ABSTRACT

The contact between the Goodland and overlying Kiamichi Formation represents a sharp lithologic change and is important to Lower Cretaceous stratigraphy because it separates the Fredericksburg and Washita divisions. The purpose of this investigation was to resolve the nature of this contact in the study area (conformable or unconformable) and to determine the depositional environment of the Goodland and lower Kiamichi formations. Detailed lateral and vertical facies relationships indicated that the Goodland Formation represents a shoaling upward sequence of a westward prograding carbonate ramp which suggests that the depositional strike was roughly north-south. The formation of a ramp may be related to the Paleozoic Broken Bow uplift or to an actively subsiding North Texas-Tyler basin. The Goodland-Kiamichi contact appears to be a submarine disconformity surface in the off ramp areas and a weathered, subaerial disconformity surface in the ramp area. Deposition of the lower Kiamichi Formation was probably in response to a return of deeper water conditions as regional subsidence deepened the North Texas-Tyler basin.