mascot district. At one time it was well erposed along 

State Highway 92 about 2% miles north of Jefferson 

City, at the point where the highway crossed the divide 

on the west side of Mossy Creek; these exposures are 

now covered by Cherokee Dam and Lake. It was also 

noted in creekbank exposures along Legg and Strong 

Creeks in the John Sevier quadrangle and at many other 

places. Normally, where the clay is found, the upper 

beds of the Maynardville member fail to crop out, but 

the basal beds of the Copper Ridge are Apell exposed. 

In other areas, notably along Richland Knobs and 

Shields Ridge, the fine-grained limestones of the Maynardville resist solution more than the ccarse-grained 

dolomites of the Copper Ridge, and commonly they crop 

out, forming the crest of the ridge, whereas the Copper
STRATIGRAPHY 13

Ridge is represented on the south slope of the ridge by 

an orange-red cherty soil in which there are few outcrops.

The contact of the Maynardville limestone member 

with the main body of the Nolichucky shale is gradational, and it is drawn at that level in the section above 

which limestone predominates over shale. It is a f acies 

and not a time boundary.

The contact between the Maynardville and the overlying Copper Ridge dolomite is marked by a change 

in types of rock. Below the contact there is blue crystalline commonly fossiliferous limestone of the type 

common in the Maynardville (and found locally, 

though rarely fossiliferous, in the Maryville and Rutledge limestones) or fine-grained thin-bedded wellstratified light-colored noncherty unfossiliferous somewhat calcitic dolomite. Above the contact there is 

more coarsely crystalline rather heavy-bedded poorly 

stratified virtually unfossiliferous dark dolomite typical of the Copper Ridge. The contact is not abrupt. 

The rock types alternate through a zone of several feet; 

there is no evidence of a disconformity. Oder states 

that in sections along the west side of the Valley of 

East Tennessee the contact is "usually marked by 2 feet 

of dark-gray, shaly dolomite, with an undulating upper 

contact" (Oder, 1934, p. 475). Such undulating contacts are common throughout the lower Paleozoic sequence in the Appalachian Valley, and no especial importance is to be attached to most of them. For convenience in mapping, the writer has consistently drawn 

the base of the Copper Ridge dolomite at the base of 

the lowest bed of dark coarsely crystalline dolomite; 

this practice has been followed by most field parties in 

recent years. The advantages of this boundary are

1. The first appearance of the dark coarse dolomite reflects 

a change in the conditions of sedimentation; it is readily picked 

in well-exposed sections.

2. The dark coarse dolomite produces much chert on weathering; therefore the boundary can be readily determined in 

areas covered by residual materials by mapping the edge of the 

residual chert.

3. The boundary lies between the upper limit of the Aphelaspis fauna, which is the highest of the Dresbach faunas and is 

here confined to the Maynardville, and the lower limit of Franconia faunas, representatives of which are found sparingly in 

the Copper Ridge. Thus it corresponds to an important faunal 

change that has been recognized and used as a datum plane 

over a large part of North America.

As thus drawn, the boundary is one of the more easily 

recognized and mapped contacts in the area. In the 

Thorn Hill section it is placed at the base of unit 203 of 

the Hall and Amick section (1934). This is essentially 

the contact pointed out to the writer in 1929 by Ulrich 

as the boundary between the Cambrian and "Ozarkian"

systems, and he believed that a great unconformity 

existed at this contact.

The following detailed sections show the character 

of the Maynardville member in the Mascot-Jeflforson 

City district and adjoining territory.

New type section of the Maynardville limestone member of the 

NolicfmcTcy shale, exposed on the south side of State Highway 

33, between the bridge across Cox Branch and the Clinch River 

bridge across Norris Lake (pi. SB)

[Measured by Josiah Bridge, probably about 1938]

Copper Ridge dolomite:

Covered interval, concealing possibly 50 ft of beds. Hillside above road is strewn with chert float of Copper Ridge 

type, and there are scattered outcrops of coarse-grained 

dolomite. No outcrops in road ditch. 

Nolichucky shale:

Maynardville limestone member: Feet inches

47. Limestone, blue, fine-grained, heavily 

bedded with gray, coarser grained 

mottlings. This limestone is similar 

to rocks in unit 32, and the gray 

mottlings are evidently a weathered 

phase of the buff and tan mottlings 

in the lower beds——————————— 3 0

46. Dolomite, dark-bluish-gray, finely crystalline ; weathering moderately light, 

thick bedded, laminated, the laminae standing in low relief on weathered surfaces. A few layers of irregular soft porous siliceous nodules 

along the bedding planes in the 

upper portion of the unit______ 28 0

45. Shale, olive-green, hard, well-bedded, 

with thin dolomite layers near top. 

Hand specimens would be indistinguishable from the bulk of the 

Nolichucky shale__-________ 2 4

44. Dolomite, similar to unit 46 but without the siliceous nodules_—___ 2 6

43. Limestone, light-blue, fine-grained, becoming dolomitic toward the top— 3 4

42. Dolomite, similar to unit 46 but without siliceous nodules; shaly at top 

and base________________ 2 0

41. Limestone, dove - colored, sublithographic, massive _-___—___ 1 10

40. Shale, olive-green, hard, well-bedded, 

with thin platy fine-grained limestone layers averaging less than 1 

in. thick____________________ 1 8

39. Dolomite, like unit 46_________ 9

38. Shale, olive-green, hard, with thin

platy layers of dolomitic limestone_ 1 0

37. Dolomite, dark bluish-gray; weathering light colored, finely crystalline, 

heavy bedded, finely laminated__ 6 6

36. Limestone, dark-blue, finely crystalline 2 0

35. Dolomite, like unit 37___________ 4- 6

34. Limestone, like unit 36___————_— 2 10

33. Dolomite, similar to unit 37__—___ 2 4
14 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

Nolichucky shale—Continued

Maynardville limestone member—Continued Feet inches

32. Limestone, dark-blue, weathering to 

bluish gray, finely crystalline to 

sublithographic, with broad irregular 

tan and buff stripes and mottlings 

arranged roughly parallel to the 

bedding surfaces _-_——__-_ 11 0

31. Dolomite, similar to unit 37————— 1 4

30. Limestone, light-blue to dove-colored, 

fine-grained to sublithographic, mottled and striped__________— 3 10

29. Limestone, dark-blue, crystalline, 

oolitic and conglomeratic; pebbles 

of limestone, seemingly from the 

underlying beds, flat, as much as 

6 to 8 in. long; most abundant in 

lower 10 in. of unit__________ 1 10

28. Shale, greenish-gray, hard; well-stratifled with thin layers of dark-blue 

fine crystalline laminated dolomite____________________ 2 6

27. Dolomite, finely crystalline, laminated, 

dark-blue-gray, weathering light; 

locally crossbedded; one layer of 

stylolites________________ 3 0

26. Limestone, dark-bluish-gray, with tan 

stripes and mottlings similar to unit 

32; upper part badly shattered—_ 28 6

25. Limestone, light-dove-gray, fine-grained 

to sublithographic; in some places 

showing mottlings as above, other 

places with no traces of bedding__ 6 0

24. Limestone, blue, crystalline, somewhat

banded, massively bedded_____ 3 6

23. Limestone, dark-blue, somewhat 

banded with irregular buff and 

tan stripings and mottlings similar 

to unit 32; rather poorly exposed__ 7 0

22. Limestone, dark-blue, coarsely crystalline, magnesian, with few but 

broad bandings and mottlings___ 15 0

21. Limestone, dark-blue, finely crystalline 

to sublithographic, with buff and 

tan stripings and mottlings as in 

unit 32__________________ 12 0

20. Shale, olive-green, hard, well-stratified___________________ 6

19. Limestone, finely crystalline to aphanitic, massively bedded, with irregular tan stripes and mottlings similar 

to those in preceding units, a 2-ft 

bed at top—_____________ 13 0

18. Covered interval_____________ 10 0

17. Limestone, blue, nodular________ 8 0

16. Shale, olive-green, hard, well-stratified ___________________ 3 0

15. Limestone, similar to unit 19_____ 2 0

14. Covered interval _____________ 4 0

13. Limestone, similar to unit 19, largely

covered ________________ 3 0

12. Shale, olive-green, hard, well-stratified—_________________ 2 0

Nolichucky shale—Continued

Maynardville limestone member—Continued Feet inches 

11. Limestone, dark-blue, finely orystTlline, massive—————————————— 12 0 

10. Shale, olive-green, hard————————— 4 6 

9. Limestone, similar to unit 11; expos ed

opposite south end of bridge———— 5 0 

8. Shale, olive-green, hard, well-beddec' —13 

7. Limestone, like unit 11, with bed of

edgewise conglomerate at base-— 2 0 

6. Shale, like unit 8, typical Nolichucky— 6 

5. Limestone, similar to unit 19————— 1 0 

4. Shale, typical Nolichucky, with tl in 

platy beds of fine-grained limestone, 

averaging less than 1 in. thick.— 8 0 

3. Limestone ______————————— 1 6 

2. Covered interval ___________- 10 0 

1. An alternating series of limestor^s 

and shales like units just above, the 

individual units of shale and linestone varying from 2 to 8 ft in 

thickness, but the relative amounts 

of shale and limestone about eqral. 

Top of unit, a 4-ft bed of b'ne 

coarsely crystalline fossiliferous 

limestone; the base, a 3^-ft bed of 

light-blue to dove-colored aphanitic to finely crystalline limestone, 

with narrow yellow irregularly 

clayey partings, exposed at maximum lake level, 1,020 ft______ 64 0

Total Maynardville limestone 

member ______________ 315

At low stages of Norris Lake a part of the underlying 

section is exposed; it consists of alternate beds of 

shale and limestone much as in unit 1, but the thicknesses of the individual units are greater, and shale 

predominates. This is considered the vpper part of 

the shale member of the Nolichucky shaK

This section can be divided into three- major parts. 

At the base is a division about 124 feet thick (units 1- 

16) composed of alternating beds of limestone and 

shale in about equal amounts. This is overlain by a 

division 103 feet thick (units 17-26) consisting almost 

entirely of limestone with small amounts of shale. 

Finally an upper division about 88 feet thick (units 

27-47) is composed of alternating beds of shale, limestone, and noncherty dolomite. This gradation from 

shale and limestone, to limestone, to limestone and dolomite is characteristic of sections in the northwestern 

part of the Valley.

Although the upper contact is not exp osed, it seems 

certain that the base of the dark coarse-grained cherty 

Copper Ridge is not far above the last limestone cropping out along the highway. Scattered outcrops show 

that a large part of the covered interval above the measured section is occupied by coarse-grain^-d dark dolo-
STRATIGRAPHY 15

mite, a type of rock characteristic of the Copper Ridge. 

The hillside is also covered with abundant chert float, 

which is not derived from the Maynardville or any 

older unit.

The lower contact is taken at about the point below 

which shale is the predominant lithologic type; it could 

have been drawn at the base of some other limestone 

unit either higher or lower in the section. In the Thorn 

Hill section (pi. 3J.) the writer refers units 136 to 202 

to this member (Hall and Amick, 1934, p. 166-168). 

The total thickness is 168 feet 9 inches. In the Lee 

Valley section, units 69 to 85 with a total thickness of 

181 feet are assigned to this member (Rodgers and 

Kent, 1948, p. 13-14). The gradations from limestone 

and shale, through limestone, to limestone and magnesian limestone with subordinate amounts of shale 

are much the same as in the type section, although the 

entire unit is much thinner.

The Maynardville limestone member is fairly thick 

along the northern edge of the Mascot-Jefferson City 

area and forms the crest of the north-facing escarpment known as the Richland Knobs that extends northeastward just south of U. S. Highway 11-W from the 

vicinity of Blaine in Grainger County to a point a few 

miles east of Tate Springs, near the Grainger-Hawkins 

County boundary (see Luttrell, Dutch Valley, and 

Bean Station quadrangles). The lower part of the 

member is well exposed along State Highway 92, about 

2 miles south of Rutledge (Dutch Valley quadrangle), 

where the following section was measured:

Section of the lower part of the Maynardville limestone member of the Nolichucky shale, measured in State Highway 

Department rock quarry on State Hiffhway 9B, and along 

the highway at top of hill 2 miles south of Rutledpe, Tenn.

[Measured by Josiah Bridge, 1940]

Top of quarry.

Feet inches

8. Limestone, exposed in back wall of quarry, subcrystalline to lithographic, light bluish to 

pearl gray, often mottled with buff and pink 

tones. Thick bedded, the individual layers 

8 to 10 ft thick. Individual layers often finely 

and indistinctly laminated, the laminations 

more conspicuous on weathered surfaces. 

Laminations often wavy, sometimes contorted, 

apparently caused by thin films of clayey and 

organic matter. In the lower 15 or 20 ft, 

toward the edges of the quarry are large irregular gray to buff-colored masses of finegrained dolomitic material, of irregular shape 

and size, evidently a selective replacement of 

the limestone. Thickness to floor of quarry_ 60 0

7. Limestone, exposed along road at north end of 

quarry, similar to the preceding, with fine irregular yellow laminations; weathers smooth 

and to a light bluish gray_——___——_ 10 0

Feet inches

6. Covered ________________————— 1 0 

5. Limestone, fine-grained to aphanitic, dove-colored, with semiconchoidal fracture; beds as 

much as 4 in. thick, but averaging 1 in. Massive on fresh surfaces; bedding developed 

by weathering. Bedding irregular, gently 

wavy _———__——_—————————————— 1 0 

4. Shale, thin-bedded, fissile, olive-green, weathering to small, thin, rusty, and yellowish flakes, 

interbedded with thin layers of platy aphanitic to finely crystalline limestone, the individual layers less than 1 in. thick_______ 3 6 

3. Limestone, a single bed of edgewise conglomerates; matrix of aphanitic to finely crystalline light-bluish limestone, pebbles of the same 

material as much as 1 in. thick and 6 in. long. 

Thickness of bed variable, average______ 1 0 

2. Shale, similar to unit 4, but without the

limestone partings________________ l 10 

1. Limestone, fine-grained to aphanitic, light-gray 

to dove-colored. Bedding slightly irregular, 

wavy. Some layers weather to smooth 

surfaces, others to a rough matte surface. 

Strike N. 40° E., dip 10° SE___________ 4 2

Below unit 1 the limestone units are fewer and thinner and finally give way to a mass of shale that makes 

up the great bulk of the Nolichucky. The lower contact 

of the Maynardville member in this section is gradational and for convenience is drawn at the base of unit 

7, thus giving a thickness of 70 feet for the part exposed 

in the quarry. The section extends 140 feet abcve the 

floor of the quarry to the top of the knob to the northeast and, as the average dip is 11°, this part of tl ^ unit 

has a minimum thickness of about 250 feet. Similar 

beds also crop out at intervals along the highway between the quarry and a point 0.25 mile north of Hammer 

Store (Joppa quadrangle). If the dip remains constant, the computed thickness of the Maynardville member in this section is at least 350 feet. The upper contact 

cannot be located definitely, but the characteristic residual cherts of the Copper Bidge dolomite cover tt e hillsides between the last outcrops seen and Hammer Store, 

and a few yards south of the store there are outcrops 

of typical Copper Ridge dolomite.

About 3% miles southwest, along the road through 

Owl Hole Gap (northwest corner of Joppa quaddrangle), the contact is fairly well indicated by the 

abrupt change from outcrops to residual cherty clays. 

Strata believed to lie near the top of the Maynardville 

are exposed in a roadside quarry in Owl Hole Gap. In 

this quarry several small veinlets of sphalerite have 

been found by Robert A. Laurence. The quantity is insignificant, but the locality is of interest as the only reported occurrence of sphalerite in the Maynardville in
16 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

the Mascot-Jefferson City district. A short distance 

south of the quarry all outcrops disappear, and roadside cuts show only residual clays and cherts of the 

Copper Kidge dolomite. This somewhat abrupt change 

from outcrops to residuum is characteristic of the Maynardville-Copper Kidge contact over much of the Mascot-Jefferson City area.

In the southern part of the district, the Maynardville 

member is thinner, and its limestones are commonly 

more crystalline, resembling more closely those of the 

upper Nolicliucky. The following section, measured 

in the southern part of the New Market quadrangle, 

will serve to illustrate this phase:

Section of the Maynardville limestone member of the Nolichucky 

shale, measured along the secondary road between Rocky 

Valley and Piedmont, 0.9 mile south of Rocky Valley Church

[Measured by Josiah Bridge and C. R. L. Oder, October 1940]

Feet incites

Copper Ridge dolomite: Lower part of formation 

forms top of Shields Ridge.

25. Covered, orange to red residual clays 

with fragments of black-banded 

cherts showing cryptozoan structures.

24. Largely covered but road cuts show 

thin platy black cherts in clay, preserving a rude orientation, which is 

interpreted as stratification modified 

by slump. At the base a thin platy 

brown sugary sandstone, 1 to 2 in. 

thick, also not definitely in place. 

This is taken as the base of the 

Copper Ridge. Calculated thickness_——__——————____— 30 0 

Nolichucky shale:

Maynardville limestone member:

23. Largely covered, but with a few small 

outcrops of greenish calcareous 

shale of Nolichucky type. The 

most prominent of these is about 10 

ft above the first limestones. Calculated thickness___________ 75 0

22. Limestone, dark-bluish-gray to leadcolor, slightly magnesian, weathers 

dull gray. Fine grained, finely laminated, the laminations accentuated 

by weathering, rather evenly bedded, beds from 6 in. to 2 ft thick, a 

conspicuous 3-in. shale parting 9 in. 

below the top, other thinner partings throughout the mass_____ 10 6

21. Covered (possibly shale)_______ 8 0

20. Limestone, similar to the above, with 

a few beds and lenses of light-gray 

fine-grained dolomitic limestone_ 9 0

19. Covered __________________ 4 0

18. Limestone, similar to unit 20_____ 1 0

Nolichucky shale—Continued

Maynardville limestone member—Continued Feet inches

17. Limestone, medium to finely crystalline, heavy-bedded, minor beddir* 

irregular; contains irregular dolomitic lenses, rarely more than an 

inch thick, which weather light colored and stand out in low relief. 

Strike N. 55° E., dip 30° SE. Fonrs 

summit of pass. Fossiliferous, contains typical upper Nolichucky tril->- 

bites __________________ 13 6

16. Limestone, shaly, fine-grained, thinly 

and irregularly bedded becomir^ 

more massive toward the base___ 4 0

15. Shale, hard, platy, fissile, blue to oli^e 

when fresh, weathering greenirh. 

buff. Contains a few thin beds of 

fine-grained platy sparingly fossiliferous limestone. Unit incorrpletely exposed____________ 17 0

14. Limestone like unit 17. Alternatir«r 

irregular layers of medium-crystalline dark-blue, and finely crystallir«i 

dull-blue-gray limestone, the latter 

weathering shaly and occasionally 

more nearly pure shale than limestone; lowest bed a massive crystalline limestone 2 ft thick. Nolichucky trilobites in the more crystalline layers___—_______ 19 0

13. Shale, hard, platy, olive-green_———— 5 0

12. Limestone, like unit 14, a single massive layer exposed at bend in road— 8 0

11. Shale, hard, platy, olive-green, upper

part poorly exposed, fossiliferous— 10 0

10. Limestone, fine-grained to aphanitic; 

the two varieties intricately mottle-1, 

light bluish to pearl gray; massive, 

the individual beds 8 to 10 ft thick 

but splitting into thinner slabs where 

weathered; fracture variable, subconchoidal to splintery; weathers 

dirty grayish white, with yellow mottlings which seem to represent tl 3 

more crystalline part of the original 

rock. Exposures almost continuous. 

This limestone is identical with that 

exposed in units 7 and 8 in the section south of Rutledge (p. 15)——— 15 0

9. Covered, but exposed in woods abo^Q

the road. Similar to unit 10.______ 9 0

8. Limestone, similar to unit 10, but gradually becoming more coarsely crystalline in texture and darker in color, 

toward the base, the lowermost, 

beds greatly resembling those in units 

16 and 17 above the big shale break.— 75 0

7. Shale________——————————— 6
STRATIGRAPHY 17

Nolichucky shale—Continued

Maynardville limestone member—Continued Feet inches 

6, Limestone, dark- to medium-blue, finely to medium crystalline similar to 

lowest beds of unit___________ 25 0

Total Maynardville limestone

member _______________ 308

Lower shale member:

5. Shale, hard, thin-bedded, olive-green_ 55 0 

4. Limestone, crystalline, like Maynardville ____________________ 2 0 

3. Shale ____________________ 15 0 

2. Limestone _________________ 8 0 

1. Shale, calcareous, platy with a few thin

limestone partings___________ 35 0 

Estimated thickness to base of Nolichucky shale______________ 250 0

Total lower shale member_____ 365

Total Nolichucky shale______ 673 6

The Maynardville member is well exposed at many 

other localities outside the Mascot-Jefferson City area. 

The type area north of Maynardville and the Thorn 

Hill section have been discussed. Dolomitized limestone in the lower part of the Maynardville member is 

exposed in the workings of the old lead-zinc mine at 

New Prospect (Ausmus quadrangle; Kent, Eodgers, 

and others, 1945, erroneously state that the mine is in 

the upper dolomitic part of the Maynardville), and at 

one time there was an excellent section of the lower 

limestone part of the member (not dolomitized) between the mine and the old bridge across Powell River 

(Keith, 1901, geologic map). Most of this section is 

now covered by Norris Lake. According to Rodgers 

the total thickness of the Maynardville in this area is 

350 feet. Keith (1901) included all the dolomite and 

nearly all the limestone beds in this area in the Knox 

dolomite.

Another good section is exposed in the Knox County 

workhouse quarry on Blackoak Ridge at Tecoy 

(Bearden quadrangle). The limestone is highly fossiliferous at this locality and yields a fauna similar to 

that found on Shields Ridge. Still another good exposure is in another Knox County quarry (Biagiotti 

quarry), on the northwest side of Rogers Ridge, about 

0.7 mile northwest of Bethlehem Church (John Sevier 

quadrangle). This is within the mapped area, but it is 

just north of the Saltville fault that bounds the northern edge of the Mascot belt. Strata of equivalent age 

are exposed around the Straight Creek mine (Clouds 

quadrangle), along the Kingsport-Gate City highway 

2 miles north of Kingsport (Kingsport quadrangle), 

and along Gass Creek 1 mile northeast of Greeneville

(Greeneville quadrangle). The last two localities are 

described by Oder and have not been studied in detail 

by the writer.

The Maynardville member shows considerable variation in thickness, which is what would naturally be 

expected if the interpretation of the member as a calcareous f acies of the Nolichucky shale is correct. Oder 

(1934, p. 4T5, 494, 497) gives the thickness as between 

60 and 250 feet, allowing 120 feet for the thickness in 

the Thorn Hill section (units 14T-202 of Hall and 

Amick, 1934), and 250 feet for the section on Jockey 

Creek in Greene County. He does not give the thickness in the type section. As previously stated, the present interpretation includes a greater thickness of beds 

at the base. The measurements in 6 sections here discussed are—new type section on Highway 33, 31f feet; 

Thorn Hill section, 172 feet; Lee Valley section, 181 

feet; section along State Highway 92, south of Rutledge, about 350 feet (calculated thickness); section on 

Loves Creek, north of Caswell, about 300 feet; section 

on Shields Ridge southeast of New Market, 337 feet. 

Large variations from these figures have been noted 

elsewhere in the Valley, and they suggest that Oder's 

minimum figure is correct.

Ulrich (1911, p. 636) estimated the thickness of his 

lower Knox in the Thorn Hill section at 345 feet.

GENERAL. FEATURES

FACIES RELATIONSHIPS

The limestone units of the Rutledge, Rogersville, 

Maryville, and Nolichucky formations show many 

lithologic similarities, and, in isolated outcrops where 

the sequence cannot be determined, it is commonly difficult to identify the particular formation to which the 

outcrop belongs. In general, the limestones of the Rutledge are more dolomitic, and those of the Maynardville 

member of the Nolichucky contain a greater variety of 

lithologic types and locally many thin shale layers. 

Certain types of limestone are common in all thes^ formations however, and the entire sequence was probably 

deposited in a relatively constant environment in which 

the proper conditions of deposition were frequently repeated. The most abundant type is a dark-blue to 

black finely crystalline massively bedded noncherty 

limestone that appears to be quite uniform in composition and texture when seen in fresh exposures. It is 

commonly quarried as a source of crushed stor^ for 

roadbuilding; some layers yield large blocks thr.t can 

be sawed and polished and used as a decorative marble.

Weathered outcrops are light bluish gray in color and 

commonly display a characteristic mottling of lighter 

and darker colored stripes and patches. Limestone 

showing this mottling is made up of an intricate mix-
18 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

ture of two types of rock, the difference between which 

is almost invisible on freshly broken surfaces but is 

brought out conspicuously by weathering. The two 

types of rock differ in grain size: one type is composed 

of very fine calcite crystals visible only under low 

magnification, averaging 0.04 millimeter in diameter; 

the other type is composed of coarser crystals of dolomite (with a little calcite), quite distinct to the unaided 

eye, averaging 0.1 millimeter in diameter. The finer 

grained variety may be slightly silty. The two types 

generally are arranged in rather irregular layers 0.25 

to 0.5 inch thick and roughly parallel to the bedding, 

but the coarser material lenses in and out through the 

fine and is much more abundant at some levels than 

at others. The coarser material weathers to lighter 

shades than the fine and on weathered face perpendicular to the bedding produces an unusual and highly 

characteristic striped and mottled appearance. On 

strongly weathered faces the coarser grained lenses 

commonly stand out in high relief. Weathered bedding planes show an irregular mottling, and in some 

places branching anastomosing rodlike masses that 

strongly resemble f ucoids. No limestones in the Knox 

group possess these peculiar textures or weather in this 

fashion; and the occurrence of such limestone in the 

four pre-Knox formations indicates that they are 

closely related, which is one of the reasons for excluding 

the Maynardville member from the Knox group.

Another similarity of the limestones of all four 

formations is the absence of appreciable quantities of 

chert in any of them. A single thin zone of black 

oolitic chert and one or two thin layers of rather soft, 

spongy chert nodules have been noted near the top of 

the Maynardville at a few localities (p. 12,13), but in 

general the limestones and the deep red residual soils 

derived from them are remarkably free from chert. 

On the other hand, practically all the strata of the Knox 

group yield chert under most conditions, indicating an 

entirely different set of environmental factors during 

deposition. The absence of chert in the Maynardville 

is a second reason for grouping it with the lower chertfree strata and not with those of the Knox group.

Northeastward from the Mascot-Jefferson City district the Eutledge, Craig, and Mary ville limestone units 

merge into a single limestone and dolomite unit, the 

Honaker, for the Rogersville shale ceases to be recognizable in Eussell County, Va. Still farther northeastward, between Marion and Roanoke, Va., the Nolichucky shale is also replaced by limestone and ceases 

to be identifiable as a distinct unit; here the entire limestone and dolomite mass between the Rome and the 

base of the Knox group is known as the Elbrook dolomite (Butts, 1933, p. 6-7; 1940b, p. 67,74).

Southwestward from the district, on the other hand, 

the limestones thin out and eventually disappear, the 

formations lose their identity, and the entire section 

between the Rome and the base of the Knox group is 

represented by a thick mass of calcareou^ shale with 

thin irregular limestone beds and lenses known as the 

Conasauga formation.

Thus it would appear that the limestones forming the 

Rutledge, Craig, Mary ville, and Maynardville units are 

westward-trending tongues of a great limestone unit in 

the northeastern part of the Appalachian Valley, and 

that they interfinger with shale tongues—the Rogersville and the Nolichucky—that extend northeastward 

from the Conasauga formation. The sequence is one 

of the finest and clearest examples of intergrading 

facies known in the Appalachian region (see diagram 

on chart, Howell and others, 1944, but the limestone 

tongues should be shown at the southeast side of this 

diagram) and the fact that the Maynardville limestone 

member participates in this intergradaticn. is a third 

reason for classing it with the formations of the Conasauga group, rather than with those of the overlying 

Knox group.

Still farther south in Alabama and Georgia other 

limestone and dolomite tongues invade th°- Conasauga 

shale (p. 26), but this does not alter the interpretation 

presented here.

The fossils found in the Maynardville arc yet a fourth 

reason for grouping it with the Nolichucky shale rather 

than with the Knox group; this evidence is discussed 

below under paleontology (p. 19 ff.).

TOPOGRAPHIC EXPRESSION

The alternate limestone and shale units of the Cambrian have a strong influence on the topography of the 

region which they underlie, so much so that on wellmade topographic maps, especially those ccmpiled from 

aerial photographs by the multiplex method, it is often 

possible to identify individual formationr and groups 

of formations and to trace their approximate boundaries by the characteristic topographic patterns.

The topography developed on the Rome is quite distinctive. The thick sandstones in the lower part of the 

formation are resistant to weathering, and, in areas 

where moderate or steep dips prevail, the formation 

forms long, narrow, bugged second-order ridges that 

rise from 300 to 500 feet above the valley f oors. These 

ridges are notched at intervals by wind and water gaps 

and are generally heavily forested because the soil 

developed over the Rome is not fertile. The deeply 

notched profile and the heavy forest cover are usually 

sufficient to distinguish a ridge over the Rome from 

one over the Copper Ridge dolomite.
STRATIGRAPHY 19

The Eutledge limestone commonly forms a valley 

at the foot of the dip slope of the ridge consisting 

of the Rome formation, though in some places, in areas 

of steeply dipping rocks, it may stand up as a low discontinuous ridge between valleys cut on the shales of 

the Upper Eome and Eogersville formations. The 

Rogersville shale forms a valley, commonly continuous 

with the one developed on the Rutledge. Where the 

beds are steeply dipping, the Craig limestone member 

may locally be identified by a row of low knolls scarcely 

more than 20 feet high. Where the dip is gentle, the 

Craig commonly forms a low but well-defined and persistent escarpment, the flat surface at its summit being 

developed on the upper shale member of the Rogersville and the basal beds of the Maryville. An excellent 

example of this scarp may be seen in the valleys of Ray 

and Richland Creeks, at the foot of the Richland Knobs 

escarpment, on the Joppa, Dutch Valley, and Avondale 

quadrangles. In areas where the rocks dip steeply 

(over 60°), the Maryville limestone, especially its upper 

part, forms a low steep-sided, narrow ridge cut by 

many water gaps. The Nolichucky shale forms a distinct valley behind the ridge, and the Maynardville 

member beyond forms a second, parallel, lower and less 

definite ridge, generally merely a row of spurs. Good 

examples of these features occur on the John Sevier 

quadrangle in the area north of Mascot and south of 

U. S. Highway 11-W, also on the Luttrell quadrangle 

south and east of Blaine. Where the dip of the strata 

is gentle, the Maryville forms a steep but strongly 

dissected scarp along one side of the valley, the basal 

part of the Nolichucky forms a much dissected bench 

at the top of the Maryville, and the remainder of the 

formation rises in a steep escarpment capped and upheld by the Maynardville limestone member and the 

Copper Ridge dolomite. This sequence is well shown 

in the Richland Knobs escarpment on the Luttrell, 

Joppa, and Dutch Valley quadrangles beyond the limits 

of the map, and on the north face of Shields Ridge 

on the New Market and Jefferson City quadrangles. 

The topographic profile is highly characteristic and 

easily identified and has been recognized on many of 

the new TVA quadrangles between Knoxville and 

Bristol.

PALEONTOLOGY AND CORRELATION

Many of the fossils found in these five formations 

have been listed and figured by Resser (1938). Butts 

(1926, p. 67, 72-78, pis. 5, 8, 9; 1940b, pt. 2, pis. 65-67) 

has figured many of the species and has discussed their 

distribution in equivalent strata in Alabama and Virginia; Resser and Howell (1938) have figured and described the Lower Cambrian faunas of the Appalachian 

Valley.

The Rome formation is classed as chiefly Lower 

Cambrian,6 the Rutledge, Rogersville, and Maryville 

formations as Middle Cambrian, and the Nolicl ucky 

shale as Upper Cambrian. The regional correlations 

of these formations have been discussed by Kesser 

(1938), and a somewhat revised correlation ha? appeared on the Cambrian correlation chart, prepared 

by the Committee on Stratigraphy of the National Research Council (Howell and others, 19M).

The relations of Nolichucky and Maynardville to 

each other and to the Copper Ridge are the only ones 

pertinent to the present report.

Th'e Nolichucky shale, including the Maynardville 

limestone member, is highly fossiliferous and if correlated with the Dresbach formation 7 of the Upper 

Mississippi Valley and its equivalents elsewhere in 

North America. The Cedaria, Crepicephakte, and 

Aphelasph faunal zones, which characterize the Dresbach formation as here defined, are present in the Nolichucky shale. The Oedaria zone is found in the lower 

part of the shale member, and the species listed by Hall 

and Amick (1934, p. 166) from several levels in their 

unit 131 all belong to it. The Crepicephalus zor?. occurs higher in the shale member, and elements of it are 

sometimes found in the lower part of the Maynardville 

limestone member. The number, kind, and relative 

abundance of species differ from shale to limestor°i.

The Aphelaspis fauna, as far as now known, if confined to the Maynardville limestone member, but it has 

not been found in all sections. Inasmuch as there is 

little or no evidence for unconformity at the top of the 

Maynardville, the failure to find this fauna at some 

localities is most probably due to a shift in facier that 

permitted the deposition of fine-grained unfossiliferous 

lime muds, now preserved as magnesian limestones. 

The fossils differ markedly in abundance from lith^logy 

to lithology; they are most abundant in coarse-grained 

limestones, extremely rare in the aphanitic, sublithographic varieties, and virtually unknown in the magnesian limestones. Even in the coarsely crystalline 

strata, the fossils commonly occur in richly fossiliferous beds or lenses separated by barren areas of 

otherwise similar rock. Inasmuch as most of the fossils are dissociated fragments of trilobite tests, these 

accumulations are interpreted as the result of current

6 Middle Cambrian fossils occur in the shale here classed as- upper 

Rome. This shale corresponds to the Pumpkin Valley shale of Todgers 

and Kent (1948, p. 7-9), but the fossils were erroneously listed) by 

Resser (1938, p. 27) as Rntledge.

7 The name Dresbach formation as used here conforms to thii usage 

of Trowbridge and Atwater (1934), and includes the Mt. Simcn, Ban 

Claire, and Galesville members. This is not the classification of the 

U. S. Geological Survey (Wilmarth, 1938, p. 631-632), but it ccnforms 

with generally accepted usage of Cambrian stratigraphers throughout 

North America (Howell and others, 1944).
20 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

action. The scarcity of fossils in the fine-grained limestones is probably environmental, for it is well known 

that today areas of fine-grained lime muds are almost 

devoid of benthos.

Lochman and Duncan (1944, p. 31), discussing the 

ecology of these faunal assemblages, wrote:

Although a lack of knowledge of the physiologic processes of 

trilobites precludes a positive statement of water temperatures, the large diversified faunal assemblages of the Cedaria 

and Crepicephalus zones would by analogy indicate warm temperate conditions, while the assemblage of the Aphelaspis zone, 

rigidly restricted to five trilobite genera throughout the entire 

country, and represented by large numbers of individuals, may 

indicate the introduction of cooler waters.

Further, Lochman writes (personal communication) :

The CrepiceJialus fauna contained a large number of species ; 

therefore some of the diagnostic forms are almost certain to 

be present, no matter what the lithology of the formation may 

be. It also appears that certain genera characteristic of the 

fauna, notably Crepicephalus, Uncaspis, and Llanoaspis, were 

able to live in environments containing quite a bit of clastic 

material; therefore species belonging to these genera are fairly 

well represented in shales and sandstones, as well as in limestones, and thus serve as a means of correlation between different f acies.

In his discussion of the Upper Cambrian faunas of 

the Appalachian Valley, Resser (1938, p. 28-30) listed 

species occurring in the Cedaria, and Orepicephalus 

zones, in eastern Tennessee, mentioned the presence of 

the Aphelaspis zone without listing its fauna, and stated 

that a fourth zone, his so-called Blountia zone, was present above the Aphelaspis zone. His list of species from 

this zone is lengthy and includes at least 8 forms known 

to be characteristic of the Aphelaspis zone, 23 known 

from the Orepicephalus zone, and a few species that are 

unknown in this part of the Cambrian and are thought 

to have been misidentified. Most Cambrian stratigraphers and paleontologists now believe that the socalled Blountia zone does not exist as a distinct unit, 

but that the fauna attributed to it is made up primarily 

of species from the Aphelaspis and Orepicephalus zones, 

particularly those forms characteristic of coarsegrained limestones. This would account for the extraordinary development of the so-called Blountia zone 

in sections where such limestones are abundant and its 

scarcity or absence in sections where fine-grained limestones or dolomites make up the bulk of this member.

The lists of species characteristic of the Orepicephalus 

and Aphelaspis zones given below were prepared by 

Mrs. Christina Lochman Balk and have been checked 

for changes in generic assignments by her and A. R. 

Palmer.

All species listed are from the Appalachian Valley; 

those indicated (Va.) are known only from Virginia.

Aphelaspis zone

Aphelaspis camiro (Walcott) 

hamblenensis Resser 

laxa Resser 

quadrata Resser 

simulans Resser 

tumifrons Resser 

walcotti Resser (Va.) 

