UNITED STATES DEPARTMENT OF THE INTERIOR 

Harold L. Ickes, Secretary

GEOLOGICAL SURVEY 

W. C. Mendenhall, Director

Bulletin 847 E

GEOLOGY AND MINERAL RESOURCES OF

THE WESTERN PAJIT OF THE

ARKANSAS GOAL FIELD

BY

T. A. HENDRICKS AND BRYAN PARKS

Contributions to economic geology, 1934-36 

(Pages 189-224)

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1937

For sale by the Superintendent of Documents, Washington, D. C. ------ Price 25 cents

CONTENTS

	Page 

Abstract. _..__.._..__...__. _-._-_-....._-._-._., 189

Introduction. ___-_______-__________-_----_-_--__--__---_--------_ 190

Scope of-report________-_____-__--_________-_--_____-_-------- 190

'Earlier-investigations.. _-_____--__----_-_--_-__-__-_____---__-- 190

Acknowledgments __ ___________.__-_.--_-___-_-_-_____-_-______ 191

Geography ________________________-_--___--_-----_-_-_-____-_--_- 191

Land forms__..__-.__.____--__-_---_____-_-_____---____-___ 191

Drainage- _ __-__----_-_-_____--__-_--_------------__-----__- 192

Climate and vegetation.___._._._--_-_-_-_-_-_____-__-_____._.. 193

Population and accessibility.__ ..__--.-__.-._.._-_---..._. 194

General geology__._____._______----_.-_-_-_ ___-___-_____..___ 194

Stratigraphy _______-__-_____-_-----_---_------_--_---____-.._ 194

Age and character of the rocks. .---_-_-__----__---._____. 194

Carboniferous system_______-_--_____._________..___.__.. 196

Pennsylvanian -series __ _._._--.__.-_-_--.--_._..__._.. 196

Atoka formation._________________________________ 196

Hartshorne sandstone ._---__----________-______ 198

McAlester shale___--_-----_-----_------___-__-__ 199

 Savanna-'sandstone-------------------------------- 199

Boggy shale-____----__--.-.-.-___._... 200

Quaternary (?) sy8tem____-__--_--__-----------__-_____-___ 200

Stream terraces-----.-.-------.-.---------------_..--. 200

Quaternary system.______--_---------_--_-___-_---_-_----_ 201

Alluvium____....._-'--__-------_._-_-___... 201

Structure.._._-----._.._..._.--__-.--.--___-.____.__... 201

Mineral resources._...__...._____-_-----------_---------_.___-.._. 203

Coal........-_-_---------.--...-.--.--.-.--.--.---------.---- 203

Production..._-----_-----_--------.--------_--..___.. 203

Distribution and thickness of the coal beds..__-.____-._._____ 205

Coal below the Lower Hartshorne-----.._._._.--_-__..._ 205

Lower Hartshorne coal.._-_---________-_-.__.______._ 205

Upper Hartshorne coal._____-_-__ --__-____--_-__-__-_ 206

Charleston coal.__________--_---_-__-_--.--_-_--__.___ 207

Paris coal....-...._.-__.----_---... _-_.-.----____ 208

Other coals..-----------.---.---.-----____-.-...--_ 208

Rank, quality, and uses of the coal._________________________ 209

Mining methods..._________--_----_--_--__---__-___--_--_ 209

Natural gas.___--____!__________-__-__-___--__-_-____-___---. 214

Occurrence. -__-_---_-___-_--_--_---_-_-_--_-__-..--__---- 214

Production.---__---_-._.-_-------__------.--------------- 216

Nature of the gas.________________.«__-___-_________-_-__.- 216

Gas fields.--_------.___...__..__...________.._ 217

Mansfield._.-----...-.__...____._-.-_._'_ 217

Etna._-_._._...._._.__._-.----------_-----__.-..._ 218

Vesta....__....___.___.__..___.--___._. 218

Lavaca.____......_.__.._..___._.__._..._........__.. 218

m
IV CONTENTS

Mineral resources Continued. 

Natural gas Continued.

Gas fields Continued. Page

Massard Prairie_____________________________________ 219

Shibley---.________ ______.__._____._________ 220

Alma..-_----_---_____________---_-_-________----____ 220

Kibler-Williams-_..____.._______________'_____ 221

Localities structurally favorable for accumulation of gas.______ 221

Biswell Hill anticline.__.__________--_---__.__.--______ 221

Vache Grasse anticline.-------------------------------- 221

Game Hill anticline--------.--------------------- --- 222

Closure against Bee Bluff fault-____________-_--_-_-_--. 222

Manitou anticline-_________.__________________ ________ 222

Cecil anticline-..____________________________________ 223

Closure against Mill Creek-fault________________________ 223

Closure against Mulberry fault,in T. 9 N., R. 31 W_.___ 223

Sand and gravel-___--_---_______--__-__-_----_-_----_------_- 224

Shale suitable for manufacture of brick._________________________ 224

Crushed rock...______________________________________________ 224'

ILLUSTRATION

PLATE 35. Map showing geologic structure and mineral resources of the

western part of the Arkansas coal field ______-__-__--__In pocket
GEOLOGY AND MINERAL RESOURCES OF THE WESTERN 

PART OF THE ARKANSAS COAL FIELD

By T. A. HENDRICKS and BEYAN PARKS

ABSTRACT

The western part of the Arkansas coal field covers an area of about 1,100 

square miles in Scott, Sebastian, Crawford, Franklin, and Logan Counties, Ark. 

It lies entirely within the Arkansas Valley region.

The exposed stratified rocks of the area belong to the Atoka, Hartshorne, 

McAlester, Savanna, and Boggy formations, of Pennsylvanian age, and consist 

of alternating beds of shale and sandstone and some associated coal beds. The 

total thickness of these formations is about 10,000 feet. Unconformities are 

present at the base of the Hartshorne and Savanna formations, and numerous 

minor unconformities probably occur within the formations. Overlying these 

beds in some parts of the area are deposits of unconsolidated sand, gravel, silt, 

and clay, which are present on stream terraces and in the more recent alluvial 

valleys of the streams.

The geologic structure of the area is of two types. The southern part of the 

area is characterized by long, steeply folded anticlines separated by broader 

synclines and broken at a few places by reverse faults. The structure of that 

part of the area is closely related to the structure of the Ouachita Mountains, 

which lie to the south of the coal field. The northern part of the area is characterized by gentle folds that are broken at many places by normal faults and is 

structurally similar to the Boston Mountains, which lie north of the coal field.

The most valuable mineral resources of the area are coal and natural gas. 

The western part of the Arkansas coal field has been a large coal-producing area 

for about 50 years, and it is estimated that 48,639,784 tons was produced from 

1887 to 1934. The coal is low-volatile bituminous and is an excellent steam and 

domestic fuel. All the commercial mining has been confined to three coal beds 

the Lower Hartshorne, the Charleston, and the Paris. Some coal has been mined 

for local use from other beds. A considerable quantity of coal is still available in 

the area.

Natural gas has been produced in commercial quantities in eight fields in the 

area. The producing wells generally have a low initial production, low rock 

pressure, and long life, but in the Alma field the wells are large initial producers 

and have high rock pressures, and the probable life of the field is short. The 

gas is produced from sandstones in the Atoka formation and comes from several 

different horizons. A total of about 250 to 300 billion cubic feet of gas has been 

produced in the area since the first well was drilled, in 1902. Small production 

and shows of gas have been encountered at many places in the area, and several 

folds favorable for the accumulation of gas have not been adequately tested.

Sand and gravel and shale suitable for the manufacture of brick are present in 

the area, and some crushed sandstone has been used for road surfacing.

189
190 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

INTRODUCTION

SCOPE OF REPORT

This report describes the mineral resources of the western part of 

the Arkansas coal field and considers the features of geologic structure and stratigraphy that are essential to an understanding of the 

nature of occurrence of the mineral resources. The area (see pi. 35) 

is an irregular-shaped tract of about 1,100 square miles in Scott, 

Sebastian, Crawford, Franklin, and Logan.Counties, in west-central 

Arkansas.

The Arkansas coal field, an eastward-trending belt that is about 50 

miles wide at the Oklahoma State line and tapers to a point near 

Russellville, Ark., covers an area of about 1,600 square miles in the 

Arkansas Valley. It is underlain by a thick series of Pennsylvanian 

rocks that have been greatly folded and broken and later imperfectly 

beveled off so that the truncated edges of many beds are now exposed 

at the surface.

Several beds of coal are exposed at different places in the area, and 

for many years coal has been mined from beneath the surface throughout the area. For more than 30 years natural gas has been known 

to occur in several parts of the area, and drilling at suitable places 

has yielded large supplies of gas.

From March 4 to October 1, 1934, a party of seven men under the 

direction of T. A. Hendricks, working on an allotment of funds from 

the Public Works Administration, engaged in mapping in detail the 

exposed rock formations, locating all coal mines, prospect pits, and 

gas wells, and collecting all available data on coal mines, gas wells, 

and holes drilled in exploring coal. C. B. Read, Bryan Parks, J. N. 

Payne, and W. M. Plaster did the field mapping by plane table and 

stadia traverse on a scale of 2 inches to the mile. C. J. Finger, Jr., 

C. 0. Hansard, P. A. Shaw, and W. M. Plaster served as instrument 

men.

T. A. Hendricks and Bryan Parks compiled the maps, sections, and 

tables, and T. A. Hendricks prepared the text of this report from the 

data obtained in the course of the field work.

EARLIER INVESTIGATIONS

In 1888 a report by Winslow l on the Arkansas coal field was published by the Arkansas Geological Survey. That report set forth 

briefly the general features of the geology of the coal field and gave 

fully the data on the coal that were available at that time.

In 1906 a field party of the United States Geological Survey working under A. J. Collier investigated the geology and coal resources of

i Winslow, Arthur, The geology of the coal regions; a preliminary report upon a portion of the coal regions 

of Arkansas: Arkansas Geol. Survey Ann. Kept, for 1888, vol. 3,1888.
WESTERN PART OF THE ARKANSAS COAL FIELD 191

the Arkansas coal field. In the report on that work 2 the major features of the geology and coal resources were described.

In 1910 Steele 3 prepared a very detailed and comprehensive report 

on the coal-mining industry in Arkansas for the Arkansas Geological 

Survey.

A short report on the Fort Smith-Poteau gas field of western Arkansas and eastern Oklahoma by Smith 4 was published by the 

United States Geological Survey in 1914. The geologic structure of 

a small area in the western part of the Arkansas coal field was described in that report.

In 1927 Croneis 5 compiled all available data on the geology of the 

Arkansas Paleozoic area for the State Survey and supplemented that 

compilation by field work in the parts of the area in which data were 

few. Th'at publication contains much valuable information, particularly that relative to natural-gas production and reserves.

ACKNOWLEDGMENTS

The writer wishes to express appreciation to the companies and individuals who supplied information that has been invaluable in preparing this report, and to the many mine operators who permitted 

him to sample the coal in their mines. Particular thanks are due to 

Messrs. Claude Speegle, State mine inspector; R. E. Welch, consulting 

mining engineer; A. B. Harper, of the Fort Smith Gas Co.; Leigh 

Kelly, of the Kelly Trust.Co.; Cecil Robinson, of the Arkansas Natural Gas Co.; and to the Western Coal & Mining Co., the Central 

Coal & Coke Co., and the Charleston Coal Co. ^

GEOGKAPHY

LAND FOBMS

The western part of the Arkansas coal field lies in the Arkansas 

Valley region, which is bounded on the north by the Boston Mountains and on the south by the Ouachita Mountains. The area is 

characterized by alternating ridges and valleys. The shape of the 

surface has been determined by the attitude and resistance of the rock 

beds. Throughout the area the rocks have been tilted at various 

angles, after which they have been imperfectly planed off to a surface 

of low relief. The soft shale beds have been worn down to valleys 

and slopes, and the hard sandstone beds show their edges near the 

crests of long ridges.

