Regional stratigraphy and tectonic implications of La Chona Quadrangle, Sierra Madre Oriental, northeast Mexico.

摘要

Mesozoic rocks of La Chona Quadrangle, located in the Eastern Front Ranges of the Sierra Madre Oriental, document a complex paleogeographic and tectonic history of Jurassic transtensional basin formation followed by Cretaceous carbonate basin-fill in a transpressional regime. Pelitic flysch deposition in the Upper Cretaceous signals the beginning phases of orogeny. Three distinct, coeval strategraphic successions are established which record different paleogeographic development in separate basins. Structural styles in the 956 km2 map area, including large-scale fan-folds, strike-slip faults juxtaposing stratigraphic successions, rotation of folds and faults, and zones of small scale thrust faulting, define a system of left-lateral strike-slip faults. A paleotectonic model for the development of La Chona Quadrangle and the Eastern Front Ranges is based on clock-wise rotation of faults and their fault blocks between boundary wrench faults. Uplift of the mountain ranges occurred post-Maastrichtian, in the early Tertiary.