CheilocepJialus breviloba (Walcott) 

Raaschella appalachia (Resser) (listed by Resser as

Stenochilina) 

bristolensis (Resser) (Va.) (listed by Resser as

Terranovella)

Species listed by Resser that are probably referable to the 

Aphelaspis zone:

Blountia assimilis Resser 

crassa Resser

Crepiceplialus zone

Blountia alexas (Walcott)

anser (Walcott)

mimula (Walcott)

rogersvillensis Jtesser=Blountiella lata Resser 

BlountieUa buttsi Resser (Va.) 

Coosia rofaista (Walcott) 

Crepicephalus etepansiis Resser

reotiformis Resser 

Kingstonia rotunda Resser 

Llanoaspis blandensis (Resser) (Va.)

~buttsi (Resser) (Va.)

campbelli (Resser) (Va.)

clinchensis (Resser)

peculiai"is i (Resser)

ulrichi (Resser)

virginica (Resser) (Va.)=L. roffersv'Hensis (Resser)

walcotti (Resser) 

Maryvillia arion (Walcott)

keithi Resser

sp.=Coosia alethes (Walcott) 

Pemphigaspis appalachia Resser 

TricrepicepJialus magnispinus (Walcott)

thoosa (Walcott)*

ivalcotti Lochman 

Uncaspis micans Resser

Species listed by Resser that probably belong in the Crepicephalus zone (ranges of those marked with an asterisk (*) may 

extend into the Cedaria zone) :

Blountia arcuosa Resser

*Coosella amage (Walcott) 

andreas (Walcott) 

tennesseensis Resser

*Devracephalus buttsi Resser 

Genevievella marionensis Resser (Va.)

*Kmgstonia walcotti Resser 

Terranovella typicalis Resser 

Trierepicephalus comus (Walcott)

To the above lists should be added the species assigned by Resser (1938, p. 29) to the Orepicephalus 

zone. In compiling these lists a few obvious mistakes 

have been corrected, but no attempt has been made to 

eliminate possible homonyms and syronyms as this
STRATIGRAPHY 21

would involve a detailed paleontological study that is 

beyond the scope of this report.

Eesser (1938, p. 28) also mentioned the presence of 

graptolites in some of the faunas from the Nolichucky 

shale. These are mostly dendroid forms and are commonly found associated with the Aphelaspis fauna in 

the Maynardville limestone member. One of the best 

localities is at the Knox County quarry at Tecoy 

(p. 17), but they have also been found at several other 

localities. Decker has studied this f aunule but has not 

published a list of species.

KNOX GROUP 

GENERAL, REMARKS

DEFINITION

The Knox group as used in this report comprises all 

strata above the Maynardville limestone member of the 

Nolichucky shale and below the Lenoir limestone or 

its Mosheim member. It is essentially the Knox dolomite of the Knoxville, Maynardville, and Morristown 

folios (Keith, 1895, 1901, 1896). The establishment 

of a satisfactory subdivision of the Knox dolomite was 

the major task undertaken when the author began the 

geologic work that led to this report. Such subdivision 

is important economically because mineral deposits in 

the Knox group are commonly confined to definite, 

rather thin, stratigraphic zones and at the same time 

are related to relatively minor structural features; 

therefore the more stratigraphic and structural detail 

that can be shown on a geologic map, the more valuable 

it will be to the mining geologist and mine operator and 

to any others who may have occasion to use it.

HISTORY

The history of the terminology of the Knox group 

and of the underlying and overlying formations is 

shown in chart 1. The columns of this chart list the 

names applied to Cambrian and Ordovician rocks in 

the publications cited, but the order is not necessarily 

that of the author cited; instead the names have been 

rearranged to show how the rocks included in the 

author's units are now classified. Thus, where a name, 

such as Sevier shale, was applied to two units now 

separately classified, the name appears in two places 

in the appropriate column. Similarly, Ulrich (1911, 

p. 637-638, pi. 27) places his Jonesboro limestone 

on the eastern side of the Appalachian Valley entirely 

above his "Upper Knox" on the western side; it 

is now known that the Jonesboro as originally defined includes the facies equivalent of the entire Knox 

sequence in the western belts, and it is so indicated on 

the chart.

Safford (1869, p. 203-226) proposed the term "Knoxville or Knox Group" 8 to include all the strata cropping 

out in the Valley of East Tennessee below the "Trenton 

and Nashville Series," now the Lenoir limestone and 

higher formations. (The older Lower Cambrian quartzites and shales, which he assigned to the Chilhowoe and 

Ocoee groups, do not crop out except in the mountains 

along the southeast margin of the valley.) In the 

group, he recognized three divisions: from below upward—the Knox sandstone, the Knox shale, and the 

Knox dolomite. This classification was used by others, 

notably the geologists of the early State Surveys of 

Alabama and Georgia (Smith, 1876, and many other 

publications).

The section that Safford considered "typical of the 

Knox Group" begins at the fault on "Webb's (or Rosebury's) Ridge, nearly three miles northwest from Knoxville, and extends to the Holston River. It is about 

three miles in length, and was taken along Second 

Creek." (Safford, 1869, p. 204 and fig.). Y^ebb's 

Ridge is now known as Sharp Ridge. The section 

crosses two belts of Knox dolomite, the northwestern of 

which is the southwest extension of the Mascot belt. 

Safford (1869, p. 205) gave a generalized section of the 

limestones and dolomites in this northwestern ridge and 

stated that their total thickness was 3,504 feet. This 

section is now entirely within the built-up part of the 

city of Knoxville—the valley of Second Creek is occupied by the tracks and yards of the Southern Railway—and at present little can be seen of the or'ginal 

section. The section on Loves Creek, about 6 miles 

northeast of Second Creek and in the western part of 

the area mapped for the present project, crosses the 

same belt of outcrop, and from it one can obtain a reasonably accurate picture of the Knox group of Ssifford 

in its type area. Even this is threatened by the growth 

of the city. A much better exposed section, and the 

one now commonly considered to be the most representative both of the Knox group of Safford and of the Knox 

group of present usage, is that at Thorn Hill, Grainger 

County (p. 25; pi. 3A).

In the 1890's the U. S. Geological Survey began to 

publish folios covering 30-minute quadrangles in the 

southern Appalachian region. In these, the Knox 

group of Safford was abandoned and new names were 

proposed for the two lower divisions. The upper third 

of the original Knox group retained the name of Knox 

dolomite. No attempt was made to map subdivisions 

within the Knox dolomite, although it was recognized

s "The city of Knoxville is located on a ridge made up of its limestones 

and dolomites; and this circumstance, together with the fact tJ at the 

threefold typical character of the series is well developed in Knox 

County, has induced me to. name it the Knoxville, or the Knox Proup," 

(Safford, 1869, p. 204.)
22 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

from the start that the formation contained both Cambrian and Silurian fossils. (At that time the term Ordovician period was not recognized by the U. S. Geological Survey.) The boundaries of the Knox dolomite 

were drawn on purely lithologic grounds, the presence 

of dolomite being the chief criterion. Thus it happened that, in Alabama, Georgia, and southeastern Tennessee, beds of pure limestone that are laterally equivalent to the upper third of the Knox dolomite farther 

north and northeast were excluded from the Knox and 

mapped with the overlying Chickamauga limestone. 

According to Butts (Butts and Gildersleeve, 1948, p. 

18-19), the Chickamauga at its type locality contains 

the Newala limestone, which is equivalent to the Kingsport and Mascot formations of the present report. Similarly at the lower limit, beds of dolomite in central 

Alabama, now known to be equivalent to the Nolichucky and Maryville and perhaps also the Eogersville 

formations, and therefore older than the Knox dolomite 

of Safford and Keith, were mapped as, and considered 

a part of, the Knox dolomite. At the same time, equivalents of the Knox dolomite in States farther north received other names, such as Shenandoah, Natural 

Bridge, Kittatinny, and Conococheague limestones, and, 

owing to scarcity of fossils and the failure to utilize the 

few that were found, little progress was made for many 

years in correlating the rocks in the several areas.

The first attempt at correlation and subdivision of 

the Knox dolomite was made by Ulrich (1911, p. 

633-640), who demonstrated that it could be zoned and 

divided. During the next two decades, a considerable 

amount of subdivision was accomplished in Alabama 

and Virginia through the detailed mapping of Butts 

(1926; 1933; 1940b; Butts and Gildersleeve, 1948) and 

others (Woodward, 1932) aided by the paleontological 

work of Ulrich. The correlation of certain paleontological zones throughout the length and breadth of the 

Appalachian Valley was fully established, but little 

detailed mapping was done in Tennessee until the present investigation was started.

After the publication of the Eevision of the Paleozoic Systems (Ulrich, 1911), Ulrich did not publish 

much concerning the subdivision of the Knox, but the 

subject was constantly in his mind. Some of the results 

of his studies are available in the form of correlation 

charts inspired by him and published by others (Bassler, 

1915, pis. 1, 2; Gordon, 1924, p. 34; Secrist, 1924, p. 16; 

Ulrich and Cooper, 1938, pi. 58). For many years he 

was absorbed in regional stratigraphic studies of lower 

Paleozoic rocks in the Appalachian Valley and elsewhere in the eastern and central United States and was 

consulted on many occasions by geologists of the Federal and State Surveys as well as by many others who

were interested in these problems. The impress of his 

work upon studies of Appalachian stratigraphy will 

remain for a long time to come, and it is greatly to be 

regretted that he did not find time and opportunity to 

publish more of his ideas. The writer was closely associated with Ulrich during the years that this study 

was in progress and is fully conscious and most appreciative of the help that this association r.fforded. In 

spite of this, many of the interpretations presented 

herein are directly contrary to some of Ulrich's most 

firmly held convictions. This is regrettable but unavoidable as long as so many of the facts are unknown 

or at best imperfectly understood; at the same time 

it is fully realized that the results of this rtudy are not 

final and that they will undoubtedly be modified and 

improved by subsequent workers.

In general, Ulrich believed that the sequence of 

formations and faunas in the Knox group is different 

in different areas; that facies changes are quite unimportant; that certain formations and their associated 

faunas are locally absent either because of nondeposition or because of subsequent uplift and erosion; and 

finally that formations are normally separated from 

each other by disconf ormities. Butts, who was closely 

associated with Ulrich for many years, aclHred to these 

views during much of his earlier work in the Appalachian Valley, but he recognized several important 

facies changes (for example, between the Lowville and 

Moccasin limestones and between the Conococheague 

limestone and the Copper Eidge dolomite).

As the present investigation progressec1 , and as the 

writer became familiar with the problems of the Knox 

group, the conviction grew on him that there are few, 

if any, unconformities of great magnitude within the 

Knox group; that the sequence of fauna* within the 

group is the same throughout the Appalachian Valley, 

at least in Tennessee; that any one of these faunas may 

be better developed or preserved and thus seemingly 

more abundant at one locality than at mother; and 

that this in turn may be due to the lithology of the 

rocks containing the fossils or to various environmental factors at the time of deposition.

It is now known that the Knox group contains the 

same series of faunas on both sides of the Valley, but 

that it is in a predominantly dolomitic facies on the 

northwestern side and a predominantly calcareous 

facies on the southeastern side. The intervening belts, 

among them the three belts included in the MascotJefferson City district, show various gradations between these two extremes. In general, an increase in 

the amount of dolomite in a given formation is accompanied by a decrease in the number of foss'ls preserved. 

Failure to recognize these facies relationships largely
STRATIGRAPHY 23

vitiated Ulrich's classification and correlation of the 

rocks of the Knox group, for, if fossils characteristic 

of a given unit were not recognized, the unit was presumed to be absent by unconformity. For example, 

Ulrich (1911, p. 671-674) considered the "Jonesboro" 

limestone on the east side of the Valley, which carries 

Canadian fossils in its upper part, to be much younger 

than the generally unf ossilif erous dolomite on the west 

side, but when fossils were finally found in this dolomite 

they showed that the two sequences are to be correlated. 

Similar reasoning underlies Oder's remark that the 

Stonehenge limestone "intervenes between the Chepultepec formation and the Nittany [Longview] dolomite 

in the northeastern part of the valley, not being known 

elsewhere in the area" (Oder, 1934, p. 481), yet the 

fossils show that the Stonehenge and Chepultepec are 

facies equivalents within a single formation (Grabau, 

1937, p. 66-67; Butts, 1940b, p. 101). Failure to take 

regional facies relationships into consideration was 

the cause of the unusual variations in thickness that 

Ulrich reported for certain formations, and also of the 

very great total thicknesses he assigned to the lower 

Paleozoic systems.

PRESENT USAGE

In this report the Knox group is divided into five 

formations, which are, in ascending order, the Copper 

Eidge dolomite of Late Cambrian age, and the Chepultepec, Longview, Kingsport, and Mascot formations of 

Early Ordovician age. (As previously noted, the Maynardville limestone of Oder is here considered to be a 

member of the Nolichucky shale and is excluded from 

the Knox group.) These formations are lithologic 

units; the confusion of formations with faunal units, 

that is, the definition of formations solely by their 

faunal content, has led to much of the confusion now 

existing in the correlation of the formations of the Knox 

group and of the overlying formations in the Appalachian Valley.

The names Kingsport and Mascot were chosen jointly 

by Bridge and Charles E. L. Oder for use in this report and a similar report being prepared by Oder on 

the area to the northeast. They were proposed by 

Oder and Miller (1945) and have been used in several 

abstracts and maps in the last few years. They replace the terms "Jefferson City formation" and "Cotter- Powell beds" used by Oder (1934) and also Forked 

Deer and Thorn Hill used by Hall and Amick (1934). 

Jefferson City, Cotter, and Powell are the names of 

formations exposed in Missouri and Arkansas, and 

there is no possibility that they can ever be traced into 

the Appalachian Valley. Even today, the limits of 

these three formations in their type areas and their 

relations to one another are not well known. Moreover, no two workers define them with the same limits. 

It is true that the Kingsport limestone corresponds to 

some part of the Jefferson City formation of the Ozark 

region, and the Mascot dolomite corresponds to some 

portion of the Cotter, but there is no evidence to indicate that the Jefferson City-Cotter boundary is the 

same as the Kingsport-Mascot boundary; in fa rt.t, recent studies indicate that they are not exactly the same 

(Cullison, 1944). There is at present no evidence to 

indicate that any beds in the Appalachian Valley of 

Tennessee are equivalent to the Powell formation of 

the Ozark region; on the contrary, fossils from the top 

of the Mascot dolomite in several localities correlate 

it with the upper part of the Cotter.

The five formations into which the Knox group has 

been divided are generally recognizable within the 

Mascot-Jefferson City district and over much of the 

surrounding territory, but their recognition and delineation depend to some extent on the scale of the map on 

which they are to be shown. Moreover, they are not 

always easy to map because of similarities in litl ology 

from unit to unit, both in the bedrock and in the residual cherts, and because of lack of outcrops, coHuvial 

movement of residuum, and absence of fossils anc1 other 

diagnostic criteria. Hence the boundaries on the geologic map are indefinite in many places.

For example, in the Mascot belt, the Chepultepec 

and Longview dolomites are both strongly dolomitic 

and can only be separated from one another with great 

difficulty, but in the area around Jefferson City the 

Chepultepec contains a great deal of limestone which 

makes it easier to differentiate. Similarly, the Kingsport and Mascot formations are reasonably distinct in 

the Mascot-Jefferson City district, the former being 

largely limestone, the latter dolomite. To the south 

and southwest of the Mascot-Jefferson City district, the 

percentage of limestone increases; in southern Tennessee, Georgia, and Alabama the two formations los^ their 

identity in a great mass of limestone—the Newalr, limestone. To the north and northwest, on the other hand, 

the limestone beds diminish in number and thickness 

and, except for a few layers near the base of the Kingsport, totally disappear, so that the separation of the 

two formations in the western belts of outcrop is also 

extremely difficult.

There is little evidence of an unconformity at the 

base of the Knox group. Although generally speaking 

it is fairly easy to separate the Maynardville frm the 

Copper Eidge, in practice it is often difficult to draw 

the precise boundary, especially toward the western 

side of the Valley (see p. 13).

There is now ample evidence of an unconforirity of 

some magnitude at the top of the Knox group in East
24 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

Tennessee, though even here it is sometimes difficult 

to separate the uppermost limestones of the Mascot 

dolomite from the overlying Mosheim member of the 

Lenoir limestone. Fossils collected in the upper 50 feet 

of the Mascot at a few widely separated localities indicate that faunas of latest Beekmantown age, such 

as have been found in the Warm Springs Valley and 

at other localities in western Virginia, are not present 

in Tennessee. The Lenoir limestone, including the 

Mosheim member, carries a Chazyan fauna, and there 

does not seem to be a sufficient thickness of strata between the Mosheim above and the highest fossiliferous 

beds in the Mascot below to carry the upper Beekmantown (Cassin) faunas. Furthermore, a conglomerate 

occurs locally at the base of whatever unit overlies the 

Mascot dolomite; the pebbles of this conglomerate are 

chiefly chert fragments derived from the weathering of 

the upper formations of the Knox group and are clearly identifiable as such. This unconformity and the deposits upon it are discussed more fully below (p. 57-59). 

The most probable break within the group itself is 

that between the Copper Ridge and Chepultepec dolomites, which corresponds to the break between the 

Cambrian and Ordovician periods, but even this break 

does not appear to involve a long interval of time as 

110 faunas are known to intervene elsewhere.

OZARKIAN AND CANADIAN SYSTEMS OF TJLRICH

Many of the papers cited in this report make frequent 

references to the proposed Ozarkian and Canadian systems of Ulrich. These systems, proposed by Ulrich in 

1911, were never formally adopted by the U. S. Geological Survey. They were used, however, by a considerable number of geologists for three decades and were 

adopted either formally or informally by a number 

of State organizations. As a result, the names Ozarkian and Canadian have appeared in publications and 

maps issued by several State surveys and on certain 

maps and publications of the Geological Survey, at 

least as quoted from Ulrich. Since the death of Ulrich 

in 1944 and of Butts in 1946, these systems have received little support. But many questions concerning 

them are still unanswered, and, as the Mascot-Jefferson 

City district and East Tennessee lie in an area where 

these systemic terms were applied, some discussion is 

here devoted to them.

It may be stated at the outset that no evidence favorable to the recognition of the Ozarkian has been found 

in the course of this investigation. For the Canadian 

the results are more noncommital. A case for a somewhat enlarged Canadian system can be made if the establishment of a new system for the Lower Ordovician 

seems desirable; on the other hand there seems to be no

valid reason for separating the so-callei Canadian 

rocks from the rest of the Ordovician, unless it be the 

unconformity at the top of the Canadian or Lower 

Ordovician. These results are not at all astonishing 

for, whereas the Canadian was simply split off from the 

early part of the Ordovician in order to lessen the 

amount of time allotted to that period and make it more 

nearly commensurate with other periods, notably the 

Silurian and Devonian, the Ozarkian was believed to 

be a new and hitherto unrecognized system wedged in 

between the Cambrian and the Canadian. It can now 

be stated that, with the possible exception of the Madison sandstone in Wisconsin, there is not a single formation among those assigned to the Ozarkian by 

Ulrich that cannot be and has not been properly correlated with formations that Ulrich hims3lf placed in 

either the Cambrian or the Canadian. This seeming 

paradox came about because most of the formations 

assigned to the Ozarkian are predominantly dolomitic 

in character, whereas their equivalents elsewhere are 

limestones, shales, and sandstones. The dolomites, as 

always, are sparingly fossiliferous and many of the 

fossils found are those of forms adapted to this peculiar 

environment and hence at first sight seemingly different from those found in the other rock tyj es.

In defining the Ozarkian, Ulrich (1911, p. 627) 

included

all the formations in the Appalachian Valley that can be shown 

to be younger than (1) the top of the Upper Cambrian Nolichucky shale in northeastern Tennessee and (2) the top of 

the Conasauga shale in southeastern Tennessee, northwestern 

Georgia, and northeastern Alabama and which are older than 

the base of the Stonehenge limestone of the Canadian system 

in southern and central Pennsylvania.

Thus the Copper Ridge dolomite of Ee.st Tennessee 

and its equivalents elsewhere were considered to be of 

Ozarkian age. In more recent years, however, elements of a number of faunas of Late Cambrian age 

have been found in the Copper Ridge (p. 34 ff.), and it 

can now be shown that the formation is probably the 

equivalent of both the Franconia and the Trempealeau 

formations of Wisconsin and of their equivalents 

elsewhere.

The distinguishing feature of the Ozarkian faunas, 

according to Ulrich, was an association of trilobites of 

Upper Cambrian affinities with gastropods and cephalopods of Ordovician or Canadian affinities. Not all his 

trilobites, however, are distinctly Cambrian in character; in fact, those assigned to the upper Ozarkian are 

all types unknown in the Cambrian and all have definite 

relationships to the forms occurring higher in the Ordovician. The gastropods are about equally well represented on both sides of the period boundary. Their
STRATIGRAPHY 25

association with the Cambrian trilobites in the lower 

Ozarkian is largely a matter of facies—the gastropods 

lived in a lime-mud environment, and, when this was 

invaded by trilobites, the characteristic Ozarkian assemblage was formed. Most formations recognized by 

Ulrich as being of Late Cambrian age are composed of 

crystalline limestones, shales, and sandstone. Trilobites 

are abundant in these rocks, but gastropods are comparatively rare. Even the trilobites vary in abundance, 

however, according to the type of sediment in which 

they are found. The well-known Upper Cambrian 

genus DikelocephaluS) once believed to be the index 

fossil for the Upper Cambrian, is actually restricted to 

a shale environment.

COPPER RIDGE DOLOMITE

NAME

Ulrich (1911, p. 635-637) proposed the term "Copper 

Ridge chert" for his second division of the Knox dolomite of eastern Tennessee and southwestern Virginia. 

The name was taken from Copper Ridge, the long, narrow, monoclinal ridge at the northwest base of Clinch 

Mountain, recognizable as a distinct topographic feature from Russell County, Va., to a point some miles 

west of Knoxville.9 The type locality 10 is along "the 

road from Bean Station u to Evans Ferry, on Clinch 

River" (Ulrich, 1911, p. 636), now U. S. Highway 25-E. 

It is shown on the Morristown folio (Keith, 1896) and 

on the Avondale T^-minute quadrangle sheet of the 

TVA series (pi. 3A). No detailed section was included, but the approximate thickness of the various 

formations and some description of the lithology, 

paleontology, and correlation of each were given.

This remarkable section, commonly known as the 

Thorn Hill section from Thorn Hill P. O. at its southern end, exposes almost every foot of the beds included 

in the Knox group as well as a great thickness of the 

overlying and underlying strata. It is one of the best 

exposed most continuous sections of lower Paleozoic 

rocks in East Tennessee and is now considered the standard of reference for this region, not only for the strata

•East of the gap at Speers Ferry, Va., where Troublesome Creek 

cuts through the ridge to join Clinch River, this ridge is known as 

Moccasin Ridge, and the name Copper Ridge is transferred to the next 

structural belt to the northwest (see Estillville 30' quadrangle and the 

new Clinchport and Duffleld 7%' quadrangles).

10 Wilmarth (1938, p. 519) states that the formation was "named for 

Copper Eidge, NB. of Knoxville, Tenn.,1* and Resser (1938, p. 17) says 

that "The type locality for the Copper Ridge formation is on Copper 

Ridge, Knox County, Tenn. (Ulrich, 1911)." Cooper (1944, p. 23) makes 

a similar statement. The only section of the formation on Copper Ridge 

mentioned by Ulrich in his original description is the one in Grainger 

County, discussed here, and Ulrich stated to the writer on several 

occasions that this is the section to which he was referring in the "Revision" and that he regarded it as the type section.

11 This locality is now submerged by Cherokee Lake, and Bean Station 

is in a new location, more than a mile to the west.

of the Knox group but for a number of older and 

younger formations as well. It differs in some details 

from the sections in the Mascot-Jefferson City district, 

and these differences are pointed out below in the descriptions of the various units. The section begins at 

a thrust fault about TOO feet north of the north end 

of the bridge across Indian Creek at the northwest base 

of Copper Ridge, where the Lower Cambrian Rome 

formation is thrust over the Moccasin limestone of 

Middle Ordovician age, and extends southward crossing 

Clinch Mountain to Poor Valley Ridge, where the Rome 

formation in the base of the next fault block to the 

south is thrust over the lower Mississippian Grainger 

formation.

The exposures in the older part of this section are 

practically continuous, and Hall and Amick (1934) 

measured a detailed section from the beds low in the 

Rutledge limestone exposed close to Indian Crsek to 

the lowest red beds of the Moccasin limestone opposite 

Thorn Hill P. O. This was a bed-by-bed measurement 

using planetable, alidade, and steel tape and contains 

notes on the lithology and paleontology, but, although 

the Knox was divided into four formations and new 

names were applied to two of them, no discusnon of 

formations or correlations was given. At the suggestion of the writer, Hall and Amick painted the numbers 

assigned to many of their units on the exposures. Many 

of these are still visible (1950) and make it easy for 

anyone having their paper to orient himself in the section. Rodgers and Kent (1948) reinterpreted the section in the light of the further development of ic^-as by 

the writer and others, and correlated it with a similar 

one exposed along State Highway 66 at Lee Valley 16 

miles northeast. In making these comparisons, they 

pointed out a few significant key beds missed by Hall 

and Amick and corrected a few errors in addition.

Oder (1934, p. 489-494) also measured and described 

this section, divided it into five formations, and correlated it with other sections in East Tennessee. These 

are the only detailed descriptions of the Copper Ridge 

dolomite in its type area that have been published. 

Hall and Amick's formations are not exactly tlie same 

as Oder's, and both differ in certain particulars from 

those used in this report.

As originally defined, the Copper Ridge included all 

the strata above Ulrich's "lower limestone" (roughly 

equivalent to the Maynardville limestone member of 

this report) and the base of the "Upper Knox" (Kingsport limestone and Mascot dolomite). It included, 

therefore, the Chepultepec dolomite and the Longview 

dolomite of this report. This was not Ulrich's intention but was due to failure to find the fossils characteristic of the Chepultepec and Longview in the Thorn
26 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

Hill section; the absence of the fossils was considered 

evidence that the formations were missing because of 

a disconformity (see p. 22). Later the Copper Ridge 

dolomite was studied in greater detail in Alabama and 

Virginia by Butts (1926, p. 84-87; 1940b, p. 90-95) and 

Ulrich (mostly unpublished, but see charts in Bassler, 

1915, pis. 1, 2; Gordon, 1924, p. 34; Secrist, 1924, p. 16; 

Ulricli and Cooper, 1938, pi. 58), and its position beneath the Chepultepec was clearly established. Subsequent work on the Thorn Hill section by Ulrich, Butts, 

Oder, the writer, and others has brought to light both 

the Chepultepec and Longview faunas in the upper part 

of the original Copper Ridge, and the formation in the 

type section is now restricted to the beds above the Maynardville limestone member of the Nolichucky shale and 

below the Chepultepec dolomite, more specifically to 

units 203 to 304 of Hall and Amick's section.

In Tennessee, Virginia, and northern Alabama the 

Copper Ridge is the oldest formation that has been assigned to the Knox group, but in central Alabama, particularly in the Cahaba Valley, other units, namely the 

Bibb, Ketona, and Brierfield dolomites, are believed by 

some (Ulrich, 1911, p. 633-634; Bassler, 1915, pi. 2; 

Butts, 1926, p. 81-84; 1940a, p. 6) to lie above the Nolichucky shale or its equivalent but below the Copper 

Ridge dolomite. Other geologists, including the writer, 

believe that these formations, collectively known as the 

"Sixmile series" (Resser, 1938, p. 17), represent a dolomitic f acies of the upper part of the Conasauga shale, 

being the stratigraphic equivalents of the Nolichucky, 

Maryville, and Rogersville formations of Tennessee, 

for the few fossils found in the immediately underlying 

Conasauga shale in the Sixmile area are Middle Cambrian forms similar to those found in the Rutledge limestone of Tennessee (Butts, 1926, p. 73, pis. 5, 8; 1940a, 

p. 5). If the Bibb, Ketona, and Brierfield were indeed 

younger than the Nolichucky shale and older than the 

Copper Ridge dolomite, then a notable disconformity 

would exist between these two formations in East Tennessee; this was always Ulrich's belief. The writer 

however finds no evidence for such a disconformity in 

East Tennessee (p. 13). Cooper (1944, p. 27) likewise 

found no physical evidence for an unconformity in the 

Burkes Garden area of Virginia, though he realized that 

one was to be expected if the Brierfield dolomite really 

overlies equivalents of the Nolichucky shale in Alabama. 

If, however, the Brierfield rests on equivalents of the 

Rutledge limestone, it and the Ketona and Bibb are represented in East Tennessee by the Rogersville, Maryville, and Nolichucky formations and not by the Copper 

Ridge dolomite or an unconformity beneath it.

DISTRIBUTION

In the Mascot-Jefferson City district the Copper 

Ridge covers a greater area than any othe~ formation. 

It is found in all three belts of outcrop (p. 7) but is 

most extensively developed in the northwestern or 

Mascot belt, particularly in the region between Jefferson City and Rutledge, where, because cf its nearly 

horizontal position, its outcrop belt cover? an area of 

many square miles.

The best outcrops and most complete sections of the 

Copper Ridge within this area—and for that matter 

of the other subdivisions of the Knox group—are in 

the western part of the Mascot belt between Knoxville 

and Richland (Ada on the Maynardville 30-minute 

quadrangle). Here the steeply dipping beds of the 

group form a belt 2,000 to 3,000 feet in wid*to, and there 

are good sections along almost every creek crossing the 

strike. The best sections are along Lover (p. 27-30), 

Woods, Strong, and Roseberry Creeks (all on the John 

Sevier quadrangle), and along Big Flat Creek on the 

Mascot quadrangle. Northeast of Richland the outcrop 

belt of the formation widens abruptly because of a 

sudden flattening of the dip, reaching a maximum 

width of about 8 miles in the region just north of Jefferson City and gradually narrowing nortl ^ast of this 

point to a termination about 10 miles north of Morristown. Northeast of Mascot the exposures are small, 

discontinuous, and less common, and most of the mapping has had to be done on the basis of small outcrops 

and residual materials. An excellent section of the 

Copper Ridge dolomite in the Jefferson City belt was 

formerly exposed on Pearce Branch in the Talbott 

quadrangle, but the greater part of this section is now 

submerged beneath Cherokee Lake.

LIMITS AND THICKNESS

The contact of the Copper Ridge with tiN Maynardville limestone member of the Nolichucky sHale has been 

discussed (p. 13) ; it is commonly taken at the base of 

the lowest bed of coarsely crystalline H-avy-bedded 

knotty dark dolomite, for example, unit 203 of the 

Thorn Hill section (Hall and Amick, 1934, p. 168) and 

unit 86 of the Lee Valley section (Rodgers and Kent, 

1948, p. 14).

The top of the formation lies somewhere within a 

thick zone characterized by beds of calcareous sandstone, thin-bedded fine-grained light-colored dolomite, 

and, in the lower part, oolitic chert, which taken altogether forms one of the most distinctive lit Tiologic units 

within the Knox group. This zone comprises the beds 

from unit 295 to the lower part of unit 379 of the Thorn 

Hill section and is about 540 feet thick.
STRATIGRAPHY 27

Cullison 12 placed the top of the Copper Ridge dolomite at the base of the lowest sandstone bed in this 

zone (unit 295) and, mostly for convenience, used this 

boundary consistently in all his mapping in the Norris 

Reservoir area. Oder (1934, p. 492, and personal communication in the field about 1938) placed the boundary 

about 30 feet below the top of Hall and Amick's unit 

379, about 444 feet above Cullison's contact. He also 

reported the finding of StenocMlina spinifera Ulrich, a 

Late Cambrian trilobite, in loose chert somewhere in 

the upper part of this sandy zone. Later (personal 

communication) he was inclined to place the upper contact of the formation at about the top of unit 348, the 

same point selected by Hall and Amick (1934, p. 201) 

for their Copper Ridge-Nittany 13 boundary.

The contact agreed upon at informal field conferences in the forties and used consistently by most field 

parties working in East Tennessee during the past 10 

years is at the base of a prominent sandstone, unit 305 

of the Thorn Hill section. Admittedly it is an arbitrary boundary difficult to place accurately in many localities, but its approximate position can almost always 

be determined with enough accuracy for the purposes of 

a map, such as the one in this report, by drawing it 

just above the appearance of the highest white siliceous 

oolite, which commonly crops out where exposures are 

good and occurs as large float blocks in the soil where 

mapping must be done on residual materials. (See also 

p. 38.)

Ulrich (1911, p. 636) stated that the Copper Ridge 

dolomite is 1,345 feet thick in the Thorn Hill section; 

Hall and Amick (1934) assigned it a thickness of 1,217 

feet 3 inches (after correction); Oder (1934, p. 492) 

gave it 1,379 feet; and according to the limits assigned 

in the immediately preceding paragraphs it is only 

907 feet. The discrepancies between these figures are 

largely apparent, for no two measurements include 

exactly the same set of strata. Moreover, the published 

sections are difficult to compare because of the monotonous repetition of varieties of dolomite through most 

of the sequence. Two points can be almost certainly 

identified in all sections, however, and when the measurements between these points are compared, the agreement is remarkably close. These points are the rather 

abrupt transition from dominant shale to dominant 

limestone about the middle of the Maynardville limestone member of the Nolichucky shale, and the first appearance of aphanitic structureless limestone near the 

base of the Kingsport limestone. Ulrich's original

u Cullison, J. S., 1937, Geology of Norris Reservoir basin: Ms. in 

files of Tenn. Valley Authority.

18 Hall and Amick did not recognize the presence of the Chepultepec 

in this section and, following the usage of the time, used "Nittany" for 

what is now called Longview.

Copper Ridge chert included all strata between these 

limits except for 345 feet of "lower limestone," so that 

his total was 1,690 feet. Hall and Amick's figure for 

the beds in question is 1,961 feet; Oder's is 1,975T feet. 

An unpublished section, measured by the writer in 

1929 and originally intended for this report, agrees almost exactly with Oder's figure. Ulrich's section was 

measured in 1905, when the exposures along the highway were not as continuous as at present, and some 

of his thicknesses appear to have been estimatec1 ; the 

other three thicknesses are in close agreement.

The thickness of the formation as now delimited is 

907 feet in the Thorn Hill section. Rodgers and Kent 

(1948, p. 14^19), measuring the same strata at Lee 

Valley, obtained a figure of 925 feet. Within the. Mascot-Jefferson City area, the most satisfactory section 

is that on Loves Creek at the west edge of the area; here 

the calculated thickness is 943 feet. The formation 

probably retains approximately this thickness throughout the mapped area. The Loves Creek section is given 

below.

Section of the Copper Ridge dolomite and NoUchucJoy shale 

exposed along the tracks of the Southern Railway in the 

valley of Loves Creek, at the western edge of plate 1 of this 

report

[Measured by Josiah Bridge, November 1937]

Section begins opposite iron post with sign "Station J mile" 

and continues in a north-northwesterly direction on either side 

of the track to the grade crossing where the old Millertown 

Pike crosses the tracks, 900 ft south of the present overpass. 

Traverse distances were measured along the rail with a tapeline, and thicknesses of most units were computed frorr these 

horizontal measurements and the average dips. Thicl'nesses 

of some small units were measured directly across the outcrops. 

All thicknesses are computed to the nearest foot.

Unit Total 

tfcicfc- thickness ness 

(feet) (feet)

Ordovician system:

Chepultepec dolomite (Section measured in cut 

on east side of railroad track) :

15. Traverse distance 0-122 ft, unit distance 122 ft. Strike 65°, average 

dip 45°, bearing 155°; thickness 

calculated______________ 85 85 

Dolomite, with many arenaceous == 

layers and some distinctive chert 

beds. The dolomite is very poorly exposed, the interval being 

largely covered with residual 

materials—chiefly blocks of brown 

sandstone, derived from the 

weathering of arenaceous dolomite beds, and of chert. Certain 

layers of sandstone and chert are 

still approximately in place -and 

show the general structure. A
28 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

Unit Totth thick- thickness ness 

(feet) (feet)

Ordovician system—Continued

Chepultepec dolomite—Continued

conspicuous bed of white siliceous 

oolite about 1 ft thick crops out 

about 32 ft stratigraphically (45 ft 

horizontally) below the top of the 

section; above it are some layers 

of white compact platy chert containing long, narrow, oblong slots 

arranged parallel to the bedding; 

these are believed to be the molds 

of flat limestone pebbles that have 

been dissolved. A thin bed of 

sandstone crops out about 1 ft below the oolite bed; 23 ft stratigraphically (33 ft horizontally) 

beneath this is a second bed of soft 

rusty brown sandstone about 2 ft 

thick. The base of the unit consists of about 8 ft of mediumgrained sandstone, soft, friable, 

and porous at the top, becoming 

harder and more quartzitic toward the base. This sandstone is 

commonly stained rusty brown 

but freshly broken surfaces are 

white.

