Ambiente tectónico de la región volcánica los azufres, Mich.-Zamorano, Qro.

Abstract

The Azufres, Mich. - Zamorano, Qro. volcanic field is located in the central part of the Transmexican Volcanic Belt. Three fracture systems were obscrved in the arca, one oriented NW 5 - 250 affecting only miocenic and pliocenic rocks; the others, NE·6So and E-W, affect the Quatemary rocks aÍso. The NE system Is predominant, but the E-W system is coincidently oriented on the direction of the maximum horizontal stress, as determinated by the cinder cone alignements and the normal faults distribution found in the southern volcanic fleld. The direction of the local stress of sorne pliocenic volcanoes was estimated to be NW (lO to 50<». The current orientation of the maximum horizontal stress (E-W) could suggest that the tectonic regime of the volcanic region during the Quaternary time was distensive.