Strain localization in the Pernambuco shear zone (Borborema Province, NE Brazil): Implications for the rheology of the continental crust

• Grant number: 13/11866-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: September 01, 2013
• End date: January 31, 2017
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Carlos José Archanjo
• Grantee: Luís Gustavo Ferreira Viegas
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 14/01114-2 - Strain localization at the frictional-viscous transition in the middle crust: examples from the Pernambuco shear zone (Borborema Province, NE Brazil), BE.EP.PD

Abstract

The Pernambuco shear zone, one of the main structures of the Borborema Province, consists of two sheared branches in which high- to low-temperature mylonites are deformed in distinct ways: the western branch involves partial melting and coarse-grained amphibolite facies mylonites, while the eastern branch was developed in the vicinities of two granitic batholiths. In the eastern branch, medium- to low-grade mylonites outcrop in the outer regions away from the batholiths. The structural characteristics of these rocks are poorly constrained so far. The main goal of this project is to combine microstructures, crystallographic preferred orientations, chemical analyses and thermochronological dating in order to investigate the processes of strain nucleation and further localization in the Pernambuco shear zone, particularly in the mylonitic granites outcropping away from the batholiths. These data are important to understand the deformational behaviour of the continental crust during the main Neoproterozoic Brasiliano orogeny in northeast Brazil.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

VIEGAS, GUSTAVO; MENEGON, LUCA; ARCHANJO, CARLOS. Brittle grain-size reduction of feldspar, phase mixing and strain localization in granitoids at mid-crustal conditions (Pernambuco shear zone, NE Brazil). SOLID EARTH, v. 7, n. 2, p. 375-396, 2016. (13/11866-9, 14/01114-2)