Cambrian system:

Copper Ridge dolomite:

14. Traverse distance 122 ft to 245 ft, 

unit distance 123 ft. Strike 65°, 

average dip 53°, bearing 155°; 

thickness calculated________ 98 98 

Dolomite, with arenaceous layers, 

weathering to sandstones, the exposure in the railroad cut being 

made up largely of ledges of dolomite exposed in the creek bed to 

the west. Stratigraphically 44 ft 

below the top of the unit is a zone 

of oolitic chert about 2 ft thick, 

and 52 ft stratigraphically below 

this are 2 thin beds of oolitic 

chert from 1 to 4 in. thick. These 

beds are 180 ft and 243 ft, respectively, north of the initial point 

(horizontal measurement) and are 

believed to correspond to the oolites in units 304 and 282, respectively, of the Thorn Hill section 

(Hall and Amick, 1934, p. 198- 

199). Both oolite beds are exposed in the bed of Loves Creek 

a few tens of feet west of the railroad. Beneath the lower oolite 

is about 2 ft of soft porous brown 

sandstone.

13. Traverse distance 245 to 693 ft, unit 

distance 448 ft. Strike 65°, average dip 57°, bearing 155°; thickness calculated___________ 375 473

Unit Total 

thick- thickness ness 

(feet) (feet)

Cambrian system—Continued

Copper Ridge dolomite—Continued

Dolomite, light-steel-gray with a 

few scattered layers that are dark 

gray to chocolate brown. Bedding distinct, zones with beds 1 to 

3 in. thick alternating with zones 

in which the individual layers are 

from 5 to 8 in. thick. Texture 

compact and very fine grained, 

more fine grained than in unit 12. 

Weathered surfaces light grr.y, 

lighter than those in unit 12, 

often streaked with shades of tin 

and buff. Several horizons of 

chert in beds as much as 4 in. 

thick. Chert is commonly hon^y 

colored, compact, with a waxy 

texture and splintery fracture. 

Joints normal to bedding, w?ll 

developed and closely spaced. 

12. Traverse distance, 693 to 770 ft, 

unit distance 77 ft. Strike 65°, 

dip 60°, bearing 155°; thickness 

calculated _____________________

Dolomite, medium-gray to brownish-gray ; darker than in unit 13, 

much lighter than in unit 11; be<*s 

commonly 10 in. or more thick, 

bedding planes indistinct, somewhat wavy and minutely irregular. Fracture sharp and clean, 

but not conchoidal. Weathered 

surfaces smooth to granular 

(sandpaper texture), dark gray 

with tan and buff stains. Bc4s 

cut by widely spaced vertical 

joints belonging to two systems. 

Between traverse distances 715 

ft and 747 ft is a zone about 28 ft 

thick composed largely of resMual chert with a few scattered 

outcrops of dolomite. The chert 

is platy and occurs in layers as 

much as 3 in. thick. It is bteek 

and semitranslucent when fresh 

but weathers to light-gray or 

cream-colored somewhat tripolitic 

chert. Surfaces are commonly 

stained by oxides of iron and 

manganese, and the fracture is 

hackly or splintery. Associated 

with the chert are beds of silicified cryptozoa irregular in outline 

because of crowding; the individual heads, which are as nnreh 

as 6 in. across, are grouped into 

confluent masses 2 ft or more 

across.

66 539
STRATIGRAPHY 29

Unit thickness 

(feet)

Total thickness 

(feet)

Cambrian system—Continued

Copper Ridge dolomite—Continued

11. Traverse distance 770 ft to 895 ft, 

unit distance 125 ft. Strike and 

dip as in unit 12; thickness calculated_________________ 106 645 

Dolomite, dark-gray, brown, and 

chocolate-brown, finely to medium 

crystalline; individual layers 10 

in. to 2 ft thick, little or no sign 

of laminations, major bedding 

planes indistinct, somewhat wavy, 

minutely irregular. Fracture 

sharp and clean. Weathered surfaces dark gray but lighter than 

freshly broken surfaces, often 

stained with buff and tan shades, 

smooth to minutely granular. 

Beds cut by at least two systems 

of widely spaced vertical joints. 

Chert is present at various 

levels as irregularly laminated 

roughly tabular masses parallel 

to the bedding planes. Most of it 

was originally dark gray to black, 

but some of the masses are white. 

All of it weathers to a dead chalky 

white, the surfaces usually stained 

by oxides of iron and manganese. 

It breaks into small rectangular 

blocks and splinters with sharp 

edges. (The railroad cut ends 840 

ft north of the initial point in the 

middle of this unit, and, from here 

north, the section is compiled from 

outcrops in the creekbed and in 

the fields and road cuts on either 

side of the track.)

10. Traverse distance 895 to 1,225 ft, 

unit distance 330 ft. Strike and 

dip as in units 11 and 12; thickness calculated____________ 298 943 

Dolomite, mostly light gray with —— 

some dark beds as in unit 11. 

Beds commonly 1 to 3 ft thick; 

lower beds poorly exposed. The 

base of this unit and the base of 

the Copper Ridge dolomite are 

about 140 ft south of the point 

where the road to Spring Park 

Church crosses the railroad.

Noliehucky shale:

Maynardville limestone member:

9. Traverse distance 1,225 to 1,295 ft, 

unit distance 70 ft. Strike 65°, 

dip 63°, bearing 155°; thickness 

calculated _______________ 62 

Limestone, somewhat dolomitic, 

aphanitic to very finely Crystal839223—55——3

62

Unit Total

thick- thickness ness

(feef,) (feet)

Cambrian system — Continued 

Noliehucky shale — Continued

Maynardville limestone member — Con.

line. Thin bedded, commonly with 

many alternations of limestone 

and dolomite layers. Mostly light 

steel gray with a few thin shale 

partings. The lower 15 ft more 

thickly bedded and more strongly 

dolomitic.

8. Traverse distance 1,295 to 1,489 ft, 

unit distance 194 ft. Strike and 

dip presumably as above ; thickness calculated ___________ 

Covered interval, a few scattered 

outcrops of limestone. (Road to 

church crosses railroad 1,439 ft 

north of initial point.) 

7. Traverse distance 1,489 to 1,565 ft, 

unit distance 76 ft. Strike 65°, 

dip 63°, bearing 155° ; thickness 

calculated _______________ 

Limestone, fine-grained to aphanitic, blue to bluish-gray, with thin 

nodules and seams of dolomitic 

and clayey material parallel to the 

bedding planes. These magnesian 

layers weather dark and stand out 

in relief, giving the outcrops a 

characteristic mottled and ribboned appearance. Beds 1 to 3 ft 

thick in fresh exposures but breaking down into thin plates 1 to 5 in. 

thick on further weathering. This 

sequence is well exposed in the 

fields west of the road opposite 

Spring Place Church and in the 

creekbed between the road and 

the railroad.

Lower shale member :

6. Traverse distance 1,565 to 1,875 ft, 

unit distance 310 ft. Strike 65 G , 

dip assumed to be 65°, bearing 

155° ; thickness calculated ____ 

Shale, soft, thin-bedded, olivegreen ; the interval mostly covered, best exposures toward the 

base. (At traverse distance, 1,875 

ft the section appears to be broken 

by a small strike fault (not shown 

on the map), which is probably 

a sliver of the main Saltville 

thrust, and which repeats the upper part of the lower shale member of the Noliehucky shale and 

the Maynardville limestone member. This fault was not recognized when the section was measured and has not been traced 

laterally along the strike.)

173 235

C8 303
30 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

188

Unit thickness 

(feet)

Cambrian system—Continued 

Nolichucky shale—Continued

Maynardville limestone member:

5. Traverse distance 1,875 to 2,075 ft, 

unit distance 200 ft. Strike 70°, 

dip averaging 70°, bearing 160°; 

thickness calculated_____________

Limestone, fine-grained to aphanitic, blue, with patches and thin 

layers of coarser grained lighter 

colored dolomitic material; similar to and probably a repetition 

by faulting of the beds in units 7 

and 8.

Lower shale member:

4. Traverse distance 2,075 to 2,295 ft, 

unit distance 220 ft. Strike and 

dip as in unit 5; thickness calculated _______________ 

Largely covered, but with a few 

outcrops of soft olive-green shale, 

similar to unit 6.

3. Traverse distance 2,295 to 2,345 ft, 

unit distance 50 ft. Strike and 

dip as in unit 5; calculated thickness _—_________-______

Partly covered, but with several 

small outcrops of soft olive-green 

shale, similar to unit 4. 

2. Traverse distance, 2,345 to 2,720 ft, 

unit distance 375 ft. Strike and 

dip as in unit 5; thickness calculated_________________ 352 

Shale, olive-green to greenishgray, soft, well-bedded; well exposed in low railroad cut. 

1. Traverse distance 2,720 to 3,095 ft, 

unit distance 375 ft. Strike and 

dip as above; thickness calculated_________________ 352 

Shale, similar to unit 2, not continuously exposed but with many 

exposures in low cuts on the east 

side of the Loves Creek road. 

Base not exposed but somewhere 

near the grade crossing of the old 

Millertown road and the railway.

Total lower shale unit, units 1 to 4______________

Total Maynardville limestone member, units 7 

to 9_______________________

Total thickness 

(feet)

207 207

47 254

606

958

958

303

Total Nolichucky shale_______________ 1, 261

There are many but discontinuous exposures of the 

older Cambrian formations along the railroad track 

and in cuts along the roads parallel to it from this point 

north to the trace of the Saltville fault that crosses the 

railway about 6,000 feet north of the initial point. The 

Mary ville limestone is represented by a band of red soil 

about 400 feet wide, which, assuming a dip of 65°,

would indicate a thickness of about 360 feet. The Rogersville shale is well exposed in the cuts at the overpass, where the present Millertown road crosses the 

railroad. Just north of this is a zone of limestone about 

280 feet wide, representing a stratigraphic interval of 

about 255 feet. This zone seems to be the thinned remnant of the Rutledge limestone.

North of the base of this limestone unit, the shales 

of the upper part of the Rome formation (Pumpkin 

Valley shale of Rodgers and Kent, 1948) are rather 

complexly folded, dipping both southeast and northwest, and are cut by one or more small strihe faults so 

that it is difficult to obtain an accurate estimate of their 

thickness. The shales here are now being quarried 

and expanded into lightweight aggregate.

BEDROCK LITHOLOGY

The most distinctive rock type of the Copper Ridge 

dolomite is a dark, medium to coarsely crystalline thickbedded dolomite. Freshly broken surfaces of this rock 

give off a strong fetid odor, which is one of the most 

characteristic aids in the recognition of the formation. 

A similar odor can be detected in f racturec1 rock from 

few beds in other formations in the section, and even in 

these the odor is rarely as strong as that from characteristic dark dolomite of the Copper Ridge.

The fracture is rough and hackly, and freshly broken surfaces are dark purplish gray to reddish or brownish gray. This dark color is also a distinctive characteristic. The texture appears sugary, and tl °> rock commonly shows many small veinlets and kncts of white 

dolomite or quartz. Beds are commonly from 12 to 24 

inches thick. The principal bedding planes are essentially parallel, but their surfaces are irregularly knobbed 

and pitted, these minor features having a relief of an 

inch or less. Minor bedding planes are faint or invisible. Jointing is well developed, but the individual joint 

planes are commonly rather widely spaced. Weathering accentuates the joint and major bedding planes and 

causes the outcrops to break into large blocks with 

rounded edges, more rarely into a mass of pinnacles.

Weathered surfaces are commonly dull lead gray, 

which however is of a lighter shade than the color of 

the fresh surfaces.

This dark odoriferous crystalline knotty dolomite is 

the most distinctive lithologic type found in the Copper 

Ridge dolomite, but normally it is interb°-dded with 

fine-grained light-steel-gray dolomite of a t^pe common 

throughout the Knox group. The dark dolomite is confined to the lower two-thirds or three-fourths of the 

formation and is one of the best means of identifying 

the formation in fresh exposures. This criterion must 

be used with a certain amount of caution, however, for
STRATIGRAPHY 31

this lithologic type, together with its characteristic odor, 

reappears as single beds, or in short sections composed 

of several beds, at several levels through the Ordovician 

part of the Knox group. The most conspicuous recurrence of this type is found in a zone about 20 feet thick 

near the top of the Mascot dolomite.

The lithology of the upper part of the Copper Ridge 

dolomite is quite different from that of the lower part. 

The strata are mainly medium- to thin-bedded commonly laminated fine-grained to aphanitic light-gray 

to bluish-gray dolomite, similar in many respects to the 

dolomite in the tipper part of the Maynardville limestone member and also to much of the dolomite found in 

the Ordovician formations of the Knox group. The 

distinctive lithologic features of this part of the formation are not found in these widely distributed rather 

nondescript rocks, but rather in the layers of chert, siliceous oolite, and calcareous sandstones that are interbedded with them. Many of these special lithologic types 

also persist into the overlying formations, and, as a general rule, it is the combination of several factors, rather 

than any single one, that is relied upon in making final 

identifications.

RESIDUAL PRODUCTS

The principal residual products of the Copper Bidge 

dolomite are clay, chert, and sandstone.

The clays are heavy, brittle when dry, sticky and 

tenacious when wet, and commonly orange to brick red 

where little or no soil is present. 'Soils developed on 

these clays are much lighter in color, gray and grayishbrown tints predominating.

Chert of various types, the greater part of it derived 

from the selective silicification of the dolomite during 

weathering, is extraordinarily abundant in the clay and 

soils of most areas underlain by the Copper Ridge 

dolomite. On the contrary, beds and layers of chert 

are not common in fresh exposures; many of those that 

are found seem to be replacements of structures that 

were originally deposited as limestone, that is, siliceous 

oolites and silicified algal lime secretions (cryptozoa).

Layers of flat ovoid compact chert nodules arranged 

along bedding planes, such as a^e common in the 

Chepultepec and younger formations of the Knox group 

and could be regarded as syngenetic, are not conspicuously developed in the Copper Kidge. The dolomites 

of the formation contain much interstitial colloidal 

silica, invisible in hard samples but appearing as a 

characteristic insoluble residue when fragments of the 

dolomite are dissolved in hydrochloric acid. The writer 

believes that during the process of weathering this 

colloidal silica goes into solution and is redistributed 

and concentrated as chert on exposed surfaces, and that 

this process accounts for most of the surficial chert.

The silicified layers found not only in outcrops but also 

in drill holes and mine workings in all probability represent replacement of layers along which the movement 

of ground water was especially active.

The bulk of the residual chert from the Copper Kidge 

dolomite is dull and opaque, grayish white, with the 

surfaces commonly stained various shades of yellow, 

red, and black by the oxides of iron and manganese. 

It is mostly compact and even textured, finely grarular 

to aphanitic, and free from large cavities. On further 

weathering, it breaks down into smaller and smaller 

rectangular blocks and splinters.

In wooded areas where the soil has been undisturbed 

for years and where the ground cover of vegetation is 

sparse, the surface of areas underlain by the Copper 

Ridge dolomite is commonly covered by a pavement of 

small angular light-colored chert fragments, with very 

few large blocks of chert. Chert-covered slopes of this 

type are a rather reliable index to the underlying formation. Areas that have been cultivated seldom rhow 

this pavement, but on the other hand they show a much 

larger proportion of large chert blocks.

Another variety common in the lower part of the formation and rather characteristic of it is black s ^mitranslucent chert in irregular masses, commonly stained 

a dull red on weathered faces but breaking with a 

conchoidal fracture and lacking the regular jointir g of 

the other varieties. These black cherts are particularly 

abundant in the zone of the dark dolomites.

Oolitic cherts are found throughout the formations of 

the Knox group, but they are especially numerous and 

distinctive in the residual chert of the Copper Ridge 

dolomite. Several varieties are distinguishable, and 

because they can be recognized in drill cuttings and mine 

workings (Oder and Miller, 1945, p. 9; Alien, 1P48), 

they are extremely useful for correlation. About 33 

feet above the base of the formation is a bed of oolitic 

dolomite, commonly silicified, which is a rather conspicuous marker (Oder, 1934, p. 477; Hall and Amick 

1934, p. 195, unit 214). The ooids in this bed average 

iy2 millimeters in diameter and commonly are strikingly color banded. Except for the oolite in the Maynardville limestone member (p. 12,18), this is the lowest 

bed of siliceous oolite known in the area. Other beds of 

siliceous oolite are found throughout the Copper Ridge 

dolomite, but they are most concentrated in the upper 

zone of light-colored dolomite. Some of the more conspicuous of these oolite beds in this zone are mentioned 

by Hall and Amick (1934, p. 197-199, units 271, 282, 

302), but the most persistent and widely recognized one 

is the oolite bed in unit 304 of this section which they 

list as "an 18-inch chert bed." This bed is 27 feet below 

the top of the Copper Ridge dolomite as here delim ited
32 STRATIGRAPHY OP THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

and, together with the bed 39 feet below it in unit 302, 

has been recognized in so many parts of East Tennessee 

that the two beds are commonly used as a guide to the 

top of the Copper Kidge dolomite. Beds of siliceous 

oolite believed to be equivalent to the beds at Thorn Hill 

have been recognized in the Lee Valley section (Rodgers and Kent, 1948, p. 17-19, units 132, 148, 157, 161), 

where the intervals between the two upper beds and between the uppermost bed and the top of the formation 

are 43 and 29 feet, respectively. This close agreement 

between the two sections some 16 miles apart emphasizes 

the persistence of small distinctive lithologic units and 

the importance of their recognition and use in correlation, a fact long recognized and used by Ulrich and repeatedly stressed by him.

Within the Mascot-Jefferson City area two beds of siliceous oolite—believed to be the same as those just mentioned—have been found in many places. In the Loves 

Creek section the two beds are 44 feet apart, a figure 

that is very close to the distance between the two beds in 

the Thorn Hill and Lee Valley sections. In the Loves 

Creek section, however, the uppermost bed is 48 feet 

below the heavy sandstone taken as the base of the 

Chepultepec dolomite. The greater thickness in this 

locality may be due to a local thickening of the Copper 

Ridge dolomite, or it may be due to a miscorrelation 

between the sandstones in the Copper Ridge belt and 

the ones in the Loves Creek section. It could also be 

due to local erosion of the upper beds of the Copper 

Ridge dolomite on Copper Ridge.

All these siliceous oolites are conspicuously color 

banded, and this, together with the comparatively large 

size of the individual ooids, distinguishes them from the 

smaller uniformly colored oolites of the younger formations of the Knox group.

Another common and distinctive variety of chert is 

made up of silicified masses of supposed lime-secreting 

algae, commonly and collectively known as cryptozoa. 

At some localities, notably in certain beds in the Thorn 

Hill section and also in the small abandoned quarry at 

the north end of the bridge across Holston River on 

State Highway 92 just west of Cherokee Dam, these 

structures are preserved in dolomite beds, thus indicating that the silicification so common in other layers and 

in residual materials is secondary. Thin sections, both 

of the dolomitic and siliceous varieties, have not shown 

any traces of plant structure, and because of this some 

have argued that the so-called cryptozoa are not fossils 

but merely inorganic structures. Opposed to this purely 

negative evidence are the facts that they occur at definite 

stratigraphic levels in certain formations, that certain 

broadly generalized types are restricted to certain 

stratigraphic levels, and that they have wide, though

not universal, distribution at such levels and appear to 

be reefs or bioherms. They are commonly grouped 

under the generic designation Cryptozoon and a number of "genera" and "species" have be*m described. 

Their habits of growth are variable, however, and commonly one type passes into another by almost imperceptible gradations. The distance between the individual pillars of a colony, the diameter of these 

columns, and their relative spacing do not seem to be 

specific characters, although attempts hr-ve been made 

to use them as such. In this report about all that can be 

done is to class cryptozoans as solitary or colonial.

Several varieties of each of these tv^o classes are 

known at various levels in the Knox gro'ip, but two of 

them are abundant and practically restricted to the 

Copper Ridge dolomite. One type, belonging to the 

solitary class, consists of circular or cup-shaped masses 

of chert ranging from 4 or 5 inches to more than a foot 

in diameter, the mass consisting of thin parallel plates 

concentrically arranged around a common center of 

attachment on the basal side. They resemble thickwalled shallow saucers and commonly oc",ur as isolated 

individuals distributed along certain bidding planes 

but locally as loose colonies.

A second and more common type is the colonial 

variety that consists of a series of cores or pillars spaced 

from 1 to 2 inches to a foot or more apar1:. Each pillar 

is formed by a series of thin laminae convex upward. 

Where the pillars are widely spaced the cryptozoans 

have a superficial resemblance to cabbage heads in longitudinal section; where they are tightly crowded they 

give the impression of closely contorted laminae in 

cross section and the surfaces of the laminae themselves exhibit a distinctive "waffle-iron." pattern of 

knobs and furrows. Entire layers 2 feet or more thick 

in the lower part of the Copper Ridge dolomite may 

be made up of this form and locally several such layers may be grouped together in a ratl <*T thick zone 

(Hall and Amick, 1934, units 226-232, p. 195-196). 

This small waffle-iron form is very common in the 

lower part of the Copper Ridge dolomite and was for 

many years believed to be restricted to that horizon. 

Recently, howeverf Cattermole (personal communication, 1949) has found quite similar cryptozoans in the 

Mascot dolomite. The colonies appear to be much 

smaller, seldom more than a foot in diameter, and are 

not so numerous or so widely distributed as in the Copper Ridge dolomite, so that abundant cryptozoans of 

this type are an almost certain indication of the Copper 

Ridge dolomite. One variety of this small colonial 

form has been described as Cryptozo'tn undulatum 

Bassler. It is well exposed in the small quarry at the 

north end of the bridge across Holston River near
STRATIGRAPHY 33

Cherokee Dam. Chert derived from beds of these cryptozoans is abundant on the hills just south of U. S. 

Highway 11-W about 0.75 mile north of Three Points 

on the John Sevier quadrangle and at many other localities both within and beyond the Mascot-Jefferson 

City district. A variety of this form in which the columns are more widely spaced is exposed in the bed of 

Buffalo Creek about 0.2 mile north of the road fork 

at BM 1057 on the Joppa quadrangle.

The large solitary saucer-shaped type is less common but it is also widely distributed. It has been seen 

in place in the Thorn Hill section, and at one time 

there was an excellent exposure weathered out along 

the county road just east of Mascot on the Mascot 

quadrangle, about 0.25 mile south of the crossing of 

Roseberry Creek at BM 903.

All these forms are highly characteristic of the Copper Ridge dolomite, and their abundance in residual 

materials is of great value in mapping.

Many dolomitic layers in the upper part of the Copper Ridge dolomite are highly arenaceous and when 

weathered appear both on the outcrop and in residual 

accumulations as soft, porous brown sandstone. Locally, these sandstones are recemented by silica and 

thus become hard, impervious, and quartzitic. Beds 

of this material also occur in the base of the overlying Chepultepec dolomite and with the beds in the 

upper Copper Ridge mark one of the most distinctive 

zones in the Knox group. Other thin beds of arenaceous dolomite occur at higher levels and some of these 

are important key beds, but nowhere in the Knox group 

is the concentration of sandy layers as great as near 

the Copper Ridge-Chepultepec boundary.

SUBDIVISIONS

The Copper Ridge dolomite could be logically divided into two members: a thick lower member composed mainly of dark thick-bedded cherty dolomite, 

and an upper member consisting of light-colored thinner bedded dolomite, also chert-bearing and containing many arenaceous beds. If such a subdivision were 

made, the break would come within unit 282 in the 

Thorn Hill section and at the base of unit 148 in the 

Lee Valley section (Rodgers and Kent, 1948, p. 14). 

This upper member is about 228 to 235 feet thick along 

Copper Ridge, and, although it has not been named, 

it has been separately mapped there (Rodgers, 1943).

Oder (1934, p. 476-479) also divided the Copper 

Ridge dolomite into two members, calling them the 

Morristown dolomite and the Bloomingdale limestone 

members. He assigned a thickness of 800 to 1,000 feet 

to the Morristown dolomite member and included in it 

all strata from the top of the Maynardville limestone

member up to and including some of the arenaceous 

layers. Thus his Morristown member seems to correspond approximately to the entire Copper Ridge dolomite as here delimited. The Bloomingdale limertone 

member was said to range from 170 to 650 feet in thickness in various parts of the Valley of East Tennessee, 

though no explanation of these variations in thichness 

was given. It is now thought that most of the strata 

placed in the Bloomingdale member by Oder belong 

in the lower part of the Chepultepec dolomite as now 

recognized.

FACIES RELATIONSHIPS

The Copper Ridge is a dolomite in the type area, and 

this dolomitic phase extends along the western side of 

the Appalachian Valley in East Tennessee and southeastward into and across the Mascot-Jefferson City district. To the southeast of this area, however, beds of 

limestone wedge into the section, and on the eastern 

side of the Valley, particularly in the belts southeast 

of the Bays Mountain syncline (pi. 2), the entire formation is dominaiitly a slightly magnesian limeetone. 

This limestone extends northeastward along the eastern side of the Valley into Virginia, and in the central 

and northern parts of that State it extends progressively into the western belts as well, until in northern 

Virginia, Maryland, and southern Pennsylvania the 

limestone phase extends almost entirely across the Valley, though not into the western ridges of the Appalachians.

This limestone facies is commonly known as the 

Conococheague limestone, from Conococheague Oeek, 

Franklin County, Pa. (Stose, 1908, p. 701-703), and 

the name has been extended into Virginia (Woodward, 1932, p. 37; Butts, 1933, p. 8-9) and Tenr«*5see 

(Oder, 1934). Ulrich recognized the presence of the 

Conococheague limestone in these areas but contended 

that it was older than the Copper Ridge dolomite, and 

that it thinned westward and was overlapped unconf ormably by the Copper Ridge. For a while Butt? also 

maintained this view, but later as a result of detailed 

mapping he realized that the two formations were intergrading facies equivalents (Woodward, 1932, p, 37; 

Butts, 1940b, p. 90). This has been demonstrated 

at several places, and the correlation is strongly supported by paleontologic evidence.

Still farther north in central Pennsylvania, the Conococheague limestone seems to grade northwestward into 

a sandy magnesian limestone facies, the Gatesbur^ formation (Butts and Moore, 1936, p. 15-17; Butts, 1939, 

p. 10-12; 1945, p. 2-3). The Gatesburg formation together with the overlying Mines dolomite (same reference) occupy about the same stratigraphic internal as 

the Conococheague limestone a few miles to the south-
34 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

east. Resser (1938, p. 20) correlated the Mines and 

Gatesburg with the Conococheague, without, however, 

clearly stating his reasons. Still later (Howell and 

others, 1944), Resser made the Mines dolomite an upper 

member of the Gatesburg formation, assigned two wellknown Upper Cambrian faunal subzones to it, and 

again correlated his enlarged Gatesburg formation with 

the Conococheague, without giving definite reasons.

More recently Wilson (1949), in discussing this same 

general area, writes that "A general facies change west 

to east from arenaceous dolomite (Gatesburg formation) to silt-laminated limestone (Conococheague formation) is indicated in the geosyncline." This statement, based as it is on detailed field studies, strongly 

supports the idea of facies equivalence here advocated. 

Wilson says nothing about the relation of the Mines 

dolomite to this problem, but such evidence as is available indicates that Eesser's assumption is logical and 

probably correct. This point is discussed in more detail 

below.

PALEONTOLOGY AND CORRELATION

No fossils, aside from cryptozoa, have been found 

in the Copper Ridge dolomite within the limits of the 

Mascot-Jefferson City district, and, although a few 

fossils have been found at widely separated localities 

throughout the Appalachian Valley, the formation is 

nowhere abundantly fossiliferous. This scarcity of 

well-preserved and identifiable fossils has been one 

of the most serious drawbacks in regional correlation, 

for many of the supposedly equivalent formations in 

other parts of the United States carry well-preserved 

and abundant fossils at many horizons. From, the evidence now available the writer believes that the Copper 

Ridge and Conococheague formations of East Tennessee may be correlated almost exactly with the Madison, Trempealeau, and Franconia formations of the 

Upper Cambrian section in the upper Mississippi Valley 

and their equivalents elsewhere. Some of these correlations are based on the presence of identifiable fossils, 

whereas others are merely inferred from similarity of 

stratigraphic position.

In his original description of the formation, Ulrich 

(1911,p. 636), says:

So far as the collections go, they indicate at least two 

fossiliferous horizons, both apparently near the middle of the 

Copper Ridge formation. Aside from this, their stratigraphic 

relations are unknown. One contains Syntrophia campbelli and 

fragments of so-called Cambrian trilobites, the other gastropods 

and cephalopods found in the Eminence formation of Missouri. 

The same or a close ally of the Syntrophia, also trilobites of 

very similar character to those associated with it in Tennessee, 

are found in Shannon County, Missouri, in the same formation 

(Eminence) above the gastropods. If these faunal occurrences 

are trustworthy indications of one and the same stratigraphic

zone, then a considerable hiatus is suggested in the Missouri 

section between the Eminence and Potosi formations.

It is now known that the Syntropfiia campbelli fauna 

does not occur in the Copper Ridge dolomite but is 

confined to the upper part of the Chepultepec and the 

lower part of the Longview dolomites and to similar 

parts of equivalent formations elsewhere (see p. 43,49).

The gastropod-cephalopod fauna mentioned by Ulrich does occur in the Eminence dolomite of Missouri, 

but the forms that Ulrich had in mind at the time he 

made that statement are now known to have come from 

the lower beds of the Van Buren member of the Gasconade dolomite (Bridge, 1930, p. 106-10P). The statement that "several of the Van Buren species, and sev- , 

eral others which are closely allied hare been found 

in the Copper Ridge dolomite in Alabama" (Bridge, 

1930, p. 108) is an error resulting from this miscorrelation (see p. 36).

Oder (1934, p. 478, 493) discovered the trilobite 

Stenochilina spinifera Ulrich in float cheH in the sandstone zone at the top of the Copper Ridge dolomite in 

the Thorn Hill section (p. 27). The exa ct layer is not 

known, and a careful search has yielded no additional 

specimens. From Oder's description it is entirely possible that the specimen came from beds that are included 

in the Chepultepec dolomite in this report. He also 

collected Oalmnella cf. C. ozarkensis (Walcott) and C. 

minor Ulrich near the top of the formation at an unspecified locality in Greene County. These are all high 

Upper Cambrian forms, characteristic of the upper part 

of the Eminence dolomite of Missouri and of the Jordan 

and Madison sandstones of Wisconsin.

In 1911 Ulrich and Kirk made an extensive collection 

of trilobites in thin-bedded platy black conglomeratic 

chert associated with a very fine grained black limestone and thin sandstone beds along the old Knoxville 

Pike (now approximately U. S. Highway 11-E) about 

1 mile west of the railroad station at Gre^neville, Tenn. 

The trilobites, which are rather poorly preserved, all 

seem to belong to a single species, Pleihopeltis saratogensis (Walcott), a species originally described from 

the Hoyt limestone of the Saratoga region in New York. 

The genus is also found in the Eminent dolomite of 

Missouri and in the Madison sandstone of Wisconsin. 

Its age is late Late Cambrian, and the level occupied 

by these fossils is approximately the same as the one 

carrying StenocMlina at Thorn Hill.

Ulrich provisionally referred the beds carrying this 

fauna to a new formation, the Greeneyille limestone, 

and, according to his notes, the collection came from 

a horizon between 1,450 and 1,463 feet above the top 

of the Nblichucky shale. By this he meant the top of 

the lower shale unit as herein described. Thus the
STRATIGRAPHY 35

Greeneville limestone of Ulrich included not only the 

entire Copper Ridge dolomite or Conococheague limestone but also the Maynardville limestone member of 

the Nolichucky shale (chart 1).

Ulrich never published any description of his Greeneville limestone or of this fauna. In 1924, however, Nelson published two correlation tables (Gordon, 1924, 

p. 34; Secrist, 1924, p. 16) representing his interpretation of Ulrich's views. In these the Greenville [sic] 

dolomite was placed beneath the Copper Ridge dolomite 

and was credited with a thickness of 400 feet. Thus 

the Greenville dolomite of Nelson seems to be almost 

the exact correlative of the Maynardville limestone 

member of this report.

James L. Wilson (written communication, March 3, 

1950) reports finding a specimen of Plethometopus(f] 

sp. somewhere in the upper 550 feet of the Conococheague limestone on the northwest side of the Mosheim 

dome just north of Big Spring Church, Mosheim quadrangle. This is about 7 miles west-northwest of the 

localities at Greeneville. These 4 localities are the only 

ones known to the writer from which trilobites have 

been collected in the upper part of the Conococheague 

or Copper Ridge formations of East Tennessee. In 

Virginia the trilobite Tellerina wardi (Walcott) has. 

been reported from at least 2 localities (Resser, 1938, 

p. 14,16. 22,24,101; Butts, 1940b, p. 89) where it seems 

to occur in a thin zone about 150 feet below the top of the 

formation. Another species of Tellerina is reported 

from near Scotland, Pa., where it is associated with 

Saukia stosei (Walcott). Wilson (ibid.) lists several 

trilobite genera from a locality about 1 mile northeast 

of Stonehenge, Pa., on the Chambersburg quadrangle. 

The exact stratigraphic level is not known but is believed to be near the top of the formation. These genera—Proscntkia, Plethometopus, Stenopilus, Bowtnania, 

and Leiocoryphe—all occur in the upper part of the 

Upper Cambrian, more specifically in the upper part 

of the Trempealeau formation and in the Madison 

sandstone of Wisconsin, in the Eminence dolomite of 

Missouri, in the San Saba member of the Wilberns formation of Texas, and in equivalent strata elsewhere in 

the United States. These trilobites in the Copper Ridge 

and Conococheague formations in the Appalachian Valley serve to correlate the upper part of these formations 

with uppermost Upper Cambrian formations in other 

parts of the United States.

A second faunal zone is found about 550 to 600 feet 

below the top of the formation as here drawn. The 

dominant forms in this assemblage are species of 

Scaevogyra, a form which is easily recognizable because it is the only large gastropod in any of the formations of the Knox group that is coiled sinistrally. This

fauna has been found at many localities in the Norris 

Reservoir area,14 commonly in residual cherts but locally from chert beds in place. At a locality in the 

LaFollette quadrangle, now submerged by the Norris 

Reservoir, it is associated with specimens of Plethometopus.

The Scaevogyra fauna has not been found in the 

Thorn Hill or Lee Valley sections nor within the Mascot- Jefferson City district, but it has been found at other 

localities in the Valley of East Tennessee to the south 

and southwest of the district. Presumably it occurs 

within the district, and more careful study and collecting should reveal its presence. It was originally 

found in the southern Appalachian Valley by Butts 

(1926, p. 87, pi. 14; 1927, p. 4; 1940a, p. 7) at three 

widely separated localities, all east and southeast of 

Birmingham, and it is the gastropod-cephalopoi fauna 

mentioned in Ulrich's original description of the- formation. The list of species, in which the names hs.ve been 

revised to conform with current usage, is given below:

Scaevogyra sweezyi Whitfield

elevata Whitfield 

Sinuopea htimilis Butts

typicalis Butts 

Euconia(l) sp. 

''Scen<ella" 2 sp. 

Shelbyoceras bessemerense Ulrich, Foerste, and Miller

buttsi Ulrich, Foerste, and Miller

unguliforme Ulrich, Foerste, and Miller 

Trilobite fragments

Elements of this fauna have also been found by Cloud 

(oral communication) in northeastern Alabama, From 

the above it would seem that the Scaevogyra fauna is 

widely distributed throughout the southern part of the 

Appalachian Valley, and that it is an important and 

useful faunal horizon.

Scae-vogyra sweezyi was originally described from 

the St. Lawrence member of the. Trempealeau formation of Wisconsin. It has subsequently been found in 

the upper part of the Potosi dolomite of Missouri, where 

it is associated with Shelbyoceras bessemerense Ulrich, 

Foerste, and Miller (Bridge, 1930, p. 208; Ulrich, 

Foerste, and Miller, 1943, p. 153), and in the lov^er part 

of the Eminence dolomite in the same area. Finally, it 

occurs in the Pedernales dolomite member of the Wilberns formation in central Texas (Dake and Bridge, 

1932, p. 730, pi. 12; Bridge, Bariies, and Cloud, 1947, 

p. 122, 123). In all three States Scaevogyra is commonly associated with Platycolpus and in Missouri and 

Texas with Plethometopus also. It is possible tl at some 

of the trilobite fragments in the collections made by 

Butts belong to these genera.

14 Cullison, J. S., 1937, Geology of Norris Reservoir basin: Ms. in flies 

of Tenn. Valley Authority.
36 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

SheTbyoceras, the oldest true cephalopod genus known 

in North America (Ulrich, Foerste, and Miller, 1943, 

p. 152-155), occurs sparingly in the Eminence and 

Potosi dolomites of Missouri—always in association 

with one or more of the other genera in the foregoing" 

list—and seems to be restricted to Upper Cambrian 

rocks.

Simtiopea is a long-ranging genus, common in both 

Upper Cambrian and Lower Ordovician strata. It is 

a highly generalized form in which species are drawn 

on minute differences. These differences are seldom 

well-enough preserved for exact identification, and, because of this, the genus is of little use in exact correlation.

The other forms listed are too imperfectly known to 

be of much value.

It was elements of this f amia, particularly Sinuopea 

and Shelbyocems, that Ulrich had in mind when he 

correlated the Copper Kidge fauna with the gastropod - 

cephalopod fauna of the Eminence (Ulrich, 1911, p. 

636). This "Eminence fauna" of Ulrich was subsequently found to occur actually in the base of the overlying Gasconade dolomite, the Van Buren formation 

of McQueen (1931) and of Bridge (1930, p. 98 ff.). 

