Microstructural development in ductile deformed metapelitic-metapsamitic rocks

Author(s)
Sergio Delpino, Marina Rueda, Ivana Urraza, Bernhard Grasemann
Abstract

The Pringles Metamorphic Complex, located in the central sector of the Sierra de San Luis, Argentina, is characterized by a several kilometers wide ductile shear zone developed over a geothermal gradient variable between greenschist and granulite facies. The main component of the geothermal gradient comes from the intrusion of mafic-ultramafic bodies in a sequence of metapelitic-metapsamitic rocks. The relative compositional monotony of the original country-rocks and the systematic variation of thermal conditions along profiles normal to the NNE general trend of the structures, make this area a suitable natural laboratory to study ductile deformation. The present work combines field surveys and detailed petrographic-microstructural studies with phase relation analyses, geochemistry of rocks and minerals, and geothermobarometry. The construction of a suitable pseudosection together with geothermobarometric studies, allowed us to draw a reliable thermal curve for the mylonitization event along a representative cross-section. This study aims to give the field geologists the basic tools for a quick identification of deformation microstructures in polymineral aggregates, and correlation with temperatures during the development of mylonitic shear zones in metapelitic-metapsamitic rocks.

Organisation(s)
Department of Geology
External organisation(s)
Universidad Nacional del Sur
Pages
224-249
No. of pages
26
DOI
https://doi.org/10.1002/9781118844953.ch14
Publication date
12-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
105124 Tectonics
Keywords
ASJC Scopus subject areas
Earth and Planetary Sciences(all)
Portal url
https://ucrisportal.univie.ac.at/en/publications/microstructural-development-in-ductile-deformed-metapeliticmetapsamitic-rocks(c54c2ccc-d91d-4889-890f-4e2efde302ee).html