Polyphase Deformation in San Miguel Las Minas, Northern Acatlan Complex, Southern Mexico
Mapping in the northern part of the Acatlán Complex (southern Mexico) has distinguished two lithological units: a high-grade unit assigned to the Piaxtla Suite, and a low-grade unit assigned to the Cosoltepec Formation. Two major Paleozoic tectonothermal events have been identified in these rocks. The first event produced a penetrative deformational fabric (SPS1) parallel to a compositional banding during blueschist and amphibolite facies metamorphism, which has recently been dated as ~346 Ma in a neighboring area, and a greenschist overprint during exhumation. The second event, which is recorded in both the Piaxtla Suite and Cosoltepec Formation, produced two penetrative deformational fabrics under subgreenschist metamorphic conditions. The first, high-grade tectonothermal event accompanied closure of the Rheic Ocean and tectonic juxtapositioning of the two units during exhumation of the high-grade unit in the Devono-Carboniferous. The second event records convergence along the paleo-Pacific margin of Pangea in the Permo-Triassic.
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:polyphase deformation northern acatlan complex southern mexico
Date of Publication:01/01/2006