In the northwestern part of the area, both north and south of the 

Arkansas River, the beds at the surface do not differ greatly in resistance, downward planing has been greater than throughout most of the

 Collier. A. J.. The Arkansas coal field: U. S. Geol. Survey Bull. 328, 1907.

 Steele, A. A., Coal mining in Arkansas, Arkansas Geol. Survey, 1910.

 Smith, C. D., Structure of the Fort Smith-Poteau gas field, Arkansas and Oklahoma: U. 8. Qeol. Survey Bull. Ml, pp. 23-33, 1914.

 Croneis, Carey, Geology of the Arkansas Paleozoic area: Arkansas Geol. Survey Bull. 3,1927.
192 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

remainder of the area, and the surface has been reduced to a plain of 

low relief with only a few ridges and hills capped by resistant beds 

standing prominently above it.

At the south side of the coal field are two areas in which the beds of 

rock lie horizontal or nearly horizontal. In those areas stand the 

broad eastward-trending Sugarloaf and Poteau Mountains. Those 

two mountains rise about 2,000 feet above the adjacent valleys, and 

the crest of Poteau Mountain, 2,665 feet above sea level, is the highest 

point in the area. The lowest point is on the Arkansas River, where 

it leaves the area in the northeast corner. It is about 360 feet above 

sea level and about 2,305 feet lower than the top of Poteau Mountain.

Northwest of the city of Paris, at the east side of the area, two flattopped mesas, Horseshoe and Short Mountains, capped by a resistant 

bed of sandstone, rise about 500 feet above the surrounding country. 

Scattered throughout the area are a few conical hills 100 to 300 feet 

high capped by resistant sandstone beds.

In the west-central part of the area Biswell Hill, a broad, smoothly 

rounded hill about 9 miles long, rises to a height of about 400 feet. 

Its entire surface, both the flanks and the crest, is formed by a resistant sandstone bed.

North of the Arkansas River in the eastern part of the area and to a 

small extent in the extreme western part of the area, the surface consists of broad uplands underlain by resistant sandstone beds and 

broken by valleys 200 to 400 feet deep and a quarter of a mile to half 

a mile wide.

Throughout the remainder of the area stretch long, narrow ridges', 

separated by somewhat wider valleys and breached at intervals by 

streams. The ridges rise 100 to 300 feet above adjacent valleys, 

and their crests stand at approximately the same level, both along 

the trend of the ridges and from any one ridge to those adjacent.

DRAINAGE

The entire area is drained by the Arkansas River and its tributaries. The Arkansas River pursues a meandering course across the 

northern part of the area from west to east, and most of its tributaries 

flow northward or southward into it approximately at right angles.

Most of the southern tributaries of the Arkansas within the area 

rise within the coal field and are sluggish streams heavily laden with 

very fine sediment except at stages of very low water. The James 

Fork of'the Poteau River, the largest stream south of the Arkansas, 

rises on the north slopes of Poteau Mountain and flows northwestward to a point near Hackett, where it enters Oklahoma. In Oklahoma it joins the main Poteau River, which flows northeastward and 

joins the Arkansas on the Arkansas State line at Fort Smith. In 

addition to its heavy load of sediment, the James Fork carries much
WESTERN PART OF THE ARKANSAS COAL FIELD 193

water that flows out or is pumped out of coal mines and is consequently strongly acid.

Its waters are unpalatable and will not support fish and other life 

that is characteristic of unpolluted streams of the area. The other 

permanent streams south of the Arkansas are Vache Grasse, Big, 

Sixmile, and Hurricane Creeks. Hurricane 'Creek and its tributaries 

drain most of the eastern part of the area that lies south of the river 

and unlike most of the other streams flows eastward instead of northward.

All the larger streams that enter the Arkansas River from the 

north rise within the Boston Mountains north of the coal field and 

are clear except at times of freshet. They carry larger volumes of 

water .than the streams south of the river. The largest northern 

tributaries of the Arkansas in the area are Lee Creek, Clear Creek 

(formerly called Frog Bayou), and the Mulberry River.

Most of the other streams in the area flow only in wet seasons, 

although a few of them are permanent in their lower courses.

The Arkansas, the James Fork, Lee Creek, Clear Creek, and the 

Mulberry River all flow in channels that lie about 25 feet below broad 

flood plains covered by alluvium. In times of flood each of these 

streams escapes from its banks and its waters spread across its flood 

plain except in places protected by levees.

CLIMATE AND VEGETATION

The chief climatic characteristics of the area are its short and, as 

a rule, moderately cold winters, long hot summers, ample sunshine, 

moderate extremes of temperature, excessive humidity, and heavy 

rainfall. The weather during spring and late autumn is generally 

pleasant. From June to the middle of September many of the nights 

are sultry and oppressive. During the winter there are many balmy 

and sunny days. Precipitation is general during the colder months 

but is more local during the other months, when it usually occurs 

in connection with thunderstorms. Most of the precipitation falls 

in the form of rain and averages about 46 inches a year.

There are a few areas of natural prairie within the western part 

of the Arkansas coal field, but most of the area is either wooded or 

has been cleared to supply the demand for tillable land. Most of 

the rocky hillsides support a growth of blackjack, white and red oak, 

persimmon, and some hickory. The higher mountains in the southern 

part of the area and the flat-topped hills north of the Arkansas River 

in the northern part of the area bear a sprinkling of yellow pine and 

cedar among the hardwood trees. In the valleys pecan, cottonwood, 

sycamore, and willow heavily burdened with clambering vines, grow 

along the streams and lakes and in a few larger areas that have not 

been cleared to supply the demand for rich tillable land.

75432 37 2
194 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36 

POPULATION AND ACCESSIBILITY

The western part of the Arkansas coal field is a rather thickly 

settled country in which are situated five cities that have populations 

of more than 1,000 and many smaller towns. Forth Smith, which has 

a population of 31,429 (1930 census) is the largest city and the 

industrial center of the area. It is immediately south of the Arkansas 

River in the extreme western part of the area. Five railroads, the 

St. Louis-San Francisco, the Missouri Pacific, the Kansas City 

Southern, the Midland Valley, and the Fort Smith & Western, have 

lines into Fort Smith that supply adequate railroad connections with 

all parts of the country. In addition to these railroads the Chicago, 

Rock Island & Pacific passes through Hartford, Mansfield, and 

Abbott, in the southern part of the district, and the Fort Smith, 

Subiaco & Rock Island connects with the Missouri Pacific in Paris 

and continues eastward from that city. Van Buren, adjacent to 

Fort Smith on the north side of the Arkansas River; Paris, in the 

southeastern part of the area; Ozark, in the northeast corner; and 

Hartford, in the southwestern part, are the other cities of the area. 

In addition to these cities there are more than 40 towns, villages, and 

communities distributed rather evenly over the area. All the cities 

and some of the towns are modern communities supplied with city 

water, sewerage systems, electricity, and natural gas.

Two national highways pass through the area*. One crosses the 

northern part of the area from Ozark to Fort Smith, where it crosses 

the State line into Oklahoma. The other crosses the western part of 

the area from a point north of Alma southward through Van Buren 

and Fort Smith and thence southward to Abbott, south of which it 

crosses the boundary of the area. In addition to the national highways there were six excellent State highways in the area in 1934. 

These highways, together with numerous county roads, make all parts 

of the area easily accessible.

The transportation facilities and large fuel supplies of the area have 

combined to make Fort Smith an important industrial center. The 

other cities and towns are largely dependent on agriculture and coal 

mining, which, together with the production of natural gas, constitute 

the major industries of the area.

GENERAL GEOLOGY

STRATIGRAPHY 

AGE AND CHARACTER OF THE ROCKS

Except for the terrace deposits and alluvium along the streams the 

exposed rocks of the western part of the Arkansas coal field belong to 

the Pennsylvanian series of the Carboniferous system. The section 

of rocks consists of sandstone beds alternating with thicker beds of 

shale. Some of the shale beds also contain coals and underclays.
WESTERN PART OF THE ARKANSAS COAL FIELD 195

In "general the sandstone beds are very similar and have no lithologic 

characteristics by which they can be identified from place to place. 

The shale beds do not have lithologic differences that characterize 

any single bed from place to place, but although the group of shale 

beds in the lower part of the stratigraphic column (those in the Atoka 

formation) cannot be distinguished from each other, they can be distinguished from the shale beds that are present in the younger formations. The coal beds can be identified with reasonable accuracy by 

their own characteristics and by the sequence of overlying and underlying beds. In addition, at most places the shales associated with the 

coal beds contain plant fossils that are characteristic of each horizon 

over a large area and differ from any one horizon to another. Where 

plant fossils are abundant the stratigraphic position of the beds that 

contain them can be definitely determined.

The group of sandstones, shales, and coals that are present in the 

Arkansas coal field extend westward into Oklahoma, where they were 

originally studied by Taff and Adams,6 who divided the column of 

rocks into a series of formations to which they gave names. Five of 

the formations extend eastward into Arkansas. They are, from oldest to youngest, the Atoka formation, Hartshorne sandstone, McAlester shale, Savanna sandstone, and Boggy shale. These formations, 

together with all units within the formations that can be traced laterally, have been mapped in the course of the field work on which this 

report is based. The formations present, the characteristic lithology 

of the units within the formations, and the thickness of the units for 

the southwestern and eastern parts of the area are given in the two 

columnar sections in plate 35.

In 1907 the United States Geological Survey published the results 

of an investigation of the entire Arkansas coal field conducted by a 

field party working under the direction of A. J. Collier.7 In that 

report some of the formation names mentioned above were used, but 

the boundaries between the formations were placed at horizons 

different from those used by Taff and Adams 8 in the earlier work in 

Oklahoma. In the field work on which the present report is based the 

formation boundaries were first traced eastward to the ArkansasOklahoma State line by T. A. Hendricks 9 and were then traced eastward into Arkansas from the previously determined positions at the 

State line. The Atoka formation and Hartshorne sandstone, as 

mapped and described by Collier, are identical with the Atoka formation and Hartshorne sandstone of this report. Collier called the 

McAlester shale the McAlester group and subdivided it into the Spadra

 Taff, J. A., Geology of the McAlester-Lehigh coal field, Indian Territory: TJ. S. Geol. Survey 19th Ann. 

Kept., pt. 3, p. 441,1899. Taff, J. A., and Adams, G. I., Geology of the eastern Choctaw coal field, Indian 

Territory: U. S. Gool. Survey 2lst Ann. Kept., pt. 2, p. 273,1900.

i Collier, A. J., The Arkansas coal field: U. S. Qeol. Survey Bull. 326,1907.

8 TaS, J. A., and Adams, G. I., op. cit.

8 Hendricks, T. A., Geology and mineral resources of the Howe-Wilburton district, Latimer and LeFlore 

Counties, Okla.: U. S. Geol. Survey Bull. (in preparation).
196 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

shale, Fort Smith formation, and Paris shale, and in addition mapped 

an overlying sandstone as Savanna sandstone. The correlation 

between Collier's divisions and those used in this report are given in 

the table below.

Correlation between formation divisions used by Collier and formation divisions

used in this report.

Collier (Bull. 326)

Savanna sandstone.

Paris shale.

Fort Smith formation.

Spadra shale.

Hartshorne sandstone.

Atoka formation.

This report

Boggy shale.

Savanna sandstone.

McAlester shale.

Hartshorne sandstone.

Atoka formation.