This in turn explains Bridge's miscorrelation of the 

Copper Ridge and Van Buren formations (Bridge, 

1930, p. 108, 208), a correlation that was repeated by 

Butts and Moore (1936, p. 18-19), and by others (Butts, 

1939, p. 13; Ulrich, Foerste, Miller, and others, 1943, 

p. 2, 11; 1944, p. 15). Actually the studies of Ulrich, 

Foerste, and Miller have shown that the cephalopods of 

the Copper Ridge dolomite in Alabama, formerly referred to such genera as Levisoceras, Quebecoceras, and 

Ectenoceras, all belong to the genus Shelbyoceras, and 

that this last form, so far as now known, is confined to 

the Copper Ridge, Eminence, and Potosi dolomites.

Because of its distinctive character and wide distribution, the Scaevogyra zone has been widely used in regional correlation (Howell and others, 1944, p. 994, 

chart), and its presence in the Copper Ridge dolomite 

indicates definitely that the lower part of the Trempealeau formation is also represented here.

Another form which may eventually become an important fossil for the Copper Ridge dolomite is the 

rather large planispiral gastropod Cloudia buttsi 

Knight (1947, p. 6-7, pi. 2). This species is known 

only from a rather large number of localities in central and northeastern Alabama and northeastern 

Georgia, but in all probability its geographic range 

will be extended with the progress of detailed mapping. 

It invariably occurs "just above a zone of digital Gymnosolen-likQ stromatolites in splotchy black-and-white 

chert" (P. E. Cloud, Jr., personal communication)

that occurs near the base of the middle third of the 

Copper Ridge dolomite in Alabama and Georgia. The 

exact relation of the beds carrying this fo^m to those 

carrying the Scaewogyra fauna is not knovm, but presumably they are slightly lower in the section. Inasmuch as Cloudia is unknown elsewhere, and as only 

fragmentary trilobites and possible pteropods are 

known in association with it, the genus is at present 

valueless for regional correlations. However, its large 

size and distinctive form make it extremely valuable in 

local correlation, and it (or forms closely allied to it) 

shou^l be looked for in strata of equivalent age in other 

parts of the country. Its age, based entirely upon its 

known stratigraphic position, is either lates* Franconia 

or early Trempealeau.

All these fossils indicate a definite correlation between the upper two-thirds of the Copper Ridge and 

Conococheague formations of the Appalachian Valley 

and the Trempealeau and Madison formations of the 

upper Mississippi Valley section. Not all the faunal 

zones of this section have yet been identified in the Appalachian Valley. Possibly some of them never will be 

found, but probably most of the absences are due to lack 

of detailed mapping, changes in environment, or both, 

rather than to actual absence of time units.

The lower 250 to 300 feet of these formations presumably represents the Franconia sandstone of the 

upper Mississippi Valley section, but thus far no fossils, other than cryptozoans, have been found in these 

beds in East Tennessee and southern Virginia. Lower 

Franconia faunas do occur however in tie Ore Hill 

limestone member in the lower part of the- Gatesburg 

formation in central Pennsylvania, and as the Gatesburg is considered to be the general equivalent of the 

Conococheague on other grounds, the supposition that 

these unfossiliferous beds represent the Franconia interval is materially strengthened.

Because of the lack of physical evidence of a disconformity between the Maynardville limestone member 

of the Nolichucky shale and the Copper Ridge and 

Conococheague formations, and because of the rather 

uniform thickness of the latter formations throughout 

the Appalachian region, the writer prefers to correlate 

the lower unfossiliferous beds of these form ations with 

the Ore Hill member of the Gatesburg formation of 

Pennsylvania, and through this member with the lower 

part of the Franconia sandstone of the standard Upper 

Cambrian section, and to ascribe the lack of characteristic faunas to environmental factors, such as conditions of sedimentation and preservation, rather than to 

erosion and noncleposition. It is believed that.further 

detailed mapping and collecting in the Appalachian
STRATIGRAPHY 37

Valley may eventually produce evidence of these missing faunas.

CHEPTJI/TEPEC DOLOMITE

NAME

The Chepultepec dolomite was named by Ulrich 

(1911, p. 638-640), from Chepultepec, now Allgood, a 

small village on the Louisville and Nashville Railroad 

in Murphrees Valley about 31 miles northeast of Birmingham, Ala. According to Ulrich (1911, p. 639)

the section at the type locality begins in Murphrees Valley at 

Chepultepec Station [about 1 mile southeast of the village], 

which is located on the Conasauga formation, and passes upward through about 300 feet of non-cherty dolomite referred 

to the Ketona by Butts, then through approximately 1,700 feet 

of Copper Eidge cherty dolomites, then 300 to 400 feet of concealed beds thought to be "upper Knox", followed by about 

1,000 feet of cherty magnesian limestone—the Chepultepec 

formation—and unconformably over this by Stones River limestone, which occupies the valley between Chert Eidge and West 

Red Mountain.

From this and other statements in the Eevision of the 

Paleozoic Systems and from the accompanying correlation table (Ulrich, 1911, pi. 27), it would seem that 

Ulrich originally regarded the Chepultepec as younger 

than the "upper Knox1 ' of Alabama and Tennessee, an 

error that was partly corrected without comment in 

a revised correlation table published a few years later 

(Bassler, 1915, pi. 2). The geology of the Birmingham 

30-minute quadrangle that contains the type area was 

mapped by Butts (1910), but he made no attempt to 

subdivide the Knox except to split off the Ketona dolomite member at the base. The beds at Chepultepec 

were recognized as being younger than the bulk of the 

Knox dolomite elsewhere in the Birmingham Valley, 

but the entire sequence was assumed to belong to the 

lower part of the Knox dolomite and Butts (1910, p. 

3, 4) wrote that younger beds belonging to the Knox 

are to be found in the Cahaba Valley to the southeast. 

From the meager published record and from conversations with Ulrich and Butts, it would appear that the 

type section is in the row of hills immediately northwest of the village. No further detailed study of the 

Chepultepec dolomite in its type area has been made. 

Butts, however, mapped the geology of the four 15- 

minute quadrangles immediately south of the Birmingham quadrangle (Butts, 1927, 1940a), and in these the 

Knox dolomite of the Birmingham folio was subdivided into a number of formations, one of which was 

the Chepultepec dolomite. This mapping established 

the position of the Chepultepec as directly overlying 

the Copper Ridge dolomite and underlying the Longview dolomite.

339223—55———4

As additional information was obtained, the name 

was extended to equivalent beds in Tennessee (Passler, 

1915, pi. 1; Nelson m Gordon and others, 1924, p. 34, 

and Secrist, 1924, p. 16; Oder, 1934) and into Virginia 

(Butts, 1933, p. 10; 1940b, p. 95 ff.), and the formation 

or its equivalents are now known to extend the length 

and breadth of the Appalachian Valley from New York 

to Alabama.

LIMITS

The Chepultepec dolomite, as used in this report, 

comprises units 305 to 406 of the beds in the Thorn 

Hill section (Hall and Amick, 1934, p. 199-203) and 

units 163 to 202 of the Lee Valley section (Rodg?.rs and 

Kent, 1948, p. 19-21). The lower boundary is drawn 

at about the middle of the thick series of calcareous 

sandstones that have already been described under the 

Copper Ridge dolomite (p. 26-27).

The upper boundary is more difficult to place, particularly in fresh exposures, and in most areas if rather 

arbitrarily drawn, for the changes in bedrock lithology 

are so very slight as to make the transition fr*>m one 

formation to the other almost unnoticeable. The best 

evidence for the change from Chepultepec to Longview 

is found in the changes in the residual products— 

particularly the cherts—in the fossils, and, in places, 

in topography. In the Thorn Hill section, the contact 

is assumed to lie at the base of a thin calcareouQ sandstone forming the upper 2 inches of unit 406; elsewhere this sandstone is missing or unrecognized, and 

in practice the boundary is drawn on differences in 

residual chert and, wherever possible, on fossils.

The obscure nature of the Chepultepec-Longview 

contact is all the more surprising when it is remembered 

that it has been interpreted as a plane of unconformity 

and that formations and faunas were believed to intervene between these two formations (Nelson, in Gordon 

and others, 1924, p. 34, and Secrist, 1924, p. 16; Butts, 

1926, p. 80; Oder, 1934, p. 481-482) ; in fact it was 

assumed to be a systemic boundary. Wherever tl *, writer has observed this contact throughout the entire Appalachian Valley, however, the Longview dolomite or its 

equivalents rest directly and conformably ujon the 

Chepultepec dolomite or its equivalents; and he believes 

that the same conditions will prove to hold t?ue for 

most of the areas in the central United States- where 

the correlatives of these formations are exposed. The 

principal exception seems to be in the upper Mississippi 

Valley where the presence of a formation equivalent to 

the Longview dolomite has not yet been conclusively 

demonstrated, and where beds roughly equivalent to 

the Kingsport and Mascot formations of this report 

appear to rest directly upon the Oneota dolomite which 

carries a Chepultepec fauna.
38 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

In his report on the Burkes Garden area in Virginia, 

Cooper (1944, p. 27) implies that the Chepultepec is 

absent there, for "sandstone beds, believed to be characteristic of the Copper Kidge, occur directly beneath 

Lecanospira-be&rmg limestones" (Longview of this 

report), though "about 25 miles southwest of the Burkes 

Garden area, at Marion, Smyth County, Virginia, about 

300 feet of Chepultepec limestone intervenes between 

the Conococheague (Copper Kidge equivalent) and the 

Lecam«ospira beds." Cooper concludes that "this may 

indicate the absence of the Chepultepec [in the Burkes 

Garden area] ; on the other hand it is possible that the 

Chepultepec is represented by unfossiliferous dolomites 

and sandstones in the upper part of the Copper Ridge." 

Because of the great thickness (1,800 feet) assigned to 

the Copper Kidge in this area, the present writer believes the latter supposition is more probably correct.

THICKNESS

The Chepultepec dolomite is 689 feet thick in the 

Thorn Hill section and 721 feet thick in the Lee Valley 

section. Because of the lack of well-exposed sections, 

the lithologic similarity to adjacent formations, and 

the absence of fossils, the thickness of the Chepultepec 

dolomite in the Mascot-Jefferson City district is difficult to determine; it is believed, however, to be not less 

than 550 feet in the Mascot belt and may be somewhat 

more in the eastern belts. A fully exposed section in 

the valley of Loves Creek on the John Sevier quadrangle (base described on p. 27-28) has an outcrop width 

of between 850 and 900 feet and a calculated thickness 

of 562 feet for this portion of the section; it is by no 

means certain, however, that the arbitrary boundary 

selected is actually the top of the Chepultepec dolomite. 

At the abandoned TVA quarry about 1.25 miles westnorthwest of Cherokee Dam and a mile northwest of 

the bridge of State Highway 92 across the Holston 

River, the basal sandstones are exposed in the bed of 

Holston River, and about 300 feet of beds assigned 

to the lower part of the formation are exposed in the 

quarry face (see section, p. 39). Above the quarry are 

about 170 feet of poorly exposed strata representing the 

upper part of the formation, so that the total thickness 

of the Chepultepec in this area is at least 520 feet. The 

summit of the hill is capped by residual chert from the 

Longview dolomite, but it is by no means certain that 

this is in place.

BEDROCK LITHOLOGY

In the Mascot belt the Chepultepec dolomite is made 

up primarily of moderately thick beds of light-colored 

rather finely crystalline dolomite similar in most respects to the dolomitic layers in the upper part of the 

Copper Ridge dolomite. Most of the beds are a light

steel gray but among them are a few individual layers 

that show a pinkish-brown or light-chocolate color, 

which, however, is never as deep as the color found in 

the basal beds of the Copper Ridge dolomite.

The base of the formation is commonly marked by 

from 8 to 10 feet of coarse-grained soft rusty sandstone 

derived from the weathering of arenaceous dolomite 

layers and locally recemented to form hard quartzitic 

sandstone. Thinner sandstone layers are found above 

this bed through a thickness of about 100 feet, and a 

conspicuous bed of white siliceous oolite about 1 foot 

thick occurs about 32 feet above the base cf the formation in the Loves Creek section (p. 28) and elsewhere 

through the district. This oolite differs from those in 

the underlying Copper Ridge dolomite in that the individual ooids are smaller in diameter (normally less 

than 1 millimeter), are white, and lack the conspicuous 

color banding that characterizes those in the Copper 

Ridge dolomite.

Ulrich (1911, pi. 27) did not recognize- the Chepultepec dolomite in the "Knoxville trough," a term in 

which he included all the belts in the Mascot-Jefferson 

City district, and in the early mapping of this area in 

1929 the present writer also failed to detect it. The following year, however, Oder, in extending the mapping 

of the previous year to the eastward, found Chepultepec 

fossils to the east and southeast of Jefferson City and 

conclusively demonstrated the presence of the formation throughout the district.

In the Jefferson City and Shields Ridge belts the 

formation becomes more calcareous and most of the 

strata composing it are best classed as slightly magnesian limestones. In these belts the dominant lithologic type is a finely crystalline medium- to dark-blue 

magnesian limestone. Beds commonly range from 6 or 

8 inches to a foot or more in thickness and the major 

bedding planes are sharp and well def ned. Minor 

bedding and lamination planes are uncommon. The 

rock breaks with a smooth, even, locally slightly conchoidal fracture. Interbedded with these magnesian 

limestones are beds of lighter colored more strongly 

dolomitic material. Both types contain considerable 

quantities of chert of various kinds in some layers.

The Chepultepec is one of the more soluble formations of the Knox group and good exposures are not 

common. An almost complete section of the lower part 

of the formation is exposed in and above the TVA 

quarry on the south base of the 1,500-foot hill, 1 mile 

northwest of the bridge across Holston River on State 

Highway 92 on the Joppa quadrangle, 3 miles north of 

Jefferson City. This quarry, which supplied rock for 

fill and riprap in the construction of Cherokee Dam, 

was opened after the mapping was completed, and the
STRATIGRAPHY 39

following section was measured by R. A. Laurence and 

E. A. Finley, then of the Tennessee Valley Authority.15

Section of the loiver two-thirds of the Chepultepec dolomite, 

exposed in the TV A quarry on Holston River, 1.25 miles northwest of GheroJfee Darn

Unit Total 

thick- thickness ness 

(feet) (feet)

Top of quarry about 350 ft above river level.

41. Dolomite, dark-gray, coarsely crystalline; a

single massive bed——————————————— 4. 0 4. 0

40. Dolomite, light-gray, finely crystalline, with

thin bands of light-gray chert-——————— 17. 0 21. 0

39. Dolomite, light- and dark-gray, medium to 

coarsely crystalline; some scattered chert 

nodules ______________________ 17.5 38.5

38. Chert, several types, mostly compact, white,

angular ; in dolomite matrix_______— 1. 5 40. 0

37. Dolomite, light- and dark-gray, finely crystalline, medium- to thin-bedded_______ 18. 5 58. 5

36. Dolomite, coarsely crystalline, medium- to

thick-bedded, with thin bands of chert__ 7. 7 66. 2

35. Dolomite, light-gray, finely crystalline; medium bedded at base becoming more thickly 

bedded toward the top; upper layer finely 

sandy _______________________ 17. 3 83. 5

34. Dolomite, dark-gray, medium to coarsely

crystalline, rather thin-bedded_______ 3. 5 87. 0

33. Dolomite, light-gray, medium-bedded, with

chert bands___________________ 5.0 92.0

32. Dolomite, dark-gray, medium to coarsely

crystalline, medium- to thick-bedded__ 7.2 99.2

31. Dolomite, finely crystalline, light-gray, thinto medium-bedded_______________ 9.8 109.0

30. Dolomite, finely crystalline, thin-bedded

slabby ____________________ 1.5 110.5

29. Sandstone, calcareous; light gray on fresh

surfaces, weathering rusty brown_____ . 7 111. 2

28. Dolomite, gray, finely crystalline; a single

bed _.___——_„_____________ 2.3 113.5

27. Sandstone, calcareous, similar to unit 29__ . 5 114. 0

26. Chert, gray, compact______________ .5 114.5

25. Dolomite, gray, medium to coarsely crystalline, medium- to thick-bedded________ 10.0 124. 5

24. Sandstone, calcareous, similar to units 27

and 29_____________________ 2.5 127.0

23. Dolomite, finely crystalline, banded light

and dark gray, rather thick-bedded___ 10. 0 137.0

22. Dolomite, gray, coarsely crystalline, thickbedded __————___——________ 10.0 147.0

21. Dolomite, gray, finely to medium crystalline,

thick-bedded __________________ 19.6 166.6

20. Dolomite, light-gray, coarsely crystalline,

thin- to medium bedded___________ 3.4 170.0

19. Dolomite, light-gray, finely crystalline,

thick-bedded __________________ 19.5 189.5

18. Dolomite, cherty_________________ 2.5 p.92.0

17. Sandstone, calcareous ____________ 1.0 193. 0

16. Dolomite, gray, finely crystalline, thinbedded ______________________ 1.5 194.5

15 The original notes on this section were not available, and the descriptions and thicknesses given herewith have been compiled by the 

writer from a scale drawing (1 inch to 20 feet) furnished by the Tennecessee Valley Authority.

Total Total 

thick- thickness ness 

(feet) (feet)

15. Dolomite, gray, finely crystalline, cherty— 2.5 197.0 

14. Dolomite, like unit 16______________ . 5 197. 5 

13. Dolomite, cherty, like unit 15_________ . 5 198.0 

12. Dolomite, light-gray, finely crystalline, rather

thick-bedded __________________ 11.3 209.3

11. Dolomite, dark-gray, coarsely crystalline,

medium-bedded ______—________ 4.5 213.8

10. Sandstone, calcareous____——_————__ .6 214.4 

9. Dolomite, gray, finely to medium-crystalline,

thick-bedded _____________-____ 56.8 271.2 

8. Sandstone, calcareous_____—____—-— 1.5 272. 7 

7. Dolomite, gray, finely crystalline, thickbedded _________________——— 5.8 278.5

6. Sandstone, calcareous______________ . 7 279.2 

5. Dolomite, like unit 7_______________ 7. 7 286. 9 

4. Dolomite, gray, finely crystalline, thinbedded, weathers to thin slabs________ 5. 0 291. 9 

3. Dolomite, gray, finely crystalline, thickbedded, with two or more thin (0.5 ft) beds 

of calcareous sandstone. Bottom layer is 

at level of quarry floor_____________ 15. 6 307. 5 

2. Largely covered interval between quarry floor 

and river level. A few scattered ledges 

similar to beds in unit 12__________ 40. 0 347. 5 

1. Sandstone ledge, exposed in riverbed, thought 

to be the equivalent of unit 305 of the Thorn 

Hill section, and of the sandstone at the 

base of unit 15 of the Loves Creek section 

(p. 28)______________________ 6.2 353.7

NOTE.—The banded siliceous oolites characteristic of the ufner part 

of the Copper Ridge dolomite also crop out in the bed of Holston River 

a few yards downstream from the sandstones of unit 1.

Section of beds above TV A qiiarry

[Measured later by Laurence and Finley]

Unit Total 

thick- thickness ness 

(feet) (feet)

No outcrops to top of hill. Abundant large pieces

of white chert__________——_————— 185. 0 185. 0

Dolomite, dark-gray, finely crystalline, with 

small angular chert fragments-—_————— 10. 0 195. 0

Dolomite, light-gray, finely crystalline, thickbedded, with a few thin layers of dark chert_ 20. 0 215. 0

Covered _________________________ 18.0 233.0

Dolomite, dark-gray, finely crystalline, thinbedded, with a few thin layers of dark chert_ 15. 0 248. 0

Thickness of beds above quarry___—__——— 248. 0 

Thickness of section in quarry_____———___ 353. 7

Total thickness of beds in the two sections——— 601. 7

A fair section of the dolomitic phase of the formation 

is exposed in the valley of Loves Creek in the v^estern 

part of the John Sevier quadrangle, but the fomation 

is very poorly exposed in the creeks to the east. A reasonably good section of the limestone phase of the formation is exposed in the valley of Mutton Creek in the 

Jefferson City quadrangle about 5 miles due sc^ith of 

Jefferson City. Other good exposures of the limestone
40 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

facies are found on the southeast flank of the Rocky 

Valley anticline on the eastern side of the county road 

about 0.75 mile north of Lebanon Church on the Jefferson City quadrangle; still other exposures can be found 

on either side of the road north of Buffalo Grove 

Church about 1 mile northwest of those just described. 

These outcrops expose only a small thickness of the 

formation but exhibit the composition of the limestone 

facies.

RESIDUAL PRODUCTS

The residual soils developed on the Chepultepec 

dolomite are commonly somewhat more brightly colored 

than those on the Copper Ridge or Longview dolomites. 

Dark-orange and reddish-orange tones predominate, 

and locally the soils are free from chert and sandstone 

debris.

Cherts of various types, some of them highly characteristic of the formation, are abundant at many 

localities.

One form of chert, common in the lower part of the 

formation, consists of oval flattened nodules as much as 

8 inches in diameter and 2 inches thick. These occur 

with the longer axis parallel to the bedding planes and 

are believed to be syngenetic. The surfaces of these 

nodules are commonly stained a dull orange red. 

Freshly broken surfaces are black and show definite 

liesegang banding that is brought out by closely spaced 

curved concentric parallel fine white lines. These cherts 

are well developed in the lower part of the formation 

in the vicinity of Buffalo Grove Church and in the area 

immediately south of it on the southeastern flank of 

the Rocky Valley anticline.

Another very common and highly characteristic type 

is described by Ulrich (1911, p. 639) as "always relatively soft and more or less mealy in texture, and when 

resistant to the hammer it is because of toughness rather 

than hardness." These cherts are lightweight and 

highly porous, many of the cavities preserving the 

rhombic outlines of individual dolomite crystals from 

1 to 2 millimeters in diameter. These impressions of 

dolomite crystals are an extremely constant and characteristic feature. The cherts are commonly light 

colored, ranging from white (on freshly broken surfaces) to various shades of cream, tan, yellow, and 

rusty brown. In general they are moderately fossiliferous.

Safford (1869, p. 215, and footnote) describes these 

cherts as follows:

The chert in the upper part, is to be noticed, inasmuch as it 

has supplied the gray, flinty gravel which, so extensively covers 

the ridges and knobs of this formation. This chert very generally has minute rhombohedral cavities interspersed through it, 

a character by which it may be distinguished from similar material in other formations.

I first observed these cavities many years ago. They present 

a character which has been of much use. At many points, 

loose chert is abundant on the surface, when the strata are 

entirely concealed. Among the dislocations of Eist Tennessee, 

it often becomes a question as to whether the rocks belong 

to the division under consideration, or to the S'liceous group 

[modern Fort Payne chert and associated strata], the chert 

of the two being much alike. The presence of the cavities, 

I have, so far, found characteristic of the Knor chert. They 

are the empty moulds of crystals of dolomite, once filling them. 

In rocks freshly quarried, showing chert, the crystals are 

seen. The chert of the Siliceous group, is, generally, characterized by the presence of large crinoidal buttons.

These dolomoldic 16 cherts are virtually restricted to 

the Chepultepec dolomite in the Appalachian Valley 

and are* rarely found at any other horizon. They are 

also rather characteristic of equivalent formations in 

such widely separated areas as Missouri and central 

Texas. In the latter areas some of the cherts are much 

harder than those in the Appalachian Valley, but they 

still exhibit the characteristic impression of the dolomite crystals.

These cherts appear to be developed in particular 

beds, but, as they do not appear in fresh exposures, they 

are probably selective replacements of a peculiar lithologic texture in which large crystals of dolomite were 

embedded in a more calcareous fine-grained groundmass, possibly a calcareo-siliceous groundmass. This 

type of chert is found at many localities.

A third type of chert consists of dull granular porous 

material containing many irregular brarching tubes, 

circular in cross section and averaging 0.25 inch in 

diameter. These cherts are dull gray en weathered 

surfaces, but commonly stained various tones of red, 

reddish brown, and black on freshly broken surfaces. 

In form and texture they greatly resemble the Missouri 

cherts figured by Bridge (1930, pi. 13, especially 13b). 

Like the preceding variety, they are often fossiliferous, 

and like them they appear to be siliceous replacements 

of preexisting structures (possibly algae) in the limestone. Good accumulations are found in tl e fields north 

and northwest of the road corner 1 mile west of Buffalo 

Grove Church, Jefferson City quadrangle, and at many 

other places within the district.

Silicified cryptozoans, which are such s. conspicuous 

element in the Copper Ridge residual riaterials, are 

almost completely absent in materials derived from the 

weathering of the Chepultepec dolomite. On the contrary, quartz cavity-fillings averaging 2 or 3 inches 

across are commonly found here but not in the Copper 

Ridge residuum.

18 A term proposed by Cloud and Barnes (1948, p. 17) to describe this 

texture. It replaces the earlier term dolocast, applied by McQueen 

(1931) to a similar texture.
STRATIGRAPHY 41

Arenaceous limestone or dolomite beds are common 

in the lower hundred feet and thin sandy beds rarely 

more than 2 or 3 inches in thickness occur sparingly 

throughout the formation. These weather to soft 

brown porous sandstone, fragments of which are present 

in the residual soils. These fragments are especially 

abundant near the base of the formation and in general 

they are indistinguishable from those in the Copper 

Ridge residual materials.

FACIES RELATIONSHIPS

The Chepultepec dolomite is a dolomitic or at best 

magnesian limestone unit, and until quite recently all 

regional correlations were made knowingly or unknowingly on this basis. Accordingly, the Chepultepec was 

considered to be equivalent to the Larke dolomite of 

the Pennsylvania section and to other dolomitic formations in the central United States (see p. 45). On the 

other hand, the Stonehenge limestone of Pennsylvania, 

which occupies the same stratigraphic interval and contains many of the same fossils, was correlated with the 

Tribes Hill limestone of the Mohawk Valley on the basis 

of lithologic and faimal similarity; these two formations were believed to be younger and to occupy the 

supposed time interval between the Chepultepec and 

Longview dolomites. This distinction and assumed 

difference in age was repeatedly stressed by Ulrich, 

Butts, Oder, and other workers in the Appalachian 

Valley.

Butts (1939) mapped the Larke and Stonehenge 

formations in different belts in the Tyrone, Pa., quadrangle, and commented on the absence of the latter formation in the Holidaysburg-Himtiiigton quadrangle 

immediately to the south (Butts, 1945, p. 3). He also 

extended the Stonehenge limestone into Virginia (Butts, 

1933, p. 11) but mapped it with the Chepultepec, and 

later (1940b, p. 101) suggested that it might be, in part 

at least, a facies equivalent of that formation, a suggestion that had already been made by Grabau (1937, p. 

29,66-67).

At a field conference in 1934, attended by Ulrich, 

Butts, Oder, Pond, and the writer, Ulrich recognized 

the Stonehenge limestone in northeastern Tennessee, 

particularly in the belt passing through Church Hill in 

Hawkins County, and Oder (1934, p. 481-482) published this interpretation.

In the meantime, detailed studies on the brachiopods 

(Ulrich and Cooper, 1938) and on the cephalopocls (Ulrich, Foerste, Miller, and others, 1942, 1943, 1944) and 

unpublished work on the gastropods and trilobites by 

the writer and others have shown clearly that, although 

there are some differences between the faunas of the

two groups of formations, they have many species in 

common (see discussion below under "Paleontology and 

correlation"), and it now seems certain that the Tribes 

Hill and Stonehenge limestones are facies equivalents 

of the Chepultepec.

This interpretation brings the physical and paleontologic evidence into general agreement and disposes of 

the necessity of postulating a great unconformity between the Chepultepec and Longview dolomites, an unconformity for which there seems to be no physical or 

paleontologic evidence. The two formations appear to 

be conformable at nearly every locality thus far studied 

(p. 37), and in addition there is a rather close relation 

between the faunas of the Chepultepec and the Longview dolomites, which suggests that 110 great time interval could have elapsed between them.

PALEONTOLOGY AND CORRELATION

The Chepultepec dolomite is moderately fossiliferous. Fossils are very rare in the dolomites and limestones themselves and where present are commonly unidentifiable unless silicified. The best and most abundant fossils are preserved in the cherts, commonly as 

external and internal molds. More rarely the. fossil 

itself is silicified and stands out in relief on a limestone 

surface. The fauna is doniiiiaiitly molluscar, with 

gastropods and cephalopods most abundant. Tie lat-' 

ter group, although not completely unknown in older 

formations, makes its first appearance in large numbers 

and with great diversity of form in this formation; in 

fact, the finding of cephalopod fragments of any appreciable size is almost proof positive that the beds in question are of Chepultepec age or younger. Bracl iopods 

and trilobites are next in importance among the 

Chepultepec faunas and members of these four classes 

alone make up between 90 and 95 percent of the known 

fauna. Minor elements are phyllocarid crustaceans, 

forms doubtfully classed as pteropods and chitons, and 

a few graptolites. The last were probably more abundant than their occurrence in the fossil faunas would 

indicate; their absence is most probably due to unfavorable conditions of preservation.

The complete fauna of the Chepultepec clolorrite has 

never been described as a unit. Lists of species from it 

have appeared in various publications, among them 

Ulrich m Butts (1910, p. 4), Ulrich (1911, p. 639), 

Ulrich m Butts (1927, p. 4; 1940a, p. 7), Butts (1940b, 

p. 101), and Oder (1934, p. 480-481). A few of the 

more characteristic and distinctive fossils from the 

formation have been figured by Butts (1926, pi. 15; 

1940b, pt. 2, pis. 68, 69). Some of these lists have been 

republished by others without comment or correction 

(Grabau, 1937, p. 27).
42 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

The lists mentioned above are unreliable, especially 

those that are unaccompanied by illustrations, for there 

are no descriptions and many of the generic and specific 

names were nomina nuda at the time of publication, 

and, although some of the forms have since been described under the names given, or under new names, 

many are still undescribed and the actual identity of 

some is not determinable. Furthermore, in the Alabama report (Butts, 1926), some of the specimens 

figured did not come from the Chepultepec dolomite in 

the Appalachian Valley but rather from equivalent 

strata in the central United States, statements in the 

report to the contrary notwithstanding.

A single example will suffice to show the unreliability 

of most of these lists. The list presumably prepared 

by'Ulrich and given by Butts (1927) and repeated 

without comment or correction by Grabau (1937) and 

Butts (1940a) contains 30 species referred to 19 genera. 

Of these 19 genera, 9 were nomina nuda at the time of 

publication and 2 still are, and even of the 10 that are 

valid 3 had not been formally described at that time 

and are valid only because one or more of the species 

assigned to them had been previously described and 

assigned to some other genus.

Seven of the 30 species in the above list were designated as "sp." Of the 23 named forms, 14 were nomina 

nuda at the time of description and of these, 7 have 

since been validated, some of them under other generic 

names. This leaves only 9 species valid at the time of 

publication, and 2 of these were based entirely upon figures published without description in the preceding 

year.

Thus, out of the 19 genera and 30 species listed, only 

10 genera and 9 species were actually valid at the time 

of publication and some of these were misidentified.

The list given by Oder (1934, p. 480-481) is much 

better. It contains 23 genera, all valid, although the 

presence of some of them in the Chepultepec dolomite is 

doubtful. The list contains about 54 species of which 

7 are definitely identified with described forms, at 

least 14 others are designated as "cf." or "aff." described 

forms, and the remainder are designated as "sp." 

Such a list gives the reader a much better idea of the 

actual makeup of the fauna than the one used by Butts.

Detailed studies of the brachiopods (Ulrich and 

Cooper, 1938) and of the cephalopods (Ulrich, Foerste, 

Miller, and others, 1942, 1943, 1944) have been published ; in these all the forms known from the Chepultepec dolomite and its equivalents elsewhere in North 

America are described and figured.

Lists of species, together with descriptions and illustrations of fossils from correlative formations in other 

parts of the country, have been published by Sardeson

(1896), Cleland (1900, 1903), Ulrich and Bridge, Ulrich and Foerste, and Ulrich in Bridge (1930), Dake 

and Bridge (1932), Bridge, in Sellards (1932, pis. II 

and III), Bridge and Cloud (1947), Cloud (1948), 

Cloud and Barnes (1948), and Ross (1951). The following table, which is reasonably complete, as far as 

published forms go, has been compiled from recent 

sources and the nomenclature has been revised to conform to present usage. Only species which have been 

found in the Appalachian Valley either in the 

Chepultepec dolomite or in one of its recognized equivalents are listed; their distribution elsewhers is indicated 

by appropriate symbols.

The Chepultepec fauna is one of the mosrt widely distributed faunas of early Paleozoic age in the United 

States and forms an excellent datum for regional correlation. In the Appalachian Valley the Chepultepec 

is to be correlated directly with the Larke dolomite of 

Pennsylvania and possibly with all or at least the 

greater part of the underlying Mines dolomite. It also 

seems to be equivalent to the Stonehenge limestone of 

Pennsylvania and of the Tribes Hill limestone of New 

York (see section above on facies relationships). 

Many species found in the Chepultepec-Tribes Hill 

faunas occur in the Oneota dolomite of th°. upper Mississippi Valley region; in the Van Buren and Gasconade dolomites of Missouri; 17 in the Kindblade formation of the Arbuckle uplift; and in the Tanyard 

formation of central Texas. Still farther west, elements of this fauna have been found in the so-called 

Bliss sandstone near Van Horn, Tex. (King, 1940, 

p. 154-155; Cloud and Barnes, 1948, p. 360-361) but 

not in the type area of the Bliss sandstone at El Paso. 

Elements of this same fauna also occur in the Manitou 

limestone of Colorado, in the lower part of the Pogonip limestone of the Great Basin area, anc1 in the Mons 

formation of Alberta in the Canadian area. Finally 

some of the species characteristic of this fauna have 

been found in the Cass Fiord formation of northern 

Greenland (Poulsen, 1937).

The Chepultepec dolomite has been var;ously classed 

as Upper Cambrian, Cambrian or Ordovician, and 

most recently Lower Ordovician. It seems to be separated from the older formations by a minor but widespread disconformity, the physical evider°« for which 

is clear at some places (Bridge, 1930, p. 142-145; Dake, 

1930, p. 128-129) ,18 less clear at others. As would naturally be expected, the physical evidence is strongest

17 The Van Buren and Gasconade formations as described by Bridge 

(1930) are now considered by him to be a single formation, the 

Gasconade.

18 Recent work by geologists of the Missouri Geolotfcal Survey may 

indicate that the evidence for the disconformity is no* as definite as it 

was thought to be by Pake and Bridge.
STRATIGRAPHY 43

TABLE 1.—Distribution of species from the Chepultepec dolomite

[T = States from which species was originally described: X = States from which species has been identified; ?=States from which species has been tentatively identified;

*=Deepkill shale of New York]

Graptolites:

Brachiopods:

Finkelnburgia beUatula Ulrich and 

Cooper.

Olyptotrophia marylandica Ulrich and 

Cooper.

Schizambon pennsylvanicum Ulrich and 

Cooper.

Tetralobula delicatula Ulrich and CooperGastropods:

Euomphalopsis involuta Ulrich and 

Bridge

aft. O. supraplana Ulrich and 

Bridge.

Ozarkina complanata Ulrich and Bridge.

Ozarkispira subelevata Ulrich and 

Bridge.

obesa (Whitfield).. ———— ——— ——

Cephalopods: 

Bassleroceras clelandi Ulrich, Foerste,

Bathmocerasl tennesseense Ulrich,

Burenoceras peramplum Ulrich, Foerste,

cf. B. ungulatum Ulrich, Foerste,

Caseoceras conicum Ulrich, Foerste,

Clarkoceras buttsi Ulrich, Foerste, and 

Miller

Clarkoceras'! delandi Ulrich, Foerste,

Clarkoceras curvatum Ulrich, Foerste,

iasperense Ulrich, Foerste, and 

Miller

parrisiphonatum Ulrich, Foerste,

mohaiekense Ulrich, Foerste, and 

Miller——.———.———..

Conocerinal bassleri Ulrich, Foerste, 

and Miller.— . —— ___ — — __ ..

Chepultepec dolomite

Alabama

X

T

X

T

?

Georgia

Tennessee

X

T

X

X 

X 

X 

X

X

X

X

X

X

X

X

X

X

T 

T 

X 

T

T

T 

T

T

X

Virginia

T

T

?

X 

X

X

X 

X

Maryland (Stonehenge limestone)

X

X

T

Maryland 

(Grove limestone)

T

T

T

T

———— ^

Pennsylvania (Stonehenge limestone)

X

T

T

?

X

X 

X 

X

X

X 

?

X 

X

New 

Jersey

X

X

X 

X

New 

York 

(Tribes 

Hill limestone)

*

T

T

T

T 

T

T

X 

T

T 

T 

T

T 

T

T 

T

T

T

T

T

Michigan

X

.

Minnesota

X

T

T

X

T

Wisconsin

T

X

X

T

T

T

X

Iowa

X

X

X

Missouri

T

X

X

T 

T 

X 

X

T

X 

X

T

T

T

T 

T 

T 

X 

X

X

T

?

?

