Mississippian Rocks of Western Kansas: ABSTRACT

Abstract

In western Kansas, Mississippian rocks, all marine and all in the subsurface, are correlated with rocks of the Kinderhookian, Osagian, Meramecian, and Chesteran Stages. Unconformities separate dominantly carbonate Mississippian rocks from Pennsylvanian rocks above and Cambrian to Devonian rocks below. Karst, diagenetic alternations, and facies changes complicate the problem of establishing lateral stratigraphic equivalents. Dolomitization, silicification of fossils, and chertification are widespread. Conodont faunas recovered as acetic acid insoluble residues from cores are correlated with conodont biostratigraphic zones of the type are of Mississippian rocks. Part of the study area once contained Devonian rocks; evidence of this is the presence of reworked Devonian and Kinderhookian conodonts preserves in Kinderhookian rocks. The primary sediment source of Osagian and Meramecian rocks was organic. Sediments probably were deposited in warm, shallow seas. Thin intraformational conglomerate beds, quasi-brecciated limestone beds, and local beds of anhydrite are known in upper Meramecian rocks. An increased content of clastic (quartz) rocks in upper Meramecian strata marks a change in sediment source. Siliceous sediments were provided from areas of provenance from the Central Kansas uplift and the Las Animas arch. In Chesteran rocks, sandstone, siltstone, and thin limestone beds predominate. A normal sequence of Osagian and Meramecian rocks was deposited in south-central Kansas. The term Formation should be dropped; the cherty Cowley facies is developed only locally. End_of_Article - Last_Page 1688------------