Tectonoseismic Study of the Carlos Chagas Leucogranite and Adjacent Units, Araçuaí Belt (Eastern Brazil).

• Grant number: 10/03537-7
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): September 01, 2010
• Effective date (End): November 30, 2013
• 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

Abstract

This project aims to study the kinematics and strain distribution in the eastern part of the Araçuaí Orogen, encompassing mainly the Carlos Chagas Leucogranite, which outcrops in the Ecoporanga and Barra do São Francisco regions, Espírito Santo state.Studies on strain distribution in hot lithosphere have been the topic of many discussions in the international geological community. Experimental studies sustain that partial melting weakens the rheology of these rocks, with only 10% of molten material (Rosenberg and Handy 2005). Recent models suggest that an almost totally molten middle crust has little resistance and sufficiently weak to allow gravity driven- lateral extrusion and channel flow (Clark and Royden 2000; Beaumont et al. 2001).The present research, the regional geology and the proposed objectives need data integration covering different domains of Geosciences. In summary, the main techniques to be used are as follows: Anisotropy of Magnetic Susceptibility, mainly to investigate the behavior of tectonic and magnetic fabrics of the Carlos Chagas Leucogranite and the intrusive granitoids between Barra do São Francisco and Ecoporanga towns. Additionally, Seismic Anisotropy studies will be performed in order to obtain information about the structure of the superior mantle under the alochtonous units and will also contribute to answer the question of whether there is a crust-mantle mechanical association during the deformational process.The Seismic Anisotropy measures (delay of teleseismic SKS waves) will be obtained with two broad-band stations from the Instituto de Astronomia e Geofísica of the Universidade de São Paulo, installed in the study area. These data will provide information to answer the above proposed questions, and will also allow comparison with previously obtained results in the southern portion of the Ribeira Belt (Heintz et al. 2003; Assumpção et al. 2006).The project will contribute to a deep knowledge of the geology of the eastern Araçuaí Orogen, not only in its regional aspect where a channel flow model could be tested and compared with another geologically similar regions, but also as a theme, bringing ways to comprehend the rheological behavior of partially molten deformed rocks.

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)

CAVALCANTE, CAROLINA; MEIRA, VINICIUS T.; MAGALHAES, NIVEA; HOLLANDA, MARIA HELENA B. M.; OLIVEIRA, EURIDICE. The role of Ediacaran synkinematic anatectic rocks and the late-orogenic charnockitic rocks in the development of the hot Aracuai belt. Precambrian Research, v. 365, OCT 2021. Web of Science Citations: 0.

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.

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.

CAVALCANTE, G. C. G.; VAUCHEZ, A.; MERLET, C.; EGYDIO-SILVA, M.; BEZERRA DE HOLANDA, M. H.; BOYER, B. Thermal conditions during deformation of partially molten crust from TitaniQ geothermometry: rheological implications for the anatectic domain of the Aracuaui belt, eastern Brazil. SOLID EARTH, v. 5, n. 2, p. 1223-1242, 2014. Web of Science Citations: 6.

CAVALCANTE, GEANE C. G.; EGYDIO-SILVA, MARCOS; VAUCHEZ, ALAIN; CAMPS, PIERRE; OLIVEIRA, EURIDICE. Strain distribution across a partially molten middle crust: Insights from the AMS mapping of the Carlos Chagas Anatexite, Aracuai belt (East Brazil). JOURNAL OF STRUCTURAL GEOLOGY, v. 55, p. 79-100, OCT 2013. Web of Science Citations: 10.