Oklahoma

y

X

Texas

X

X

T

X 

X

X

X

X

X 

X

T

X 

X

X

X
44 STRATIGRAPHY OP THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

TABLE 1.—Distribution of species from the Chepultepec dolomite—Continued

[T = States from which species was originally described; X = States from which species has been identified; ?=States from which species has been tentatively identified;

*=Deepkill shale of New York]

Cephalopods— Continued 

Conocerina cf. C. beani Ulrich, Foerste,

obligua Ulrich, Foerste, and Miller -

Ectenoceras arcuosutum Ulrich, Foerste, 

and Miller—— — — _ —— — __ — — _ — _

chepultepecense Ulrich, Foerste, and 

Miller___- — __-_ — _--__——

millsi Ulrich, Foerste, and Miller __

perobliquum Ulrich, Foerste, and 

Miller——— ——— ——— — ——

EUesmereoceras hotchkissi Ulrich, Foerste,

cf. E.hotchkissi-. ------- --. —— _

Endocydoceras leoorense Ulrich, Foerste,

Eremocerasl marylandicum Ulrich,

cf. E. teres Ulrich, Foerste, and 

Miller—— — — — — — —— ———

Levisoceras arcttdorsatumUlricli, Foerste,

cf. L. complanatum Ulrich, Foerste,

ellipticum Ulrich, Foerste, and 

Miller———— — ———— —— ————

instabile Ulrich, Foerste, and Miller. 

cf. L. raaschi Ulrich, Foerste, and 

Miller— — — ———— —— ————

transitum Ulrich, Foerste, and 

Miller—— --------------

percurvatum Ulrich, Foerste, and 

Miller

SP

Pachendoceras confertum Ulrich, Foerste,

Walcottoceras obliquum Ulrich, Foerste,

Trilobites: (List never completed by 

Bridge).

Chepultepec dolomite

Alabama

T

V

X

T

v

GeorgiaTennessee

T

T

T

X

X 

X 

T

X 

X

Virginia

v

Maryland 

(Stonehenge limestone)

?

T

T

T

X

~j

X

Maryland 

(Grove limestone)

T

Pennsylvania 

(Stonehenge 

limestone)

,

T

New 

Jersey

New 

York 

(Tribes 

Hill limestone)

T

X

X

MichiganMinnesota

X

X

X

Wisconsin

T

T

T

V

T

T

X

Iowa

X

X

T

Missorri

X

T

T

X 

X

T 

>'

Oklahoma

X

X

Texas

X

around old positive areas, such as the Adirondack uplift, the pre-Cambrian shield in Wisconsin and Minnesota, the Ozark dome, and the Llano uplift in Texas. 

Conversely the evidence is less strong in geosynclinal 

areas such as the Appalachian Valley, the Arbuckle 

uplift, and the Cordilleran area.

The principal evidence for drawing a systemic 

boundary between the Copper Ridge and Chepultepec 

dolomites and their equivalents is found in the abrupt 

faunal changes which occur at this boundary. These 

are of two types: the sudden development and expansion in the Chepultepec dolomite of classes of fossils 

that are absent, or at best only faintly represented, in 

the older formations, and the almost complete extinction of genera and families belonging to certain classes 

that were abundant in the older formations and their 

replacement in the younger formations by new groups.

The first type of change is represented by the nautiloid cephalopods. The early members of this group 

have recently been made the subject of an intensive 

study by Ulrich, Foerste, Miller, and others (1943,1944), 

in the course of which all forms known from the Knox

group and older formations of the Appalachian Valley 

and their equivalents throughout the United States were 

studied and described.

Only a single genus, Shelfoyoceras, represented by 

three species, has been found in the Copper Ridge 

dolomite and its equivalents,19 but beginning with the 

Chepultepec the nautiloid group is represented by 26 

genera and 199 species in which two of the three major 

divisions of this group, straight and curved types, are 

represented. The original source of this cephalopod 

fauna and the reasons for its sudden appearance are 

unknown, but the latter certainly suggests a rather sudden and drastic change in ecologic conditions.

The trilobite, gastropod, and brachiopod faunas all 

show changes of the second type. Among the trilobites 

there is an almost wholesale extinction of genera and 

families of the so-called Cambrian types at the close of 

Copper Ridge time and their replacement ir the Chepul19 R. H. Flower, in a letter in 1951, states that additional specimens 

belonging to other groups have been found in some of the high Upper 

Cambrian strata of central Texas, but even so the number of forms 

found in the Cambrian is still very small.
STRATIGRAPHY 45

tepee dolomite by new groups. Studies on this group 

are admittedly incomplete, but at present no genera are 

known to cross this boundary. Furthermore, the trilobitas cease to be the dominant element in the faunas, 

and from here 011 are always subordinate both in kinds 

and in numbers of individuals.

Among the gastropods, Simwpea, 8cfiizopea, and 

Pelagietta, are common to both groups of formations, 

though represented for the most part by different 

species; most of the abundant Cambrian genera disappear at this boundary, however, and are replaced in the 

Ghepultepec by a host of new forms whose affinities 

are largely with forms found in younger formations.

Furthermore, the gastropods, which have nearly always been a minor element in the Cambrian faunas, 

suddenly become the dominant element in the Chepultepec faunas, not only in numbers of individuals but 

also in numbers of genera and species. If the studies 

on this group had been completed in the same detail as 

those on the cephalopods, the list on page 43 would be 

nearly twice as long.

Like the cephalopods, the brachiopocls on both sides 

of the Cambrian-Ordovician boundary have recently 

been studied by Ulrich and Cooper (1938). A few longranging genera, Fitikeliiburgia. and Westonia, cross the 

boundary, but 5 genera die out at the top of the Cambrian, and 2, possibly 3, die out in Chepultepec time. 

On the other hand, 11 genera appear for the first time in 

the Chepultepec; many of these continue into higher 

beds of Early Ordovician age and some extend into 

Middle Ordovician strata. Three of these 11 genera 

are doubtfully reported from the Upper Cambrian, but 

their occurrence may be based on misidentification of 

the formations involved.

Data on other groups are less complete but seem to 

be in line with those of the four dominant groups just 

mentioned.

RELATION TO THE LONGVIEW DOLOMITE 

/

Although there appears to be no disconformity between the Chepultepec and the Longview dolomites, it 

has been repeatedly stated that such a break exists. 

The idea was first advocated by Ulrich (in Bassler, 

1915, pis. 1, 2) and was subsequently reaffirmed by 

Butts, Oder, and many others, including the writer. 

The main basis of this idea is found not in physical 

evidence of a disconformity that can be seen in any 

given section, but rather in the assumption that certain 

formations carrying specific faunas intervene between 

the Chepultepec and Longview dolomites or their recognized equivalents. The best evidence for this assumption is found in central Pennsylvania, where in some 

areas the Stonehenge limestone lies between the Mines

and the Nittany dolomites, whereas in others the Larke 

dolomite lies between the same two units. The Mines 

dolomite is correlated with the upper part of the Copper 

Eidge or the lower part of the Chepultepec dolomite,20 

and the basal part of the Nittany dolomite is admittedly 

the equivalent of the Longview.

Nowhere so far as known do all four formations— 

Mines, Larke, Stonehenge, and Nittany—occur in the 

same section; the sequence is either (1) Mines, Larke, 

Nittany or (2) Mines, Stonehenge, Nittany. From this, 

the assumption of disconformity arose. Except for 

New York State where the Tribes Hill limestone, the 

equivalent of the Stonehenge, was believed to occupy a 

similar position, there are no formations in other parts 

of the country that are known to lie between the equivalents of the Chepultepec and Longview dolomites, 

though the existence of such beds has been suggested 

by Ulrich, Oder, and the writer in Oklahoma, Tennessee, and Texas, respectively. These, however, were the 

result of miscorrelation, and the only remaining strongholds of the so-called disconformity lie in central 

Pennsylvania and in the Mohawk Valley. Butts and 

Moore (1936, p. 20) gave typical evidence for the disconformity: '"as the Larke dolomite is not generally 

recognizable and is believed to be generally absent in 

the Bellefonte quadrangle, there is a hiatus between the 

Mines and the Stonehenge due to its absence." This 

statement, of course, is not necessarily true.

In the northwestern part of the Tyrone quadrangle 

(Butts, 1939) the Stonehenge limestone is mapped as 

resting directly on the Mines dolomite, and the, belts 

in which this relationship is shown continue on to the 

Bellefonte quadrangle to the northeast (Butts and 

Moore, 1936).

In the southwestern part of the Tyrone quadrangle 

the sequence is dijferent, for in this area the Larke dolomite overlies the Mines, and in turn is overlain by 

the Nittany dolomite, the Stonehenge limestone being 

absent. The belts in which this sequence occurr continue to the southwest on to the Huntington and Hollidaysburg quadrangles (Butts, 1945), no Stonehenge 

being mapped in either of these two quadrangles. The 

geographic distribution of the two formations, £fonehenge and Larke, strongly suggests that here is an other 

example of an intergrading limestone-dolomite facies, 

limestone to the northwest and dolomite to the southand Howell (in How ell and others, 1944) placed the Mines 

dolomite in the Upper Cambrian and made it the upper member of the 

Gatesburg formation, but Butts (Butts and Moore, 1936, p. 18 ; Butts, 

1939, p. 13; 1945, p. 3) lists three species of Sinuopea from the base 

of the Mines. In the first two reports Butts also classes the formation 

as Cambrian but in the final one he places it at the base of the Ordovician. If these gastropods are correctly identified, they indicate that the 

Mines is post-Copper Ridge and equivalent to the lower part of the 

Chepultepec dolomite.
46 STRATIGRAPHY OP THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

east. This supposition is strengthened by various comments in the texts of the publications just cited which 

indicate that the distinctions between the Larke and 

the Stonehenge are not nearly so clean cut as the mapping would suggest and that occasionally there has 

been some doubt in the mind of the author as to which 

formation was actually present. For example, in the 

Hollidaysburg-Huntington folio (Butts, 1945, p. 3), it 

is stated that

in these quadrangles the Stonehenge, which underlies the Nittany farther east, is not certainly known, but it may be represented by a few feet of dark, compact limestone at the base of 

Nittany exposed about four-fifths of a mile southeast of Ore 

Hill. About 10 feet of thin-bedded dolomite is exposed beneath 

this limestone at that point.

On the other hand it is stated (Butts and Moore, 1936, 

p. 19) that

the Larke is not generally recognizable or mappable in the 

Bellefonte quadrangle, but [that] limestone believed to represent 

the Larke is exposed in an old ore pit 1% miles N. 75° W. of 

Scotia. . . . Here about 200 feet of vertical rock has been exposed. It is mainly dolomite but includes thick layers of fossiliferous limestone near the middle. In this bed of limestone 

occurs a large gastropod provisionally referred by Ulrich to 

Helicotmna loinonensis (Sardeson) ; a large Ophileta shown in 

cross section and not positively identifiable specifically, but 

comparable to O. grandis; and numbers of specimens of a species of Hemitheca [Hemithecella]. ... As the Larke also bebelongs to this general zone, the fossiliferous beds at the old 

ore pit are identified with the Larke. However, as the Larke 

is elsewhere unknown in the region and its known area in the 

old pit is very small, it is mapped with the Stonehenge in what 

seems to be a small fault block as shown on the geologic map.

Both of these quotations suggest the presence of an 

intergrading limestone-dolomite f acies, and it is rather 

surprising that Butts, who was usually keenly aware 

of such gradations and their stratigraphic significance, 

failed to recognize it. He had his doubts on the subject, however, for in 1935 in the course of a field trip 

into the Tyrone area he remarked to the writer that it 

was very strange that the belt between the Mines and 

Nittaiiy dolomites was always wide enough for one 

formation, either the Larke or the Stonehenge, but 

never wide enough for both, and at that time he seemed 

to be trying to convince himself of their equivalence. 

Later on (Butts, 1940b, p. 101), he stated that

the occurrence of several common species in the Chepultepec, 

Stonehenge, and Tribes Hill of New York has led some geologists to the tentative conclusion that those formations are all 

the same.

And at that time he had practically accepted this view 

in spite of seemingly later statements to the contrary 

such as the following (Butts, 1945, p. 3) : a

a lt should be remembered that the texts of the Bellefonte (Butts 

and Moore, 1936), Tyrone (Butts, 1939), and Hollidaysburg-HuntingAt Bellefonte, in Centre County, the Mines dolomite is succeeded above by the Stonehenge limestone, which is 662 feet 

thick. Throughout most, if not all, of these quadrangles [the 

Hollidaysburg and Huntington quadrangles], however, the 

Stonehenge limestone is absent and the Larke dolomite is overlain unconformably by the Nittany dolomite.

Recognition of this f acies relationship appears to have 

been delayed by Ulrich's view that the faunas of the two 

groups of formations are different and that the fossils of 

the Tribes Hill and Stonehenge limestones are younger 

than those of the Chepultepec and its equivalents. 

While differences do exist, the two groups of formations have many species in common, and had the f acies 

relationship been recognized at the time when certain 

fossils were being described, more identical species 

would probably have been recognized in the two groups.

The writer's present view is that there is no convincing evidence, either physical or faunal, to prove the existence of a hiatus between the Chepultepec and the 

Longview dolomites and their equivalents elsewhere, 

and they are here regarded as a part of a conformable 

sequence.

LONGVIEW DOLOMITE

NAME

The name, Longview dolomite, was firs* published by 

Nelson, in a correlation chart based on Ulrich's ideas 

(Gordon, 1924, p. 34; Secrist, 1924, p. 16). The formation was first described by Butts (1926, p. 92-95) as the 

Longview limestone. The name was tr.ken from exposures near Longview, Shelby County, Ala., and the 

formation was subsequently mapped in the BessemerVandiver and Montevallo-Columbiana folios (Butts, 

1927, 1940a), the latter folio containing the town for 

which the formation was named and whr.t may be considered its type area. No type section was ever described, and Butts states that the formation boundaries 

are not well exposed in the vicinity of Longview. He 

also lists (Butts, 1926, p. 92) three sections in Cahaba 

Valley and on Little Cahaba River which may well serve 

as typical sections.

The name was reintroduced into Tennersee during the 

course of this investigation as a substitute for the Pennsylvania name Nittany dolomite (Hall and Amick, 1934; 

Oder, 1934). This was done at the suggestion of Ulrich, 

who claimed that the Nittany formation in its type area 

in central Pennsylvania contained more time and faunal 

units than its so-called equivalent in Tenr°.ssee and suggested that until more detailed information about the 

Nittany in its type area became available it would be

ton (Butts, 1945) reports had all been written many years before their 

publication and that Butts' report on the geology of the Appalachian 

Valley in Virginia, though dated 1940, actually presented his last published views on this subject.
STRATIGRAPHY 47

advisable to discontinue use of the name in Tennessee. 

The name Longview has been used as a formation name 

in Tennessee in several recent publications, notably 

Oder and Miller (1945) and Rodgers and Kent (1948). 

Though these publications do not entirely agree on the 

limits of the formation, both, as well as most other recent papers, have considered the Longview to be a formation. Alien (1947) on the other hand has regarded 

it as the lower member of an enlarged and expanded 

Kingsport formation.

LIMITS

The Longview dolomite in East Tennessee comprises 

units 406 to 458 of the Thorn Hill section (Hall and 

Amick, 1934, p. 203-205) and units 203 to 239 of the 

Lee Valley section (Eodgers and Kent, 1948, p. 22-25). 

Throughout the Valley of East Tennessee it is invariably underlain by the Chepultepec dolomite and overlain by the Kingsport limestone; these relations extend northward into Virginia and southward into Alabama and Georgia. The gradational contact with the 

Chepultepec dolomite has been described (p. 37). The 

upper contact is likewise conformable with the overlying Kingsport, but, because of sharp lithologic differences, the topography resulting from them, differences in the residual cherts, and differences in fossil 

content, it is generally much easier to place. In the 

Thorn Hill and Lee Valley sections and throughout 

the Mascot-Jefferson City district, this contact is commonly drawn at the base of a unit of aphanitic lightbluish to brownish semilithographic and normally 

moderately fossiliferous limestone from 25 to 50 feet 

thick. The individual beds of this limestone unit are 

in general a foot or more thick and are characterized by 

thin crinkly shale partings at intervals of about an inch. 

Locally, as on Copper Kidge and elsewhere, the upper 

part of the Longview also contains beds of fine-grained 

to aphanitic limestone that superficially resembles the 

limestone assigned to the overlying Kingsport in color 

and general texture. These layers are commonly much 

thinner and more discontinuous, however, and typically 

they lack the irregular crinkly shale partings that characterize the basal limestone of the Kingsport. Oder, 

Alien, and others have suggested that these thinner 

limestones also be included in the Kingsport, but the 

presence of Lecanospira in these beds in the Thorn Hill 

section and elsewhere indicates that they belong with 

the Longview dolomite.

THICKNESS

The Longview dolomite is 230 feet 8 inches thick 

in the Thorn Hill section and 264 feet thick in the Lee 

Valley section. It maintains a comparable thickness

throughout the Mascot-Jefferson City district, though 

exact measurements between its contacts have been 

difficult to obtain. The calculated thickness of th?, section on Loves Creek is between 458 and 554 feet, but 

here, as noted above, there is uncertainty as to the position of the contact between the Chepultepec and Longview dolomite, which may have been placed too low 

in the section.

In the chart published by Nelson, the Longview is 

given a thickness of 1,000 feet, but this thickness doubtless included beds now assigned to underlying and overlying formations. Butts (1926, p. 93, and elsewhere) 

gives a thickness of from 400 to 500 feet for sections in 

Alabama, and Oder (1934, p. 482) states that the thickness varies from 25 to 250 feet. These abnormally large 

and small thicknesses appear to depend on the assumption that unconformities exist at the top and bottom of the formation and upon miscorrelations. The 

failure to find the distinctive faunal zones of the Longview has many times resulted in its strata being placed 

either in the Chepultepec dolomite or in the overlying 

formation.

As pointed out by Rodgers and Kent (1948, p. 25-26), 

the contact between the Longview and Kingsport used 

herein lies about 100 feet above the contact as d^awn 

by Oder and Miller (1945) and appears to correeioond 

exactly to the "zero bed" or "footwall sand" of the 

Mascot mine section described by them, though rot to 

the "zero beds" of the New Market or Jefferson City 

sections.

BEDROCK LITHOLOGY

The bulk of the formation is composed of thin- to 

thick-bedded well-bedded fine-grained light-colored 

dolomite that closely resembles the dolomite in tin underlying Chepultepec. The upper half or third cf the 

formation may include beds of fine-grained to aphanitic light-bluish-gray limestone, which locally may 

make up half of the upper part of the formation. Both 

the limestone and the fine-grained dolomite are locally 

replaced by a coarser grained "recrystalline" dolomite 

that is clearly younger than either of the primary types 

of rock. The transition from original carbonate, into 

recrystalline dolomite is commonly sharp, and hand 

specimens showing both at once are easy to obtain. The 

recrystalline material is common in areas of structural 

complexity, along fault and shatter zones, and in areas 

of brecciation; it is invariably present where there is 

zinc mineralization though not all recrystalline areas 

contain zinc. As a general rule, the limestone is much 

more commonly replaced than the fine-grained dolomite, yet examples of both types of replacement c^ti be 

found.
48 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

RESIDUAL PRODUCTS

The rocks of the Longview dolomite commonly 

weather to a light-ash-gray soil that is in rather sharp 

contrast with the more highly colored soils developed 

on the Chepultepec and Kingsport formations. Weathered surfaces of the Longview rocks are commonly 

lighter than the fresh rock; light-gray, bluish-gray, 

and tan tones predominate. In the fine-grained dolomites, solution appears to be most active along closely 

spaced microscopic fracture planes. These are practically invisible in the unweathered rock but appear on 

weathered surfaces as narrow subparallel sets of gashes 

that intersect each other at various angles and give the 

dolomite a curious slashed appearance that is particularly noticeable on exposed bedding surfaces. This 

type of weathering is not confined to the dolomites of 

the Longview but is associated with fine-grained dolomite throughout the Knox group; it is one of the most 

useful criteria for distinguishing between limestone 

and dolomite.

Ordinarily the Longview yields abundant chert 011 

weathering, but locally there may be almost none. 

Most of the chert belongs to a type that is highly characteristic of the formation, and a study of the residual 

materials affords the best means of separating the Longview from the associated formations. The bulk of it 

consists of massive porcellaneous dead-white to light 

pink, brown, and gray chert in large blocks as much 

as 2 feet or more in diameter. This chert is brittle and 

compact, very rarely cavernous, and never mealy or 

porous. Like the dolomite from which it is derived, it 

is cut by many closely spaced microscopic joints, and 

upon weathering it breaks down into small rectangular 

blocks and splinters that are normally white or light 

yellow though fairly commonly stained with iron and 

manganese oxide. Round or oval chert nodules occurring in specific layers, such as are characteristic of the 

Chepultepec and Kingsport formations, are not common in the Longview. Oolitic chert is sparingly present, and dolomoldic chert and the porous, ropy, and 

anastomosing chert that is such a conspicuous feature 

of certain parts of the Chepultepec dolomite are rare. 

Sandstone beds are thin and inconspicuous, though 

rounded sand grains occur in certain dolomite and 

limestone layers.

The chert of the Longview is well displayed in the 

ridge north of the John Sevier railway yards, on the 

low hill just west of Roseberry Creek at Mascot, in the 

ridge north of Friends Station, and in the high part of 

Crockett Ridge about 3 miles northwest of Morristown.

PALEONTOLOGY AND CORRELATION

Fossils are not abundant in the Longview dolomite, 

and most of those found occur as intern?,! or external 

molds in residual cherts derived from th^ weathering 

of the formation. It is almost useless to search for 

fossils in fresh or even well-weathered exposures of the 

dolomite and limestone; the best collecting is commonly 

on the chert-covered hillsides where there are few or 

no outcrops. For this reason it is generally difficult or 

impossible to attribute collections to def nite parts of 

the section, and only in a few places is th°re the fortunate combination of circumstances that makes this 

possible.

The fauna thus far recovered from the Longview 

dolomite and its equivalents in the Appalachian Valley 

is given in the following table.

The brachiopods occasionally provide an exception 

to the foregoing statements concerning the rarity of 

fossils in limestone, for locally they do occur as silicified shells in a limestone or dolomite matrix, from 

which they can be freed by etching witl acid. They 

are, however, not abundant in the Appalachian Valley, only six species having been recorded and only 

two of these from Tennessee. They ar«- much more 

abundant in equivalent formations in'Oklahoma and 

Texas and there they form a most important element 

in the faunas.

The most important and characteristic fossils of the 

Longview dolomite, both from the standpoint of 

abundance and ease of recognition, are tH gastropods, 

particularly the genera Leccmospira and Rhombella, 

both of which seem to be confined to this formation and 

its equivalents. Of these, Lecmwspira is by far the 

more abundant, the more widely distributed, and the 

more easily identified. Specimens belonging to various 

species of the genus have been found throughout the 

length of the Valley from Alabama to Quebec, and also 

in Newfoundland and in the Durness limestone at the 

northern tip of Scotland. The genus ie abundant in 

the Roubidoux formation of Missouri (Bridge, 1930, 

p. 124) and in the German formation of central Texas 

(Dake and Bridge, 1932, p. 737; Clone1 and Barnes, 

1948, p. 40). It also occurs in the Cool Creek formation of the Arbuckle and Wichita Mountains and possibly at a level equivalent to the Gormar formation in 

the El Paso limestone of West Texas (Cloud and 

Barnes, 1948, p. 359). It has not yet been reported 

from the Rocky Mountains or from arear farther west.

Rhombella (formerly called Roubidouwia) is nearly 

as widely distributed, and about as characteristic, but 

it is much less abundant than Lecanospira. It is found 

mostly as molds in residual cherts, but specimens in 

limestone have been found at a few localities, parti cu-
STRATIGRAPHY 49

TABLE 2—Distribution of species from the Longview dolomite and equivalent formations 

[T = Species described from State or Province indicated; X=Species reported from State or Province indicated; cf=Similar species reported from State or Province indicated]

Brachiopods: 

Diaphelasma pennsylvanicum Ulrich and 

Cooper

Finkelnburgia virginica Ulrich and Cooper _

Syntrophina campbelli (Walcott)

Syntrophinella typica Ulrich and Cooper

fradiata (Whitfield)

Gastropods: 

Lecanospira compacta (Salter)

conferta Ulrich

salteri Ulrich and Bridge _

biconcava Ulrich and Bridge

sigmoidea Ulrich and Bridge

Rhombella umbilicata (Dake and Bridge) __

Sinuopea spp

Cephalopods: 

Allopiloceras breve Ulrich, Foerste, and 

Miller

Cumberlandoceras buttsi Ulrich, Foerste, 

and Miller

Endocycloceras perannulatum Ulrich, 

Foerste, Miller, and Unklesbav

Bassleroceras bridgei Ulrich, Foerste, Miller, 

and Unklesbav

Leptocyrtoceras virginianum Ulrich, Foestre, 

Miller, and Unklesbay__ _

Monogonoceras alabamense Ulrich, Foerste, 

Miller, and Unklesbay_ _ __ _ ,

magnisiphonatum Ulrich, Foerste, 

Miller, and Unklesbay

Pachendoceras newportense Ulrich, Foerste, 

Miller, and Unklesbav -

Parendoceras jeffersonetise Ulrich, Foerste,

clinchburgense Ulrich, Foerste, Miller,

Trilobites: 

Hystricurus spp ___ _

Longview dolomite

Alabama

T

X 

T

X

T

X

Tennessee

X

T

X 

X 

T

X 

T

Xw

T 

T

T

X

T

X

Virginia

X 

T

X

X 

X 

X

X 

X

X

T

T 

T

T 

T

T

X

Maryland

X

Pennsylvania

T

X

New 

York

rp

X

Quebec

T

X

X

Missouri

X

X 

X 

X 

T 

X 

T

Texas

cf

X 

cf

X

X

X

Oklahoma

X

larly in Oklahoma and Texas and to a lesser extent in 

the northern Appalachians, in Pennsylvania and New 

York, and in certain areas in Quebec.

KINGSPOBT LIMESTONE

NAME

The Kingsport limestone is named from exposures 

along U. S. Highway 23, beginning about 0.5 mile 

north of the junction of this road with U. S. Highway 

11-W just north of Kingsport, Sullivan County, Term. 

The name was originally suggested by Oder (personal 

communication about 1937 for use in the present report. It replaces the names Jefferson City formation 

(Oder, 1934) and Forked Deer formation (Hall and 

Amick, 1934).

The name Jefferson City was discarded as a formation name in Tennessee to avoid confusion with its 

long-standing use in Missouri and Arkansas. The name

has had a long and varied history in the Ozark region, 

and its present status there is not very well defined. 

The Jefferson City formation of the Ozark region, as 

originally proposed by Winslow (1894, p. 331), included 

all strata between the Roubidoux sandstone beneath and 

the Saccharoidal (St. Peter) sandstone above. Ulrich 

(1911, p. 632-633, pi. 27) restricted the Jefferson City 

limestone to the lower third of the rocks in this interval; 

subsequently Purdue and Miser (1916, p. 4-5) introduced the names Cotter dolomite and Powell limestone 

for the remaining two-thirds of the original Jefferson 

City of Winslow. Still later, Dake (1921, p. 12) raised 

the Jefferson City to the rank of a group composed of 

three formations, the Jefferson City formation (restricted) at the base followed by the Cotter and Powell 

dolomites. The boundaries of the three formations 

were never clearly defined. In brief, in the typ?, area 

of the Jefferson City dolomite in and around Jefferson
50 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

City, Mo., 110 Cotter is present, whereas at Cotter, Ark., 

the type locality for the Cotter dolomite, which is about 

140 miles to the south on the opposite flank of the Ozark 

dome, the contact between Jefferson City and Cotter is 

below river level. As a result, the assumed contact 

between the two formations was a fairly arbitrary 

boundary.

On the basis of detailed stratigraphic and paleontologic studies, Cullison (1944) redefined the Jefferson 

City formation of Missouri, raised it to a group, and 

divided it into two formations—the Theodosia formation above and the Eich Fountain formation below. 

He discussed the relationship of the Jefferson City 

group to the overlying Cotter dolomite and described 

and figured many of the fossils characteristic of each 

of these formations, adding materially to our knowledge of these units in their type region. His conclusions, however, have not been adopted by either the 

Missouri or the U. S. Geological Surveys.

Although the Kingsport limestone is f aunally equivalent to a part of the Jefferson City, there is still uncertainty and much difference of opinion as to exactly 

what is contained within the limits of the Jefferson City 

in Missouri.

The other older name, Forked Deer formation, was 

taken from Forked Deer Creek at the Thorn Hill section and was used only as a heading for a group of 

descriptions of individual strata in that section (Hall 

and Amick, 1934, p. 205). No attempt was made to 

define it as a formation or to give any account of its 

geographic or regional correlation. It was never formally adopted by the Tennessee Division of Geology 

and has never been used outside the original publication. 

In the meantime Oder's name Kingsport limestone was 

adopted informally by the various mining companies 

and formally by the State Division of Geology and the 

U. S. Geological Survey, and it is now well established 

in geologic literature.

The name Kingsport limestone was first published 

without description on several strategic mineral maps 

issued during and after the Second World War 

(Eodgers, 1943; Dunlap and Rodgers, 1945; Kent, 

Eodgers, and others, 1945; Dunlap, 1947). The first description of the formation was by Oder and Miller 

(1945), but this applied only to mine sections in the 

Mascot-Jefferson City district. Subsequently the formation was briefly described by Miller and Fuller 

(1947) for southwestern Virginia and by Rodgers and 

Kent (1948, p. 25-26) for the Thorn Hill and Lee Valley 

sections, but the present report contains the first description of the type section.

LIMITS

As here defined, the Kingsport limertone includes 

units 459 to 519 (lower 3 feet, 3 inches) of the Thorn 

Hill section (Hall and Amick, 1934, p. 205-208) and 

units 240 to 256 of the Lee Valley section (Rodgers and 

Kent, 1948, p. 25-27). The contacts in the Thorn Hill 

section are those originally selected by Oder and the 

writer about 1937 and subsequently used by the writer 

in revising the map of the Mascot-Jefferson City district. The base of the formation is drawn at the bottom 

of a thick unit of aphanitic sublithogr^phie "dove"- 

colored limestone with thin crinkly shale partings; the 

top is drawn at the base of a thin but persistent sandstone whose grains are cemented with white chert—the 

chart-matrix sandstone of Oder, who discovered this 

valuable key bed. There are actually two or three chertcemented sandstone layers in most sections examined; 

the one here used, however, occurs at the top of a finegrained dolomite bed forming the lower part of unit 

519 at Thorn Hill and unit 257 at Lee Valley. What is 

believed to be this same sandstone is well exposed in 

unit 68 in the type section of the Kingsport limestone 

on U. S. Highway 23 (p. 51) and at many localities in 

the Mascot-Jefferson City district and elsewhere.

The boundaries of the Kingsport limestone as here 

drawn are not exactly the same as those of the Jefferson 

City formation of Oder or of the Forked Deer formation of Hall and Amick. Furthermore, the lower limit 

does not agree with the lower limit of the Kingsport 

limestone as now drawn by Oder and his associates 

(Oder and Miller, 1945; Alien, 1947,194?). In naming 

the Kingsport limestone, Oder and Miller (1945, p. 1) 

stated that the names Kingsport and Mascot had been 

selected by Oder and Bridge for use in their forthcoming reports on the Knox dolomite of East Tennessee. 

In their paper, the stratigraphic sections as developed 

in the mines at Mascot, New Market, and Jefferson City 

are described in considerable detail, and the characters 

and importance of a number of marker beds useful in 

subsurface correlation are thoroughly discussed; no 

attempt is made, however, to correlate this information 

with surface data, although residual materials from 

many of the marker beds have been found to be extremely useful in surface mapping. The top of the 

formation is placed at the base of the chert-matrix sandstone (Oder and Miller, 1945, p. 5), but no mention is 

made of the contact with the Longviev7 dolomite beneath ; in fact, one gets the impression on reading the 

paper that all the sections end below within the Kingsport. This is still Oder's opinion, but other workers 

including the writer now place the base of the formation 

at the "zero bed" in Oder and Miller's Mascot section, 

at the — 66 bed in their New Market section, and some-
STRATIGRAPHY 51

where in the 10-3 (T) bed in their Jefferson City section, for these beds are believed to correspond almost 

exactly to the base of the Kingsport limestone in the 

Thorn Hill and Lee Valley sections (Rodgers and Kent, 

1948, p. 25-26; Brokaw, oral communication, 1950) and 

to the base of the formation as exposed in the type section on U. S. Highway 23.

The type section of the Kingsport limestone is on the 

east side of U. S. Highway 23 just northwest of Kingsport (pi. 3E). The top of the formation is 0.55 mile 

north of the traffic light at the intersection of U. S. 

Highways 23 and 11-W; the base is 0.23 mile farther 

north. The section of the Kingsport proper was measured by Oder and the writer in 1940; the other details 

have been added by the writer on subsequent visits. 

The area is shown on plate 3#.

Section of the Kin-gsport limestone and associated formations 

on U. S. Highway 23 north of the junction with U. 8. Highway 11-W, Kmgsport quadrangle, Tennessee (pi. 3E)

[Units 68-85 measured by Josiah Bridge, 1951]

The contact of the Mosheim member of the Lenoir limestone 

and the Mascot dolomite crosses the highway about 0.15 mile 

north of the intersection and passes northeastward to the north 

of the school. It is not well exposed but is marked by a sudden 

break in topography and by a line of shallow sinks.

Between this point and the entrance to the Kingsport cemetery 0.45 mile north of the intersection, the section is largely 

covered, but scattered outcrops of Mascot dolomite appear in 

the fields along the east side of the highway. Specimens of 

Ceratopea, keithi Ulrich and Orospira sp., both characteristic 

Mascot fossils, were found in the dolomites about 80 ft stratigraphically above the base of the formation.

Section begins at the top of the continuous outcrops near the 

powerline pole north of the cemetery entrance.

Mascot dolomite: Feet Inches

85. Dolomite, fine-grained; light gray on freshly broken surfaces, darker on weathered 

surfaces —————_—_—_________ 4 0

84. Dolomite, similar to unit 85 but with thin 

layers of chert, chert nodules, and small 

siliceous geodes.:______________ 7 0

83. Dolomite, similar to unit 84. Two beds,

each about 9 in. thick__________ 1 6

82. Dolomite, similar to unit 83, with many 

thin (half-inch to two-inch) chert layers, and with layers of small chert 

nodules and geodes near the top of the 

unit. The chert nodules are smooth, 

rounded, light gray to white on fresh surfaces, rusty tan on weathered surfaces. 

The geodes resemble small cauliflower 

heads averaging less than 1 in. across, 

rusty red on the outside, and filled with 

small clear quartz crystals________ 7 0

81. Dolomite, like unit 82, but no chert; a

single layer______———_____— 1 6

80. Dolomite, like unit 82, but no chert; a

single layer———_____————_—————— 2 6

Mascot dolomite—Continued Feet inches

79. Chert, brittle; china white on fresh surfaces, rusty on weathered surfaces, banded and brecciated_————————————— 3 0

78. Dolomite, fine-grained, well-bedded; light 

bluish gray on freshly broken surfaces, 

dull gray on weathered surfaces. Many 

layers of small ovoid chert nodules, most 

of them 1 in. or less across, but with some 

as much as 2 in. Chert is light gray on 

freshly broken surfaces but rusty orange 

on the outside rind where weathered. 

Some layers of small siliceous geodes 

similar to those in unit 82. A powerline 

pole is opposite this exposure_______ 7 0

77. Chert, brittle, white, porcellaneous; bluish 

white and semitranslucent where fresh, 

dead white with yellow stains where 

weathered __—_____——_—_— 2 6

76. Dolomite, similar to unit 78, with many 

scattered ovoid chert nodules (mostly 

less than 1 in. across) and with one or 

two layers of larger flat chert nodules__ 4 0

75. Chert, like unit 77_______________ 3 0

74. Dolomite, similar to units 76 and 78, wellbedded ; individual beds from. 8 in. to 3 

ft thick, a few thin bands of chert 

nodules ____________________ 19 6

73. Dolomite, similar to unit 74, a single thick 

bed with widely spaced layers of small 

chert nodules (less than 1 in. across) arranged along incipient irregular poorly 

developed bedding planes_________ 4 6

72. Dolomite, fine-grained, well-bedded, lightbluish-gray, similar to unit 78, a single 

bed. Contains a few scattered chert 

nodules _——______—________ 10

71. Dolomite, like unit 72_____________ 10

70. Dolomite, fine-grained, light-bluish-gray; 

weathering yellowish gray to dull gray. 

Contains from 6 to 8 bands of small ovoid 

chert nodules, most of them less than 1 

in. across———_—————————————— 1 9

69. Dolomite, like unit 70 with conspicuous 

band of chert nodules from 1 to 2 in. 

across, 9 in. above the base. Several 

thin bands of chert nodules less than 1 in. 

across in the upper 9 in—————————— 2 0

68. Dolomite, gray, fine-grained, almost pure 

at the top but becoming arenaceous 

below. The sand grains are well 

rounded, frosted, increasing in abundance toward the base of the unit; the 

lower 3 to 4 in. are almost pure sand 

cemented by chert, forming a chertmatrix sandstone. This sandstone is 

hard and white in fresh exposures, becoming rusty and crumbly in weathered 

pieces _—————————————————— 9

Thickness, measured part of Mascot 

dolomite ———————————————— 73
52 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

The total thickness of the Mascot dolomite in this section is 

calculated as either 545 or 670 ft, assuming uniform dips of 

20 and 25 degrees, respectively. The larger figure is probably more nearly correct.

