Abstract

Mississippian depositional systems in the subsurface of Oklahoma consist of a mix of carbonates and siliciclastic rocks that were variously interpreted as deposited on a regional shelf, ramp, or distally steepened ramp. These varied interpretations resulted in significantly different models for associated facies types and distribution, including potential reservoir types and the distribution of these units that may occur in the subsurface. Fundamental differences in the facies types and distribution of a shelf and shelf margin system versus a ramp or distally steepened ramp include the varying regional distribution for high- and low-energy facies, reef facies, and downslope mass transport deposits. Recent work in both the subsurface of Oklahoma, as well as local outcrops in Arkansas and Missouri, indicates that the facies were deposited on a distally steepened ramp due to the lateral facies distribution and the vertical facies successions identified throughout the system. The presence and characteristics associated with debris flows as described in this study, especially when defined within the context of a sequence stratigraphic hierarchy, supports the interpretation of a distally steepened ramp conceptual model and provides insight into similar mass transport deposits that may occur in the subsurface.