HAWORTH AND BENNETT.|] General Stratigraphy. 67 
3200 feet. Drill-cuttings were preserved for every screw and 
were carefully examined, from which a tolerably accurate 
record of the well was obtained and is included herein. This 
well, like all the other deep wells now known, fails to furnish 
oil or gas in commercial quantities. 
The above descriptions of deep wells penetrating the Mis- 
sissippian and underlying formations have been given princi- 
pally because it is important economically as well as theo- 
retically to learn, if possible, whether or not these formations 
contain oil or gas in commercial quantities. It may be stated, 
also, that an added interest is attached thereto in connection 
with theories regarding the origin of oil and gas. Much 
money has been spent in Kansas based upon the belief that the 
Trenton limestone underlies this oil-field and is the original 
source of the oil and gas, from which it has escaped upwards 
through fissures in the overlying formations and was finally 
caught by the impervious Coal Measure shales, which was the 
dominating principle governing the present location of oil and 
gas pools. Others have believed that the oil and gas were 
formed at.a still greater depth by chemical processes and es- 
caped upwards from the crystalline rocks below and through 
fissures of the stratified rocks as just named. A more lengthy 
discussion of these theories will be found in the proper chapter 
in this volume. 
UPPER SURFACE. 
The upper surface of the Mississippian limestone in some 
places was greatly eroded during pre-Coal Measure time. This 
has been commented upon by various geologists, has been illus- 
trated by drawings and photographs by different authors, and 
varied and important conclusions have been drawn from such 
effects. Already various irregularities of surface in south- 
eastern Cherokee county have been described, which are proba- 
bly due to this surface erosion. The extent of such erosion 
further to the northwest can only be conjectured, as the sur- 
face of the Mississippian soon becomes covered to a great 
depth with the overlying Coal Measures. It is known, how- 
ever, that the upper surface is very decidedly irregular, and 
not infrequently two wells beginning on a level surface reach 
the Mississippian at surprisingly varying distances. A num- 
_ ber of instances of this kind have come to light in the vicinity 
of Independence. In some instances wells less than half a mile 
apart, beginning at practically the same height above sea-level, 