At many places throughout the area unconsolidated sand, gravel, 

and clay occur in deposits a few feet to about 50 feet thick above the 

bedded rocks of Pennsylvanian age. These unconsolidated materials 

are alluvial deposits laid down by streams in Quaternary (?) and 

Quaternary tune.

CARBONIFEROUS SYSTEM

PENNSYLVANIAN SERIES

ATOKA TOEMATION

Beds of the Atoka formation are exposed in five places in the area. 

The largest belt of outcrop lies in the southeast corner of the area. 

A somewhat smaller area lies along and south of Backbone Ridge 

between Greenwood and the Arkansas-Oklahoma State line. A small 

outcrop is present on Massard Prairie southeast of Fort Smith. An 

elongated belt of outcrop occurs along the south side of Mill Creek 

Ridge in the north-central parts of the area, and beds of the Atoka 

formation extend along the entire north side of the area.

In the belt of outcrop along Backbone Ridge about 6,500 feet of 

the Atoka formation is exposed, and near Mansfield, in the southeastern part of the area, about 3,300 feet of the Atoka crops out at the 

surface, and an additional 2,700 feet has been penetrated in wells 

drilled for gas. In the other areas of outcrop only the uppermost 

beds of the Atoka formation are exposed.

The exposed parts of the Atoka formation consist of alternating 

beds of sandstone and shale with a few streaks of coal present locally
WESTERN PART OF THE ARKANSAS COAL FIELD 197

in the shale. . The sandstones vary greatly in thickness and lithology, 

both from bed to bed and from place to place in a single bed. In 

general the sandy zones continue for considerable distances, although 

a thick sandstone may pass laterally into a sandy shale that is con- 

.siderably thinner. The sandstones range from coarse-grained, almost 

white, and pure to fine-grained, brownish, and very shaly. Considerable amounts of mica are present in the sandstones at all places. 

. At some places in the areas sandstone beds in the Atoka formation 

thicken from 10 to 15 feet to as much as 150 feet in distances of a 

quarter to half a mile. At those places the base of the sandstone cuts 

downward across the bedding of the underlying shale in the direction 

of the thickening. The thicker part of the sandstone was deposited 

in a stream channel that had cut downward into the underlying shale! 

A conspicuous example of such a channel sandstone is exposed in the

bluff on the north side of the Arkansas River immediately west of the 

bridge that crosses the river at Ozark. Brownish sandy micaceous 

shale either overlies or underlies the sandstone beds at most places,, 

and the transition from sandy shale to shale in one direction and from 

sandy shale to sandstone in the other direction is gradual. The 

remainder of the formation consists of black slightly gritty, splintery 

shale that contains much coarse mica. This splintery shale differs 

greatly in appearance from the shales of the McAlester, Savanna, and 

Boggy formations that lie higher in the section.

The beds of the Atoka formation that are exposed or have been 

penetrated by drilling in the northern part of the area vary only 

slightly in thickness. From the Backbone fault southward, however, 

the upper part of the Atoka formation thickens rapidly. A thick 

sandstone bed that is 2,450 feet below the top of the formation near 

the Backbone fault lies 4,250 feet below the top of the formation in 

wells drilled near Mansfield, about 12 miles farther south. 

. In many exposures near Mansfield and in a few exposures southeast 

of Greenwood, sandstones in the Atoka formation contain plates of 

shale as much as 3 inches long and half an inch thick that lie in the 

sandstone at various angles to the bedding. The plates of shale are 

similar hi appearance to the black shale of the Atoka formation. 

Their presence in the sandstones indicates that previously deposited 

Atoka shale was being eroded while the sandstone was being deposited. 

The large size of the plates of shale indicates that they were transported only a short distance before being deposited in the including 

sandstone. This feature, together with the presence of channels in 

which some of the sandstones were deposited, indicates that, at 

least locally, breaks occurred in the deposition of the Atoka beds and 

that minor unconformities or diastems are present in that formation.

The Atoka formation of the Arkansas coal field is identical with the 

Atoka formation of the Oklahoma coal field. It contains abundant 

macerated plant material, and a few thin beds containing poorly
198 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

preserved invertebrate animal remains have been noted. No horizon 

marked by invertebrate fossils can be traced beyond a single local 

outcrop, however.

HARTSHORNE SANDSTONE

The Hartshorne sandstone rests on an irregular surface of the Atoka 

formation, and a minor unconformity probably separates the two 

formations. The Hartshorne sandstone ranges from about 10 to 

about 300 feet in thickness in exposures in the western portion of the 

Arkansas coal field. Where it is thick it is generally coarse-grained, 

pure, and thick-bedded or massive, and where it is thin it is finegrained, thin-bedded, and shaly. In all exposures, however, fresh 

surfaces of the sandstone have an ashy-white color that is characteristic and serves to distinguish the Hartshorne from other sandstones in 

the area, although in some outcrops the next two sandstones above the 

Hartshorne have a similar appearance for short distances.

The Hartshorne sandstone in Arkansas is defined as the first continuous sandstone underlying the Lower Hartshorne coal. Taff and 

Adams 10 defined the Hartshorne sandstone in Oklahoma as extending 

from the top of the first sandstone below the Upper Hartshorne coal 

to the base of the first continuous sandstone below the Lower Hartshorne coal. Thus it is apparent that the sandstone lying between the 

Upper and Lower Hartshorne coals in Oklahoma is not a part of the 

Hartshorne sandstone as mapped in Arkansas. That sandstone is 

present only as a lenticular bed at a few places in the extreme southwestern part of the Arkansas coal field, and the lack of continuity of 

its top makes it unsatisfactory as a formation boundary. In all 

earlier work in the Arkansas coal field the definition of the Hartshorne 

sandstone has been identical with that of the present writer.

The fact that the Hartshorne sandstone extends over the entire 

area without interruption indicates that it was laid down beneath a 

body of water that extended over the entire area. The presence of 

thick, coarse-grained facies of the sandstone, alternating with thin, 

fine-grained, and shaly facies, suggests that channels existed in the 

sea or lake bottom and that the coarser material transported into the 

sea or lake was deposited in those channels while the finer materials 

were more widely distributed and form a blanket of sediment in th,e 

interchannel areas.

Invertebrate animal remains are rare in the Hartshorne sandstone, 

but plant remains are present in great abundance. Most of the plant 

remains hi the sandstone proper are fragments of stems and twigs that 

probably were transported into the body of water from nearby land 

areas, although some are of types that grow in shallow water and 

may have lived in the sea or lake in which the Hartshorne was laid 

down.

"> Taff, J. A., and Adams, O. I., Geology of the eastern Choctaw coal field, Indian Territory: U. S. Qeol. 

Survey 21st Ann. Kept., pt. 2, pp. 274-275,1900.
WESTERN PART OF THE ARKANSAS COAL FIELD 199

MCALESTER SHALE

The McAlester shale overlies the Hartshorne sandstone conformably throughout the area. It ranges in thickness from about 1,820 

feet in the southwest corner of the area to about 1,050 feet in the 

east-central part. The bulk of the formation consists of dark gritty 

shale that is somewhat platy. In the southwestern part of the area 

five sandstones and five coal beds are present in this shale. In the 

eastern part of the area it includes only one sandstone and two coal 

beds.

The Lower Hartshorne coal lies near the base of the McAlester 

shale. This coal bed is the most valuable one in the Arkansas coal 

field, because of its thickness and the extent of the area underlain 

by it, both of which are greater than those of any other coal bed. 

The Upper Hartshorne coal lies about 50 feet above the base of the 

McAlester shale but is present only in the southwestern part of the 

area. This coal may possibly be mined commercially at a few places. 

The other coal beds in the formation are thin and are not of commercial importance.

The sandstones in the McAlester shale are generally thin-bedded, 

ripple-marked, fine-grained, and gray to buff. Locally, however, the 

lowest sandstone in the southwestern part of the area and. the one 

sandstone present in the eastern part of the area are coarse-grained, 

pure, and white. At those places they resemble the coarse-grained 

thick facies of the Hartshorne sandstone.

A few poorly preserved invertebrate animal remains were noted 

locally in the McAlester shale, and abundant plant remains are 

present at a few horizons, notably in the roof shale of the Lower 

Hartshorne coal. The plant remains are identical with plant remains 

in the McAlester shale of Oklahoma and corroborate the correctness 

of the tracing of the formation into Arkansas.

SAVANNA SANDSTONE

The Savanna sandstone rests with a somewhat irregular contact on 

the McAlester shale. Near the Arkansas State line, on the part of 

Sugarloaf Mountain that extends into Oklahoma, the basal sandstone 

of the Savanna cuts downward across the beds in the upper part of 

the McAlester shale at an angle of several degrees. These features 

indicate that at least a minor unconformity is present at the base of 

the Savanna sandstone.

The formation consists of 1,140 to 1,610 feet of alternating beds of 

sandstone and sandy shale in which several coal beds are present. 

The sandstones are generally thin-bedded, ripple-marked, fine-grained, 

and buff to brown. Locally, however, they are coarse-grained and 

irregularly bedded. The shales are sandy and gray to brown. Two 

coal beds are present in the formation in the southwestern part of
200 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

the area, and at least five are present in the eastern part. The 

Cavanal coal in the southwestern part of the area and the Charleston 

and Paris coals in the eastern part of the area are the only coals of 

any possible commercial importance.

A few poorly preserved remains of invertebrate animals and an 

abundance of well-preserved plant remains are present in the formation. The plant remains, together with the lateral tracing of continuous beds in the formation, served as the basis of correlation of the 

Savanna sandstone in Arkansas with that formation in Oklahoma.

BOGGY SHALE

The Boggy shale overlies the Savanna sandstone conformably at a 

few places in the area. Less than 100 feet of Boggy shale is present 

on the top of Poteau Mountain in the southwestern part of the area. 

About 500 feet of Boggy shale is present south of Charleston, and 

about 900 feet is present on Short and Horseshoe Mountains near 

Paris, in the eastern part of the area.

The part of the formation present in the area consists of dark clay 

shale and gritty shale, with three sandstone beds that lie about 760 

to 900 feet above the base. The shales are poorly exposed, and 

possibly some coal beds are present in them, though none were seen. 

The sandstone is coarse-grained, medium-bedded, and bufT to brown.

No fossils of any kind were noted in this formation, but fossils 

may be present and might have been found had exposures of the formation been better or more numerous. The correlation of this formation with the Boggy shale of Oklahoma is based on its similar position above the Savanna sandstone and on the similarity in lithologic 

character of the beds in the Arkansas and Oklahoma areas.

QUATERNARY (?) SYSTEM

STREAM TERRACES

Extensive deposits of gravel, sand, silt, and clay occur about 50 

feet above the Arkansas River and on both sides of it in the northern 

part of the area. They have a maximum thickness of about 50 feet 

and are made up of silt, clay, and coarser deposits that consist chiefly 

of quartz, chert, quartzite, sandstone, and other siliceous materials. 

Some of the sand is probably of local origin, but most of the material 

is unlike any rocks present in the western part of the Arkansas coal 

field. It was probably transported into the.area from the west by 

the Arkansas River and from the north by the major tributaries of 

the Arkansas and was deposited in the alluvial valleys of those streams. 

Since that time the streams have cut downward and now occupy 

valleys that lie about 50 feet below their former deposits, which now 

cover terraces along the sides of the valleys. Similar terraces are 

present along the courses of many of the streams that flow northward
201

from Poteau Mountain, but the material in those terraces was nil 

derived from the beds of rock exposed on Poteau Mountain.

The precise age of the deposits has not been determined, and they 

are only provisionally considered as of Quaternary age.

