Geology and Coal Resources of the Southeastern Kansas Coal Field in Crawford, Cherokee, and Labette Counties
by W. G. Pierce and W. H. Courtier
with a report on
Pennsylvanian Invertebrate Faunas of Southeastern Kansas
by James Williams
Originally published in 1938 as Kansas Geological Survey Bulletin 24. This is, in general, the original text as published. The information has not been updated.
by Raymond C. Moore
Coal is one of the very important mineral resources of Kansas, development of which has contributed greatly to industrial growth, not only in eastern Kansas, but in bordering states. There are four coal-mining areas in Kansas: (1) the southeastern Kansas field, located chiefly in Crawford and Cherokee counties, but including a part of Labette County, (2) the eastern Kansas field, lying mainly in Bourbon and Linn counties, (3) the northeastern Kansas field, including Leavenworth County mines, and (4) the east central Kansas field, comprising mainly areas in Osage County, south of Topeka. Of these, the first is much the most important. It is the field described in this report. The other fields, except northeastern Kansas, are developed in higher coal beds than those of southeastern Kansas.
Publication of this report by the State Geological Survey of Kansas is made possible by cooperative arrangement with the United States Geological Survey, under the auspices of which the fieldwork and preparation of the report were done. The work done is not only a valuable contribution to knowledge of the coal resources remaining to be developed in this district, but it represents a considerable addition to geologic information concerning the lowermost Pennsylvanian rocks of the state. This part of the Carboniferous section has been much less studied, up to the present time, by geologists of the State Geological Survey, than higher beds. A part of this report that makes the study of especial value to areas outside of Kansas is the paleontologic description of lower Pennsylvanian deposits, and this is important also to knowledge of the geology of Kansas.
The area described includes parts of Crawford, Cherokee, and Labette counties, Kansas, and a small area in Barton and Vernon counties, Missouri, comprising in all about 1,160 square miles. It includes the Cherokee-Crawford district, originally determined by the extent of the Weir-Pittsburg coal, which extends northeastward from northern Cherokee County through eastern Crawford County and into the northwestern part of Barton County, Missouri, and is the oldest and most important coal-mining area in Kansas. Pittsburg is the largest city and is the commercial center of the coal industry.
Since the early development of the coal field most of the prospecting has been done by drilling test holes. The logs of most of them are remarkably accurate, so that they may be correlated with little difficulty. In this investigation approximately 4,500 well logs and drill records of prospect holes were assembled and used in conjunction with detailed plane-table mapping.
Due to coal, zinc, and lead mining, the region is more densely populated than the agricultural areas of the state. The three southeastern counties of Kansas have an average population of 60 people per square mile. In Crawford County over one-fifth of the people are employed in coal mines, and in Cherokee County over one-fourth are employed in coal, zinc, and lead mines.
The oldest rocks exposed in the area are of Mississippian age. They consist principally of limestone and chert and contain the zinc and lead deposits. They are exposed in a belt trending northeast across the southeast corner of Cherokee County. Except for thin deposits of recent strata, all the rest of the rocks in the area are of Pennsylvanian age. The Cherokee shale, of early Pennsylvanian age, unconformably overlies the Mississippian limestone and consists of shale, sandstone, a few thin beds of limestone, and a number of coal beds from a few inches to 3 1/2 feet thick. It increases in thickness to the west and southwest from 375 to 560 feet, as shown by an isopach map with lines of equal thickness at 20-foot intervals. Two members of the Cherokee which have been recognized in northeastern Oklahoma are extended into Kansas. One is the Little Cabin sandstone member, a brown to buff, medium-grained sandstone that is similar to other sandstones higher in the Cherokee. It is from 10 to 20 feet thick, is underlain by the Riverton coal, and its base is normally 15 to 20 feet above the base of the Cherokee. The other is the Bluejacket sandstone member, which occurs slightly below the middle of the Cherokee, at approximately the horizon of the Bartlesville sand. It is 20 to 50 feet thick and is underlain by the Columbus coal. The Ardmore limestone member of the Cherokee--definitely correlated with the Rich Hill limestone of Vernon County, Missouri, and the probable equivalent of the Ardmore limestone of northern Missouri--is a valuable stratigraphic marker. It is only 2 to 5 feet thick, but is of wide lateral extent and is normally about 100 feet below the top of the Cherokee. Near the top of the Cherokee is a sandstone of variable thickness, which is widely known by drillers as the Squirrel sand. Its top lies just below the Breezy Hill limestone and the base grades into shale. The Breezy Hill limestone member of the Cherokee is about 5 feet below the top of the Cherokee and in most places consists of 6 inches to 2 feet of gray, impure, concretionary to nodular limestone, but may exhibit considerable variation in thickness and character of material.
The unconformity at the base of the Cherokee, although representing a considerable time interval, is of low relief except for troughs and depressions attributed principally to solution of the underlying limestone. These solution irregularities are considered as mostly Cherokee or later in age, rather than pre-Cherokee. Erosional irregularities within the Cherokee occur at the base of the Little Cabin and Bluejacket sandstones and occasionally at the base of higher sandstones in the Cherokee.
