Geologic evolution of the Burgos Basin, northeastern Mexico
Perez Cruz, Guillermo A.
Bally, Albert W.
Doctor of Philosophy
The Burgos Basin in northeastern Mexico has been the site of interaction of the Cordilleran thrust and fold belt of western North America with the passive margin of the Gulf of Mexico. The primary tectonic episodes in this region include: (1) Middle-Upper Eocene compression associated with foreland deformation of the Sierra Madre Oriental and Coahuila fold and thrust belts, (2) Upper Oligocene regional uplift and the emplacement of granodioritic plutons, and (3) Miocene-Pleistocene regional uplift and volcanism. Compressional deformation extended from the Sierra Madre Oriental and Coahuila fold and thrust belts approximately 100 km east into the Burgos basin, interacting with the passive margin of the western Gulf of Mexico. Eocene compression created (1) large-scale, southwest-vergent thrusts and folds involving basement, (2) salt-cored, complex folds developed in strata overlying thick Upper Jurassic salt, (3) partially inverted structures, and (4) tight folds with multiple decoupling levels. Upper Oligocene regional uplift and erosion west of the basin margin caused deposition of a thick package of conglomerates in the western areas of the basin. Rapid subsidence, siliclastic deposition, and growth faulting occurred further the east. Regional uplift was contemporaneous with emplacement of granodioritic plutons, now exposed in the cores of some of the basement-involved anticlines in the western portion of the basin. Regional western uplift and erosion continued in the Miocene to Pleistocene, producing increasing amounts of siliciclastic influx into the basin. Sediments were accommodated within the downthrown blocks of expanded growth fault systems. The Cenozoic normal fault trends of coastal Texas extend southward into the Burgos Basin, but their amount of expansion and orientation has been modified by periods of thrusting, folding, regional uplift, and plutonism.