Rheological evolution of the continental crust: microstructures and deformation mechanisms in the Além-Paraíba-Pádua shear zone (Ribeira Belt)

• Grant number: 14/10146-5
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: August 10, 2014
• End date: July 30, 2015
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Marcos Egydio da Silva
• Grantee: Geane Carolina Gonçalves Cavalcante
• Supervisor: Andrea Tommasi
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Université Montpellier 2, France
• Associated to the scholarship: 13/19061-0 - Rheological evolution of the continental crust: microstructures and deformation mechanisms in the Além Paraíba-Pádua shear zone (Araçuaí-Ribeira belt), BP.PD

Abstract

The Além Paraíba-Pádua shear zone system (Southern Brazil) represents the northern termination of a transcurrent shear zone network that is located in the central part of the Ribeira belt. It consists of high temperature (>800°C) mylonitic segments with mainly N70E and N40E trends. The nucleation and the development of this system comprised the deformation of rocks at distinct crustal levels (granulites, migmatites and syntectonic granites) and, therefore, with different rheological competence. The main goal of this project is to investigate the mechanical behavior of these rocks during the nucleation of this shear zone system. Through the characterization of the main microstructures and deformation mechanisms recorded in these rocks (using the SEM-TEM-EBSD techniques), we intend to examine the rheology of continental crust during orogenic evolution of the Ribeira belt. Considering that the rheological behavior of continental crust changes with depth in response to several factors (mineralogical composition of the rocks, temperature, pressure, viscosity, strain rate, etc), an additional thermal study (TitaniQ thermometry) will be performed to evaluate the temperature conditions during the orogenic deformation. The combination of the aforementioned techniques will contribute to our understanding of the rheological behavior of the continental crust of the southern region of the Ribeira belt during the development of the Além Paraíba-Pádua shear zone system. (AU)

Scientific publications

(5)

(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)

CAVALCANTE, CAROLINA; FOSSEN, HAAKON; DE ALMEIDA, RENATO PAES; HOLLANDA, MARIA HELENA B. M.; EGYDIO-SILVA, MARCOS. Reviewing the puzzling intracontinental termination of the Aracuai-West Congo orogenic belt and its implications for orogenic development. Precambrian Research, v. 322, p. 85-98, MAR 2019. (10/03537-7, 14/10146-5, 15/23572-5, 13/19061-0)

EGYDIO-SILVA, MARCOS; VAUCHEZ, ALAIN; FOSSEN, HAAKON; GONCALVES CAVALCANTE, GEANE CAROLINA; XAVIER, BRUNA CATARINO. Connecting the Aracuai and Ribeira belts (SE - Brazil): Progressive transition from contractional to transpressive strain regime during the Brasiliano orogeny. Journal of South American Earth Sciences, v. 86, p. 127-139, OCT 2018. (13/19061-0, 14/10146-5)

KONOPASEK, JIRI; CAVALCANTE, CAROLINA; FOSSEN, HAAKON; JANOUSEK, VOJTECH. Adamastor - an ocean that never existed?. EARTH-SCIENCE REVIEWS, v. 205, JUN 2020. (10/03537-7, 14/10146-5, 13/19061-0, 15/23572-5)

CAVALCANTE, CAROLINA; LAGOEIRO, LEONARDO; FOSSEN, HAAKON; EGYDIO-SILVA, MARCOS; MORALES, LUIZ F. G.; FERREIRA, FILIPPE; CONTE, THAILLI. Temperature constraints on microfabric patterns in quartzofeldsphatic mylonites, Ribeira belt (SE Brazil). JOURNAL OF STRUCTURAL GEOLOGY, v. 115, p. 243-262, OCT 2018. (13/19061-0, 14/10146-5)

FOSSEN, HAAKON; CAVALCANTE, GEANE CAROLINA G.. Shear zones - A review. EARTH-SCIENCE REVIEWS, v. 171, p. 434-455, AUG 2017. (15/23572-5, 13/19061-0, 14/10146-5)