ART. LI.-Stratigraphy of the Kansas Coal Measures; by ERASMUS HAWORTH. With Plate IX.

Areal Extent.-The eastern fourth of Kansas is covered with Coal Measure rocks. A small triangular area of about thirty square miles, lying in the extreme southeastern corner of the state, is covered with the Mississippian formation. The western limit of the Coal Measures has not yet been fully determined, as the line between the Coal Measures and the Permian has not been definitely located. From paleontologic evidence, according to Proeser, it is above the Cottonwood shales, but probably less than a hundred feet, so that the eastern limit of the Cottonwood Falls limestone is rarely more than ten to fifteen miles east of the western limit of the Coal Measures, and in many places the two are only a few rods apart. The limits of this limestone are now pretty well known, having already been published,† subject to correction, in map form. Approximately the four eastern tiers of counties lie east of this limit, which would give about nineteen thousand square miles for the Coal Measure area.

The Floor.-The Coal Measures rest directly upon the Mississippian formation, which extends at varying depths below the surface far to the westward. The recent extensive prospect. ing for oil and gas in the southeastern part of the state has made it possible to study the position and character of the floor to a great extent. In the extreme southeast corner of the state, in the vicinity of Galena where it covers the whole surface, the hill tops are a little over a thousand feet above the sea level. The Coal Measures approach to within four miles of the east state line opposite Galena. The Mississippian surface declines to the west, so that at Oswego, where it has been reached by at least two wells, it is about 500 feet below the surface, or about 400 feet above sea level, which is a decline of fully 475 feet from the valleys along the eastern part of the state twenty five miles away, or of about 600 feet from the hill tops, giving an average decline of about twenty feet to the mile. Wells at Stover and Mound Valley did not reach the Mississippian, but at Cherryvale, fifty miles away, it was reached 1008 feet below the surface, which places it 180 feet below sea level. As this well was made with a diamond drill and an excellent core preserved, there can be no reasonable doubt *Journal of Geology, vol. iii, p. 702.

Haworth, Kan. Univ. Quart., vol. iii, pp. 271-309.

This core has recently been lodged in the museum of the University of Kansas in a well preserved form, where it can be examined by any geologist wishing to do so.

about the correctness of these figures. This gives a westward inclination of more than twenty feet to the mile. At present we have no definite data regarding the depth to the surface to

the Mississippian west of Cherry vale. A well three miles west of Independence reached 1100 feet without striking it, one at Niotaza 1158 feet, and one at Wichita 1950 feet, so we

can only say it lies below these several depths at the respective places. To the northwest it was reached at Neodesha 135 feet below sea level, at Fredonia 310 feet, and at Fall River 430 feet below sea level, giving a little less than a twentyfoot decline to the northwest. At Osage Mission, thirty nine miles from Galena, a well 700 feet deep failed to reach it. At Chanute, fifty-eight miles away, it was reached 36 feet below sea level, and at a few other points in that vicinity at similar depths. The decline from Galena to Chanute, straight northwest, is consequently about sixteen feet to the mile, considerably less than in a more westerly direction. Northward along the east line of the state it was reached at Girard 493 feet above sea level, at Fort Scott 385 feet above sea level, at Pleasanton 206 feet above sea level, at Paola* 182 feet below sea level, at Kansas City at sea level, and at Leavenworth over 300 feet below sea level. A well 1638 feet deep, or about 775 feet below sea level, at Topeka failed to reach it. The inclination from Galena to Kansas City is, therefore, only about 6.5 feet to the mile. But as the southeastern boundary of the Coal Measures is a line running northeast and southwest, the latter points should be reckoned not from Galena, but from the nearest points of surface exposure of the Mississippian. According to the geological map of Missouri published by Winslow, the Mississippian occupies the surface at Sweet Springs and a few miles to the west, bringing it to within 50 miles or less of Kansas City. Reckoning in this way, we have a decline of the floor from near Sweet Springs to Kansas City of about 15 feet to the mile, and to Topeka about 14 feet, how much more we cannot say, which is considerably less than the decline along the southern line of the state. From the above data we can calculate the decline in any direction. From Kansas City to the southwest we find almost a level in the floor towards Chanute and Cherryvale.

From these and other similar data we may conclude that the Mississippian formation underlies all or nearly all of the Coal Measures in Kansas, and that its upper surface is strongly inclined westward, equaling 20 feet to the mile for the first fifty miles along the south line of the state, and at least 10 feet to the mile for the whole distance to Wichita, and probably more, while to the north as far as Kansas City the inclination averages only about 6.5 feet to the mile, and an intermediate value in intermediate directions. According to Winslow,‡ in a direc

A little doubt has been expressed regarding the correctness of this well record. The record used is preserved in the City Public Library at Paola. The criticism is to the effect that the Mississippian comes about 200 feet nearer the surface, which would correspond better with its depth at Pleasanton and Kansas City. Preliminary Report on Coal, 1891, and succeeding volumes.

+ Ibid., p. 24.