QUATERNARY SYSTEM

ALLUVIUM

Deposits of alluvium are present in wide areas along the courses of 

the Arkansas River and its major tributaries, and smaller alluvial 

deposits are present in the valleys of the smaller streams. The alluvium along the courses of the tributaries of the Arkansas River is 

mostly silt that ranges in thickness from a featheredge at the sides of 

the flood plains to about 20 feet in the stream banks. Numerous 

gas wells have been drilled through the alluvium of the Arkansas 

River southeast of Van Buren, and many have passed through 30 to 

50 feet of silt, which is the type and thickness of alluvium that might 

be expected on the flood plain of the river. Two wells encountered 

255 and 260 feet of sand and gravel. That material probably was 

deposited in abandoned channels of the river and represents approximately the maximum thickness of alluvium that may be expected.

STRUCTURE

The Arkansas coal field lies in a long, comparatively narrow structural basin that extends eastward along the Arkansas Valley from the 

Oklahoma State line and lies between the Boston Mountains on the 

north and the Ouachita Mountains on the south. The geologic 

structure is very different in these two mountain areas. The rocks 

of the Ouachita Mountains have been folded and locally broken or 

faulted by intense pressure exerted from the south. In the folds 

and along the faults the beds of rock are now inclined at high angles 

to their original horizontal position, and in many places they are 

vertical or even overturned. The rocks of the Boston Mountains, 

however, have been tilted southward at a low angle to the horizontal, 

are only gently folded, and are broken by steep faults, along most 

of which the beds on the north side have been raised in relation to 

the beds on the south side. Faults along which the movement of 

the rocks was chiefly horizontal and due to compressive forces, such 

as the faults of the Ouachita Mountains, are called thrust or reverse 

faults, and faults along which the movement was chiefly vertical, 

such as the faults of the Boston Mountains, are called normal faults.

The geologic structure of the western part of the Arkansas coal field 

is essentially a combination of the structure of the Ouachita Mountains with that of the Boston Mountains. In the southern part of 

the coal field the rocks have been strongly folded and broken by a 

few reverse faults. The structure of that part of the area is similar 

to that of the Ouachita Mountains, which lie adjacent to it on the

75432 37 3
202 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

south, but the intensity of the folding and faulting is less than that 

of the Ouachita Mountains. In the northern part of the coal field 

the rocks have been gently folded and broken by normal faults. The 

structure of that part of the area is similar to that of the Boston Mountains, but the folding and faulting are somewhat greater.

The geologic structure of the western part of the Arkansas coal 

field is highly varied. In the southern part of the area the large, 

steeply folded Mansfield anticline trends eastward through Hartford 

and passes south of Mansfield and Abbott. It lies between the broad, 

shallow Poteau Mountain and Sugarloaf synclines, along whose axes 

lie the two high mountains from which the synclines were named. 

North of these structural features lies a belt of anticlinal folding that 

trends eastward across the entire area and passes a short distance 

south of Bonanza, Jenny Lind, Greenwood, Chismville, and Paris. 

The Backbone, Washburn, and Pine Ridge anticlines, which form 

this belt, are large steep folds with many vertical and locally overturned beds on the north flanks and dips of 65° or less on the south 

flanks except in a few small areas where the dips are steeper. The 

Backbone fault, a reverse fault that extends from the vicinity of 

Bonanza eastward to a point between Jenny Lind and Greenwood, 

breaks the rocks along the crest of the Backbone anticline. Several 

smaller faults are present along the north flanks of the folds, particularly near Jenny Lind and Paris. Throughout the area north of a 

line extending eastward from Bonanza to Chismville and thence to 

Paris the rocks have been warped into a series of alternating anticlines 

and synclines in which the rocks dip at low angles, mostly less than 

10°. In general those folds trend eastward, but some trend northeastward, and a very few trend slightly south of east. Most of the

anticlines are broken by normal faults that lie approximately parallel 

to their axes, and the River Ridge fault, a long normal fault that 

passes south of Alma and Mulberry, lies near and approximately 

parallel to the axis of the Bectum Hill syncline. A number of small 

normal faults with various trends are present throughout this part 

of the area but bear no consistent relationship to the major structural 

axes.

Some evidence indicates that the formation of the folds in the 

southern part of the area began at least as early as Atoka time. 

Sandstones in the Atoka, Hartshorne, and McAlester formations 

along the flanks of the anticlines in that part of the area contain large 

plates of shale that lie in the sandstones at various angles to the bedding. The inclination of the plates of shale to the bedding of the sandstone shows that these fragments of shale were deposited in the sand 

as shale rather than as mud that was changed to shale when the 

including sand was changed to sandstone. Thus the plates of shale 

were derived from previously deposited shale beds that were being 

eroded while the sand was being deposited. In modern streams plates
WESTERN PART OF THE ARKANSAS COAL FIELD 203

of shale can be transported only short distances before disintegrating 

into mud. This fact indicates that the plates of shale were being 

eroded from some place or places close to the localities where they are 

now present. As the fragments of shale are found only in sandstone 

beds that lie on the flanks of anticlines and close to their axes, the most 

logical source for the shale is on the crests of the anticlines. For 

these reasons the writer concludes that the anticlines were being 

warped upward while the sandstones that contain the shale plates 

were being deposited and that their crests were sufficiently elevated 

to be undergoing erosion while the sandstones were being deposited 

on the flanks of the anticlines. The presence of shale plates in sandstones in the Atoka, Hartshorne, and McAlester formations indicates 

that the crests of the anticlines rose at least slightly many times 

during the deposition of the sediments of the coal field. 

The folding and faulting in the Arkansas coal field was not completed until after the deposition of the youngest Pennsylvanian rocks 

present in the area, because even the youngest of those rocks were 

also folded and faulted.

The details of the structure are shown by structure contours on 

plate 35-and are not further considered here.

MINERAL RESOURCES 

COAL

The presence of coal in Arkansas has been known since the days of 

the earliest settlers, and according to Winslow, 11 written mention of 

its occurrence appeared as early as 1818. Prior to 1870 the annual 

production of coal in Arkansas was about 200 tons, obtained from 

small strip mines and used almost entirely in blacksmithing. Commercial production began about 1870, when a steam plant was put 

into operation at the Old Spadra mine, near Spadra, in the eastern 

part of the Arkansas coal field. Production in the Coal Hill and 

Spadra districts began to increase about 1873, when the Little Rock & 

Fort Smith Railway was extended through those districts. Prior 

to 1887 production in the western part of the Arkansas coal field was 

confined to a few small mines located within wagon-hauling distance 

of Fort Smith. With the extension of the St. Louis-San Francisco 

Railway southward from Fort Smith in 1887, extensive mining operations were begun at Jenny Lind, Hackett, and Huntington, in Sebastian County. From that time until 1903 production in the western 

part of the Arkansas coal field increased progressively.

From 1903 to 1918 the production fluctuated from year to year but 

was consistently above 1,200,000 tons. Since 1918 it has decreased

» Winslow, Arthur, The geology of the coal regions a preliminary report upon a portion of the coal regions of Arkansas: Arkansas Geol. Survey Ann. Eeot. for 1888. vol. 3, p. 27,1888.
204 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

at an irregular rate to the present time. This decrease in production 

has been due almost entirely to increased competition from natural 

gas and fuel oil. (See details of production in the table.)

Coal produced in the western part of the Arkansas coal field and total production for 

the State, 1880-1932, in net tons 1

Year

1880

1881 

1882.- . 

1883... ... 

1884 

1885-- . 

1886-. 

1887-- 

1888.. 

1889 

1890... ....... 

1891 

1892. 

1893...- 

1894... 

1895.. 

1896-. 

1897.- 

1898 

1899 

IQOft

1901 

1902-. .

1903- 

1904.................................,. .-.

1905.- 

1906..........................................

1907.. ....................... ....... .

1908-- . 

1909 

1910 

1911-. 

1912-- 

1913 

1914. ... 

1915... . 

1916-- 

1Q17

1918.- 

1920... ---

1921.- 

1922.-. 

1923 

1924-- 

1925-- 

1026 

1927-- 

1928. .. . - 

1929 

1930.. . 

1931 

1932-. 

Sebastian 

County

39, 500

160, 594

165, 884

300, 000

451, 379

420, 098

448, 901

341,110

339, 384

446, 663

568, 891

871, 067

580, 358

999, 479

1, 305, 190

1, 325, 181

1, 528, 888

1, 234, 794

1, 189, 455

1, 278, 497

1, 875, 386

1,425,357

1, 484, 532

1, 454, 128

1, 635, 379

1, 423, 202

1, 152, 402

1, 352, 402

1, 433, 355

1, 447, 268

903, 414

1, 321, 465

826, 821

692, 601

642, 717

703, 186

468, 125

610, 559

1, 832, 000

792, 021

719, 028

628, 562

578, 195

402,011

43, 198, 988

Logan 

County

5,000

10, 000

15, 000

21,751

27, 286

35. 300

26, 090

26, 647

29, 970

30, 723

25, 169

15, 492

11,974

15, 272

10, 000

7,172

29, 505

42, 128

46, 950

49, 368

42, 937

66, 636

74, 962

59, 861

. 84, 526

206, 237

224, 051

925, 000

191, 643

265, 234

318, 567

296, 018

171,272

2 3, 567, 260

Franklin 

County

1,688

3,000

5,000

7, COO

9,879

. 338,013

394, 884

408, 494

420, 384

330, 000

440, 000

270, 000

281, 399

296, 725

421,591

373, 314

346, 682

168, 746

190, 237

243, 118

210, 152

240, 149

144, 541

278, 450

168, 046

168, 654

254, 041

229, 404

191, 014

224, 893

282, 825

274, 972

263, 370

226, 737

184, 153

100, 027

3 8, 425, 015

Total production for 

the State

14, 778

20, 000

25, 000

50, OCO

75, 000

100, 000

125, 000

129, 600

276, 871

279, 584

399, 888

542, 379

535, 558

574, 763

512, 626

598, 322

675, 374

856, 190

1, 205, 479

843, 554

1,447,945

1, 816, 136

1,908,966

2, 180, 336

2, 009, 451

1, 889, 848

1,864,268

2, 670. 438

2, 078, 357

2, 377, 157

1, 952, 968

2, 106, 789

2,100,819

2, 234, 107

1, 836, 540

1, 652, 106

1, 994, 915

2, 143, 579

2, 227, 369

1,429,020

1, 231, 777

1, 110, 046

1, 233, 242

1, 461, 503

1, 220, 039

1, 469, 017

3, 415, 904

1, 660, 973

1, 695, 108

1, 533, 434

1, 349, 905

1, 081, 494

68, 317, 118

Production of the western part of the Arkansas coal field:

Sebastian County_____________._________________________ 43,198,988 

Logan County...-.--.--.-..-----.--.-.---.-...-. .. ....___ 3,567,260 

Franklin County... ........................ 1,873, 536

48,639,784

1 Figures for period 1880-1923 compiled from U. S. 009!. Survey Mineral Resources of the United States. 

Figures for period 1924-31 compiled from U. S. Bur. Mines Mineral Resources of the United States. Figures for 1932 taken from U. S. Bur. Mines Minerals Yearbook.

2 Only 1 mine has operated commercially in the part of Logan County that lies outside the area covered 

by this report, and as its production has been small no deduction has been made for it in the figures given 

above.

s Of the total production from Franklin County, 1,873,536 tons came from the portion of the county that 

lies in the area covered by this report.
WESTERN PART OF THE ARKANSAS COAL FIELD 205

Only three coal beds have been mined commercially in the western 

part of the Arkansas coal field. These are, from oldest to youngest, 

the Lower Hartshorne, Charleston, and Paris. About 88.4 percent 

of the coal mined has come from the Lower Hartshorne bed, about 7.7 

percent from the Paris bed, and about 3.9 percent from the Charleston bed. In addition to these beds, numerous thin beds of coal are 

present, and several have been mined locally. In general these thin 

coals are less than 18 inches thick, although in a few places one or more 

of them may exceed 18 inches in thickness for a short distance.

