According to the Kansas Geologic Survey:
The surface of Elk County, in southeastern Kansas, is underlain by bedrock of Virgilian (Pennsylvanian) and Wolfcampian (Permian) age.
Limestone crops out extensively in Elk County. The separate beds have been quarried at several places in the county. The limestone quarry operating near Moline is one of the largest of its kind in central United States; therefore, limestone constitutes one of the county's most valuable natural resources.
As far as is known only the Nodaway and Elmo coals, both in the Wabaunsee group of rocks have been mined in Elk County.
According to published data, the cumulative coal production from Elk County totaled 3,615 tons from 1894 to 1902. It is known that coal was mined in the county for local domestic use as early as 1877; mining activity was discontinued in 1922. Total cumulative production of coal in the county is estimated at 10,000 tons, most of which was Elmo coal.
Elk County has a total recoverable measured coal reserve of 2,125,000 tons.
http://www.kgs.ku.edu/General/Geology/Elk/index.html