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

• Grant number: 13/19061-0
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): December 01, 2013
• Effective date (End): January 31, 2016
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal researcher: Marcos Egydio da Silva
• Grantee: Geane Carolina Gonçalves Cavalcante
• Home Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 14/10146-5 - Rheological evolution of the continental crust: microstructures and deformation mechanisms in the Além-Paraíba-Pádua shear zone (Ribeira Belt), BE.EP.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 Araçuaí-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 sintectonic granites) and, therefore, with different rheological competences. 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 MEV-EBSD technique), we intend to examine the rheology of the continental crust during the orogenic evolution. Considering that the rheological behavior of the 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) plus viscosity estimates (using the Kware Magma software) will be performed to evaluate the temperature conditions and the rheology of the rocks during the orogenic deformation. The combination of the aforementioned techniques will contribute to understand the rheological behavior of the continental crust of the central region of the Araçuaí-Ribeira belt during the development of the Além Paraíba-Pádua shear zone system.

Scientific publications

(7)

(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)

FOSSEN, HAAKON; CAVALCANTE, CAROLINA; KONOPASEK, JIRI; MEIRA, VINICIUS T.; DE ALMEIDA, RENATO PAES; HOLLANDA, MARIA HELENA B. M.; TROMPETTE, ROLAND. A critical discussion of the subduction-collision model for the Neoproterozoic Aracuai-West Congo orogen. Precambrian Research, v. 343, JUL 2020. Web of Science Citations: 0.

KONOPASEK, JIRI; CAVALCANTE, CAROLINA; FOSSEN, HAAKON; JANOUSEK, VOJTECH. Adamastor - an ocean that never existed?. EARTH-SCIENCE REVIEWS, v. 205, JUN 2020. Web of Science Citations: 0.

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. Web of Science Citations: 0.

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. Web of Science Citations: 4.

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. Web of Science Citations: 6.

FOSSEN, HAAKON; CAROLINA CAVALCANTE, G.; DE ALMEIDA, RENATO PAES. Hot Versus Cold Orogenic Behavior: Comparing the Aracuai-West Congo and the Caledonian Orogens. TECTONICS, v. 36, n. 10, p. 2159-2178, OCT 2017. Web of Science Citations: 5.

FOSSEN, HAAKON; CAVALCANTE, GEANE CAROLINA G. Shear zones - A review. EARTH-SCIENCE REVIEWS, v. 171, p. 434-455, AUG 2017. Web of Science Citations: 52.