DISTRIBUTION AND THICKNESS OF THE COAL BKDS

Coal below the Lower Hartshorne. A local coal bed is present between 

the Lower Hartshorne bed and the top of the Hartshorne sandstone 

in T. 6 N., Rs. 31 and 32 W. This coal lies about 30 feet below the 

Lower Hartshorne bed and is reported to be 30 inches thick in sec. 

13, T. 6 N., R. 32 W., and sec. 17, T. 6 N., R. 31 W. In these areas 

small mines, now abandoned, have worked on this bed. At the points 

where the coal has been mined it is said to be impure and of poor 

quality. In the other parts of T. 6 N., Rs. 31 and 32 W., available 

records show less than 10 inches of coal at the horizon of this coal.

Lower Hartshorne coal. The Lower Hartshorne coal is the most 

valuable coal bed in the western part of the Arkansas coal field. 

It underlies a much larger area and has a greater average thickness 

than any other coal bed. The largest area underlain by this coal 

lies in Sebastian County and is shown in detail on plate 35. The 

map shows zones of equal thickness of the coal based on more than 

550 sections that have been measured at outcrops, in mines, and in 

holes drilled to determine the depth to the coal, its thickness, and its 

purity. In the part of Sebastian County north of Backbone Ridge 

and Biswell Hill the coal has no partings in about half the sections, 

a 1- to 6-inch parting in the middle of the bed in about 40 percent of 

the sections, and a parting greater than 6 inches in the remaining 10 

percent of the sections. In the part of the area that extends eastward from Greenwood for about 3 miles a parting that ranges from 

1 to 27 inches in thickness irregularly from place to place is present 

in the middle of the coal in about half the measured sections. From 

Huntington westward to the western limit of the mine workings and 

southwestward to the Hofman mine a parting that is 6 inches to more 

than 3 feet thick is present in the middle of the bed. The parting is 

so thick that throughout that area only the upper bench of the coal, 

which is slightly thicker than the lower bench, has been removed. 

In the remaining parts of the area partings in the coal are either 

absent or are very thin and extend for only short distances.

The thicknesses of the coal used in compiling the data on which 

the zones of thickness shown on plate 35 were based were corrected 

to eliminate any partings present. The system used was that
206 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

adopted by the United States Geological Survey for classifying split 

coal beds on the public domain. That system of classification was 

based on the obvious fact than an unbroken coal bed is worth more 

than a bed containing the same thickness of coal but also containing 

a clay or shale parting. Tbe Survey therefore prescribes that any 

parting or bench of bone or impure coal injures the value of the coal 

of the bed in amount equal to the thickness of the parting. Thus a 

bed consisting of 18 inches of coal, 6 inches of shale, and 18 inches 

more of coal is regarded as equivalent to a solid bed 30 inches thick 

(36 inches of coal minus 6 inches of parting equals 30 inches). If a 

parting is thicker than the thinner adjoining coal bench, that bench 

is considered to be of no value, and the thickness of the coal in the 

bed is considered to be that of the thicker bench.

The areas of mine workings shown on plate 35 were obtained from 

all mine maps filed with the State mine inspector and brought up to 

date as of July 1, 1934. All mines shown on plate 35 as having no 

mine workings are wagon mines of small extent, except the Fendergrass shaft, in sec. 5, T. 6 N., R. 32 W., which is a new mine and has 

as yet removed very little coal. The greater part of the area of mine 

workings may be considered as completely mined out, although some 

coal may be removed from pillars in a few of the operating and 

recently abandoned mines.

Throughout the areas in Crawford, Franklin, and Logan Counties 

that are underlain by the Lower Hartshorne coal, data on the thickness of the coal are few. The few available measured sections and 

all reports of thickness indicate that the Lower Hartshorne coal is 

about 18 inches thick throughout those areas, and only a few small 

mines have operated on that coal.

The structure contours on plate 35 are drawn on the top of the 

Lower Hartshorne coal and show the altitude of the coal in relation 

to sea level. In order to determine the depth from the surface to the 

Lower Hartshorne coal at any point it is necessary to determine the 

altitude of the surface at that point and then subtract the altitude 

of the coal from the altitude of the surface.

Upper Hartshorne coal. In T. 5 N., Rs. 31 and 32 W., a coal bed 

occurs 40 to 90 feet above the Lower Hartshorne. No outcrop of 

this coal was seen, but it has been recorded in many drill holes. 

Wherever this coal is present it is separated from the Lower Hartshorne by shale and sandstone. The sandstone is lenticular and 

similar in appearance to the Hartshorne sandstone. Both the 

position of this coal and the character of the underlying beds are 

similar to those features for the Upper Hartshorne coal in Oklahoma, 

and the writer, believes this local coal in Arkansas to be the equivalent 

of the Upper Hartshorne. Where this coal has been encountered in 

drill holes, it has been logged as dirty or bony coal if more than 18
WESTERN PART OF THE ARKANSAS COAL FIELD 207

inches thick. This Upper Hartshorne coal may possibly be worked 

locally in the future, but it is not likely to be of commercial importance.

Charleston coal. The Charleston coal occurs in four separated 

basins in the western part of the Arkansas coal field (see pi. 35). 

The westernmost of these four areas is in the Central syncline just 

south of the town of Central, in T. 7 N., Rs. 30 and 31 W., where the 

Charleston coal underlies an area of about 3% square miles. This 

coal ranges from 12 to 18 inches in thickness in measured sections in 

the Central syncline and has been mined in six small strip pits and 

four small slope mines. Any future mining in this area will probably 

consist of small-scale operations, because of the thinness of the coal 

bed.

The largest area of occurrence of the Charleston coal is in the 

Bloomer syncline and the adjacent northeast end of the Greenwood 

syncline. This area, underlain by the Charleston coal, extends from 

sec. 3, T. 6 N., R. 30 W., northeastward to sec. 29, T. 7 N., R. 29 W., 

and thence eastward to the east side of sec. 25, T. 7 N., R. 28 W., 

and contains a total of about 40 square miles. Measured sections 

and reported thicknesses indicate that the Charleston coal is about 

18 inches thick throughout this basin. In 16 measured sections 

scattered along the outcrop in the basin the coal ranges from 15 to 22 

inches in thickness. Many small mines and strip pits have operated in 

the Charleston coal in this basin, and if its thickness is as consistently 

near 18 inches as is indicated by the scattered measured sections, 

the coal in this basin may possibly be mined commercially in the 

future.

The third area underlain by the Charleston coal lies about 3 miles 

northeast of the town of Charleston, in the Charleston syncline, and 

covers about 3 square miles. The coal has been removed beneath 

about 1 square mile of that area in large strip mines operated by the 

Charleston and the McMillan coal companies. Numerous sections 

measured in the strip pits and in drill holes show the coal to be 14 to 

17 inches thick, with a few sections as low as 4 inches or as high as 

20 inches. A considerable amount of the remaining coal in this 

basin may be mined in strip pits in the future.

The fourth area of occurrence of the Charleston coal is around the 

west end of the Paris syncline. The outcrop of the coal extends 

from the northwest corner of sec. 13, T. 7 N., R. 27 W., westward to 

the center of the south side of sec. 34, T. 8 N., R. 28 W., thence northward and eastward to the center of sec. 23, T. 8 N., R. 27 W. The 

area between these two lines of outcrop is underlain by the Charleston 

coal, but the coal has not been found farther east, although beds at 

the horizon at which it should occur are present. Throughout this 

area 4 to 23 inches of coal has been recorded in 26 measured sections 

and drill holes. In 18 of these records the coal is 14 to 20 inches
208 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

thick, and the remaining sections, in which the coal is either thicker 

or thinner, are scattered and appear to represent only local features. 

The coal has been removed from about one-fourth of a square mile in 

five strip mines operated near the outcrop around the west end of 

this basin by the W. E. B. Coal Co. Seven small wagon mines have 

also operated on this coal in sees. 3, 10, and 11, T. 7 N., R. 27 W. 

In the future some coal may be removed from this area by slope 

mines or by strip mines located near the outcrop of the coal bed.

Paris coal. The Paris coal is present in three areas in the western 

part of the Arkansas coal field. (See pi. 35.) Two of these areas lie 

about 3 miles south of Charleston, are practically continuous, and 

constitute a total area of about 3% square miles that is underlain by 

the Paris coal. The coal ranges from 14 to 22 inches in thickness in 

these two areas and averages about 18 inches. It has been worked 

in 11 small strip mines and 1 small slope mine in these two areas. 

If the thickness of 18 inches of this coal is relatively uniform under the 

two areas, this coal may possibly be mined commercially in the future.

The largest area of occurrence of the Paris coal is in the Paris 

Basin, which lies north and west of Paris and covers a total area of 

about 14 square miles. Throughout most of the Paris Basin the 

thickness of the coal is 18 to 20 inches and is remarkably uniform. 

In the northwestern part of the basin, however, the thickness of the 

coal averages about 22 inches and is locally as great as 34 inches. 

The coal is also reported to have been more than 20 inches thick in 

the area mined out by the Grand No. 1 mine, in the extreme southeast point of the basin. The coal has been removed beneath about 

3% square miles of the total area of this basin, and 37 mines were 

operating or prepared to operate in the basin in 1934. In addition 

to the operating mines, there are 38 abandoned mines in this basin. 

Eventually all or nearly all of the coal in this basin will probably be 

mined commercially.

Other coals. Numerous thin coal beds are present in the western 

part of the Arkansas" coal field, and locally coals as much as 18 inches 

thick have been recorded in drill holes. Coal 16 inches thick and 

about midway between the Lower Hartshorne and Charleston coals 

has been reported at three places. One place is in a diamond-drill 

hole in sec. 7, T. 7. N., R. 30 W., one in the abandoned Sullivant 

wagon mine in sec. 13, T. 9. N., R. 31 W., and the third in the bed 

of the Arkansas River at Moores Rock, in sec. 13, T. 8 N., R. 30 W., 

where the coal has been dug for local use at times of low water. The 

coal at these three places is at or near the same horizon. This coal 

may be thicker at other points, and possibly it may be mined a! least 

locally in the future. In the extreme southwest corner of the area the 

Cavanal coal has been mined at one place for local use.

It is unlikely that any other coal beds in the area are sufficiently 

thick at any point to be mined even locally.
WESTERN PART OF THE ARKANSAS COAL FIELD 209 

RANK, QUALITY, AND USES OF THE COAL

All the coal in the western part of the Arkansas coal field is of lowvolatile bituminous rank. (See table of analyses.) It is low in 

content of volatile constituents, high in fixed carbon, and high in 

heating value as compared with coal of other ranks. In general it is 

very friable and must be handled carefully both in mining and transporting, in order to avoid shattering and excessive production of slack coal.

Most of the coal mined in the western part of the Arkansas coal 

field contains either a low or moderate amount of ash-forming materials. Practically all the coal mined in the area is used as domestic 

and steam-producing coal, uses for which it is well suited because 

of its high heating value and relatively low content of ash-forming 

materials.

