58 University Geological Survey of Kansas. 
on the north they dip to the north, on the west they dip to the 
west, etc. Along the south line of Kansas the maximum dip is 
a little south of west, and further south, in the Cherokee Na- 
tion, it gradually veers to the southwest. 
The Mississippian series is not composed entirely of lime- 
stone, as is popularly supposed by well-drillers and oil-opera- 
tors. On the contrary, here and there throughout are thin beds 
of shales, and quite likely sandstone may be found at many 
places. Beneath the Mississippian one would ordinarily ex- 
pect to find in a descending order the Devonian, Silurian, Ordo- 
vician, and Cambrian. Whether or not they occur under the 
oil-fields will remain problematic until they are actually dis- 
covered. Throughout this oil region, therefore, a drill might 
pass through the following series successively: Coal Measures, 
Mississippian, Devonian, Silurian, Ordovician, Cambrian, and 
into the fundamental granites or gneisses. 
East of the oil regions in the Ozark area these underlying 
rock masses come to the surface and have been studied with 
great care by various geologists. It seems that the Devonian 
system is almost entirely wanting in the Ozark region, which 
would lead one to suspect it would be wanting likewise under 
the oil-beds. In his report on Green county, Missouri, Pro- 
fessor Shepard? gives the following scheme of classification 
for the rocks exposed in that county. If the term Coal Meas- 
ures was substituted for the term Des Moines used by Shepard, 
the sequence just given for the oil-fields would be the same as 
that given in Shepard’s classification. 
Doctor Adams,‘ in writing about the Mississippian or lower 
systems or series for the entire Ozark region, gave the follow- 
ing scheme, which differs but little from that of Shepard. 
3. Shepard, Prof. E. M.: Mo. G. S. Rep., vol. XII, p. 49. Jefferson City, 1898. 
4. Adams, Dr. George I.: U. S. G. S., 22d Ann. Rep., pt. 11, pp. 76-94. Washing- 
ton, 1901. 
