INTERPRETATION OF LATE-CENOZOIC PALEO-STRESS REGIMES OF WEST TENNESSEE

Meeman-Shelby State Park of West Tennessee, located within the Chickasaw bluff adjacent to the Mississippi River, is a prime location for identifying and interpreting Late Cenozoic paleo-stress fields of the central Mississippi embayment. Exposures in the streams along the bluffs include Eocene Claiborne and Jackson Groups, Pliocene Upland Complex, Pleistocene Roxana and Peoria loesses, as well as Holocene alluvium in the bottom of the valleys. Field work includes measuring the attitudes (strike & dip) of outcrop-scale structures (joints, faults, folds) in each of these stratigraphic units. These data will allow an estimation of paleo-stress regimes during fracturing and folding and changes in the stress regime between the deposition of each stratigraphic unit. Preliminary investigation shows faulting sub-parallel to the strike of the New Madrid Rift Margins as well as perpendicular jointing within Eocene and Pliocene strata. Correlating these two data sets will provide workable local paleo-stress fields of West Tennessee. Because of high fluvial activity, distinction between structural and geomorphic processes such as slumping will be difficult, but interpretation between these two will be a necessity.