TECTONIC ORIGINS OF THE C-O-W ESCARPMENT: CORRELATION OF SUBSURFACE STRUCTURE WITH SURFACE FEATURES

The Cutoff Creek-Overflow Creek-Wham Brake (C-O-W) escarpment forms the western margin of the Mississippi alluvial plain in northern Louisiana and southern Arkansas. Neotectonic evidence suggests that this escarpment is the result of neotectonics, but the local surface data does not clearly define the structural character of this activity. Analysis of the subsurface structure in the eastern edge of the Monroe Gas Field beneath the C-Ow escarpment precludes the presence of a normal fault system. Rather, it suggests that the area has experienced reverse faulting with two shortening directions - 325º & 005º. The interference of these two thrust systems produces a complex fold system in the subsurface, and accounts for the localized breaks in the escarpment at Bayou Bartholomew and Little Bayou Boeuf. Neotectonic features along the length of the escarpment indicate that these fault systems are active.