Geology of Western Shawnee County, Kansas, and Vicinity
by William D. Johnson, Jr., and H.C. Wagner
Originally published in 1967 as U.S. Geological Survey Bulletin 1215-B, prepared in cooperation with the State Geological Survey of Kansas as a part of a U.S. Department of the Interior program for the development of the Missouri River basin.
This is, in general, the original text as published in 1967. The information has not been updated. Volume A, Geology of Eastern Shawnee County, Kansas, and Vicinity, is also online.
Abstract
The western Shawnee County and vicinity study area, encompassing about 358 square miles of northeastern Kansas, was mapped as part of a study of Upper Pennsylvanian and Lower Permian rocks. The area includes western Shawnee County and parts of eastern Wabaunsee and southwestern Jackson Counties.
Subsurface sedimentary rocks range in age from Late Cambrian to Late Pennsylvanian and are as much as 3,300 feet thick. Granite of the Precambrian basement complex has been penetrated in one well.
The exposed sedimentary rocks, about 600 feet thick, are in the Wabaunsee Group, of Late Pennsylvanian age, and in the Admire and Council Grove Groups, of Early Permian age. Relatively thick units of claystone, siltstone, and sandstone and alternating thinner units of fossiliferous limestone record a cyclic pattern of deposition that occurred throughout Late Pennsylvanian and Early Permian time. Local channels have eroded several formations, particularly the Wood Siding Formation, which is the uppermost unit of Pennsylvanian age.
Scattered deposits of brown chert gravel of pre-Kansan age are present locally but are too small to map. Kansan glacial drift covers much of the northern two-thirds of western Shawnee County and vicinity. Thick stratified glacial-outwash deposits locally occur across the southern part of the area and, to the north, along the Kansas River valley.
The Kansas River and Wakarusa River valleys and the larger creek valleys are filled with alluvial material of Quaternary age. In the Kansas River valley extensive deposits making up the Newman terrace of Wisconsin age occupy much of the valley fioor, and a broad deposit of Recent alluvium borders the river. The alluvial fill in the Wakarusa River valley is correlated with the Newman terrace. Terrace remnants correlated with the Buck Oreek terrace of Illinoian age are in the Kansas River valley near the west edge of the area and along many of the larger tributaries of that river.
The area studied is in the western part of the Forest City basin. Outcropping rocks in the area strike about N. 15°-30° E. and dip to the northwest, generally 15-30 feet per mile. The regional dip is interrupted by a few small folds that have less than 20 feet of surface closure.
Commercial quantities of oil and gas have not been found in the area, but traces of oil have been reported from sandstone in the Cherokee Group (Middle Pennsylvanian) and from dolomite in the Simpson Group (Middle Ordovician). Oil stains have been noted on rock samples from the part of the Hunton Formation that is of Devonian age, from the Viola Limestone (Middle and Upper Ordovician), and from the Simpson Group (Middle Ordovician). Drillers' logs have reported shows of gas from rocks in the Wabaunsee, Douglas, Kansas City, and Pleasanton Groups of Late PennsyIvanian age, and the Marmaton and Cherokee Groups of Middle Pennsylvanian age.
Kansas Geological Survey, Geology
Placed on web October 2005; originally published 1967.
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