[Units 1-67 measured by C. R. L. Oder and Josiah Bridge, 1940]

Kiiigsport limestone: Feet inches

67. Dolomite, fine-grained, light-gray, wellbedded with very little chert; unit partly 

covered __-_____________-__ 6 9

66. Chert layers, almost continuous, white, 

stained with yellow and orange, thick 

and nodular_________________ 4 6

65. Dolomite, fine-grained, light-gray, with 

scattered layers of flat ovoid chert nobules as much as 2 in. across and a few 

thin layers of white chert along bedding planes. A conspicuous layer at the 

top _______________________ 2 8

64. Chert, dark-gray, with a sugary testure_ 6

63. Dolomite, fine-grained, light-gray, without

chert ______________________ 1 4

62. Dolomite, fine-grained, light-gray, with 

thin chert layers in the base and siliceous rosettes or geodes in the upper 

part________________________ 4 6

61. Dolomite, like unit 62, with thin slabby 

chert nodules, 1 in. thick and 8 to 10 in. 

long; also thin black shale partings___ 1 8

60. Largely covered, probably dolomite with

heavy white chert bands_________ 3 0

59. Dolomite, in part fine-grained, in part

"recrystalline" _______________ 15 2

58. Covered interval ________________ 1 10

57. Chert, compact, white, ropy, in part conglomeratic and containing false oolite, 

fossiliferous __________________ 1 10

56. Largely covered; about 1 ft of "recrystalline" dolomite at top____________ 30 0

55. Limestone, blue, the lower inch coarsely

"recrystalline," the remainder aphanitic_ 7 4

54. Limestone, blue, aphanitic, no clay partings, with layer of black chert nodules 

at base_____________________ 9

53. Dolomite, light-gray, fine-grained, with

Ceratopea capuliformis Oder______ 4

52. Dolomite, with an irregular band of siliceous oolite (the C oolite of the Mascot 

geologists, 130 ft below the top of the 

formation at Mascot) ___________ 6

51. Dolomite, fine-grained, light-gray______ 8 6

50. Limestone, very fine grained to aphanitic, 

light-blue; Ceratopea capuliformis Oder 

seen on upper surface___________ 5 0

49. Dolomite and limestone, most of the dolomite coarsely "recrystalline" ______ 4 6

48. Chert, white, brittle, enclosed in gray very 

fine grained dolomite. Top and bottom 

surfaces brecciated; top fairly smooth, 

bottom with waffle-iron pattern. _____ 4

Kingsport limestone—Continued Feet inches

47 Limestone, mostly fine-grained to' aphanitic, light-blue; some beds near top 

coarsely "recrystalline"; fine-grained 

material fossiliferous-—— ———————— 9 4

46. Dolomite, with thin bands of flat ovoid 

white chert nodules as much as 8 in. 

long. Upper 2 ft coarsely "recrystalline"____________—__—————— 7 8

45. Limestone, thin-bedded, with some si ale

partings_____.._.._————————————— 1 10

44. Limestone, fine-grained to aphanitic, at out

1 in. of black chert at base—_________ 4 6

43. Limestone, blue, aphanitic to subcrystalline, with wavy very thin clay partings, 

subconcholdal fracture. The limestone 

weathers light blue; the clay partings 

weather to a chalky white and stand out 

in low relief. The "brown rock" of the 

Mascot district. Strike N. 60° E., dip 

20° SE _____________________ 5 3

42. Chert, ropy, porous, white, weathering to

yellow ________———————————— 4

41. Shale, black, platy_______ ______ 1

40. Dolomite, fine-grained, light-gray, two

beds _______.._-.-____- ._____ 2 6

39. Limestone, like unit 43, thick-bedied, 

aphanitic to subcrystalline, fossiliferous ________________________ 14 0

38. Clay, with flattened banded nodules* of 

dead-white chert with black translucent 

streaks that weather yellow like chert 

of the Chepultepec dolomite________ 10

37. Limestone, like units 43 and 39, tl'ckbedded, aphanitic, fossiliferous—————— 8 8

36. Covered interval, much platy chert in the

residual materials____________ 2 0

35. Dolomite, light-gray, fine-grained-__-_ 1 0

34. Limestone, like unit 43. A single bed 45 in.

thick overlain by a 10-in. bed-_—_ 4 7

33. Shale parting_________________ 6

32. Limestone like unit 34, largely covered_ 14 0

31. Covered interval, probably limestone (not 

recorded) ______——______~

30. Limestone like unit 34. Three marsive

beds exposed in small quarry_______ 8 8

29. Covered interval, probably limestone—_ 2 0

28. Dolomite, coarsely "recrystalline," n^edium-gray, with pink vugs. A cast-iron 

pipe crosses this outcrop_—————___ 1 6

27. Limestone, blue, aphanitic to subcrystalline, with thin crinkly shale partings_ 8 4

26. Covered interval, probably limestone—_ 2 0

25. Chert, brittle, white, platy, with algal impressions on bedding planes, weathers 

yellowish on surface, oolitic and conglomeratic ______——__——————— 4

24. Covered interval, mostly limestone—_ 5 0

23. Limestone, like unit 27, blue, aphanitic to

subcrystalline ——————————————— 10

22. Covered interval, with limestone like unit

23 at base______——_——————— 7 0
STRATIGRAPHY 53

Kingsport limestone—Continued

21. Dolomite, fine-grained, light-gray, with 

scattered vugs of pink dolomite, weathers buff to tan__——_—_______________

20. Chert, brittle, white, platy, and laminated 

19. Chert, rusty, porous, with many rectangular slots which may represent leached 

limestone pebbles. Fossiliferous, Hormotoma on upper surface________- 

18. Dolomite, like unit 21___________________

17. Limestone, blue, aphanitic to subcrystalline, with wavy clay partings, subconchoidal fracture. Weathers very light 

blue, the clay partings weather to chalky 

white and stand out in low relief, grades 

upward into unit 18____—______

16. Dolomite, fine-grained, blue-gray_________

15. Limestone, similar to unit 17_________

14. Dolomite, very coarsely "recrystalline"_

13. Covered interval, some outcrops of blue

limestone like unit 15_____________

12. Dolomite, in part fine-grained, in part 

coarsely "recrystalline." Some layers 

of chert nodules at the base and a few 

thin seams of chert________________

11. Dolomite, medium-gray, sandy and "recrystalline" ; chert layers at the base. 

Grades laterally down the dip into a finegrained sandy limestone______________

10. Limestone, like unit 15, with a drusy network of dolomite crystals and wavy 

green clay partings___________________

9. Dolomite, light-gray, fine-grained, sandytextured, with several layers of ovoid 

chert no.dules________________________

8. Shale, with ovoid chert nodules__________

7. Dolomite, like unit 9____________________

6. Shale, greenish-gray_____________________

5. Limestone, like unit 15__________________

4. Shale, parting, with platy chert__________

3. Limestone, blue, like unit 15____________

2. Dolomite, light-gray, coarsely "recrystalline" ; grades locally into blue aphanitic 

limestone like unit 3__________________

1. Dolomite, sandy-textured, fine-grained, 

light-bluish-gray. Weathers buff gray 

and locally to a rusty coarse sandstone. 

Two or three beds. Strike N. 55° E., dip 

20° SE_______________________________

Feet inches

1 

o

13

1

6

10

10

Total Kingsport limestone_______ 283 0

Longvievv dolomite:

Top 10 ft massive, fine-grained, light-steel-gray, fine-grained 

dolomite. Some layers partly "recrystalline." Weathers 

cream colored. Overlies a massive chert bed.

Lower part of section not measured.

The Chepultepec and Longview dolomites are exposed to the north in a rather thickly settled area, and 

the contact between them could not be determined with 

certainty. About 0.7 mile north of the base of the 

Kingsport limestone are thick sandstones believed to 

mark the base of the Chepultepec; still farther north

are fair exposures of the Copper Ridge dolomite. On 

the north face of the hill about 1.33 miles north of the 

base of the Kingsport, the contact between the Copper 

Ridge dolomite and the Maynardville limestone member 

of the Nolichucky shale is well exposed, and from here 

to the base of the hill the exposures are all Nolichucky 

shale.

Oder (unpublished mimeographed notes, distributed 

during Kentucky Geological Society field trip in Nay 

1947) gives thicknesses of 346, l73i/2 , and 605 feet for 

the Kingsport, Longview, and Chepultepec formations, 

respectively, in this section. Apparently he drew the 

base of the Kingsport 63 feet below the base as here 

described. These 63 feet should be added to the Longview dolomite, making its thickness in this section 

2361/0 feet.

THICKNESS

The Kingsport is about 280 feet thick in its type 

section along U. S. Highway 23 at Kingsport. It thins 

to the west, being but 218 feet thick in the Lee Valley 

section and 232 feet in the Thorn Hill section, both 

of which are in the Copper Ridge belt on the northwest 

side of Clinch Mountain. The formation becomes 

thicker to the south; in the Mascot-Jefferson City district, Oder and Miller (1945) give thicknesses of 266, 

306, and 320 feet, respectively, for those beds in the 

mine sections at Mascot, New Market, and Jeffevson 

City that are included in the Kingsport limestone by 

the present writer.

At Eve Mills in Monroe County southwest of Knoxville, approximately on strike southwest of the MascotJefferson City district, the formation averages 300 feet 

thick (Dunlap, 1947), but, to the southeast of Pays 

Mountain on the Mosheim anticline, it appears to have 

thinned to about 200 feet (Dunlap and Rodgers, 1£45). 

According to Kent, Rodgers, and others (1945), the 

Kingsport limestone is about 250 feet thick in the 

Powell River area.

BEDROCK 1ITH010GY

The Kingsport limestone is composed of dolomite 

and limestone with subordinate amounts of shale, chert, 

siliceous oolite, and sand. The most abundant rock 

type is dolomite, but the most striking is the pure limestone, thick beds of which make up the bulk of the lower 

third to half of the formation; the limestone forms a 

conspicuous new element in the monotonous sequence of 

dolomitic strata that make up the formations of the 

Knox group.

The limestone is thick bedded (6 inches to 2 foet), 

compact, aphanitic, sublithographic, bluish gray to 

pinkish brown on freshly broken surfaces, bluish white 

to gray on clean weathered surfaces, breaking with a
54 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

splintery to subconchoidal fracture. Some weathered 

surfaces show a thin white chalky rind. The limestone 

beds show rather closely spaced very thin irregular, 

wavy clay partings that are dark gray to black on fresh 

surfaces and weather tan to white and stand in low relief on weathered surfaces. The great bulk of the insoluble residues obtained from these limestones consists 

of thin flakes, representing fragments of these films. 

The limestones are the "brown rock" of the miners at 

Mascot, and the "dove limestones" of the miners at 

Jefferson City.

The dolomites are of two types: first, the very fine 

grained and light-colored variety that is common 

throughout the middle and upper parts of the Knox 

group, and second, a more coarsely crystalline granular 

gray and blue-gray variety. The latter, commonly 

called "recrystalline" in this district, is evidently a replacement of both the limestones and the fine-grained 

dolomites; the transition between the country rock and 

this coarse-grained phase may be seen at many places, 

both in surface exposures and in mine workings. No 

direct evidence bearing on the origin of the fine-grained 

dolomites can be cited; it is thought that they are also 

of secondary origin, but that they were formed at a 

much earlier time than the coarse-grained varieties.

Certain beds contain an abundance of small cavities, 

normally less than an inch in diameter, which have been 

filled or partly filled with calcite, dolomite, or milky 

quartz. The quartz fillings stand out in relief on 

weathered surfaces and are commonly found as small 

cauliflowerlike masses in the residual clays.

Chert occurs in several forms. Flattened nodules of 

light-gray compact chert occur in rows parallel to the 

bedding in certain layers and are so distinctive of particular layers that those layers can be recognized from 

one mine to another throughout the district. In addition, compact to finely porous white rusty-weathering 

chert occurs sparingly as layers in weathered exposures 

and abundantly as small blocks and chips in the red or 

orange residual clay derived from the dolomite and in 

the overlying soil.

A few thin layers consist of sandstone or of dolomite 

containing scattered rounded frosted sand grains; like 

the layers containing chert nodules, these sandy layers 

can be traced for miles even where the sand is confined 

to a layer an inch or two thick.

Detailed sections of the Kingsport limestone in the 

zinc mines of the district are given by Oder and Miller 

(1945, table 2).

CORRELATION

Fossils are more common in the Kingsport limestone 

than in the older formations of the Knox group, though

still hardly abundant. They include the oldest species 

of the genus Ceratopea, G. capuliformis Oder, and also 

of several characteristic gastropods, notably Orospira. 

The Kingsport limestone is shown by its fossils to be 

equivalent to the lower portion of the Newala limestone 

(Butts, 1926, p. 95-99) in southeastern Tennessee, 

northwestern Georgia, and northeastern Alabama and 

to a portion of the Jonesboro limestone in the northeastern part of the Valley in East Tennessee where it is 

not possible to divide the Ordovician part of the Knox 

group into separate formations. It is also roughly 

equivalent to the Jefferson City of Missouri, but the 

exact correlation is not yet certain.

MASCOT DOI/OMITE

NAME

The Mascot dolomite is named for the town of Mascot, Knox County, Tenn. The history of the name 

closely parallels that of the name Kingsport, and the 

reasons for preferring it to the older names CotterPowell beds (Oder, 1934) and Thorn Hill formation 

(Hall and Amick, 1934) are identical. The name first 

appeared on the geologic map of the Cc r>per Ridge district (Eodgers, 1943) without description; it was subsequently published by Oder and Miller (1945) and 

there credited to Oder and the writer. No description 

of the formation is contained in that pp.per, but several 

preliminary reports published as a result of the wartime 

investigations of the zinc deposits of East Tennessee 

contain brief descriptions of the formation and show 

its areal distribution in small areas.

LIMITS AND THICKNESS

The Mascot dolomite overlies the Kingsport limestone wherever the two have been reco^ized. In turn 

it is overlain by limestone belonging to various Middle 

Ordovician formations; in the Mascot-Jefferson City 

district, the overlying unit is either the Mosheim member of the Lenoir limestone or more rirely the Lenoir 

limestone itself. The Mascot dolomite includes all beds 

from the upper 2 feet of unit 519 to tin top of unit 687 

in the Thorn Hill section (Hall and Amick, 1934, p. 

208-214) and unite 257 to 315 in the Lee Valley section 

(Rodgers and Kent, 1948, p. 27-32). No complete section is exposed in the vicinity of Mascot, but several 

partial sections are exposed nearby. The thickness at 

Thorn Hill is 520 feet 10 inches, and at Lee Valley 510 

feet. In the Mascot-Jefferson City district, the formation may be as much as 600 feet thick. It is certain that 

the thickness varies considerably because of later erosion, which produced a pronounced disconf ormity at the 

top of the formation.
STRATIGRAPHY 55

BEDROCK LITHOLOGY

The Mascot consists chiefly of dolomite, similar to 

that in the Kingsport limestone, with chert layers, layers of chert nodules, and scattered bods of sandy dolomite that weather to rusty poorly cemented sandstones. 

Near the top in some sections, particularly in the 

Mascot-Jefferson City district, layers of aphanitic blue 

limestone are interbedded with the dolomites; these 

resemble the limestones of the Kingsport but lack, in 

the main, the thin clay partings. They also resemble 

the limestones of the overlying Mosheim member but in 

general lack the small clear calcite crystals that are so 

common in the Mosheim.

The chert of the Mascot is much like that of the 

Kingsport but is rather more abundant in the residuum 

over the lower part of the formation. The sandstone 

layers, especially close to the base of the formation, 

produce thin slabs and small blocks, which may also be 

found in the residuum over that part of the formation.

CORRELATION

Fossils, chiefly gastropods and cephalopods, serve to 

establish the general equivalence of the Mascot with 

the upper Newala limestone of Alabama, the uppermost 

Jonesboro limestone of northeast Tennessee, the Cotter dolomite (but not the Powell dolomite) of Missouri and Arkansas, and the Shakopee dolomite of the 

Upper Mississippi Valley region. Ceratopea is common, and the formation includes the zones of G. keithi 

Ulrich and G. tennesseemis Oder in its lower part, and 

locally the zone of G. arikylosa Cullison close to the top 

(seep. 59).

TOPOGRAPHIC EXPRESSION

Areas underlain by the formations of the Knox 

group develop a characteristic topography that commonly is in sharp contrast to that developed on the underlying and overlying rocks. The details of this topography are beautifully shown on many of the new 

7%-minute quadrangles of the TVA series, and elements of it can even be recognized on some of the old 

30-minute quadrangles made a generation or more ago.

In general, this topography is characterized by moderate to gentle broad smoothly rounded slopes, without 

cliffs or abrupt changes of slope except along major 

streams. These characteristics are due, of course, to 

the homogeneous nature of the underlying rock. Although the area is well drained, the main drainage lines 

are widely spaced and commonly have gentle gradients, whereas the minor tributary valleys are shallow 

and also rather widely spaced. This again is due to the 

homogeneously resistant underlying rocks.

Belts underlain by these formations where they have 

moderate to steep dips commonly rise above th°, surrounding country as ridges of the second order, reaching approximately to the level of the so-called "^alley 

Floor or Harrisburg peneplain. They are about as 

high as the ridges developed on the Rome formation 

but are normally separated from those by a valley developed on the nonresistant Middle and lower Upper 

Cambrian rocks. The topographies of the two types 

of second-order ridges are entirely different: the 

ridges developed on the Rome formation are nr.rrow, 

steep, intricately dissected, and commonly cut by 

closely spaced water and wind gaps; the Knox ridges 

are broader, with gentle slopes and few conspicuous 

gaps. Because of the nature of the underlying rocks 

and the sterility of the soils developed from them, 

Rome ridges are commonly forested, whereas Knox 

ridges are normally partly cleared and localh7 are 

farmed to their summits. Where associated with 

mountain ridges of the first order, such as Clinch 

Mountain (Avondale and Luttrell quadrangles), the 

second-order Knox ridges are separated from the firstorder ridge by a broad shallow high-level valley developed on the less resistant Middle Ordovician limestones and shales.

The same open rolling topography is found in areas 

where the strata of the Knox group are essentially horizontal, as, for example, over most of the Joppa quadrangle. The principal difference between the topography developed on the Knox group in this area ani that 

in the belts of steep dips, for example, the central part 

of the John Sevier quadrangle, is the dendritic drainage pattern and the absence of any conspicuous alinement of topographic features.

Where the formations of the Knox group dip at moderate to steep angles, it is often possible to recognize 

the approximate limit of the several formations from 

the topography alone. For example, on the Jol^n Sevier quadrangle, between the west edge of the map and 

Ellistown, the Copper Ridge dolomite forms a high 

continuous ridge along the northwestern side of the 

belt, the Longview dolomite forms a somewhat 1 igher 

and even more prominent ridge to the southeast, and 

the Chepultepec dolomite occupies a series of straight 

valleys and low saddles between.

The Kingsport and Mascot formations have less obvious topographic expression. The limestone in the 

lower part of the Kingsport may be recognized by a flat 

terrace or a series of saddles, commonly accompanied by 

sinks, developed on the southeast slope of the Longview ridge, whereas the somewhat more resistant lower 

part of the Mascot dolomite is indicated by the row of
56 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

low inconspicuous knobs parallel to the Longview ridge 

and at a still greater distance from it.

This same sequence of topographic belts is even better shown on Copper Ridge in the western part of the 

Dutch Valley quadrangle, where the three ridges 

formed by the Copper Ridge, Longview, and lower 

Mascot dolomites and the strike valleys and sags developed on the Chepultepec and Kingsport formations 

are remarkably clear. Still farther northeast on Copper Ridge in the Avondale quadrangle, the ridges 

formed by the Copper Ridge and Longview dolomites 

unite to form a single high ridge on which the Chepultepec dolomite is represented by a break in slope which 

gives the effect of a broad terrace.

These are the normal aspects of the topography developed on the formations of the Knox group. There 

are also some surprising abnormalities. One of the 

most interesting of these is the band of sinkholes on 

the Talbott quadrangle southeast of TJ. S. Highway 

11-E, between Rocktown Church and Alpha. This 

area of about 7 square miles is literally honeycombed 

with sinks of various sizes and depths, so much so that 

in the whole area there is virtually no surface drainage. 

At least three-fourths of the area is underlain by 

the Kingsport and Mascot formations. The explanation of this abnormal topography is that the area is a 

part of a belt of complex structure (p. 64-65) in which 

the Mascot dolomite has been crushed and broken by 

large and small faults and joints. This shattering 

together with the gentle sloping surface has favored the 

work of solution over that of normal surface erosion and 

produced the highly abnormal pitted plain shown on the 

map.

This general area is described by Safford (1869, p. 

219) as follows:

There is an interesting plateau of this formation [the Knox 

dolomite] in Jefferson County, between the Holston and the 

so-called Bay's Mountain, and extending from the vicinity of 

New Market to Russellville; these towns, and Morristown, being upon it. This area is from 300 to 400 feet above the Holston, 

and presents some excellent and extensive farming regions. 

A portion is called the New Market Valley, and is noted for its 

fertility. The rocks of this plateau, are at many points, but 

little .inclined. They are, in reality, at the northern disappearing end of a synclinal trough.

Originally, the ridges of the Knox group were covered with a thick stand of hardwood timber, chiefly 

oak and hickory, and these were in sharp contrast 

to the pine-covered slopes of the ridges of the Rome. 

Much of this hardwood has been cut, and today the 

ridges are largely cultivated or used for pasture. 

Their soils, though stony, are among the best upland 

soils in the Valley, though like most soils derived from 

limestone they are commonly deficient in lime. The

American Zinc Co. has for years marketed the finely 

ground fresh tailings from its mills as agricultural limestone, and some of the best farms in the area have been 

consistently treated with this material.

POST-KNOX FORMATIONS 

THE NAME CHICKAMAUGA LIMESTONE

The Chickamauga limestone was named by Hayes 

(1891, p. 142-144). The name replaced tiH term "blue 

limestone group" of Safford, the change, being made 

in conformity with the practice of using geographic 

rather than lithologic names for formations. No type 

section was ever designated or described, but the name 

was taken from the area around South Chickamauga 

Creek in southeastern Tennessee and northwestern 

Georgia. As originally denned the formation included 

all limestone above the Knox dolomite and beneath the 

Sevier shale (which at that time was extended to include the Martinsburg and Reedsville shales), and in 

this sense it was used in all the folios of the southern 

Appalachian region, beginning with Hayes (1894) and 

ending with Butts (1910).

The Chickamauga limestone, as mapped in the folios, 

included the equivalents of the Kingsport and Mascot 

formations of this report in those areas IE southeastern 

Tennessee, northwestern Georgia, and northeastern 

Alabama where they are represented by the Newala 

limestone (Butts and Gildersleeve, 1948, p. 19). With 

the close of the folio mapping in the Appalachian 

region the name Chickamauga fell into disuse, but it 

has recently been revived as a convenient general term 

by Roclgers (1953). In reviving the name, he has removed from it all beds known to be equivalent to strata 

of the Knox group, so that as now define! the unit includes limestone strata of Middle and Late Ordovician 

age. The unit is thinnest along the southeastern edge 

of the Valley where it represents a very short span of 

time; it is thickest in the sections near the Cumberland 

Plateau front where it represents practically all of 

Middle and Late Ordovician time.

About 1900 Ulrich began dividing the Chickamauga 

limestone into a number of formations. Some of these 

were described in the Revision of the Paleozoic Systems 

(Ulrich, 1911, pi. 27); others appeared only as names 

in correlation charts; and others were simply names 

used in notebooks and unpublished manuscripts.^ Only 

a few were ever adequately described, and still fewer 

have been mapped in detail over any considerable area.

In making these subdivisions Ulrich v^as influenced 

by several ideas. He believed that sedimentation during this period took place in a number of parallel 

troughs, an idea he took from Safford (18C9, p, 229-239) 

and greatly elaborated and expanded. He believed that
STRATIGRAPHY 57

these troughs were at times connected and at other 

times separate basins of sedimentation, and that some 

were dry or receiving terrestrial sediments while others 

were submerged. His units were based on specific 

faunas and lithology, for he had no concept of the lateral gradation of formations. These views seemed especially plausible because of the peculiar structural pattern of the region, for the formations in any structural 

belt may be quite different from those in adjoining 

belts, as a result of shortening by the thrusting of one 

belt over another.

Ulrich's general concept of the stratigraphy of the 

Chickamauga limestone is given in his Revision (Ulrich, 

1911); later it was more fully elaborated by Butts 

(1928) and by Ulrich himself (1930). In general 

Ulrich believed that the strata included in the Chickamauga group consisted of a few widely distributed 

formations at the base, correlating with formations of 

Ghazy age elsewhere; other widely distributed formations at the top, correlating with formations of Black 

River or later age elsewhere; and a great thickness of 

strata in between not equivalent to any formations elsewhere, the so-called Blount group, wedged in the middle 

between the Chazy and Black River beds (Butts, 1928, 

fig. 2). No complete section of the Blount group has 

ever been found, and at present the idea that such a unit 

exists, intermediate in age between the Chazy and Black 

River and represented only in, the southern Appalachians, has been completely discarded.

The present theory is that there is a thick limestone 

sequence, the Chickamauga limestone, developed in the 

central and western parts of the Valley of East 

Tennessee and adjacent States, and that this grades 

laterally southeastward into a complementary shale and 

sandstone sequence, the Sevier shale and higher formations, developed along the southeastern side of the 

Valley. The two sequences intertongue in a central belt, 

and by the close of Middle Ordovician time shale deposition had lapped westward almost completely across 

the Valley. No complete statement of the details of 

Chickamauga stratigraphy can be given here, as they 

are in the course of being worked out by G. A. Cooper, 

B. N. Cooper, R. B. Neuman, and many others.

In the Mascot-Jefferson City district, the Chickamauga limestone—the Middle Ordovician limestone sequence—is made up of three units originally classed as 

separate formations. These are, in ascending order, 

the Mosheim limestone, the Lenoir limestone, and the 

Holston marble. These were all considered as distinct 

formations by Ulrich, Butts, and many others, including the writer, and are so shown on the map of the district published in 1945 (Bridge, 1945). The boundaries 

between them are rarely sharp and distinct, however,

and the units commonly intergrade laterally. The 

Mosheim is best regarded as a member of the Lenoir 

limestone; it is considered separately below. Th«, name 

Holston has been indiscriminately applied to the first 

marble (that is, coarsely crystalline pink or gray limestone that will take a polish) beds above the Lenoir in 

all parts of the Appalachian Valley, but it is by no 

means certain that all the beds so mapped represent a 

continuous unit, or that the top of the Lenoir t;°jieatli 

is everywhere the same. In fact, the preponderance of 

evidence would indicate otherwise. 

. The areas underlain by the Lenoir and Holston are 

normally characterized by gently rolling topography. 

Sinkholes are locally abundant, and in such places surface drainage lines are poorly developed. Cedar glades 

are practically limited to the outcrop of these limestones.

UNCONFORMITY AT BASE OF LENOIR LIMESTONE

The contact between the Knox group and th?- overlying Middle Ordovician units in East Tennessee is 

marked by a surface of unconformity or, better, disconformity, which is inconspicuous at many localities 

but which actually extends far beyond the boundaries 

of the State and marks one of the most widespread 

interruptions in deposition during Paleozoic time in 

eastern and central North America.

In general, throughout East Tennessee the uppermost 

formation of the Knox group is the Mascot dc^omite, 

and the writer knows of no place within the State where 

this formation has been completely removed l N y preMiddle Ordovician erosion, though such places may 

exist. Such erosion has occurred locally, however, in 

Alabama, Georgia, and Virginia, and in those States 

Middle Ordovician rocks are known to rest on various 

older formations down to the Chepultepec dolomite— 

and possibly in Alabama even the Copper Ridge dolomite (Butts, 1926, p. 115, 117; Cooper, 1944, p. 33-34; 

Butts and Gildersleeve, 1948, p. 20). In other parts of 

Virginia, the reverse may be true, for fossils collected 

in Warm Springs Valley, near Healing Springs, suggest the presence of a Lower Ordovician formation of 

post-Mascot age. Similarly the Odenville limestone of 

Alabama (Butts, 1926, p. 99) appears to be Early Ordovician but post-Mascot.

Within the Mascot-Jefferson City district, the Mascot 

dolomite is overlain by the Mosheim member of the 

Lenoir limestone or, where this is locally wanting, by 

the typical Lenoir limestone itself. The contact is 

rarely well exposed, but it can commonly be located 

within a distance of a few feet. At most places, even 

where clearly exposed, it could easily be taken for a 

conformable contact. It is normally marked by an 

abrupt transition from dolomite beneath to limestone
58 STRATIGRAPHY OP THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

above, but the upper part of the Mascot dolomite may | 

contain individual limestone beds as much as 6 feet 

thick, and at a few places these beds coalesce to make 

up the greater portion of the upper part of that formation. These limestones are lithologically similar to 

those in the overlying Mosheim member, and, where the 

two are in contact, the boundary may be difficult to 

locate. Often it can be located because abundant minute clear bits of calcite are present in the Mosheim 

but absent in the limestone in the Mascot. In other 

parts of East Tennessee the contact is further obscured 

by earthy clolomitic beds at the base of the Middle Ordovician, but these have not been found in the MascotJefferson City district.

A fair section across the contact is exposed on the 

south side of the 1,240-foot knob 0.8 mile southeast of 

Hodges Station in the New Market quadrangle. Here 

the upper beds of the Mascot dolomite are dominantly 

limestone and seemingly grade upward into the lithologically similar beds assigned to the Mosheim member 

of the Lenoir limestone. The chief distinction here is 

the presence or absence of the small clear calcite crystals 

believed to characterize the Mosheim.

A few localities show definite evidence of unconformity. At the mouth of Legg Creek in the John 

Sevier quadrangle, just west of McMillan Station between the Southern Railway and the Holston River, 

small outcrops of the basal limestone of the Mosheim 

member containing angular fragments of chert as much 

as 2 inches in diameter, clearly derived from the weathering of the Mascot dolomite, are exposed in the bed 

of the creek. The top of the Mascot dolomite is also 

exposed a few feet farther upstream, though the actual 

contact was not observed.

The contact is cleanly exposed in a cut on the Mascot 

road, at the crest of the slope about 0.65 mile west of 

the underpass beneath the Southern Railway about 

1 mile west of Strawberry Plains, in the Mascot quadrangle. Slight irregularities in the contact can be detected, and the lower beds of the Mosheim member 

contain a conglomerate composed chiefly of small pebbles and fragments of dolomite, most of them less than 

0.5 inch in diameter.

Chert conglomerate in the base of the Mosheim member, just like that found at McMillan Station, is exposed 

in the bed of a small tributary of Lewis Branch where 

it crosses the county road 1.5 miles north of the intersection of this road with old U. S. Highway 11-E just west 

of Friends Station, in the northwestern part of the New 

Market quadrangle.

A fourth locality for basal conglomerate was uncovered during construction of the new U. S. Highway

11-E 22 about 0.6 mile southwest of its intersection with 

the road leading south from Friends Station. The 

exposure is in the ditch on the south side of the highway, 

0.15 mile south of BM TGS 112 (1,033 fe^t), and consists of a deep-red hematitic clay containing small pebbles and fragments of chert. The actual contact is 

not exposed, but Mascot dolomite dipping gently southeast is exposed in the fields north of the Hghway, and 

conglomeratic red and gray limestone in the Mosheim 

member is exposed at the base of the hill just south 

of the highway. The sequence is normal and there is no 

doubt of the position of the conglomerate.

These are the most conspicuous examples that were 

found during the detailed mapping of the district; 

doubtless there are others that were overlooked.

The most striking physical evidence of this unconformity in East Tennessee has been found at Douglas 

Lake, about 10 miles south of the Mas cot-Jefferson 

City district. During the construction of the dam, 

an Ordovician sinkhole, 60 by 90 feet in plan and 150 

feet deep, was encountered. This sink was filled with 

volcanic ash and shaly dolomite unlike any other rock 

in the region (Laurence, 1944; Caster, 1944). The contact of the Mascot dolomite and the Lenoir limestone 

is well exposed along the north shore of the reservoir 

at low stages of the lake (Bridge, 1955). In an area 

about a mile long, the relief on the surf aco of the Mascot dolomite measures at least 140 feet. There are also 

two sinks, each about 50 feet deep, filled in part by 

debris from the Mascot dolomite. This old surface is 

generally covered by impure dark-gray to black dolomite, locally as much as 50 feet thick, thr.t grades upward into typical, nodular Lenoir limestone. In places 

the dolomite is absent, but, where present, it fills channels, sinks, and solution cavities along jcmt and bedding planes in the Mascot dolomite, some of which 

extend to depths of 50 to 60 feet below the old surface. 

The lower beds are conglomeratic, containing angular 

and rounded bits of chert and dolomite and weathered 

chert nodules, all derived from the weatl ?-ring of the 

Mascot dolomite, in a matrix of fine-grained dolomite. 

The conglomerate is thickest and coarsest in the large 

depressions on the upper surface of the Mascot dolomite; it becomes fine grained and thins to extinction 

on the intervening high areas. Where the dolomite is 

absent and the basal beds of the characteristic nodular 

Lenoir limestone overlap onto the Mascot dolomite, 

they are also finely conglomeratic; elsewhere within 

this area no conglomerate was seen above the dolomite.

82 In 1950, U. S. Highway 11-E was completely relocated, beginning 

0.5 mile west of the junction of the old highway with U. S. Highway 70 

on the Mascot quadrangle and extending eastward across the remainder 

of the mapped area.
STRATIGRAPHY 59

Filled channels on the eroded surface of the Mascot 

dolomite have been mapped and discussed by Rodgers 

(1943) and Rodgers and Kent (1948, p. 32) on the 

south side of Copper Ridge, Grainger and Hancock 

Counties. One of these, near Shiloh School (Pressmens Home quadrangle), indicates a relief of nearly 

200 feet on the surface of the Mascot dolomite. What 

are believed to be similar occurrences have been mentioned by Keith (1901, p. 2; 1905, p. 8) in East Tennessee, by Campbell (1894, p. 2) and by Cooper (1944, 

p. 33) in southwest Virginia, and by Munyan (1951, 

p. 54-59) in Georgia, but they have not been investigated by the writer. These widely scattered occurrences show that the disconf ormity extends throughout 

the region.

Within the Mascot-Jefferson City district there is 

also indirect evidence of unconformity, based entirely 

on the presence or absence of certain f aunal zones. In 

the western part of the Mascot belt, C'eratopea ankylosa Cullison has been found at two localities, one near 

John Sevier Station, the other on the Mascot farm of 

the American Zinc Co. At the present writing (1953), 

it has been found only at two other localities in East 

Tennessee, one just north of Lickskillet in the Maynardville quadrangle, the other on the north shore of 

Douglas Lake in the western part of the area described 

above. At all four localities it occurs within a few feet 

of the top of the Mascot dolomite. At Douglas Lake 

the beds carrying this fossil are cut off by the unconformity, and this truncation can be clearly demonstrated.

Because of the intensive study that the Mascot-Jefferson City district has been given not only by the 

writer but by some of his associates on the Geological 

Survey and by geologists employed by the various zinc 

companies, the failure to find this fossil elsewhere 

within the area suggests very strongly that the beds 

carrying it were removed by erosion from most of the 

region before the deposition of the Middle Ordoviciaii 

rocks.

LENOIR LIMESTONE

The Lenoir limestone was named by Safford and 

Killebrew (1876) from Lenoir City, Loudon County, 

Tenn.; the beds so named had previously been called 

the Blue or Maclurea limestone by Safford (1869, p. 

232-233). Plate SF is a sketch map of the area 

around Lenoir City, based on a manuscript map prepared by J. C. Dunlap and P. P. Fox for the Geologic 

Division of the Tennessee Valley Authority, and kindly 

lent to the writer by Berlen C. Moneymaker, chief of 

the Division.

In the Mascot-Jefferson City district, the lower part 

of the Lenoir limestone has been separately mapped as 

the Mosheim member.

MOSHEIM MEMBER

The Mosheim, considered in this report to be a brsal 

member of the Lenoir limestone, was named from Mosheim, a small village on the Southern Railway about 7 

miles west of Greeiieville, Greene County, Tenn. (Ulrich, 1911). No type section was ever published, bu* in 

1933 Ulrich took the writer to a cut on the Southern 

Railway about 1 mile southwest of Mosheim and stated 

that the exposures in this cut were the type section. 

