Steven L. Dorobek1,
(1) Texas A&M University, College Station, TX
(2) Chinese Petroleum Corporation, Miaoli, Taiwan
Abstract: Tectonic and Subsidence Controls on Carbonate Platform Evolution Across a Broken Foreland: Late Paleozoic Sedimentation in the Permian Basin, West Texas and SE New Mexico
The Permian Basin of West Texas and SE New Mexico is located in the foreland of the late Paleozoic Marathon-Ouachita orogenic belt. The Permian Basin can be characterized as a broken foreland with several prominent, fault-bounded, basement-involved uplifts including the Central Basin Platform (CBP), Ozona Arch, Diablo Platform, and Eastern Shelf, which partition the region into a series of sub-basins with complex bathymetric profiles. Flexurally driven subsidence due to the Marathon-Ouachita orogenic load can only explain subsidence in the Val Verde Basin and southernmost parts of the Delaware Basin. The Ozona Arch, however, is likely a broken peripheral bulge. Faults bounding the Ozona Arch (e.g., Big Lake fault) modify the expected flexural profiles from the orogenic load.
During earliest stages of intraforeland deformation, various structural elements (e.g., faulted anticlines, evolving peripheral bulge) deformed older Paleozoic carbonate units. This deformation created potential structural-stratigraphic traps in deeper parts of the Midland and Delaware basins. After Pennsylvanian-Wolfcampian deformation and uplift was complete, the fault-bounded basement uplifts became substrates for carbonate-platform sedimentation. Crustal shortening along the margins of the CBP caused flexure in the adjacent Midland and Delaware basins. Where structural relief was significant along the edges of the Central Basin Platform (on order of several km), Permian platform margins were never able to prograde into adjacent basinal areas. Loading of the Central Basin Platform by nearly 2 km of carbonate, evaporite, and sandstone facies during Permian time may have caused additional flexure in the Midland and Delaware basins, which in turn, affected the depositional gradients that influenced dispersal of siliciclastic sediment in deep-water environments.
AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana