78 University Geological Survey of Kansas. 
western part of the oil-fields imply a thickness of less than 400 
feet, while others show more than 650 feet. 
The well at Topeka passed entirely through them, but it 
shows 704 feet of shale at the bottom of the well. The Mc- 
Farland well, although 2006 feet deep, seems to have pene- 
trated the Cherokee shales nearly 174 feet, thus leaving us in 
doubt as to their total thickness at that place. 
The Atchison diamond drill well went entirely through the 
Cherokee shales and into the Mississippian beyond. At that 
place they are 598 feet thick. Southward at Emporia is a 
well recently drilled by the city, under the immediate super- 
vision of Alva J. Smith, who kindly furnished the Survey with 
a record. According to this record the Cherokee shales were 
reached at 1600 feet and the Mississippian limestone at 1951 
feet, making them nearly 351 feet thick. Still further south, in 
the Osage and Cherokee territories, these shales begin to 
thicken and apparently grow thick very rapidly further south. 
It would seem, therefore, that the Cherokee shales in general 
thicken to the north and northwest in the direction of Atchison 
and Topeka and become thinner westward towards Emporia 
and gradually grow thicker southward in the Cherokee and 
Osage country. 
Area.—The Cherokee shales occupy the surface over nearly 
all of Cherokee county, the southwestern half of Crawford 
county and a small portion in the southeast corner of Labette 
county. The Marmaton river in Bourbon county has cut its 
valley through the overlying limestones and exposes them, as 
do also the upper waters of the Drywood in southeast Bourbon 
and northeast Crawford counties. 
Beyond the limits of the state on the south the Cherokee 
shales are known to cover a wide area in the Cherokee Nation, 
and quite likely they appear eastward across into the coal-fields 
of Arkansas south of the Arkansas river. Mr. Taff® and as- 
sistants on the United States Geological Survey have demon- 
strated the existence of a heavy bed of shale in the Choctaw, 
Creek and Cherokee Nations which connects directly with the 
Arkansas coal-fields just mentioned. There is no reasonable 
doubt but that they are a southern extension of the Kansas 
Cherokee shales, although a short interval of space intervenes. 
between the south line of the state and the areas mapped and 
9. Taff, Joseph A.: Nineteenth An. Rep. U.S. G.S., pt. 111, pp. 423-583. Wash- 
ington, 1899. 
