Characterizing the Geometry and Time of Deformation of the Meeman-Shelby Fault, Near Memphis, TN
A 10 km-long high-resolution seismic reflection profile was acquired in the summer of 2010 in West Memphis, AR to constrain the location and character of the Meeman-Shelby Fault (MSF), near Memphis, Tennesse, in the Central US. The fault, previously identified by a marine reflection survey as deforming the base of the Quaternary alluvium and the recent sediments along the Mississippi River, is a ~45km-long structure that strikes N25Ã‚ÂºE and dips west-northwest ~80Ã‚Âº, exhibiting an up-to-the-west sense of motion, with a possible right-lateral strike-slip component.
The survey imaged the fault at the predicted location, confirming the trend and character of the previously identified feature. At the fault, the top of the Paleozoic and Upper Cretaceous units are folded and display an elevation of ~56 and ~42 m respectively at the crest of the fold. The fold propagates to the Tertiary sediments and the top of the Paleocene is warped up ~21 m, and deformation is visible up to 380 m from the surface. Consistently with the other locations where the MSF was imaged, the fault dips ~80Ã‚Â° to the west and shows an up-to-the-west sense of motion.
The MSF is the best documented fault close to Memphis yet discovered, and exhibits a recurrent fault history. Understanding its slip history and characteristics is therefore crucial for seismic hazard assessment in the region.