This area has been mapped by J. C. Dunlap (Dunlap 

and Rodgers, 1945), and the sketch map, plate 3Z>, 

has been compiled from his map with additions and 

details by the writer. At this locality, the beds strike 

N. 65°-70° E. and dip about 55° SE. The strike of the 

railway cut is almost parallel to that of the beds, so 

that the belt of outcrop crosses the cut very gradually 

and the same units are exposed for long distances along 

its walls. The Middle Ordovician limestones are very 

thin at this point, measuring only about 180 feet across 

the outcrop from the base of the Athens shale to the 

top of the Mascot dolomite and having a calculated 

thickness of slightly less than 150 feet. Forming the 

basal member of the Athens shale is 30 to 35 feet of 

moderately crystalline compact dark-blue limestone, 

which crops out in conspicuous ledges on the hills 

south of the railway cut and especially toward the 

western edge of the cut. This limestone is underlain 

by 5 to 10 feet of thin irregularly bedded shaly noiular blue limestone, which grades laterally into and is 

underlain in turn by 100 to 110 feet of thick-bedded 

very fine grained to aphanitic light-blue limestone, v^ell 

exposed along the south wall of the railway cut. 'T'he 

base of this unit is concealed, but it evidently rests upon 

a series of alternating fine-grained gray dolomites and 

fine-grained somewhat nodular blue limestones, which 

are exposed in the north wall of the cut. The compact 

crystalline limestones represent the Whitesburg limestone of Ulrich (1930, p. 2, footnote), the 5 to 10 feet 

of shaly nodular limestone appears to be typical Leroir 

limestone, and the massive aphanitic limestones are the 

Mosheim member, whereas the alternating dolomite 

and limestone beds represent the top of the Mascot 

dolomite. Strata near the base of the Athens shale are 

exposed in the road crossing the railway at the eastern 

end of the cut about 50 feet south of the tracks, and the 

compact limestone believed to represent the Whitesburg 

cross the cut about 300 feet west of this road crossing. 

No Mosheim appears on the north wall of the cut, the 

space where it should appear being covered. The ex-
60 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

posures in the cut are about 0.25 mile long and the top 

of the Mascot apparently crosses the tracks about 0.4 

mile west of the road crossing at the eastern end. To 

the west of the cut, the aphanitic limestone of the 

Mosheim intertongues with the typical nodular limestone of the Lenoir.

In the Mascot-Jefferson City district, the Mosheim 

member occurs in all three belts and commonly intervenes between the Mascot dolomite and the typical 

Lenoir limestone. Locally, however, it is absent—for 

example, in much of the area south of Friends Station 

and on the south side of the small knob of Mascot dolomite between the highway bridge and Mascot. In these 

areas it seems to have been overlapped by the typical 

Lenoir on an uneven surface of Mascot dolomite. Locally, as for example on the north side of this same 

knob, it is replaced by a crystalline limestome which 

at places is red and resembles the Holston marble.

At two other localities, both of them on the west side 

of the Strawberry Plains basin, coarsely crystalline red 

fossiliforous limestone, closely resembling the coarser 

and darker phases of the Holston marble, crops out 

where the Mosheim member should occur. The larger 

of these two areas begins in the woods just west of the 

American Limestone Co.'s quarry on Holston River 

just north of the Southern Railway bridge and extends 

in a southwesterly direction to within about 100 yards 

of the county road on the north side of the Holston 

River. The other outcrop is about a mile to the northwest, just west of the north-south road that connects 

the county road just mentioned with U. S. Highway 

11-W. In both localities these beds rest on the Mascot 

dolomite and are overlain by typical nodular Lenoir 

limestone. Although the evidence is by no means conclusive, there is apparently a lateral gradation from 

typical aphanitic limestone of the Mosheim to red crystalline limestone in the woods west of the limestone 

quarry on Holston River.

At other localities coarsely crystalline limestone replacing the Mosheim is gray and resembles the basal 

beds in the type section of the Lenoir limestone at Lenoir 

City.

The distribution of the Mosheim member through the 

Appalachian Valley is at present uncertain. Ulrich 

(1911, p. 544) and Butts believed it to be widespread 

and they identified it in all belts from southeast to northwest and from Alabama far into Virginia. Actually 

they were applying the name Mosheim to the lowest 

fine grained lithographic limestone in the Middle Ordoyician section. It is now known that the beds called 

Mosheim in the western belts are much younger than

the true Mosheim of the central part of the Valley, and 

it is believed that the true Mosheim does not extend 

northwest of Clinch Mountain, but knowledge of its 

exact distribution will have to await the results of detailed studies now in progress.

The Mosheim member is composed cf thick-bedded 

very pure structureless light-pearl-gray or bluish-gray 

limestone, a typical lime-mudstone or calcilutite. It 

somewhat resembles the limestone of the Kingsport and 

Mascot formations, especially on weathered surfaces, 

but it lacks the crinkly shale partings that characterize 

the Kingsport limestone. In addition, the Mosheim is 

much bluer, locally almost black, although this dark 

phase is rare in the Mascot region. An additional peculiarity of the formation, and one which is a ready means 

of identification, is the abundance of very small crystals 

of clear calcite scattered through the aphanitic groundmass. The rock weathers to a deep-red clay and develops no chert. Weathered surfaces are either rounded 

or subpyramidal and are commonly radially fluted. 

This fluted weathering has also been seer on outcrops of 

the limestones in the Mascot and Kingsport formations, 

and it seems to be characteristic of the weathering of 

these aphanitic limestones.

LENOIR LIMESTONE EXCLUSIVE OF MOSH7IM MEMBER

The typical limestone of the Lenoir is composed of 

thick- to thin-bedded irregularly bedded to nodular finegrained dark-blue to bluish-black limestone. Weathered surfaces are lighter bluish in color, and in weathering the rock commonly breaks up into small irregularly rounded nodules. The residual soils developed on 

the Lenoir limestone, including its Mosheim member, 

are a deep maroon red, similar to those on the overlying 

Holston marble.

In the Mascot-Jefferson City district, the Lenoir 

limestone exclusive of the Mosheim member is rarely 

more than 250 feet thick.

The index fossil of the Lenoir limestone is the large 

gastropod Maclurites magnus Lesueur. In the MascotJefferson City district it is abundant r-t many localities, one of the best being the outcrops r,bout 31/2 miles 

due south of New Market. Average specimens are 3 

to 4 inches in diameter, but individuals as much as 8 

inches across have been found. A number of smaller 

and less conspicuous gastropods are associated with 

Maclurites, and certain other beds are crowded with 

poorly preserved sponges.

[Bridge left no material describing the hig-her stratigraphic 

units of the Mascot-Jefferson City district—the Holston marble, 

the Tellico sandstone, and the Ottosee shale.]
STRUCTURE 61

STRUCTURE 

APPALACHIAN VALLEY

The major structural features of the Appalachian 

Valley have been described in many reports and only a 

brief discussion need be given here. The Valley in 

East Tennessee is a portion of a belt of faulted and 

folded Paleozoic rocks which extends from northern 

Alabama and Georgia through East Tennessee into 

Virginia and on to the northeast.. The rocks exposed in 

the Valley range from Early Cambrian to early Pennsylvanian in age, and the proportion of rocks belonging 

to each period varies greatly in different parts of the 

Valley. Cambrian and Ordovician rocks predominate 

in the Valley in East Tennessee.

In East Tennessee the Valley is from 40 to 60 miles 

wide; it is bounded on the east by the major low-angle 

thrust faults of the Unaka and Great Smoky Mountains and on the west by the great east-facing escarpment of the Cumberland Plateau, beyond which the 

strata lie virtually flat. Its boundaries are thus determined by major structural features. Within the Valley 

itself, the outstanding structural features are a series 

of subparallel southeast-dipping thrust faults, which 

may be traced for long distances, and which divide the 

Valley into narrow, linear belts, each of which repeats, 

in general, the stratigraphic succession in the adjacent 

belts. The structure in most of these belts is homoclinal, and the prevailing dip is to the southeast. Anticlines and synclines are locally developed and may be 

the dominant structure in a given belt or portion of a 

belt, but in East Tennessee such structures are not as 

abundant as homoclines. Where developed, the axes 

of the anticlines and synclines are, in most places, 

roughly parallel to the thrust faults. This repetition 

of formational sequences of different degrees of resistance to erosion by folding and faulting is responsible 

for the peculiar and distinctive valley and ridge topography and the attendant trellis drainage that characterize the Appalachian Valley.

As noted above (p. 7, pi. 2), the Mascot-Jefferson 

City area includes three of these narrow, linear belts, 

here termed the Mascot, Jefferson City, and Shields 

Ridge belts. These belts strike northeast, and each extends beyond the limits of the area mapped. Each is 

a portion of a fault block that has been thrust out upon 

the block lying to the northwest of it. The faults forming the boundaries of these belts are here called (in 

order from northwest to southeast) the Saltville,23 

Mill Spring, Rocky Valley,23 and Dumplin Valley 

faults.

88 On the geologic map and sections published in 1945 (Bridge, 1945), 

the Saltville fault Is called the Rlchland fault, and the Rocky Valley 

fault Is called the Bays Mountain fault. See footnote, p. 6. 

339223—55———5

MASCOT BELT

The Mascot belt is the northwesterly of the three 

belts. It is a portion of a major thrust slice that can 

be traced as a narrow continuous zone across the State. 

Beginning at the Tennessee-Georgia line this slice 

passes northward through Cleveland and swings northeasterly through Loudon, the northwestern portion of 

Knoxville, and Mascot. Throughout this entire distance of about 110 miles it averages about 2.5 miles in 

width; the rocks are homoclinal, and dip to the southeast. A short distance east of Mascot the belt logins 

to widen, reaching a maximum width of about 8 miles 

in the area northwest of Jefferson City, changing from 

a homocline to a shallow syncline, pitching southwest. 

Northeast of Mooresburg (pi. 2) the belt again becomes 

narrow but continues northeastward as a distinct structural unit at least to the Virginia-Tennessee linQ.. In 

this section the principal structure is again homoclinal 

with the prevailing dip to the southeast; there are, however, many minor structural irregularities.

Only that small portion of the Mascot belt extending 

from the northeastern city limits of Knoxville to the 

vicinity of Mill Spring is shown on the geologic map 

accompanying this report.

The northwestern edge of the Mascot belt is bounded 

by the trace of a major overthrust, which extends without interruption across the State. This is the Saltville 

fault, named for Saltville, Va., where it was earJy recognized by Lesley (1862, p. 33) and named by Stevenson 

(1887, p. 265). In the present study, this fault ha-* been 

mapped only on the John Sevier quadrangle in the extreme western part of the area, between Loves Creek 

and Strong Creek, but its general course is shown on 

plate 2 and on the geologic map of the Maynardville 

folio (Keith, 1901). The average dip of the fault plane 

in the area mapped is about 40° southeast.

Immediately northwest of the trace of the Saltville 

fault in this same general area are two small fault slices 

or slivers, which are clearly related to it. Only the 

southeastern one is shown on the accompanying- map, 

but both are shown on the geologic map in the Maynardville folio (Keith, 1901). They are bounded along 

their northwest edges by small thrust faults th^t are 

presumably offshoots of the Saltville fault.

The southeastern fault diverges from the mair fault 

just west of Woods Creek and rejoins it between Strong 

and Roseberry Creeks. The sliver included between 

this and the main thrust is a block of Nolichucky shale 

and the overlying Maynardville limestone member and 

not Knox dolomite as shown by Keith.24

» On the 1945 map the dotted line connecting the northern end of 

this fault with the main fault along the 05' parallel Is a printer's line 

used to delimit the color pattern and should have been removed before 

the edition was printed.
62 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

The northwestern fault diverges from the Saltville 

fault about 2 miles west of Loves Creek and encircles 

the southeastern one. It encloses a block composed almost entirely of Copper Ridge dolomite. It was not 

mapped during this study, but its trace is believed, to 

lie in the valley of Murphy Creek, and, according to 

Keith, it also rejoins or passes beneath the main Saltville thrust in the area between Strong and Roseberry 

Creeks.

The structure of the Mascot belt within the mapped 

area is comparatively simple. From Loves Creek at 

the western edge of the mapped area to Mascot, the 

belt is narrow and the strata strike N. 60°-65° E. and 

dip southeast, the average dip ranging from 50° at 

Loves Creek to 25° along Flat Creek at Mascot. The 

creeks that cross the belt between these limits expose 

the best and most complete sections of the Knox group 

within the mapped area.

Two tear faults displace the Maryville limestone 

along this belt near the west edge of the mapped area, 

and, though they have not been traced above the base 

of the Nolichucky shale, it is possible that the dolomite 

in the Knox group has been shattered in these areas 

by the same forces that produced the tear faults. It is 

noteworthy that both strike directly towards gaps in 

the topographic ridge underlain by the Copper Ridge 

dolomite. They also strike toward notches or gaps in 

the ridge to the northwest formed by the Rome formation; in fact, the one in the vicinity of Bethlehem 

Church may actually go through the gap. Both tear 

faults strike northwest obliquely to the strike of the 

rocks, and the southwest side of each has moved relatively northwest; in these respects they resemble many 

other tear faults in East Tennessee, for example, those 

in the Copper Ridge zinc district (Rodgers, 1943).

Near Mascot, the strike of the formations swings 

from N. 60° E. to N. 35° E. In the pre-Knox formations the swing is gradual, but in the formations of 

the Knox group, especially those near the top, the swing 

is fairly abrupt and forms a blunt anticlinal nose 

plunging southeast about a mile east of Mascot, close 

to the eastern end of the mine workings.

Northeast of Mascot the.strike remains N. 35° E. 

and the dip is 20° to 30° SE. as far as Richland (Ada 

011 the Maynardville 30-minute quadrangle); no irregularities are known. Near Richland, however, the structure changes considerably. The formation from the 

Nolichucky shale down continue northeastward along 

Richland Valley with little change in strike or dip, but 

the formations above the Chepultepec swing abruptly 

east and southeast through 90° around a synclinal mass 

of Ottosee shale centering in the unmapped area northeast of Strawberry Plains. This synclinal structure is

here called the Strawberry Plains basin. Beyond this 

swing, the formations between the Ottosee and the 

Chepultepec strike about S. 65° E. and dip 10° to 

25° SW., until they pass beneath the Mill Spring fault 

that forms the northern edge of the Jefferson City belt. 

Between these diverging strike belts, the intervening 

formations flatten out into a broad and slipllow syncline 

in which few dips exceed 10° and most are less than 5°. 

This syncline contains some minor folds and small 

faults. It plunges gently southwest toward the Strawberry Plains basin of which it is the northeastern continuation. To the northeast it extends for some miles 

beyond the limits of the map. For the most part it 

includes nearly horizontal strata belonging to the 

Copper Ridge dolomite, though some of th?, higher hills, 

especially along the southeastern limb, are capped by 

remnants of the Chepultepec and Longvi°.w dolomites.

JEPFEBS01T CITY BELT

The Jefferson City belt is part of a thrust slice that 

can be traced from Strawberry Plains r ortheastward 

beyond the area mapped. To the southwest it seems to 

merge with the Mascot belt in the vicinity of Mascot, 

because of the dying out of the Mill Spring fault, which 

in this area forms the boundary between these two belts. 

The displacement along this fault diminishes in a southwesterly direction; the fault itself has not been traced 

beyond the general vicinity of Mascot.

The Mill Spring fault is named for Mill Spring, a 

small settlement in the southeastern part of the Joppa 

quadrangle, about 3 miles northwest of Jefferson City. 

It is a minor thrust fault which emerges from the eastern side of the Strawberry Plains basin about 1.25 miles 

north of East Hodges Station and has be^n traced in a 

northeasterly direction through Mill Spring to the 

northern edge of the map. It has not been traced beyond this point; it is believed to die out in the long, 

shallow syncline that forms the northeast extension of 

the Strawberry Plains basin. The trace of this fault 

can be readily observed along both side? of the road 

leading north from U. S. Highway 11-E to Nances 

Grove Church. The fault has not been napped to the 

southwest across the central part of th°> Strawberry 

Plains basin, because this structure is filled with a mass 

of structurally complex Ottosee shale, th^ mapping of 

which was not a part of the project. In g.ll probability 

it does cross this unmapped area and connects with one 

of the faults shown emerging from the southwest side 

of the basin.

The surface evidence for the faults on the southwest 

side of the basin is well shown along both sides of the 

county road, about 1.5 miles east of Mascot, that connects the Mascot-Strawberry Plains road with U. S.
STRUCTURE 63

Highway 11-W, along Holston Kiver on the west side 

of Big Bend, and along the road in Big Bend. The 

general trend of the faults was established by these observations, and the projection to the southwest through 

the Mascot mine of at least the northern fault coincides, 

according to Harley M. Coy (personal communication, 

1940), with zones of extensive shattering in the mine 

which have permitted extensive leakage in the past from 

both Big Flat and Eoseberry Creeks. This fault may 

continue to the southwest beyond the mine and eventually die out in the thick mass of Lenoir limestone between Mascot and John Sevier.

None of these faults was recognized by Keith (1901) 

in his mapping of the Maynardville quadrangle, but 

the course of the Mill Spring thrust across the Strawberry Plains basin is indicated on his map by sharp 

zigzags in the formation boundaries on both sides of 

the basin.

The relatively straight traces of the faults in the 

area to the southwest of the Strawberry Plains basin 

would seem to indicate that the fault planes dip at 

comparatively steep angles. The small amount of offset of formation boundaries suggests that the amount 

of displacement is relatively slight (pi. 1, sections 

E-E',F-F' and #-#').

On the eastern side of the Strawberry Plains basin 

the fault plane dips at a much lower angle, as is shown 

on the map by the sinuous trace of the fault in the vicinity of the Nances Grove Church road. Further confirmation of the low dip of the fault plane in this area 

is to be found in the logs of certain drill holes put down 

many years ago by the American Zinc Co. According 

to M. H. Newman (personal communication, 1929), 

these holes were drilled in the fields adjacent to the 

road south from Nances Grove Church, about 0.25 

mile south of the outcrop of the fault. They started 

in the Mascot dolomite and passed through the fault 

plane into Lenoir limestone within a few hundred feet 

of the surface.

For 3 to 4 miles northeast of a point about a mile 

east of the Nances Grove Church road, the trace of the 

Mill Spring fault is only approximately located. This 

is partly because of lack of outcrops and also partly because much of the area through which this portion of the 

fault passes has been under cultivation for many years, 

so that large quantities of the residual chert boulders 

have been removed from the fields by successive generations of farmers. Further evidence for the approximate 

position of the fault is found in the large blocks of 

sandstone, from high in the Copper Eidge dolomite, 

in cuts along the road 2.25 to 2.5 miles east of Nances 

Grove Church, and in the abundance of Copper Eidge 

residuum on the northwest slope of a wooded hill

about 0.5 mile north of this point. Still farther northeast, in the vicinity of Mill Spring, the evidence for 

the fault becomes much more definite, and displacement of strata caused by it can be seen in the low bluff 

on the southwest side of Holston Eiver about 1 mile 

northwest (downstream) of Cherokee Dam, and also 

in the riverbed when the water is low. At this point 

the fault plane dips steeply southeast and the displacement is small. Both of these features suggest that it 

is dying out to the northeast. Hence in this direction 

also the Jefferson City belt merges with the Mascot 

belt.

The structure of the Jefferson City belt is dominated 

by the large anticline lying just southeast of the Cherokee Dam, here called the Cherokee anticline. Tte axis 

of this fold strikes N. 40° E. near the dam and extends 

in this direction for 10 miles or more to the northeast. 

The northeastern part of this fold lies beyord the 

boundaries of the map and was not studied in the preparation of this report. It is fairly well shown, however, 

by the mapping of the Cambrian formations on tH geologic map of the Morristown folio (Keith, 1896). The 

axial part of this fold, including most of the exposures 

of the Nolichucky shale and all those of the formations 

beneath it, is now submerged beneath Cherokee Lake. 

To the southwest of Cherokee Dam the axis of tt^ fold 

turns more nearly south, and the anticline plunges 

southward, passes between the towns of Jefferson City 

and New Market, and heads into the large reentrant in 

the trace of the Eocky Valley fault between T'omas 

and Koppick Knobs. Near the dam the dips on the 

flanks of the fold range from 15° to 30°, but farther 

south the dip is much more gentle, rarely exceeding 10° 

as each formation of the Knox group swings around the 

plunging nose of the anticline.

West of the south-plunging portion of the Cherokee 

anticline is a broad, shallow syncline, plunging south 

past New Market beneath a large projecting mass of 

the Eocky Valley thrust block, and broken by minor 

faults parallel to the axis. On the west limb of this 

syncline the higher formations of the Knox group strike 

S. 70° W. and dip gently south for 2 miles; then the 

strike swings northwest and north around an ant: ?linal 

nose until the rocks are cut off by the Mill Spring fault. 

This nose appears to represent the anticline out of 

which the Mill Spring fault developed.

Farther southwest, extending to and beyond JT^rawberry Plains, is an area of complex structure lying between the Strawberry Plains basin and the Eocky 

Valley fault. This area has not been completely 

mapped because it involves chiefly beds younger than 

the Knox group and therefore was not relevant to the 

project. The structure of the narrow central p<vrt of
64 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

this area, where the Strawberry Plains basin and the 

Rocky Valley fault come closest together, seems to be 

a succession of thrust slivers, but at the ends of the belt 

the structure is more open and includes two small domical uplifts: one in the Lower Bend of Holston Eiver 

west of Strawberry Plains, the other between the 

valleys of Beaver Creek and Lost Creek south of East 

Hodges.

These domes, though minor, are among the most unusual structural features of the region. They do not 

seem to be directly related to any of the major structural features of the area but are a part of the highly 

irregular fold pattern developed in the Jefferson City 

block. Possibly they are complementary to the deep 

Strawberry Plains basin that lies just north of and between them, though it is presumably cut by the Mill 

Spring fault and more of it is on the Mascot block than 

on the Jefferson City block. The two domes expose 

strata of the upper Mascot dolomite in their centers and 

show gentle quaquaversal dips both in the Mascot and 

in the overlying and surrounding formations.

The western dome is elongated east and west, and its 

main crest is on the summit of a low grass-covered hill 

rising about 80 feet above the surrounding country and 

composed entirely of the Mascot dolomite. A minor 

crest about 0.75 mile to the east appears on the map to 

be larger than it actually is because of the Holston 

quarry excavated in its center.

The structural center of the East Hodges dome is 

eccentric to the area of outcrop of the Mascot dolomite 

and to the topography. It is about 0.5 mile due south 

of East Hodges in the northwest corner of the Mascot 

outcrop area. To the southeast is a hill more than 250 

feet high composed of Mascot dolomite overlain by the 

Mosheim member and a small thickness of typical 

Lenoir limestone and capped by a small klippe of 

residual chert from the Copper Ridge dolomite, a remnant of the Rocky Valley fault.

Both domes clearly owe most of their present structural elevation to the major post-Pennsylvanian period 

of folding (p. 68), but the irregular wedging in and 

out of the encircling Mosheim member and the abrupt 

f acies changes within it (p. 60) suggest that both domes 

may originally have been low hills formed during the 

erosion of the pre-Mosheim surface, standing slightly 

above the general level at the time of Mosheim and 

early Lenoir sedimentation, and that this slight relief 

may have been a significant factor in determining their 

later deformation.

The southeast flank of the Cherokee anticline exhibits 

several marked changes in the strike of the beds exposed 

along it. Between Lost Creek and the southern part 

of Jefferson City the strike of the Kingsport limestone averages N. 50° E.; in the eastern part of Jefferson City it changes to an average of N. 20° E.; and 

about 0.5 mile north of the Southern Railway it swings 

back again to an average of N. 65° E., close to the average regional strike.

In the area east of Jefferson City the Mr.scot formation and the Lenoir formation (including the Mosheim 

member) are deformed in two tightly folded and 

faulted complex synclines. The axes of these folds 

trend approximately N. 60° E., and the folds themselves are asymmetrical, the southeastern limb being 

the steeper, and in places overturned (pi. 1, sections 

Q-Qf and R-R'). The faults associated with them 

are minor thrusts whose strikes roughly parallel the 

fold axes. They are best seen where they cut and 

offset the contacts between the different formations. 

They are difficult to locate and in fact may be entirely 

absorbed in the mass of tightly folded incompetent 

somewhat metamorphosed Lenoir limestone that occupies the center of these synclines.

The western of the two synclinal masses shown on 

the map is bounded along its southeastern side by a 

small but well-defined thrust which dips steeply southeast. Although the trace of this fault has been located 

definitely only in that part of the area wher^ the Mascot 

is thrust onto the Lenoir, it is believed to extend a considerable distance in both directions. To the northeast 

it may connect with the fault shown cutting the Mascot 

dolomite just south of Talbott; to the routhwest it 

probably extends into the highly distur^jed belt of 

Mascot in the valley of Mossy Creek and its most western tributary. North of this is a second steeply dipping 

thrust, presumably of smaller magnitude. This fault 

has been observed to cut all the contacts from the Lenoir 

to the Kingsport, and it may extend westward into the 

pits in the southern part of the old Mossy Creek mine. 

It is known that there are other small thr ist faults in 

this area, but they are all of small displacement and it 

has not been possible to trace them into the formations 

of the Knox group.

In the valley of Mossy Creek and its north-flowing 

tributaries just east and southeast of Jefferson City is 

an area about 2 miles long and a mile wide of extremely 

complex structure that is related to and a continuation 

of the structure just described. This area is underlain 

by the Mascot dolomite, and within it the rocks have 

been strongly deformed and crumpled into a series of 

minor folds, none of which can be traced for any appreciable distance, and whose axes strike in vrrious directions. Many of the folds are roughly parallel to the 

regional strike, but others cut directly acrors it. Minor 

faulting undoubtedly accompanies this folding though 

no faults large enough to show on the map were found.
STRUCTURE 65

Some exposures show obvious evidence of bedding slips. 

The uniform lithologic character of the rock and the 

lack of continuous exposures increase the difficulties 

of interpretation.

Most of these structural features are probably the 

result of crumpling in the synclinal trough between the 

Cherokee and Rocky Valley anticlines during the main 

period of deformation. Subsequently the area has been 

profoundly affected by solution, and it now has a welldeveloped subterranean drainage. The surface shows 

many sinks, and it is reasonable to assume that some of 

the aberrant dips are caused by recent slumping.

Traced toward the southwest the structure tends to 

become more regular and larger and to merge into a 

single strongly compressed and overturned syncline 

whose axis strikes about N. 70° E. This axis is well 

exposed on the crest of the ridge 0.6 mile north of the 

cross roads at Gravelly Hill. If the interpretation of 

structure given on p. 68-69 is correct, the overturned upper strata of the Mascot dolomite in this exposure could 

represent the lower part of the ruptured middle limb 

between this syncline and the Rocky Valley anticline.

Between this outcrop and State Highway 92, many 

oval flattened chert nodules of the type commonly found 

along bedding planes in the dolomite layers of the 

Mascot and Kingsport formations are strewn through 

the soil, especially in the cultivated fields. They have 

clearly weathered from the enclosing dolomites, and 

in this area almost all have been fractured by one or two 

sets of joints, and then have healed so that the nodule 

is as solid as ever. These joints are commonly normal 

to the long axes of the concretions, indicating that they 

are also normal to the bedding planes of the parent 

rock. The various parts of the nodules have been displaced in varying degree along these fractures, giving 

the effect of step faulting in miniature. In some the 

displacement is confined to a single fracture, in others 

it is spread through a zone of fractures, and in still 

others it is distributed over the entire nodule. Fractured nodules similar to those just described have been 

found in residual soils in other areas of intense deformation, notably on the sides of the valley south of the 

Athletic mine in the southeastern edge of Jefferson 

City. They have not been found in place in the unweathered rock.

Another area of complex structure lies in the center 

of Rocky Valley along and east of the New MarketPiedmont road, extending to and perhaps in part hidden 

under the Rocky Valley fault. This area is cut by a 

series of parallel thrust faults of small displacement 

into closely spaced slices, each one partly overlapping 

the slice immediately northwest, and each repeating 

parts of the upper Mascot dolomite and the Lenoir limestone, including its Mosheim member. Some of these 

faults were traced to the Rocky Valley fault under 

which they may disappear, whereas others were lost 

in the incompetent closely folded slightly metamorphosed homogeneous mass of the Lenoir. To the 

northeast they appear to die out in the more competent 

dolomites of the upper Mascot. They may, however, 

continue farther into the Mascot dolomite, and it is 

worthy of note that they trend toward and are in direct 

prolongation of the closely folded and faulted area 

near Jefferson City, described above. Surface mapping 

alone can hardly be expected to show whether the deformation is continuous between these two arens, for 

the uniform lithology of the Mascot dolomite r.nd the 

lack of outcrops in the intervening area make the recognition of shatter zones and faults of small displacement difficult if not impossible.

The structure of the complex area in Eocky Valley 

is too complicated to be shown accurately on tl Q. scale 

of the map accompanying this report; therefore the 

fault pattern shown is to be regarded only as a generalization of the actual structure. In 1944 and 194f, Kent, 

Brokaw, and others commenced detailed planetable 

mapping of this area and of part of the area east of 

Jefferson City and found many additional details too 

small to be shown here.

The several areas of complex structure just described 

strike toward one another and are alined along the 

southeast flank of the Cherokee anticline roughly parallel to the regional strike. Together they form a belt of 

generally synclinal structure in which the rocks are 

tightly compressed and intensely crushed and sliced, 

presumably because they lie just under the Rocl*y Valley thrust fault. This fault is nearly horizontal and 

probably originally passed not more than a few hundred feet over the whole belt of tight folding, which 

represents a zone of drag under it. The difference in 

structure of the several areas reflects the difference in 

competence of the rocks involved.

Between the complex area in Rocky Valley and New 

Market, three more widely spaced faults, all trending 

northeast, displace the strata in the Jefferson City block 

and seem to pass beneath the Shields Ridge block. 

These faults appear to dip more steeply than those in 

Rocky Valley and may be strike-slip faults ins*:ead of 

thrust faults. They are most easily recognized in the 

incompetent beds of the Lenoir limestone and seem to 

die out in the more resistant beds of the Mascot and 

Kingsport formations, but just north of New Market 

the northern fault displaces the chert-matrix sardstone 

at the base of the Mascot dolomite 0.1 mile. Along 

the northern and southern faults, the block on the northwest appears to have moved relatively northeast; along
66 STRATIGRAPHY OP THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

the center fault the displacement is the opposite. Thus 

between the center and northern faults a narrow prism 

of sediments forming the axis of the shallow syncline 

already mentioned (p. 63) has been displaced southwest 

(or up) relative to the limbs.

A similar fault crosses U. S. Highway 11-E 0.5 mile 

east of East Hodges station, and may be seen in the 

railroad cuts and in the fields north of the highway.

SHIELDS RIDGE BELT

The Shields Ridge belt takes its name from Shields 

Ridge, a conspicuous ridge south of Jefferson City. 

The ridge is also locally called Bays Mountain (see 

footnote on p. 6). The belt begins as a distinct topographic and structural feature about 1 mile south of 

Morristown and extends southwestward across much of 

the mapped area to the area south of Strawberry 

Plains, beyond which its continuation is uncertain.

The northern boundary of the Shields Ridge belt is 

marked by the trace of the Rocky Valley fault, a lowangle thrust of considerable magnitude. The general 

course of this fault is shown on the geologic maps of 

the Morristown and Maynardville folios (Keith, 1896, 

1901), but the present work has shown that it was incorrectly located in several places, especially east of 

Jefferson City. The generally low angle of dip (3° 

to 5°) of the fault surface and the well-dissected topography make the fault trace very sinuous in the area 

between Koppick Knob and Strawberry Plains; in 

places on the hills southeast of U. S. Highway 11-E in 

the vicinity of East Hodges, small areas of the overthrust mass have been completely or almost completely 

separated from the main block, forming small klippen 

and semiklippen.

The map accompanying the Maynardville folio 

(Keith, 1901) shows the fault dying out to the west 

about 2 miles southwest of Strawberry Plains. 

Whether the fault actually terminates as shown by the 

folio, continues across the crumpled mass of Ottosee 

(Sevier) shale south of Mascot to join the fault passing 

through Knoxville in the extreme southwest corner of 

the area here mapped, or turns southward and joins a 

fault mapped in the folio south of Trentville and Wooddale, was not determined in the fieldwork for this report.

In tracing this fault for the Morristown folio (Keith, 

1896, map), Keith was evidently misled by the breccias 

in the workings of the old Mossy Creek mine, for the 

fault is drawn north from Koppick Knob through the 

mine, and thence northeastward along the north face 

of Crockett Ridge for about 18 miles. The beds adjacent to this "fault" have been examined at a number of 

localities between Jefferson City and Morristown, and 

in all places a perfectly normal stratigraphic sequence

has been found. Actually the trace of the fault plane 

turns eastward along the north face of Koppick Knob 

and has been traced in a northeasterly direction along 

the northwest slope of the ridge south of Mossy Creek 

to a point south of Talbott. Here the results of surface 

mapping have since been confirmed by drilling. Undoubtedly the fault continues in the direction of Morristown for a considerable distance.

On Koppick Knob itself the upper beds of the Nolichucky shale and its Maynardville limestone member 

rest on the Mascot dolomite. Traced eastward in the 

valley of Lost Creek south of the knob, the I lascot soon 

disappears beneath the floor of the valley, but the Cambrian formations are well exposed in the eroded center 

of the Rocky Valley anticline (p. 67) and extend eastward for about a mile, finally passing beneath the surface a few hundred feet west of the junction of the 

Rocky Valley road and State Highway 92. This is the 

most easterly exposure of these formations in the 

Shields Ridge belt within the mapped arer..

The fault relation of the Maynardville to the Mascot 

is plainly demonstrated on the southwest slope of 

Koppick Knob on the hillside just east of the road fork 

1.2 miles south of the Davis mine and 0.6 mile west of 

the knob. The lower part of this slope is a grassy pasture containing several small outcrops of Mascot dolomite. One of these is a small abandoned cuarry,. now 

largely filled with trash. In 1929, on the v^alls of this 

quarry, Ulrich, Butts, and the writer collected specimens of Ceratopea and a few other fossils characteristic of the Mascot dolomite. Scattered outcrops of the 

Mascot dolomite are found on the hillside above this 

quarry. In the woods just east of the secondary road 

these scattered exposures are replaced by almost continuous outcropping ledges to the summit of the low 

knob 0.25 mile west of the main summit. The lower 

ledges carry white chert and belong to the Mascot 

dolomite; they are succeeded above by a thick series 

of ribboned noncherty limestone belonging to the Maynardville limestone member. These uppe-r beds dip 

gently north and northeast in conformity with the 

structure of the Rocky Valley anticline. In this particular knob, the relation of the Maynardville to the 

Nolichucky shale is somewhat confused by the minor 

fault described on page 67, and the rocks in these exposures have been correlated with the Leno^r limestone 

by some geologists, but mapping to the north and east 

shows that they occupy the normal position of the Maynardville limestone member and their lithology and 

fossils are characteristic of that unit.

For most of the distance between KoppicV Knob and 

the eastern edge of the mapped area the trace of the 

Rocky Valley fault lies between rocks of the Mascot
STRUCTURE 67

dolomite in the Jefferson City block and rocks of all 

the units of the Knox group in regular succession in 

the Shields Ridge block, until near the eastern edge 

of the area the fault lies entirely within the Mascot 

dolomite. Locally, however, the beds below the fault 

are Lenoir limestone in one of the synclines described 

(p. 64). Throughout this stretch of the fault, there 

are very few outcrops above the fault in the Shields 

Ridge block, but outcrops of the Mascot dolomite are 

abundant at many localities in the underlying Jefferson 

City block. Over most of this distance the trace of 

the fault has been mapped chiefly on the character of 

the residual materials and on the general absence of 

outcrops in the Shields Ridge block, supplemented of 

course by the discordances in strikes and dips in those 

few limited areas in which outcrops are found. For 

example, in the area between Koppick Knob and the 

point where the fault trace crosses State Highway 92, 

at a place 0.3 mile north of Gravelly Hill and again 

on the hills northwest of Buffalo Grove Church, the 

trace of the fault is mapped almost entirely on the distribution of residual materials. Gravelly Hill itself 

was undoubtedly so named because of the thick accumulation on its summit of finely broken chert and sandstone blocks from the Copper Ridge dolomite.

About 0.6 mile due north of the crossroad at Gravelly 

Hill the Mascot dolomite is exposed in the axis of the 

tightly folded overturned syncline (p. 65). Less than 

0.1 mile south of these extensive outcrops the north 

face of Gravelly Hill is completely mantled with thick 

Copper Ridge residuum in which no outcrops were 

found. The topographic relations here are such that, 

even with due allowance for creep in the residual materials, the nearly horizontal plane of the Rocky Valley 

thrust must have passed only a few tens of feet above 

the outcrops mentioned.

Similar relations were noted in the creek valley immediately east of Gravelly Hill and at other places between this valley and the eastern edge of the mapped 

area.

The southern boundary of the Shields Ridge belt is 

formed by another thrust fault, the Dumplin Valley 

fault, which begins southeast of Morristown and extends southwestward along or just northwest of Dumplin Valley. This fault marks in general the southeastern limit of the mapped area and was not studied in 

detail.

About 1 mile south of Mount Horeb, a small thrust 

either splits off or emerges from beneath the Dumplin 

Valley fault and extends northeastward approximately parallel to it for about 2.5 miles, dying out half a 

mile northwest of Mt. Vale Church, about 5 miles east

of Jefferson City. The narrow sliver between it and 

the main Dumplin Valley fault repeats a part of the 

Mascot-Lenoir succession.