The Fort Scott limestone, which lies conformably, on the Cherokee shale, consists of a lower limestone member about 13 feet thick overlain by 3 to 7 feet of shale, and an upper member composed of about 17 feet of limestone. The Labette shale rests conformably on the Fort Scott and consists principally of gray shale with some beds of sandstone and sandy shale and a few thin beds of limestone and coal. It is from 50 to 75 feet thick. The Englevale channel sandstone occurs in the northeastern part of the area, in the vicinity of Englevale. It is light brown with reddish-brown specks, micaceous, somewhat massive, and crossbedded. The upper limit of the Englevale is gradational into the lower part of the Labette shale and its base cuts across the Fort Scott limestone and in places rests upon the upper part of the Cherokee shale. The Pawnee limestone overlies the Labette shale; it consists of about 22 feet of light-gray to white, finely crystalline, and somewhat cherty limestone, similar in general appearance to the Fort Scott.
The structure of the area is depleted by structure contours, drawn at intervals of 10 feet in the coal area and at intervals of 20 feet in the zinc-lead area. The region lies west of the Ozark uplift, and the prevailing dip is to the northwest. The regional strike is northeast, but in detail in most places it is either north or east; the changes in trend are abrupt, and when represented by contour lines form a zigzag pattern. A northwest-trending fold in southeastern Crawford County, named the Pittsburg anticline, has a maximum structural relief of about 70 feet; a small dome on the anticline has a minimum closure of about 20 feet. The zinc-lead district, in southeastern Cherokee County, has two directions of structural trend--one northeastward and the other northwestward. The Miami trough is the most prominent feature and is a northeast-trending depression which seems to represent along its extent a combination of folding, faulting, and solution followed by collapse. Both recent and ancient sink holes are present in the area and are due to solution of the Mississippian limestone. The recent sinks have formed since 1905; the ancient sinks are probably older than Quaternary and younger than the Cherokee.
The economically important coal beds occur in the Cherokee shale. The Weir-Pittsburg coal, near the middle of the formation, is the thickest--increasing southward from an average of 2 feet 10 inches to 3 feet 8 inches--and until recently it has been the principal producing bed. A separate map of the Weir-Pittsburg bed shows (1) the areas that have been shaft-mined and strip-mined, (2) the amount of overburden or depth to the coal, and (3) the approximate western limit of workable coal. Several thin coal beds occur below the Weir-Pittsburg, but normally they are all less than 18 inches thick and are mined at only a few places. Two thin coal beds occur between the Weir-Pittsburg and Mineral bed 75 feet above, but are unimportant commercially and are not mined. The Mineral coal is the second thickest coal bed of the area and is extensively mined by stripping, from the northeast corner of the area southwestward to Mineral. It is 17 to 24 inches thick. The Fleming and Croweburg coal beds lie above the Mineral bed, but are not extensively mined, due to lack of sufficient thickness in most parts of the area. The Bevier coal overlies the Ardmore limestone and is about 100 feet below the top of the Cherokee. It is strip-mined, principally in Crawford County; there the average thickness is 18 inches. The strata between the Bevier coal and the top of the Cherokee are noncoal bearing in Crawford and Cherokee counties. In southeastern Labette County there are several thin beds in the interval, including the Stice coal. The Fort Scott coal is in the uppermost part of the Cherokee and lies only a few feet below the base of the Fort Scott limestone. The coal is from 8 to 12 inches thick in the northeastern part of the area, extending southward to Arma; between Arma and Girard it is discontinuous and is not present farther south. It has been strip-mined at many places along its outcrop.
The coal in the southeastern Kansas field is of bituminous rank, is somewhat friable, practically nonslacking, and has a bright appearance. A little pyrite is present and films of calcite commonly occur along joints and fractures. The Weir-Pittsburg bed is the only one that carries a large amount of clay; it occurs in the form of veins or "horsebacks." Proximate analyses of 26 samples collected during the fieldwork are given in Table 1.
The southeastern Kansas coal field has produced about 88 percent of the total output of the state, and in 1934 produced 91 percent of the state's output. The tonnage production of strip mines and shaft mines, by counties and for the district as a whole, is shown by graphs covering the period from 1885 to 1934. The field produced 2,300,000 tons of coal in 1934; this represents a progressive advance since 1931, but is less than one-third of the tonnage produced in the peak year of 1918.
The coal is mined both from underground workings and open pits. The Weir-Pittsburg bed is the only coal that has been extensively mined underground. Inasmuch as about 75 percent of the workable area of this bed has already been mined, production in recent years has been coming increasingly from the thinner beds, which can be worked profitably only from open pits or strip-mines. Steam shovels were first used for stripping the overburden in the open pit mines, but many of them are now replaced by large electric shovels. Although much of the coal is marketed as run-of-mine, a considerable proportion is size-graded. A large amount of the coal is used for steam raising, the railroads being the largest group of consumers. Large quantities are also used for domestic purposes, for power stations, packing plants, and other industries, both in the surrounding territory and in the vicinity of Kansas City. The market area includes western Missouri, eastern and central Kansas, northeastern Oklahoma, eastern Nebraska, and part of western Iowa.
Petroleum is produced in small quantities from the McCune field, which is about 2 miles northwest of McCune. Production comes from a sand 175 to 200 feet below the top of the Cherokee shale. A small amount of gas is produced from wells near Oswego and at other places, mostly in Labette County.
Tile and brick are manufactured at Pittsburg and Weir from a sandy shale below the Weir-Pittsburg coal. Underclay is used on a small scale for making pottery. Chats, or tailings, from the zinc-lead mills are extensively used for road metal. Gravel, shale from coal-mine dumps, and black, slaty shale are also used for road surfacing.
Kansas Geological Survey, Geology
Placed on web July 27, 2011; originally published Sept. 1938.
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