Depositional Controls and Reservoir Character of Mississippian (Osagian–Meramecian) Tropical, Shallow-Water Heterozoan and Biosiliceous Carbonate Ramp Strata in Kansas

During the Osagian–Meramecian (lower Mississippian), the majority of continental U.S. was located in the tropics and covered by a shallow-water sea. Under these conditions, abundant photozoans (e.g., algae, ooids, corals, larger benthic foraminifera) would be expected, which is the case for areas west and north of the Transcontinental Arch (TA). However, shallow-water areas east and south of the TA, including Kansas, lack photozoans and instead are dominated by heterozoans (e.g., crinoids, bryozoans, molluscs, brachiopods) and siliceous sponges due to upwelling from adjacent basins, which created adverse conditions (e.g., excess nutrients, turbid and cold waters) that were not conducive to photozoans. This study focuses on the Osagian–Meramecian ramp system that developed in Kansas to further develop an understanding of environmental controls on deposition. Cores, well logs, and seismic data from areas west and southwest of the Central Kansas Uplift are being used to develop a sequence stratigraphic framework and provide details on the paleogeography and facies distributions to aid in delineating depositional controls, and relevance to reservoir character. Mississippian rocks throughout the continental U.S. form important petroleum reservoirs (e.g., Mississippian Lime Play in Kansas) and are potential for long term CO2 storage. Studying heterozoan–biosiliceous systems is significant as these systems are not as well understood and behave much different in terms of reservoir character (e.g., facies distributions, stratal geometries, mineralogy, and diagenesis) as compared to photozoan-dominated systems. Recognizing controls on local and regional facies distributions on heterozoan–biosiliceous systems can aid in predicting and better understanding of reservoirs.