Abstract

The lithostratigraphic architecture of outcrops of Lower to Middle Mississippian rocks in SW Missouri, NW Arkansas, and NE Oklahoma are a template for interpreting correlative subsurface strata in Kansas and Oklahoma. As in outcrops, deposition of the subsurface St. Joe Group was affected by Ouachita-related tectonism, the main effect of which was uplift of the Kanoka Ridge in southern Kansas and northern Oklahoma. The presence of the ridge resulted in dip reversal of the southern Burlington Shelf such that low-energy limestones in the group pass southward in Kansas onto a shallower-water, higher-energy platform. Farther southward, along the axis of the ridge, the group thins by erosion and on-lap and facies comprise very shallow-water deposits with unconformities and evidence of periodic subaerial exposure. Collapse of the Kanoka Ridge in the middle Osagean accompanied increased subsidence and then southward progradation of the Bentonville-Reeds Spring shelf-slope depositional system across Kansas and into Oklahoma. Subsequent uplift and deep erosion along the former Kanoka Ridge in the latest Osagean to earliest Meramecian created a regional paleo-low within which the spiculitic Cowley Formation was deposited. Petroleum reservoirs and potential exploration objectives of contrasting lithology and petrophysical attributes are present within each of these units in Kansas and northern Oklahoma.