MINING METHODS

Coal is mined commercially in the western part of the Arkansas 

coal field both in large strip mines and in underground mines. The 

strip mines are confined to the Charleston Basin and the west end of 

the Paris Basin, and all operate on the Charleston coal. The underground mines operating on the Lower Hartshorne coal are both slope 

and shaft mines, most of which operate on the double-entry roomand-pillar method. However, a few mines have used a modified 

long-wall system of mining on the Lower Hartshorne bed. In most of 

the mines operating on the Lower Hartshorne coal undercutting 

machines and middle-band cutters are used, but in a few mines the 

coal is shot from the solid face or undercut by hand. The Lower 

Hartshorne coal is hand-loaded in all mines. The mines operating 

in the Paris coal are both slope and shaft mines in which the advancing 

long-wall system is used. In all the large mines operating on the 

Paris coal undercutting machines are used together with loading 

machines of the scow-pan and conveyor-belt types.
210 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

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Johnson County

Lower Hartshorne coal bed 

Sterling Coal Co.:

McAlester Fuel Co. (Fernwood No. 2):

Clark & McWilliams Coal Co.:

Logan County

Lower Hartshorne coal bed 

New Deal Coal Co. (Scranton):

Composite of A99831, A99832, A99825 .

Paris coal bed 

Eureka Coal & Mining Co.: 3

Composite of A99406, A99407, A99408. 

A99386

A99387

A99388

A99389

A99394

A99395

A99396

A99397

A99390

A99391

A99392

A99393

A99831

A99832

A99825

A99834

A99406

A99407

A99408

A99409

A

A

A

A

C

D

A

A

A

A

C

D

A

A

A

A

C

D

A

A

A

A

C

D

A

A

A

A

C

D

3.1

2.3

2.3

2.6

2.4

2.3

2.2

2.3

2.6

2.5

2.5

2.5

7.0

4.9

4.1

5.4

1.7

1.8

1.5

1.6

10.3

10.9

10.3

10.6

10.8

11.7

11.0

11.3

11.2

11.2

11.5

12.2

11.4

10.6

11.3

10.9

11.2

12.1

11.3

10.8

10.7

10.5

11.1

11.8

17.9

17.1

17.5

17.6

17.9

19.8

79.5

78.2

80.6

79.3

81.5

88.3

80.9

80.0

80.0

80.2

82.1

87.8

78.1

79.8

79.1

79.2

81.2

87.9

75.0

78.2

80.5

78.1

82.6

88.2

71.1

70.7

72.4

71.3

72.4

80.2

7.1

8.6

6.8

7.5

7.7

5.7

6.4

6.6

6.3

6.4

7.9

7.1

7.1

7.4

7.6

6.7

6.1

4.7

6.0

6.3

9.3

10.4

8.6

9.5

9.7

1.

2.

1.

1.

1.

1.

1.

1.

1.

1.

1.

1.

1.

2.

1.

1.

1.

2.

1.

2.

1.

1.

1.

1.

2.

2.

2.

2.

2.

3.

1 For additional analyses of Arkansas coals see Fieldner, A. C., Cooper, H. M., and Osgood.F.D., Analys

L. C., A study of Arkansas coals: Arkansas Univ. Bull., vol. 22, no. 13. 

' A, Coal as received; C, moisture free; D, moisture and ash free. 

8 Mines in the western portion of the Arkansas coal field (locations given on pi. 35).
Analyses of standard mine samples of Arkansas coals collected by T

[Analyses by H. M. Cooper, U. S. Bureau of 

Mine, locality, and coal bed

Logan County Continued 

Paris coal bed Continued 

Jewel Mining Co.: 3

Superfuel Coal Co.: 3

Composite of A99828, A99829, A99384. _-.-..

Pope County

Lower Hartshorne coal bed 

McAlester Fuel Co. (Bernice No. 3):

Composite of A99410, A99411, A99412.......

Sebastian County

Lower Hartshorne coal bed 

Majestic Coal Co.: 3

Composite of A99402, A99403, A99404. ......

Sample

Laboratory no.

A99833 

A99824 

A99826

A99828 

A89829 

A99384 

A99830

A99410 

A99411 

A99412 

A99413

A99402 

A99403 

A99404 

A99405

Condition

A 

A 

A 

C 

D

A 

A 

A 

A 

C 

D

A 

A 

A 

A 

C 

D

A 

A 

A 

A 

C 

D

Proximate

Moisture

1.9 

2.5 

2.2

1.6 

1.8 

2.0 

1.8

2.5 

2.9 

2.6 

2.7

3.5 

3.3 

3.4 

3.4

Volatile 

matter

16.5 

16.7 

16.6 

16.9 

18.7

18.6 

17.7 

18.2 

18.2 

18.5 

20.3

11.3 

10.7 

10.7 

10.9 

11.2 

12.4

16.2 

16.6 

16.5 

16.2 

16.7 

18.4

Fixed 

carbon

.73.5 

70.9 

72.0 

73.7 

81.3

71.4 

70.9 

71.3 

71.1 

72.5 

79.7

77.4 

77.7 

77.6 

77.6 

79.7 

87.6

72.1 

70.7 

71.9 

71.8 

74.4 

81.6

Ash

8.1 

9.9 

9.2 

9.4

8.4 

9.6 

8.5 

8.9 

9.0

8 8 

8 7 

9 1 

8 8 

9 1

8.2 

9.4 

8.2 

8.6 

8.9

Sulphur

2.

2.

2.

2.

2.

2.

3.

2.

2.

2.

2.7

1.

1.

2.

2.

2.

2.

.9 

.1.

.

1.

1.

1.
Excelsior Producer Coal Co. (Bianca) : »

Composite of A99414, A99415, A99416 __ --

Excelsior Coal Co., Inc. (Skinner mine): 3

Composite of A99827, A99836, A99837--.-- -

Barr Coal Co.: 3 .

Composite of A99418, A99419, A99420..---.-

B. A. Young & Son Coal Co. (Western No. 18): 3

Composite of A99398, A99399, A99400. ------

A99414

A99415

A99416

A99417

A99827

A99836

A99837

A99838

A99418

A99419

A99420

A99421

A99398

A99399

A99400

A99401

A

A

A

A

C

D

A

A

A

A

C

D

A

A

A

A

C

D

A

A

A

A

C

D

7.0

5.7

5.7

4 9

2.9

3.8

. 3 9

3.5

3.8

1.7

2.1

2.1

16.5

15.5

15.5

16.5

17.3

15.7

16.4

16.7

17.2

1 1 <t

114.

15.5

16.1

17.0

15.4

14.7

14.8

15.1

72.6

73.7

73.5

73.3

77.7

82.5

77.0

77.3

76.8

77:1

80.2

82.8

75.4

76.2

75.7

78.7

83.0

76.7

77.5

76.8

76.8

78.5

83.8

5.2

5.4

5.3

5.5

5.8

2.4

3.2

3.0

3.0

3.1

5.1

5.0

5.0

5.2

6.2

5.7

7.0

6.3

6.4

1.2

1.3

1.8

1.5

1.5

1.6

. .7

.7

.7

.6

.7

.7

1.1

1.0

1.0

1.1

1.1

1.2

1.0

1.0

1.2

1.1

1.1

1.2

3 Mines in the western portion of the Arkansas coal field (locations given on pi. 35).
214 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

NATURAL GAS 

OCCURRENCE

Natural gas was discovered in Arkansas in' March 1902, when the 

Choctaw Oil Co. No. 2 well, at the northeast corner of lot 7, sec. 1, 

T. 4 N., R. 31 W., in the Mansfield gas field, blew in with an original 

volume of 550,000 cubic feet. Since that time seven other fields 

have been discovered in the western part of the Arkansas coal field, 

and producing areas have been discovered in other parts of the 

State. In addition to the producing fields, many exploratory v[$$s 

have been drilled that have yielded only shows of gas. Most of the 

unproductive wells, however, have been located at points where the 

geologic structure is unfavorable for the accumulation of gas or were 

not drilled to sufficient depth to reach beds known to carry gas in 

other parts of the area. Several areas in the western part of the 

Arkansas coal field in which the geologic structure is favorable for 

the accumulation of gas have not been adequately tested. 

^ The gas-producing areas of the western part, of the Arkansas coal 

field are the Alma, Shibley, Kibler-Williams, Massard Prairie, 

Lavaca, Vesta, Etna, and Mansfield gas fields. Condensed well 

data for those fields are given in the table below.

Well data for gas fields in the western part of the Arkansas coal field, compiled in 

part from data obtained from field work and in part from data supplied by 

operating gas companies

Interval in feet from top of Atoka formation to top of producing gas sands:

Third siad.. .....................

Fifth sind ... ................ ..

Sixth sinci-... ---------...........

Altitude in feet above sea level of the 

Lower Hartshorne coal at crest of

Structural closure in the field in feet. . 

Initial production of largest producing 

well in thousands of cubic feet ..---. 

Altitude in feet above or below sea 

level of Lower Hartshorne coal in

Rock pressure (pressure of gas exerted 

at the top of the hole) in pounds per 

square inch for each sand:

Third sand.-...... ............

Fifthsand.-.- -- -...-_ 

Number of wells brought in as commercial producers as nearly as can 

be determined from available data..

Alma

1,730

0

700 

42, OOC

-520

330

420

 

29

Shibley

2,050

'540

50 

2,050

220

265

3

KiblerWilliams

1, 845-2, 120

380

300 

24, 000

220

265

77

MasSard 

Prairie

«

2, COO

620

700 

4,250

220

265

63

Lavaca

925

2,375

150

±50 

15, 000

288

220

265

16

Vesta

2,000

425

-50 

3,100

495

2

Etna

1,465

550

±50 

750

+480

615

12

Mansfield

4,075

4,300

5,050

4,150

1,600 

5,000

220

360

315

20

1 Small producers.
WESTERN PART OF THE ARKANSAS COAL FIELD 215

All the gas produced commercially in the western part of the 

Arkansas coal field has come froiu sandstones in the Atoka formation, although small amounts of gas have been obtained in shale of 

the Atoka formation in a few wells. In the Massard Prairie, KiblerWilliams, Shibley, and Alma gas fields two sands are productive. 

The upper one is a sandstone or group of sandstones about 250 feet 

thick that lies between 950 and 1,325 feet below the top of the Atoka 

formation. The lower one is a sandstone 40 to 200 feet thick that 

lies 1,730 to 2,120 feet below the top of the Atoka formation. The 

sands at both horizons, as well as one about 500 feet above the upper 

sand, are productive in the Lavaca field. In the Vesta field, only 

the lower sand is productive, but a flow of about 100,000 cubic feet 

came from a sand about 100 feet below the upper sand. In the 

Etna field the upper sand is the only one for which production is 

recorded. In general the lower sand is the more productive, but in 

a few wells the upper sand yields more than the lower. The two 

general horizons marked by sands are undoubtedly continuous over 

the northern part of the area, but it is unlikely that any single sandstone at either of these horizons is continuous.

In each of these fields the relation between the structural altitude 

and relative amount of production of the different wells is very 

irregular. Large producers are as common on the flank of an anticline as on the crest. This relation indicates that the accumulation 

of gas is controlled partly by structural altitude and partly by the 

porosity of the gas-bearing sand. Except in the Vesta and Alma 

fields, the producing wells in the area in general have a low rock 

pressure, rather low initial production, and a relatively long life. 

These features indicate that the gas migrates slowly in the producing 

sands, probably because of the low pressure and low porosity. The 

producing sands probably contain considerable amounts of silt or 

clay that reduce the effective porosity, for it is reported that "shooting" the sands with nitroglycerine has not appreciably increased the 

flow in the wells and in some wells has even decreased the initial 

flow. This suggests that clay or silt in the sand was packed by the 

force of the shot and the porosity thus reduced. If clay and silt 

were not present in the sand the rock would shatter and additional 

conduits would be opened, thus increasing the flow of gas into the 

well. In the greater part of the area wells drilled even near synclinal 

axes have yielded small amounts of gas, and, according to available 

records, salt water has been encountered at only a few places in the 

area. The absence of salt water in the synclines in most of the 

area explains the presence of at least small quantities of gas in the 

synclines, and the lack of hydrostatic pressure exerted on the gas by 

salt water is in part responsible for the relatively low pressure and 

initial flow.
216 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

In the Alma gas field, salt water was encountered in a well in which 

the Lower Hartshorne coal is about 520 feet below sea level. The 

salt water rose 871 feet in the well because of hydrostatic pressure. 