Just north of Piedmont at the western end of the 

mapped portion of the Dumplin Valley fault, a similar 

thrust fault encloses a block of Copper Ridge dolomite 

north of the main fault. South of this sliver, the s^ructure of the area in the immediate vicinity of Piedmont 

is extremely complex and was not mapped for the present report; it involves chiefly the Cambrian formations 

older than the Knox group.

These small faults and the slivers they enclose are 

similar to those along the Saltville fault (p. 6).

The major structure of the Shields Ridge blo?,k is 

anticlinal. The axis of the anticline strikes about N. 

70° E. and lies just north of Shields Ridge, following in 

general the long dimension of Rocky Valley; it is here 

called the Rocky Valley anticline. The fold is strongly 

asymmetrical; the northeast flank includes vertical and 

even overturned beds, especially to the west, whereas 

the southeast flank is rather gentle and conforms to 

the general pattern of the homoclines in this region. 

The northwest flank of the anticline has been greatly 

eroded, and between Jefferson City and New Market 

erosion has cut back across the crest into the southeast 

flank, creating a great reentrant in the trace of the 

Kocky Valley fault that accommodates the plurging 

end of the Cherokee anticline on the Jefferson City 

block. Farther west a lesser reentrant nearly surrounds the domical uplift on the Jefferson City block 

south of East Hodges.

At each end the Rocky Valley anticline plunges away 

from Rocky Valley. To the east it terminates in a 

simple nose which plunges northeast and can be traced 

as far as the eastern edge of the area mapped. The 

Copper Ridge dolomite swinging around the nose forms 

a conspicuous topographic feature when viewed from 

U. S. Highway 11-E or the hills farther north. A small 

fault, possibly a split from the main thrust fault, offsets the strata of the Maynardville and Copper Pidge 

on the west side of Koppick Knob. Aside f rone this 

minor fault and the downward truncation of the northeastern limb of the fold by the Rocky Valley faul% the 

northeastern end of the Rocky Valley anticline is a 

textbook example of a plunging anticlinal nose.

At the west end, the Rocky Valley anticline is double, the northern anticline being broken by a ninor 

thrust fault that may be a split from the Rocky Valley 

fault. This anticline dies out a mile or so west cf the 

edge of the mapped area, but the southern anticline 

continues southwest as far as the south environs of 

Knoxville.
68 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

MECHANICS OF BOCK STRUCTURE

The Mascot-Jefferson City district is unusual for the 

Appalachian Valley of East Tennessee. Although 

some parts of the district, notably the area west of 

Mascot, exhibit typical homoclinal thrust slices in 

which the rocks all strike northeast and dip southeast, 

most of it is characterized by more irregular structure 

with prominent anticlines and synclines whose axes 

strike in various directions, so that rocks strike northwest nearly as commonly as northeast and dip in all 

directions. There is no strictly comparable area anywhere else in the Valley of East Tennessee.

The district exhibits in general the typical structural 

asymmetry of the Appalachian Valley; that is, the 

thrust faults and the axial planes of the folds (whether 

broken by faults or not) dip to the southeast, but generally speaking the folds are more open than is normal 

in the Valley, and the entire area appears to have been 

less strongly compressed. The best example of an asymmetrical fold in this area is the Kocky Valley anticline 

(pi. 1,sections H-H',K-K',L-L',M-M'). Thisasymmetry reflects the predominant horizontal force couple 

of the Appalachian orogeny: over to the northwest, 

under to the southeast. In the irregular structure of 

the Mascot-Jefferson City district, this couple was probably resolved in different directions in different parts, 

of the area, but its impress is clear even in the most 

irregular and complex areas. Such a couple could presumably have been caused by an active orogenic force 

pushing northwestward in the upper layers of the 

earth's crust from the general vicinity of the present 

Atlantic Coastal Plain—under this assumption all the 

thrust faults in the area are overthrust faults—but 

there is no evidence in this district to prove or disprove 

the assumption.

The time of application of the forces must have been 

post-Mississippian, for just north of the mapped area 

the Saltville fault cuts Mississippian rocks. Elsewhere 

in East Tennessee, structures that are almost certainly 

of the same age cut Pennsylvanian rocks, and there is 

little doubt that the main structural features of the 

region were formed during or at the end of the Permian period in the Appalachian orogeny. There is no 

evidence in the district for more than one period of 

major deformation. The unconformity at the top of 

the Knox group represents, however, a period of widespread uplift and erosion and perhaps of gentle warping. It is possible that the sandstones close to the Cambrian-Ordovician boundary record a period of less pronounced uplift and warping in this or adjacent areas. 

Evidence outside the area studied in detail also suggests 

other periods of warping, one of the most conspicuous 

preceding the deposition of the Upper Devonian Chattanooga shale. The number of unconformities in the 

Mascot-Jefferson City district and, for that matter, in 

East Tennessee, is, however, much fewer than has been 

advocated by some writers.

The combination of folds and thrust faults in the 

area makes it possible to suggest several stages in the 

process by which the typical thrust faults of East Tennessee developed out of folds (Willis, 1893, p. 269). 

It seems probable that the stresses that finally broke the 

rocks to form faults first caused the strata to buckle, 

the buckle in most cases taking the forir of a pair of 

folds—an anticline to the southeast and a syncline to 

the northwest. The flank between the axes of each pair 

of folds, which is shared by them and commonly termed 

their "middle limb," dipped northwest and hence was 

in a weak position athwart the force couple, and here 

the break began. After the rocks had broken the fault 

grew by further movement along the fault surface 

rather than by an increase in the size of the folds. 

Thus the thrust fault grew at the expense of the folds, 

and where the process was carried to completion the 

remnants of the original folds are no longer evident— 

the anticlinal axis and the upper part of the middle 

limb having been removed by erosion and the synclinal 

axis and the lower part of the middle limb having been 

buried beneath the thrust fault.

The first stage in this development may be exhibited 

by the fault in the valley of Blue Spring Branch north 

of Roderick Mountain at the west end of Kocky Valley 

(pi. 1, section H-H'). Here the northem of the two 

anticlinal noses at the west end of the Rocky Valley 

anticline is broken by a small thrust far It. The total 

movement is small and most of it was taken up by the 

fold rather than the fault.

Another stage may be shown by the Mill Spring fault 

northwest of Friends Station on the New Market quadrangle (pi. 1, sections K-K' and L-L'}. Near Lost 

Creek, an anticline lies just south of the fr.ult and a syncline just north of it; these probably ar"> remnants of 

the buckle out of which the fault developed. The total 

movement on either fold or fault is not great at this 

point, but most of the movement is now represented by 

the fault rather than the fold.

A further stage is excellently displayec1 by the Rocky 

Valley fault (pi. 1, sections K-K' to Q-Q' ; on the map 

published in 1945 the fault is called the Bays Mountain 

fault). Part of the original buckle from which the 

fault developed is represented by the Rocl~y Valley anticline on the Shields Ridge block. The complementary 

syncline on the Jefferson City block is mostly buried 

beneath the overriding thrust block, but it appears to be 

represented by the belt of complex structure extending 

from east of Jefferson City southwest into Rocky Val-
ECONOMIC GENERALIZATIONS 69

ley; its probable location is suggested on some of the 

cross sections (pi. 1, sections P-P' to R~R'} . The anticline, which originally lay southeast of the syncline, has 

been moved bodily until it rests on top of the syncline 

or even lies northwest of it. Where this has happened, 

the thrust surface beneath the anticline lies nearly horizontal, though southeast of the anticlinal axis it probably dips southeastward 20 or 30 degrees. In the area 

just east of Strawberry Plains, the fault surface also 

becomes steeper northwest of the horizontal portion, 

but in the vicinity of New Market and eastward this 

steep portion has been removed by erosion. Thus the 

movement of the Shields Ridge block on the Rocky 

Valley fault probably was in order: up, across, up. 

Where the Rocky Valley anticline plunges to the west 

(pi. 1, section H-H'), and perhaps also where it plunges 

to the northeast (pi. 1, sections Q-Qf and R-R'), the 

horizontal portion of the fault descends below ground 

level and probably narrows and disappears.

The final stage of fault development is exhibited 

within this area by the Saltville and Dumplin Valley 

faults and outside it by the majority of the thrust faults 

in the Valley of East Tennessee. Along these faults 

practically no traces remain of the anticline and syncline that were originally present; the crest of the anticline was presumably carried upwards and eroded away, 

the southeastern limb remains as a homocline, and the 

syncline is presumably buried. The slices along these 

faults appear to represent last remnants of the middle 

limb, caught and dragged along the fault surfaces.

It is of interest that the major faults in the district 

(the Saltville, Rocky Valley, and Dumplin Valley) all 

bring the Rome formation to the surface but that none 

of them cuts lower in the section. This same general 

rule holds for all the major faults in the Valley of East 

Tennessee, Virginia, and Alabama; only the great lowangle thrusts along the front of the Unaka and Great 

Smoky Mountains on the southeast side of the Valley 

reach into lower beds. Presumably the rule indicates 

that the lower beds of the Rome (beneath the thick sandstone beds) were incompetent and served as a gliding 

plane on which the sedimentary rocks of the Valley area 

tore loose from the crystalline basement when they 

were deformed into the present folds and fault slices. 

Possibly the lower Rome is the first such incompetent 

layer above the pre-Cambrian basement, for many of the 

pre-Rome sedimentary formations now exposed in the 

mountains southeast of the Valley may never have been 

deposited in the central and western parts of the Valley.

ECONOMIC GENERALIZATIONS

There is no evident structural explanation for the 

unusual geological character of the Mascot-Jefferson

City district, but perhaps it is more than a coincidence 

that this district, characterized by diverse and irregular 

structure, should also be the most important zinc-irining 

district in the southeastern United States. Within the 

mapped area, the zinc deposits are confined to the Mascot 

and Jefferson City belts, none being known south of 

the Rocky Valley fault. The Mascot belt contains the 

Mascot mine of the American Zinc Co. of Tennessee and 

a number of prospects; the Jefferson City belt contains 

the following mines that are either active or have been 

worked during the course of this investigation: Gr^sselli 

or New Market mine and Jarnagin mine of the American Zinc Co., Davis mine and Athletic mine of tho Tennessee Coal & Iron Division, U. S. Steel Corp., and also 

a number of abandoned mines and prospects. The location of practically all the mines and prospects is shown 

on the accompanying map, and descriptions of m ost of 

them may be found in reports on the zinc deposits of 

East Tennessee (Purdue, 1912; Secrist, 1924; Brokaw, 

1955).

A thorough investigation of the zinc deposits of East 

Tennessee was carried out by the U. S. Geological 

Survey in cooperation with the Tennessee Division of 

Geology during World War II. A number of preliminary maps and short reports were issued during the 

war, and final reports have either been published 

(Rodgers, 1948) or are in preparation (Brokaw, 1955).

The zinc in the district occurs partly as the sulfide 

sphalerite disseminated in the bedrock and partly as the 

carbonate smithsonite and the silicate hemimorphite 

(calamine) in irregular bodies scattered in the c^erlying residual clay, commonly close to or against the 

weathered surfaces of pinnacles of the bedrock. The 

oxidized (carbonate and silicate) deposits have resulted 

from the weathering of former upward extensions of 

the sulfide deposits. Practically every mine am? prospect in the area was originally worked for oxidized 

ore, but all mining at present is for sphalerite. The 

ensuing remarks refer entirely to the sphalerite deposits 

and their relation to the stratigraphy and structure of 

the district.

The sphalerite in the district is a very pale honey 

yellow and is entirely free from appreciable amounts of 

galena, pyrite, barite, or fluorite; one or more of these 

characteristics distinguish the sulfide ore of this district 

from the ores of most of the other zinc districts in the 

southern Appalachians. Moreover all the mines and 

prospects within the mapped area occur in a definite 

stratigraphic zone not over 300 feet thick including the 

uppermost 50 feet or less of the Longview dolomite and 

the lower half or two-thirds of the Kingsport limestone. 

This zone consists largely of an alternation of limestone and dolomite, limestone predominating below and
70 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

dolomite above. (See p. 47, 53.) The upper and lower 

boundaries of the ore-bearing zone vary somewhat in 

different areas but rarely transgress the limits given 

above (see Oder and Miller, 1945, table 2; as noted on 

p. 50, however, the Kingsport-Longview contact used in 

the present report corresponds to the "footwall sand" 

or "zero bed" of the Mascot section as given by Oder 

and Miller; see also Brokaw, 1955). Because the zinc 

deposits are restricted to this zone, prospecting and 

mining can be greatly aided by close attention to the 

stratigraphy; for example, when prospecting is carried 

on by drilling, the drill holes can be aimed at the significant stratigraphic zone and can be bottomed as soon 

as this zone is passed.

The distribution of prospects illustrates this stratigraphic restriction. Thus in the belt 14 miles long 

between Mascot and Knoxville there has been a zinc 

prospect at practically every point where a stream 

crosses and exposes the lower part of the Kingsport, but 

at no other place in that area. Similarly there is a 

horseshoe of mines and prospects from New Market to 

Jefferson City where the outcrop belt of the Kingsport 

limestone swings around the southward plunging end 

of the Cherokee anticline.

Locally the ore-bearing zone is strongly brecciated, 

and in general it may be said that the stronger the brecciation, the larger the ore deposit is likely to be. There 

are exceptions, however; extensively brecciated areas 

may be entirely barren, and on the other hand very rich 

deposits of sphalerite have been found in places that 

are only slightly brecciated. The breccia ranges from 

crackle and mosaic types, in which the fragments are 

rudely oriented and the relations of adjacent fragments 

to one another are obvious, to breccias in which the 

disruption of the rock has been much more complete 

and no relationship is apparent between adjacent fragments. The fragments themselves range from minute 

particles to masses several feet across. In most areas 

they are composed of fine-grained dolomites of various 

colors, from light gray'to black, the darker shades predominating. At a few localities, notably at the Grasselli mine, fragments of the dove limestones are abundant in the breccia, but they are not common elsewhere. 

The cementing material is white coarsely crystalline 

dolomite and pale sphalerite.

The brecciated bodies are very irregular in shape. 

Within this area they appear largely in the ore-bearing 

zone or in the overlying upper Kingsport and Mascot 

strata.

Another feature always present where ore is found, 

though by no means absent elsewhere, is granular 

coarsely crystalline dolomite, the so-called "recrystalline" (p. 47-54). This dolomite evidently replaced preexisting limestone (and perhaps fine-grained dolomite) 

at about the time of brecciation and ore deposition 

(Oder and Miller, 1945, p. 3-4). The richest ore bodies in the district, though not necessarily the largest, 

are in this rock, whose regional distribution is not 

greatly different from that of the breccia.

The origin of these breccias has been the subject of 

considerable controversy. The older workers (Keith, 

1896, p. 5; Purdue, 1912, p. 27-28; Secrist, 1924, p. 

104-105) were inclined to believe that the breccias lay 

along major thrusts, and Keith postulated a major 

fault through the Mossy Creek mine on the evidence 

of the breccias there (p. 66). An alterrative theory, 

which also assumes that the breccias are caused by 

major displacements, postulates that they are produced 

by movement along large-scale bedding slips.

Ulrich (1931), on the other hand, interpreted the 

breccia at the Mossy Creek mine as a cave breccia and 

extended this explanation to all the other breccias in 

the area.

Oder and Hook (1950), following their colleague 

Odell, though accepting much of the brecciation as 

tectonic, ascribe some of it to the foundering of dolomite blocks into cavities formed by th°- solution of 

limestone by hydrothermal fluids.

The writer's interpretation, which he owes largely to 

• Currier (1935, also many informal discussions), is that 

the breccias are of tectonic origin, but that they are 

related to minor folds, faults, and bedding slips, especially local cross folds and cross faults, rather than to 

the major thrust faults of the region.

The outstanding objection to the first interpretation 

is that in no place are these breccias directly associated 

with the major thrust faults, and that instead they are 

restricted to certain stratigraphic zones- in relatively 

undisturbed areas.

The cave hypothesis was originally advanced by 

Ulrich to explain these two facts: restriction to a certain 

zone and lack of relation to major faults. In addition, 

the general appearance of the breccia in the pits of the 

Mossy Creek mine, where it has been somewhat weathered, lends support to the idea. The evidence against 

the cave hypothesis is best seen in fresh exposures, particularly in the mine workings, and may be summed up 

as follows:

1. Although the breccias may be sharply bounded 

above and below by bedding planes, ther°, is no definite 

border along the sides of the deposit v^hich could be 

compared to the wall of the cave. On the contrary, 

the intensity of the brecciation diminishes laterally, 

passing by very gradual stages from rubble to mosaic, 

from mosaic to crackle, and from crackle into the unfractured rock.
ECONOMIC GENERALIZATIONS 71

2. There is no evidence around the brecciated masses 

of the inward-dipping rim rock which is so characteristic of filled caves.

3. The brecciated fragments are clean and sharp and 

show no evidence of transportation.

4. The fragments are all derived from the strata 

peculiar to that part of the section, chiefly the finegrained dolomites and secondarily the interbedded limestones. There is no admixture of material from 

younger formations and no residual cherts, cave marble, 

or cave earth.

The statement by Ulrich (1931, p. 31) that "fossiliferous residual material of the Cotter [Mascot] formation has slumped down into the horizon of the Jefferson City [Kingsport] formation" is unquestionably true 

at certain places around the old Mossy Creek pits, but 

this slumping probably occurred during the present 

cycle of erosion and long after the formation of the 

breccias. It is an interesting and significant fact that 

no fossils have been found in place in the matrix of the 

breccias, though they have been found in the pinnacles 

of unbrecciated rock between the brecciated zones.

The breccias are clearly tectonic in origin and were 

presumably formed during the deformation of the region. They probably owe their stratigraphic distribution to differences in the competence of the strata. 

They are most common in that part of the section that 

consists of interbedded limestone and dolomite. The 

limestone is more plastic under deformation than the 

dolomite and tends to flow under forces that shatter 

the more brittle dolomite. Thus great numbers of 

joints cut the dolomite, but few cut the limestone in the 

same areas. The amount of fracturing suffered by the 

dolomite is naturally proportional to the amount of 

deformation which it has undergone, but the amount of 

displacement which individual fragments in the breccia 

have suffered depends in part on the relative competence of the different lithologic types involved, for the 

presence of beds of weaker more incompetent limestone 

allows a freer movement of the fragments of the more 

resistant dolomite beds than would occur were the entire 

mass homogeneous.

The geographic distribution of the breccias seems to 

indicate that they are closely related to the folding and 

faulting, for, although there is little or no brecciation 

along the major faults themselves, the heaviest brecciation seems to occur along the prolongation of faults 

that die out in a series of alternating dolomites and 

limestones. For example, in the vicinity of the Mascot 

mine, the Mill Spring fault zone dies out in strata of 

the Mascot and Kingsport formations, and a zone of 

brecciation extends in these strata from Mascot southwest to Knoxville. The amount of brecciation in this 

zone decreases generally to the southwest, though it is 

greater close to Legg and Woods Creeks, where the zone 

crosses the projection of the tear faults that cut the 

Cambrian rocks to the north. It is interesting and perhaps significant to note that although the Mascot belt 

can be traced as a distinct structural unit from Knoxville to the southern boundary of the State, and although it contains throughout this distance the same 

stratigraphic divisions of the Knox group, there are 

no zinc prospects (nor even barite prospects) in the 

belt from Knoxville to Cleveland.25 The published folio 

sheets and also local mapping in selected areas by others 

show no faults dying out in the Knox group of this belt 

in this distance.

Similarly the breccias exposed in the old Mossy 

Creek mine workings and those in the Davis mir^ of 

the Tennessee Coal & Iron Division, U. S. Steel Corp. 

lie southwest of the zone of complex small-scale tl rust 

faulting east of Jefferson City; the faults of that zone 

head toward the mines, one of them directly toward the 

Mossy Creek cut, where the brecciation is so well displayed. The brecciation in this area is not directly 

connected with the Eocky Valley thrust to the soutl x but 

rather with these minor faults in the Jefferson City 

block. No faulting was proved in other brecciated 

areas in the block.

It is also entirely possible that some of the breociation in the region is related to minor longitudinal and 

transverse folding.

Breccias thus occur at many places in the district, 

especially where faults of small displacement ente~ the 

the ore-bearing zone, and zinc showings can be found 

in many of these places. Only a relatively few of 

these mineralized breccias contain minable zinc ore, 

however, and presumably some additional factor is responsible for the difference between ore-bearing breccias and barren or sparsely mineralized breccias. An 

examination of the geologic setting of the known major 

deposits in the district reveals that they lie not merely 

in areas where the Kingsport limestone is broken by 

minor faults of the sort that cause brecciation but exclusively in areas near marked changes of strike that 

outline anticlinal noses. Similar synclinal changes in 

strike are barren. Thus, around the Mascot mine the 

strike changes from N. 70° E. along Eoseberry Creek 

to N. 25° E. north of the Mascot Eocks; yet the even 

sharper synclinal change in strike at Eichland only 3 

miles to the northeast is as far as known quite barren.

25 Secrist's map (1924) shows the Harwick mine (his no. 51) in this 

belt south of Cleveland, but the mine Is actually located In the be't next 

to the west, a little north of Blue Spring.
72 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZINC DISTRICT, TENNESSEE

The group of mines from the Grasselli to the Jarnagin 

is draped in an almost continuous arc around the southplunging nose of the Cherokee anticline; at either end 

the belt of mines stops abruptly just short of synclinal 

changes in strike. As an empirical rule, therefore, it 

may be suggested that in this district commercial bodies of zinc ore are to be expected only where the Kingsport limestone is cut by faults of small displacement as 

it passes around the noses of anticlines.

To summarize, the following generalizations may be 

of value in future prospecting in the Mascot and Jefferson City belts:

1. Hie great bulk of the ore occurs in a zone about 250 

feet thick centered in the lower part of the Kingsport 

limestone. (This does not apply to other zinc districts 

in the State; in each strike belt the ore appears to occupy a definite stratigraphic zone of limited vertical 

extent, but the zone is different from belt to belt. Occurrences are known in the Shady and Rome formations 

(Lower Cambrian), in the upper Honaker dolomite 

(Middle Cambrian), in the Nolichucky shale and especially in its Maynardville limestone member (Upper 

Cambrian), and in all the formations of the Knox 

group.)

2. The ore is commonly associated with extensive 

brecciation and the richest ore with secondary dolomitization. Areas that are not extensively brecciated, even 

though in the correct stratigraphic zone, are apt to be 

barren or at best only slightly mineralized.

3. The breccias do not occur along the major faults 

of the region but appear to be localized (a) in prolongation of faults that are dying out and (b) along minor 

folds, especially cross folds.

4. Breccias containing commercial zinc ore seem to be 

further restricted to the vicinity of marked anticlinal 

changes in strike.

Application of these generalizations to the district 

resulted during the war in recommendations for "wildcat" prospecting for zinc northwest and west of Friends 

Station, where the Kingsport limestone swings around 

the small anticline close to the Mill Spring fault, and 

on the dome exposing the Mascot dolomite south of 

East Hodges.

[Exploration by the American Zinc Co. of Tennessee in 

these two localities between 1946 and 1952 resulted in 

discovery of two major ore bodies. One is now in 

production, as the North Friends Station mine; the 

other is in the development stage (shaft sinking began 

in June 1953) as the Young mine. This is one of the 

most outstanding recent examples of ore discovery resulting from geologic prediction. Note contributed by 

Robert A. Laurence, July 1953.]

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74 STRATIGRAPHY OF THE MASCOT-JEFFERSON CITY ZDSTC DISTRICT, TENNESSEE

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INDEX

Acknowledgments_________-_______....—__.__„___-. 5-6

American Zinc Co. of Tennessee________________._____. 4,5,56,59,63 

mines_____________________._______..._.___.__ 69,72

Aphelaspis zone, list of characteristic species. 

Appalachian Valley, structural features__

Balk, Christina Lochman. See Lochman, Christina.

Bays Mountain..________________________........_..... 6,56,66

Bays Mountain fault_______________.______.......___ -.. 7,61,68

Bays Mountains————___—..______________.______.__ 6,7 

Breccias, origin___.__....___________._.__ ———......... 70-71,72

Butts, Charles, quoted...____.______.______.______..__ 45,46

0 

Canadian system of Ulrlch..._________________________________ 24-25

Cedaria zone, fauna.___________._ —____--.._.__-...___. 20 

Chepultepecdolomite--———————__-————————— 23,27-28,33,55,56

correlation.._————————— —— —————————.-- —— ._ — 42,44,45

description..______________.__________.___......__ 37-46

distribution of species._________.________________ — -_ 43-44

facies relationships.. — ___________....__.._-_____ — ____.—_._ 41

fossils....___.__......__._——— — ————— — — ——— — — —— 41-45

quartz cavity-fillings—.„—______.______.____.„.-__.. 40 

relation to Longview dolomite_____________.__...__.....__ 45-46

residual chert_______. ______. _______________. __ 40

TVA quarry section_____________.____.__.___...__ 39

Chepultepec-Longview contact._.___.__..._______._._____.__ 37,53

Cherokeet-Qticline——.—.—— — — ————.—.— 9,10,63,64,65,67,70,72

Cherokee Dam.____________________.______.___ 12,33,38,39 

Cherokee Lake...__.........__....................__-—......__- 10,12,25

Chert residual----————.——— ———— ——— 12,13,15,31-32,40,48,54,55,65

Chickamauga limestone, description___________________ ___. 56-57 

Clay, residual........———-----——-_ — _-.——- — .-.. — ___.- 31,54,60

Cooper, B. N., quoted_____._________.______..._____. 38 

Copper Ridge dolomite—.................................. 13,16,23,53,55,56,62,63

correlation...___.-..---.——....—-.—.-...—....-...-.__„.——. 34-36

description.___________.._____._______...______. 25-37 

facies relationships__._____________.______...__.___. 33-34 

fossils—-——————————. — — ————————— — .. 34-37

Loves Creek section__.___. ____________—..._.____. 27-29 

residual chert______________.________________ _ __. 31-32

Craig limestone member of Rogersville shale._——..___..._.......__ 7-8

type section________ ______ -____ - _____ — ___._. 9

topographic expression.___________________. _ _. _____. 19

Cre-picephalus zone, list of characteristic species_______. _.__....__. 20

Cryptozoans____.____________._______...______. 32-33,40

D 

Domes..-_..._—————..—————— ———————.—.————— — . 64,72

Douglas Lake.—__——---..-.--.___________.__.______.._ 58,59

Drainage.____________._______.__________________ 55

by Holston River____________._______________._ 6

underground__-.--.-...-__-__________..._____._ 6,56,65

Dumplin Valley thrust fault--..-_.——————___............... 7,61,67,69

Duncan, D. C., quoted____________.______.___________ 20

F % 

Faults____._____.____...—.___...._____........ 61-66,68-69,71,72

Faunallists, Aphelaspis zone...__________________________ 20 

Cedaria zone..——.—.——...„_._____...___.______ 20 

Chepultepecdolomite.._________.______.__________ 43-44 

Crepicephcdus zone..__________________________ 20 

Longview dolomite__________..______..._______. 49

Folds———__——_————————————————————— 68-69,70,71,72

Q 

Geography-.._________...„___________—..._______._ 6-7

Highways.----- 

Holston marble .

6-7

57

JeffersonCitybelt-———-——————————— ————. 7,38,61,62-66,69,72

Joints.._________________________._______________ 71 

in chert nodules.--..___________________.-._____-- 65

K

Kingspori limestone_______________________________._ 23,69 

correlation____--______________________________ 54 

description-..___-.-__________-.______________ 49-54

fossils________________________________________ 54

occurrence of ore__________________. ______. __ _ 69-70,71,72

section________.______.______._____________ 51,52-53

Kingsport-Longview contact_____________ __________ __ __ 70

Klippen.—____-_......_....____._-__.___....__..._ 64,66

Knox dolomite...__.______.______._________________ 21-22

Knox group..--._________________.______________. 21-60,71

history of terminology_______._____________.__ 21-23 chart I

present usage—.. ——————————————— ————————————.——— 23-24

recent work..—.. —— _ ___________ ———........... ——... — _________ 3-5

ridges.--— — — - — __________ _ — —... —... —— — — ___- — ______.. 55-56

unconformity at top of.—.—. ——- — -- —— —— ——— — ————— — - 23-24

work before 1929__________. ______. _______________ 3 

Koppick Knob...------------..--.-__...___—.——._.__———— 5,66,67

Laurence, R. A., color measurements. -----_-----------..-----_------.- 9,11

Lenoirlimestone._.-._--.-—... ——._——-———. ————————.—_ 57,59 

description_——. ——————.——————————————————————— 60 

fossils._---_----_----..----__._.--.------.——-------—._.-—. 60

unconformitj at base.- ————— -- —— ——— -_. —————— —— —. ——. 57-59 

See also Mosheim member. 

Location of area....————— ———————————— -——————————————— 1

Lochman, Chiistina, quoted_- —— ——— ——— —— ————— ———— —— - 20

Longview dolomite. _________________—__________ 23,53,55,56,69 

correlation————————————————————————————————————— 48-49 

description.. — ——— —— - — — -- ——————— —— ———.- —————— — 46-49 

distribution of species.-------- — —————— —————— —————— - 4*

fossils—————— ————————————————— ———— 48-49

relation to Chepultepec dolomite...— —— —— ———— ——. ——————. 45-46

residual chert.....—.——————————————————————.——————— 48

M

Mapping by U. S. Geological Survey.—————————————————————— 3,4 

Mapping procedures—.——————————————————————————————— 5 

Maryville limestone....——.———————...—.——-—-———————— 7,9,30

description.--————— ——————————— -- —————— ————————— 10 

facies relationships—.————— ——————— ————————————————— 17-18 

topographic expression—.——.. — —— — ——— ——————————— —— 19

Mascot belt.— ---_------ — -—— —— _ 7,9,10,12,21,26,38,61-62,63,69,71,72

Mascot dolomite__...__—— ———— — ———__—-—— 23,55, 56,57-58,*72

correlation— — ————— —— - ——————————————— ————————— 55

description...---..- — — — -- ——————— ——————— ————— —— —— 54-55

relief on surface.. - —.____. —— —————— —————— ————————— 58,59

section_—— — ———— —. ——— ——. — ———— — ————— —— 51

Maynardville limestone member of Nolichucky shale————. ————— 7,8,53,61,72 

Aphelaspis fauna.-.-- — —... ——————— ———————.. ——————.— 19,21 

description.-----.------------——-———-—————— ————— 11-21

Loves Creek section.—.-_——————————.——————————————-— 29-30 

sections——— —————————————————_— 13-14,15,16-17

topographic expression....----- ——— ——— ————————————— -— 19

MiU Spring thrust fault. — ——————————————— 7,61,62,63,64 68,71,72

Mines, Athletic..----------------------——.——— ————-————— 69

Davis- —— — ——— — —————————————————— 69,71

distribution------ — -- ——————-—-———————————— 69,70

75
76 INDEX

Mines—Continued

Grassellior New Market—.- — — - ——— — — ._— — -.__— — — __ 53,69,70,72

Jarnagin_--_..———____-_--- — ... — .._._..________ 69,72 

Mascot__ ———„—------ — — ------.-....-......„.-. — . 47,53,69,71

fault..--..-..____ — -- — --------- — .---------- — ....—— 63

Mossy Creek--...-————__— — — — - — -—.- — - — — — -_-...___ 70,71

Rocky Valley fault through. _.. — — _— - ——— -_ — — — -_____ 66,70 

North Friends Station...-—-.___- — — — — — __.......______ 72

Young____._ ———— ___ —._---_-.____-----______ 72

Moccasin Ridge_____.—.________...____._________ 25 

Moore, E. S., quoted-_____________.__. ____.________ 45,46 

Mosheim anticline__————__.__---——....______________ 63

Mosheim member of Lenoir limestone.——————_____-...——____ 57,58 

description...__—————_—_...——..______.________ 59-60

N

Nolichucky shale_______________________. _______ 7,8.61,72 

description.-———————————————————__-...-...-———___. 10-11 

facies relationships————....————————...___.._._.__... 17-18

faunal zones..„_-———___...———-..._______ ..______ 19 

Loves Creek section.———_____..._...________________ 29-30 

topographic expression ..............———..._______________ 19

See also Maynardville limestone member.

NorrisDam.__———————————————————.....—.—————__. 11 

.———..—..———..—............................. 11,13,14,17

Oder, C. R. L., quoted..——..___...————...__-__._____.__ 13,23 

Ore-bearing zone of sphalerite.._____————________——. 69-70,71,72 

Owl Hole Gap, veinlets of sphalerite in quarry——.———....——————— 15 

Ozartlan system of Ulrich——....————————___.____——___ 24-25

Pre-Knoxformations.. —————————————————————.——————--- 7-21 

names and distribution.—___—.—————________——___ 7-8 

Prospects, distribution... ———————————————————.———————— 70 

Pumpkin Valley shale.—.——....„———————..„._....————__. 8,19,30 

Purpose of present report———————— ——————————————-—— 1-2

Q

Quarries, BiagiottL-———————.....————————————-----———....— 17

Craig. 9; pi..3C7

Knox County at Tecoy.——...————————.._..——————__.. 21 

Knox County workhouse......————————___..——————__— 17

near Cherokee Dam.———___._..————_______..——___ 32-33 

Owl Hole Gap, veinlets of sphalerite...———_____..————___. 15 

State Highway Department-—————————....————————_.... 15

TVA....——..—---.—.-.-..—.——.-—....——....-.—.-...-. 38-39

Quartz cavity-fillings, Chepultepec dolomite_—._-____......___. 40

R 

"Recrystalline" dolomite,_.________.....______________ 47,54

ore bodies.-____———___--—————____——————_--.- 70 

Relief, of the area-——————————————————————————————— 6

on surface of Mascot dolomite..——————————.———.——————... 58,59 

Resser, C. E., quoted——.———...——.———.——'....................... 25

Richland fault———————————————————————————— 7,61

Richland Knobs escarpment_______....——____..—————_. 10,15,19

Ridges, description___———....————————_...—————.————— 55-56

Roads, county____————___——.————___——————————— 7 

Rock structure, mechanics_......—.......———___—————————— 68-69

Rocks of the Appalachian Valley. _____———__——.—————....— 7

Rocky Valley anticline——__.___—.—.......__._..__ 9,40,66,67,68-69

- material in crest..————_....———————_..._————————— 8

Page 

Rocky Valley thrust fault....—_————————— 7,61,63-64,65,66-«7,68-69

Rogersville shale__.________...—__________________ 7,30 

description...——..——————————.—————————__.__..._ 8-10 

facies relationships_—.————————...————.———________ 17-18 

topographic expression___—————....——.——.—________ 19

See also Craig limestone member. 

Rome formation______________....________________ 7,30,69,72

description........________„——__————————_______ 8

ridges .....————————————————...————————————————— 55-56,62

topographic expression_——————————————————_.._. ___ 18 

Rutledge limestone.—.____—————_———.————________ 7 

description.. ______.__—.——___...__——...________ 8 

facies relationships______________________________ 17-18 

topographic expression___—.——____._.......________ 1ft

S 

Safford, J.M., quoted————————————_..._._......._ 21,40,56

SaltvUle thrust fault—————————————————_ 7,29,30,61,62,67,68,69

Sandstone, residual..——————————.————————__.. 33,41,48,54.55

Scope of present report......——————————————.————.....———.. 1-2

Shady dolomite—..—-___——————.......—————..___..___ 8,72

Shields Ridge-————.———.—————...——_——__................ 6

Shields Ridge belt——.__———...——————_......____ 7.8,38,61,66-67

Sinks————————_—.————————————._........... 6,55,57,58,65

Soils————————————__———————__ . __ 31,40-41,48,54,56,60,65

Sphalerite, ore-bearing zone..————-—————————————————— 69-70,71,72

veinlets in quarry in Owl Hole Gap. — .—————————————————— 15 

Stratigraphic columns____————————.————————_.__.. 7; chart 1. 

Stratigraphy.—.——————————————————————————..——.—— 7-60 

Strawberry Plains basin________________———_______ 62,63-64 

Structural belts——————————————————————— — - 7,55-56,61-68

Structural features_—__—————————————————————.———— 61-69

formation—————_———————————————————————————— 68 

Synclines, between Cherokee and Rocky Valley anticlines—-________ 65

east of Jefferson City. __—————————————————————————— 64

Strawberry Plains basin..._...————.—————————.—————— 62

T

Tennessee Coal & Iron Division, U. S. Steel, mines——————_...———... 69,71 

Tennessee Valley Authority, Geologic Division, work in East Tennessee—„ 4 

Topographic expression, pre-Knox formations————————————————— 18-19 

Topography, Knox group......————————————————————————— 55-56

Towns, principal-..—__——————————————————————————— 6 

Troughs, parallel________————————————————————————— 56-57

U 

Ulrich, E. O., quoted..—.————————————————...... 11,24,34,37,40

Unconformity, at base of Lenoir limestone._...——————————————— 57-59 

at top of Canadian or Lower Ordovician....———————————————— 24

at top of Knox group..._...——.—......————......—-——. 23-24,68

Veinlets of sphalerite in quarry in Owl Hole Gap.——————————————— 15 

Volcanic ash—_——————————————————————————————————— 58

W

Wilson, J. L., quoted-_——————————...—————————————————— 34 

Work before 1929-._..__———————————————————— 3

Zinc————————————————————————————— 69,70,71,72

O