Haworth—Stratigraphy of the Kansas Ooal Measures. 462 
shown, and the two vertical sections, the one the well at 
Topeka and the other a generalized section, will show the rela- 
tive vertical positions of the different formations. 
Division of the Coal Measures.*—The ordinary custom of 
dividing the Coal Measures into two or three divisions is so 
well known that it need not be described here. In the dif- 
ferent parts of the Mississippi Valley where such divisions 
have been applied there seems to have been no special reason 
for placing the lines of demarcation just where they were 
located rather than either above or below. In Missouri Broad- 
head+ in each case used a sandstone formation which is by no 
means as extensive laterally as different limestones are. In 
Iowa Keyest has laid aside the older terms “Lower” and 
“Upper” and has substituted the geographic names “ Des 
Moines” and “ Missouri” for what seems to be practically the 
same general divisions. In Kansas it has already been sug- 
gested§ to use one division plane located at the upper surface 
of the Pleasanton shale or the base of the Erie limestone and 
to employ the older terms upper and lower as adjectives placed 
before the name Coal Measures. These terms have the advan- 
tage of priority in American geologic literature, and should 
be laid aside only when more convenient and expressive ones 
are offered as substitutes. The location chosen for the division 
plane is the most strongly marked physically of any plane 
within the whole Coal Measures of the state. At Kansas City 
it leaves nearly eight hundred feet of lower Coal Measures, 
while this thickness is maintained or slightly increased south- 
ward. At Kansas City the division is at the base of the 
Bethany Falls limestone, which correspond with the division 
plane already chosen in Iowa to separate the Des Moines and 
Missouri formations.| In Kansas the division plane does not 
lie at the top of the Cherokee shales. The Oswego limestone 
and the Pawnee limestone both fall within the lower Coal 
Measures. It is probable these limestones do not extend into 
Jowa, but their existence in Kansas is incident to the general 
thickening of the different formations southward. By this 
mode of division the heavy coal beds in the vicinity of Pleasan- 
ton and Boicourt, second in importance only to the Weir City- 
Pittsburg coal, are left in the lower Coal Measures, while the 
coals in the Thayer shales, the Lawrence shales, and the Osage 
City shales are in the upper Coal Measure. As mining is now 
conducted, about three-fourths of the total coal output of the 
state comes from the lower Coal Measures. 
* Haworth, Kan. Univ. Quart., vol. iii, p. 291, April, 1895. 
+ Broadhead, Mo. Geol. Rept., 1872, part ii. 
¢ Keyes, Iowa Geol. Sury., vol. 1. 
§ Haworth, loc cit. 
|| Keyes, this Journal, vol. 1, p. 243, Sept., 1895. 
