Influence of Mississippian Karst Topography on Deposition of the Cherokee Group: Ness County, Kansas

Abstract

The Cherokee Group (Desmoinesian, Middle Pennsylvanian) of Ness County, Kansas was deposited on the western flank of the Central Kansas uplift. Eleven lithofacies were defined in the Cherokee Group to better understand the stratigraphy and depositional processes. Sandstone facies represent the primary oil-bearing reservoirs in the Cherokee Group. An extensive network of groundwater-sapped paleovalleys is present on the Mississippian karst surface and two primary drainage patterns were identified. Groundwater-sapped valleys and dolines exhibit a strong structural control and develop along gravity and magnetic lineaments. Three sequences were identified and mapped, two complete and one incomplete sequence. Potential reservoir sandstone bodies are confined to lowstand and transgressive systems tracts. Sand development is strongly influenced by Mississippian paleotopography. Thick sandstone successions were deposited in groundwater-sapped Mississippian valleys and along the paleoshoreline. Two depositional models were created to explain the lateral and vertical distribution of facies in the Cherokee Group.