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Tectostratigraphic evidence for Late Paleozoic Pacific plate collision and post-Upper Jurassic transpression in northeastern Chihuahua, Mexico

Conference · · Geol. Soc. Am., Abstr. Programs; (United States)
OSTI ID:6461630

The rocks of Mina Plomosas, Chihuahua include a structurally complex association of Ordovician to Permian and Upper Jurassic strata. The structural deformation has historically been considered as two-fold including late Paleozoic compression associated with the collision of North and Afro-South America followed by loosely defined Laramide influences. These interpretations, however, are inconsistent with respect to timing, direction and style of deformation and the tectostratigraphic development of northeastern Mexico. Paleozoic strata which are folded, overturned and thrusted to the southwest are in opposition to the predicted, and elsewhere observed, northwestward compression. More likely, deformation is the result of late Paleozoic, northeastward directed Pacific plate collision causing underthrusting of the Paleozoic strata. Typical Laramide deformations are also in question. Upper Jurassic La Casita-equivalent rocks are twisted into distally thrusted, arcuate, en echelon, omega-folded anticlines which rotate into the trend of the suspected continuation of the oblique strike-slip San Marcos Fault. Such structures are diagnostic of transpressive mobile belts. The implications of late Paleozoic Pacific plate interactions and post-middle Paleozoic transpressive tectonics are that northern Mexico was located to the northwest during the Paleozoic and was repositioned following deposition of Upper Jurassic strata.

Research Organization:
Univ. of Texas, Dallas (USA)
OSTI ID:
6461630
Report Number(s):
CONF-8510489-
Journal Information:
Geol. Soc. Am., Abstr. Programs; (United States), Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Vol. 17; ISSN GAAPB
Country of Publication:
United States
Language:
English