Abstract: Burial Depth, Missing Stratigraphic Section, and Geothermics in the Cherokee Basin of the Midcontinent

Andrea Forster, D.F. Merriam

The Cherokee basin, a northern shelf extension of the Arkoma basin located farther south in Oklahoma, contains a stratigraphic section consisting mostly of Permian-Pennsylvanian alternating clastics and carbonates overlying a carbonate section of Cambrian-Ordovician units on a Precambrian crystalline

basement. It is estimated that about 88% of post-Precambrian time is not recorded in the basin. A major structural event in the late Mississippian-early Pennsylvanian formed the Cherokee basin and associated features. Subsequently, the Permian-Pennsylvanian sequence was deposited and buried up to 6,000 feet in Chautauqua County. Based on burial history models for different maximum depths and erosional amounts, the nonsteady state geothermal conditions during the deposition of sediments were calculated. The one-dimensional heat-transfer modeling is based on the numerical solution of the heat conduction equation by a finite-difference method. It can be assumed that since the last erosional event at the end of the Cretaceous, the paleotemperatures in the basin equal present-day formation temperatures known from thermal logging in boreholes. From temperature patterns determined by BHTs/DSTs, fluid circulation through the system can be outlined. The circulating fluids, mainly through the Cambrian-Ordovician and Mississippian carbonates, are warm brines migrating northward out of the Arkoma basin and mingle with cooler fresh waters from the recharge area in the Ozarks. Vitrinite reflectance values were calculated for the different history models. It is postulated that the location and time of emplacement of oil and gas and mineral deposits were controlled by a combination of burial history, structural development, geothermics, and geohydrology.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994