Late Paleozoic and Early Mesozoic geologic evolution of the Arklatex Area
Milliken, Jeffrey Van
Bally, Albert W.
Master of Arts
A structural and sedimentological history for the Late Paleozoic and Early Mesozoic is formulated from subsurface and seismic reflection data for the Arklatex Area. The Ouachita structural belt is the product of Pennsylvanian folding and thrusting of an Early Paleozoic passive margin wedge. An Atokan thin-skinned thrust complex (Ti Valley) was deformed during the DesMoinesian by basement-involved duplexing, which carried with it Early Paleozoic foreland carbonates. These carbonates and the underlying Precambrian basement may be mapped about 80 km south of the outcrop areas of the Ouachita Mountains. Following regional post-Atokan peneplanation, post- to synorogenic deposition commenced in the continental backarc (Paleozoic Arklatex) basin which formed on the hinterland side of the Ouachita arc. This successor basin contains over 8000 feet (2400 meters) of Pennsylvanian and Permian shelf carbonates and clastics. Following another regional unconformity, over 7000 feet (2100 meters) of discontinuous Triassic redbeds were deposited in structural troughs formed during a poorly-documented rifting event. Finally, Jurassic Werner clastics and anhydrite buried most remaining Triassic topography during the initial episode of evaporite deposition.