74 University Geological Survey of Kansas. 
interbedded shales; then the heavy Pleasanton shale-beds, suf- 
ficiently pronounced to mark prominent escarpments, that may 
be traced across the state; then another complex of heavy lime- 
stones and relatively thin shales, followed by a second heavy 
shale-bed, the Lawrence shales, with a correspondingly prom- 
inent scarp line entirely across the state. Above this second 
prominent shale-bed there is not so great a difference in thick- 
ness of consecutive shales and limestones, and correspondingly 
there is no particularly prominent escarpment line produced 
at the surface. 
The prominent escarpments produced by these unusually 
heavy shale-beds may be observed by any one while riding 
across the country, and are so prominent features of the Iand- 
scape they become appropriate means of subdividing the Coal 
Measures. The scheme of classification mentioned and illus- 
trated in plate III has been worked out and is based upon con- 
ditions which actually exist and are prominent entirely across 
the state from north to south. It will be explained briefly 
here before taking up the several minor subdivisions for de- 
tailed description. 
CHEROKEE STAGE. 
At the bottom of the Coal Measures lie the Cherokee shales, 
with occasional calcareous lentilles and large masses of sand- 
stones. These sandstones are the principal oil and gas pro- 
ducers. Their horizontal extent is not sufficiently great, 
neither is their occurrence sufficiently regular, to permit of a 
definite division of the shale-beds. It is proposed to speak of 
this entire complex as the Cherokee Stage. (See plate III.) 
MARMATON STAGE. 
Above the rocks of the Cherokee Stage we find a series of 
four limestone formations, alternating with as many shales. 
They are, reading from the bottom upwards, the Fort Scott 
limestone, Labette shales, Pawnee limestone, Bandara shales, 
Altamont limestone, Walnut shales, Coffeyville limestone, and 
Pleasanton shales. The four limestones with the three inter- 
bedded shales are relatively hard to distinguish by casual ob- 
servation. The Fort Scott limestone caps a prominent scarp 
which distinguishes it from rocks in the Cherokee Stage, but,: 
on account of the thinness of the interbedded shales, there are 
no direct surface features in connection with the other three. 
limestones named. Above them we find the thick Pleasanton 
shales, which, in connection with the first limestone above, pro- 