That pressure is also exerted on the gas in the producing area of the 

Alma field and accounts for the high rock pressure in that field. The 

high pressure in turn accounts for the high initial flow of the wells. 

Eventually, as more gas is produced in the Alma field, wells that are 

successively higher structurally will cease to yield gas and begin to 

show salt water in the bottom of the hole.

Salt water was encountered at several horizons in a well near the 

axis of the Central syncline in sec. 34, T. 8 N., R. 30 W. The Lower 

Hartshorne coal lies about 140 feet below sea level in that well. 

About 6 miles farther southeast, salt water was encountered in a well 

at about the same structural altitude, on the north flank of the 

Greenwood syiicline in sec. 28, T. 8 N., R. 29 W.

Salt water was encountered in a well at a structural altitude of 

about 480 feet on the north side of the Etna anticline. No other 

wells have recorded salt water, and as the water was encountered 

over a range of 1,000 feet in structural altitude it is impossible to 

predict the level of salt water in other areas.

PRODUCTION

Available statistics of production are inadequate to determine the. 

total production of gas in the western part of the Arkansas coal field 

since 1904, but it is probable that between 250 and 300 billion cubic 

feet of gas has been produced. Gas production and reserves in producing fields were considered at length by Croneis 12 in a report on the 

geology of the Arkansas Paleozoic area prepared for the Arkansas 

Geological Survey in 1927 and are not duplicated here.

NATURE OF THE GAS

The gas produced in the western part of the Arkansas coal field is 

of high quality. It is high in methane (CH4 ), and only a few samples 

contain ethane (C2H6 ). It contains small amounts of carbon dioxide, 

oxygen, and nitrogen.

Analyses of Arkansas natural gas ! 

[U. S. Bureau of Mines, analyst]

Massard Prairie... ____________

Kibler- Williams.... ........ ......... ..

Do................... .................

Do.. ____..._ _ _-...-.

Do...................... ......... ..

Do..... .. ..... ..-. - .

Do......... ...........................

Methane

97.96

98.21

98.03

93.20

95.30

98.03

98.21

Ethane

None

None

4.31

1.74

Carbon 

dioxide

0.08

.33

.32

.33

.33

.08

Oxygen

1.55

.92

.83

.32

.41

.83

.92

Nitrogen

0.32

.62

.66

1.75

2.07

.66

.62

After Croneis, Carey, op. cit., p. 371.

» Croneis, Carey, Geology of the Arkansas Paleozoic area: Arkansas Qeol. Survey Bull. 3, pp. 368-440, 

1927.
WESTERN PART OF THE ARKANSAS COAL FIELD 217

The Mansfield gas field was discovered in 1902, when the Duncan 

No. 2 well of the Choctaw Oil & Gas Co. was brought in with an 

original production of 550,000 cubic feet. It is reported that 32 wells 

have been drilled in this field, but the field party working under the 

direction of the writer could find the locations of only 28 wells. Of 

the wells located, 8 were either dry holes or produced so little gas as 

to be of no commercial importance. The remaining 20 wells have 

produced gas in commercial quantities, and most of them are still 

potential producers.

A study of the available drillers' logs of wells in the Mansfield gas 

field indicates that the commercial production comes from sands at 

three horizons 4,075, 4,300, and 5,050 feet below the top of the 

Atoka formation. Each of these sands appears to be highly variable 

in both thickness and character, ranging from 200 feet of hard sandstone to mostly sandy shale with about 40 feet of sandstone. The 

production comes from different levels in these sands in different 

wells and is probably controlled by the variations in the character 

of the sands. In most of the wells the production comes from sand 

at the uppermost horizon, which lies about 800 to 1,200 feet beneath, 

the surface in the wells. In addition to the commercial production, 

shows of gas have been recorded at seven horizons in beds of shale or 

thin sandstone that lie above the first producing sand. It seems 

improbable, however, that commercial production may be expected 

from any of those beds. No attempt has been made to test sands 

below the lowest producing beds, and although no prediction can be 

made it is possible that additional producing beds might be discovered 

by deeper drilling in the proved area. A small but permanent yield 

of gas was obtained from a well in the NW%SW% sec. 3, T. 4 N., 

R. 31 W., on the axis of the Hartford anticline, though about 500 feet 

lower structurally than the producing wells of the main gas field. A 

show of gas was also obtained in a well near the center of sec. 35, 

T. 5. N., R. 30 W., a short distance south of the axis of the anticline 

and about 1,000 feet lower structurally than the producing wells of 

the proved gas area. -These wells suggest that the producing area 

may be extended southwestward and northeastward along the axis 

of the anticline. Three dry holes drilled no more than 150 feet below 

the crest of the anticline on the south flank indicate that extension 

of the field north or south of the axis seems improbable.

The wells in tin's field are small, the greatest production being 

4,500,000 cubic feet a day. The small production is compensated for, 

however, by the long life of the wells. Both these features are illustrated by the history of the discovery well, which was completed in 

March 1902 with an initial production of 550,000 cubic feet and a 

rock pressure of 220 pounds. Three years later the volume had
218 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

increased to 915,000 cubic feet and the pressure to 305 -pounds. 

Throughout the years since that time the well has been alternately 

closed in and turned back into the pipe line. During each period of 

production the volume and pressure decreased gradually, and during 

the periods when the well was shut in the volume and pressure increased gradually but not to the level of the preceding shut-in period.

ETNA GAS FIELD

The Etna gas field lies on the Etna anticline, which extends northeastward across T. 8 N., R. 28 W., and eastward across T. 8 N., Rs. 

27 and 26 W. Six wells have been drilled on the Etna anticline in 

sees. 14, 15, and 16, T. 8 N., R. 27 W., and the two wells nearest the 

axis of the anticline have yielded a small production from a sand 

about 1,465 feet below the top of the Atoka formation. Wells no 

more than 50 feet lower structurally have yielded salt water, how.ever, 

and production may be expected only on the axis of the anticline or 

very near it. The anticline plunges slightly to the west, and only 

slight production might be expected west of the well in the SE%NE% 

sec. 16, T. 8 N., R. 27 W. Eastward, however, the anticline rises 

slightly, and small production might be expected in wells on or very 

near the axis of the anticline as far east as the Arkansas River. Some 

gas also may be present on the north side of the Etna fault hi the 

NX sees. 1, 2, 3, 4, and 5, T. 8 N., R. 27 W.

VESTA GAS FIELD

Two producing gas wells have been drilled in sec. 24, T. 8 N., R. 

29 W., near Vesta. These wells are on a terrace on the south flank of 

the Cecil anticline. In the one well of which records are available 

100,000 cubic feet of gas was obtained in a sandstone about 50 feet 

thick, 1,500 feet below the top of the Atoka formation, and 3,100,000 

cubic feet in a sandstone about 80 feet thick, 2,000 feet below the top 

of the Atoka formation. The initial rock pressure was 495 pounds. 

Exposures in that area are poor, and it is impossible to determine the 

extent of the fold in which the gas has accumulated. Possibly, 

however, the fold may continue eastward from the wells already 

drilled.

LAVACA GAS FIELD

The Lavaca gas field is in sees. 21, 22, 27, 28, and 29, T. 8 N., R. 

30 W. Sixteen producing wells have been drilled in this field, and one 

dry hole has been drilled in the Central syncline just south of the field. 

Sands at three horizons have produced gas. Two wells have'produced from a sandstone that lies about 925 feet below the top of the 

Atoka and is about 100 feet thick. All the other wells in the field 

have passed through this sand without yielding gas. Three wells 

have encountered a small flow of gas from a sand about 1,400 feet
WESTERN PART OF THE ARKANSAS COAL FIELD 219

below the top of the Atoka and in the lower part of a sandstone about 

250 feet thick. The major production in the field, however, comes 

from a sandstone 150 feet thick that lies about 2,375 feet below the 

top of the Atoka. No well has been drilled far enough beneath the 

main producing sand to test any possible producing sands lower in the 

Atoka formation. Other gas-bearing sands may lie lower in that 

formation and may be tested in the future. The production comes 

from the Lavaca anticline, which plunges westward at a low angle 

and has no structural closure that can be recognized from either 

surface exposures or well logs. Additional production may possibly 

be obtained along the axis of the anticline northeastward from the 

area that has already been tested. A study of the drillers' logs of 

the wells indicates that the wells in the NW^NW^ and the N W^NE^ 

sec. 29 are separated from the remainder of the field by a fault that 

dropped'the beds on the southeast'side in relation to the beds'on the 

northwest side. Gas may have accumulated on the north side of 

this fault from the well in the northwest corner of sec. 29 as far west 

as the Massard Prairie gas field.

MASSARD PRAIRIE GAS FIELD

The Massard Prairie gas field is in the northeast corner of T. 7 N., 

R. 32 W., the southeast corner of T. 8 N., R. 32 W., and the southwest 

corner of T. 8 N., R. 31 W. The production in this field comes from 

sands of two horizons. The upper horizon is marked by a group of 

sandstones that lies about 1,100 feet below the top of the Atoka 

formation and is about 270 feet thick. Gas has been encountered 

throughout the group. Most of the wells in the field have stopped in 

or <&t the 'base of this group of sandstones, and consequently most of 

the production in the field comes from these beds. The sand at the 

lower horizon is near the top of a sandstone about 200 feet thick that 

lies about 2,000 feet below the top of the Atoka formation. Small 

amounts of gas have been recorded in sandstones above the 1,100-foot 

sand but were not great enough to be of commercial importance. The 

producing wells have been drilled on the northwest side of the Massard 

Prairie fault, which closes the Massard Prairie anticline on the south 

side. Probably the field could be extended southwestward for about 

1% miles, and some production might be expected on the north side 

of the Massard Prairie fault as far east as the Lavaca gas field. 

Additional gas could be produced by drilling some of the wells that 

have produced from sands at the upper horizon down to the lower 

producing sand in the parts of the field where the lower sand has not 

been drained by old wells. Small producing wells in sees. 1 and 12, 

T. 8 N., R. 32 W., near the axis of the Fort Smith syncline, which lies 

north of the Massard Prairie anticline, indicate that some additional 

gas might be obtained by driUing north of the present producing area.
220 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

SHIBLEY GAS FIELD

The Shibley gas field is in sees. 15 and 22, T. 9 N., R. 32 W. Records are available for three producing wells, three small producers, 

and one well with a show of gas in this field. The production comes 

from sands at three horizons. The uppermost is a sandstone 150 to 

200 feet thick that lies about 950 feet below the top of the Atoka 

formation. The second is a sandstone 50 to 150 feet thick with its top 

.about 1,450 feet below the top of the Atoka formation, and the lowest is 

a sandstone logged as only about 45 feet thick that lies about 2,050 feet 

below the top of the Atoka formation. The production has come from 

a small area of structural closure on the Shibley anticline, and it is 

improbable that the field .can be extended very much in any direction.

ALMA GAS FIELD

The Alma gas field is in the northwest corner of T. 9 N., R. 30 W. 

Production in this field comes from sands at two horizons. The upper

 ore is a sandstone and sandy shale zone about 200 feet thick that lies 

about 1,020 feet below the top of the Atoka formation, and the lower

 one is a sandstone about 1,730 feet below the top of the Atoka formation. According to drillers' logs this lower sandstone ranges from 30 

to 100 feet in thickness in the wells that penetrate it. The sands in 

strong producing wells have a structural range of about 450 feet, which 

is greater than that in any other field in the area covered by this report. 

The initial production from wells in this field was extremely high, the 

largest well being reported to have an initial flow of 42,000,000 cubic 

feet. The original rock pressures were 330 pounds for the upper sand 

.and 420 pounds for the lower sand. Both the production and the 

pressure have declined rapidly in this field, and, although the total 

production will be great because of the high initial volume of the wells, 

the life of the field probably will be much shorter than that of other 

fields in the area considered in this report. Structurally, the field is

 closed on the north and west by the Mulberry and River Ridge faults. 

On the south it is closed by the southward dip of the beds into the 

Bectum Hill syncline. Salt water rose 871 feet in a well drilled into 

the upper producing sand in the SW%NW% sec. 9, T. 9 N., R. 30 W. 

This salt-water table marks the southern limit of the field, and the 

hydrostatic head indicated by the rise of 871 feet in the hole probably 

accounts for the high pressure and high initial production in the field. 

The structural closure on the east side of the Alma gas field is not

 clearly marked. However, in a well drilled in the SW%NE% sec. 2, 

T. 9 N., R. 30 W., near Dyer, the beds are structurally more than 300 

feet lower than in a well drilled about a quarter of a mile farther 

northeast in the same section. This difference suggests that a fault 

is present between those wells. The writer believes that the fault 

.also lies south of a well drilled in the SE% sec. 34, T. 10 N., R. 30 W., 

joins the Alma fault somewhere near the west line of sec. 34, and forms 

the structu ral closure on the east side of the Alma field.
WESTERN PART OF THE ARKANSAS COAL FIELD .221 

KIBLER-WILLIAMS OAS FIELD

The Kibler-Williams gas field lies in the southwest corner of T. 9 N., 

R. 30 W., the northwest corner of T. 8 N., R. 30 W., the northeast 

corner of T. 8 N., R. 31 W., and the southeast corner of T. 9 N., R. 

31 W. The proved productive area in this field is about 15 square 

miles. The production in this field comes from sands at two horizons. 

The upper one is a sandstone or group of sandstones about 250 feet 

thick that lies between 1,070 and 1,325 feet below the top of the Atoka 

formation. The lower and more productive one is a sandstone 40 to 

165 feet thick that lies 1,845 to 2,120 feet below the top of the Atoka 

formation. The producing area lies on the crest and flanks of the 

Kibler anticline, and the volume of gas yielded in each well is only 

roughly related to the structural altitude of the producing sands, as 

large producers lie near small producers, both on the flanks and on the

crest. Possibly the field may be extended eastward for a short distance and westward for 3 or 4 miles in the southern part of T. 9 N., 

R. 31 W. A well in the SE%SW% sec. 33 of that township and outside the area of structural closure, which yielded 750,000 cubic feet 

of gas, lies only a short distance west of the area in which commercial 

-production may be expected.

LOCALITIES STRUCTURALLY FAVORABLE FOR ACCUMULATION OF GAS

BISWELL HILL ANTICLINE

The Biswell Hill anticline extends eastward from the southwest 

corner of sec. 27, T. 7 N., R. 31 W., to the northeast corner of sec. 

29, T. 7 N., R. 29 W. An area of structural closure about 8 square 

miles in extent is present on the anticline. The closure is about 200 

feet and is structurally favorable for the accumulation of gas. Three 

wells have been drilled on this anticline, and all have yielded shows of 

gas. Two of the wells were drilled outside the area of structural 

closure, but one was high on the anticline in the SW%SE% sec. 18, T. 

7 N., R. 30 W., and was drilled to a depth of 2,504 feet. The failure 

of this well to yield more than a show of gas is discouraging but is not 

sufficient to qondemn the anticline as a possible producing area. 

Wells drilled to a depth of about 2,700 feet near the center of the NE% 

sec. 19 and near the center of the west side of sec. 22, T. 7 N., R. 30- 

W., should test the anticline adequately.

VACHE GRASSE ANTICLINE

The Vache Grasse anticline extends almost due eastward about 6 

miles from the SE% sec. 31, T. 8 N., R. 31 W. There is no structural 

closure on this anticline, but a small producing well was drilled in 

the SE% sec. 34, T. 8 N., R. 31 W., and possibly additional production 

might be obtained in wells drilled near the axis of the anticline as far 

west as the center of the S% sec. 32. Test wells on this anticline 

should be drilled to a depth of at least 2,900 feet.
222 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

GAME HILL ANTICLINE

The Game Hill anticline extends eastward from sec. 3, T. 7 N., 

R. 30 W., to sec. 5, T. 7 N., R. 27 W., where it ends against a fault. 

There are two areas of structural closure on this anticline. One is 

a roughly elliptical area of about 2 square miles that extends from 

the NEK sec. 2, T. 7 N., R. 30 W., to the SWK sec. 32, T. 8 N., R. 29 

W., and has a closure of less than 100 feet. A well drilled to a depth 

of 3,235 feet in the center of this area of closure obtained about 

250,000 cubic feet of gas at 2,558 feet. This well does not prove the 

entire area of structural closure to be nonproductive, although it does 

discourage additional drilling. The second area of structural closure 

covers about 5K square miles, chiefly in sees. 1, 2, 3, and 4, T. 7 N., 

R. 28 W., and sees. 5 and 6, T. 7 N., R. 27 W. The closure is about 

150 feet. It is reported that a well was drilled to a depth of, about 

800 feet in the northern part of sec. 3, T. 7 N., R. 28 W., which is 

inside the area of closure. This well was not deep enough to be considered a test of the anticline, and possibly wells drilled near the axis 

of the anticline in the area of closure may yield gas. Possibly, however, the fault that forms the closure on the north side of the anticline 

may have served as an avenue of escape for any gas that may have 

been present in the anticline.

CLOSURE AGAINST BEE BLUFF FAULT

An area of structural closure lies in the northwestern part of T. 9 N., 

R. 27 W., on the east side of the Bee Bluff fault and between the 

Ozark and River Ridge faults. As the exact position and trend of 

the Bee Bluff fault cannot be determined from surface outcrops, the 

western limit of this area of closure is indeterminate. About 2 miles 

east of tliis area of closure is a small dome, in sees. 14, 15, 22, and 23, 

T. 9 N., R. 27 W. Both these areas are structurally suited for trapping gas, but possibly the Bee Bluff fault may have served as an 

avenue of escape for any gas present. The Hartshorne sandstone 

caps the higher ground in both areas, and beds in the Atoka formation 

are present in the valleys. In order to test either of these areas for 

gas it would be necessary to drill about 2,700 feet beneath the surface 

of the higher ground capped by the Hartshorne sandstone.

MANITOU ANTICLINE

The Manitou anticline is a broad domelike fold that extends eastward for about 2 miles from the SEtf sec. 36, T. 10 N., R. 28 W., and 

thence southeastward to the Ozark fault in sec. 4, T. 9 N., R. 27 W. 

The structural closure on the anticline is about 140 feet, and the 

area of closure is about 1% square miles. The Hartshorne sandstone 

caps the high tablelike hill in the central part of the anticline, and 

beds in the Atoka formation crop out at the surface over the remainder 

of the area. A well drilled to a depth of 1,980 feet in the SW% sec. 34,
WESTERN PART OF THE ARKANSAS COAL FIELD 223

T. 10 N., K. 27 W., within the area of structural closure, was reported 

to be a dry hole, as was also a well drilled to a depth of 1,100 feet about 

a mile" farther northeast, on the edge of the area of closure. The 

failure of the deeper of these two wells to yield gas is discouraging, 

but possibly some gas may be present in the structurally higher part 

of the anticline.

CECIL ANTICLINE

The Cecil anticline is a broad fold that extends from the Arkansas 

River in sec. 36, T. 9 N., R. 30 W., eastward to the River Ridge fault 

in sec. 20, T. 9 N., R. 27 W. The structural closure on this anticline 

is about 200 feet and covers a large area. Four wells have been 

drilled on this anticline. One well, in sec. 27, T. 9 N., R. 28 W., was 

on the structurally highest part of the anticline. It is reported to 

have been drilled to a depth of 2,700 feet and to have obtained a 

small -flow of gas. The failure of this well to produce more than a 

small quantity of gas is definitely unfavorable, but additional testing 

of the anticline would be justified on the basis of small production 

having been obtained in nearby fields in wells as favorably situated 

as large producers only a short distance away on the same fold. 

Small producing wells have been drilled structurally lower on the 

west end of this anticline in sec. 29, T. 9 N., R. 29 W., and sec. 36, 

T. 9 N., R. 30 W. A well reported to be a dry hole was drilled near 

the axis on the east end of the Cecil anticline in sec. 29, T. 9 N., 

R. 27 W. These three wells indicate that any gas that may be discovered on this anticline is likely to be in the structurally high part. 

Gas could be present on either side of the Cecil fault, which divides 

this anticline into two parts, and could be lacking on the opposite 

side. Failure to obtain production on one side of the Cecil fault would 

not condemn the other side until it also had been tested.

CLOSURE AGAINST MILL CREEK FAULT

The Mill Creek fault lies south of the axis of the Cecil anticline and 

parallel to it. There is about 250 feet of structural closure against 

this fault. The presence of gas in the small terrace or anticline at 

Vesta, which lies immediately south of this area of closure and structurally lower, suggests that gas may have migrated up the northwardrising beds and may have been trapped in the area of structural 

closure south of the fault. Possibly also the fault may have served 

as an avenue of escape for northward-moving gas. This area can be 

tested only by drilling.

CLOSURE AGAINST MULBERRY FAULT IN T. 9 N., R. 31 W.

A well drilled in the NE^NWK sec. 15, T. 9 N., R. 31 W., about a 

mile north of the Shibley gas field, yielded a show of gas. Northwestward from this well the beds rise about 300 feet structurally to the 

Mulberry fault. The structural rise is closed to the northeast by the
224 CONTBIBUTIONS TO ECONOMIC GEOLOGY, 1934-36

River Ridge fault and to the southwest by a small fault that joins 

the Mulberry fault near the center of the south side of sec. 8, T. 9 N., 

R. 31 W., and trends southeastward for about 1% miles from that 

point. Possibly the three faults have sealed the beds, and gas may 

be present in the area of structural closure. Wells to test this fold 

should be drilled to a depth of about 2,200 feet in order to penetrate 

the producing sands that are present in the nearby Shibley gas field.

SAND AND GRAVEL

Sand and gravel are produced in Fort Smith and Van Buren, in the 

western part of the Arkansas coal field. In both places they have been 

removed from the bed of the Arkansas River by means of dredges, 

and the supply available is adequate to meet all demands. The 

materials dredged range in size from gravel to clay. The clay and 

silt are removed by washing, and the sand and gravel are separated 

by screening. The gravel is made up of pebbles of quartz, chert, and 

quartzite, together with occasional fragments of silicified wood and 

well-cemented sandstone. The sand is clean and is composed of subangular to subrounded fine to coarse grains of quartz. Both the sand 

and gravel are used locally in making concrete.

SHALE SUITABLE FOB MANUFACTURE OF BRICK

Several brick plants have used shale in the Atoka, McAlester, and 

Savanna formations for the manufacture of brick. One plant, that 

- of the Acme Brick Co., of Fort Smith, is still in operation. The shale 

that has been used for brick is gray, clayey, slightly carbonaceous, 

and free from nodules or concretions of carbonates, pyrite, or other 

impurities that might affect the quality of the brick. Paving bricks 

and common red brick are the only two kinds manufactured.

CRUSHED ROCK

Sandstone in the McAlester and Savanna formations has been 

quarried in several places in Fort Smith and crushed for use as road 

ballast and to a lesser degree for road surfacing. The sandstones that 

have been quarried are fine-grained, moderately hard, and of low 

porosity and contain no shale or clay blebs.

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