Crystallographic, deformational and thermocronological analysis of mylonites of Taxaquara shear zone (São Paulo)

• Grant number: 18/00320-9
• Support Opportunities: Scholarships in Brazil - Master
• Start date: April 01, 2018
• End date: November 30, 2019
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Ginaldo Ademar da Cruz Campanha
• Grantee: Bruno Vieira Ribeiro
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 15/03737-0 - The Rio de La Plata Craton and the Western Gondwana Assembly, AP.TEM
• Associated scholarship(s): 18/16307-1 - A geochronological and thermochronological approach to assess timing of deformation of Taxaquara Shear Zone, Ribeira Belt (Brazil), BE.EP.MS

Abstract

The development of the Ribeira Belt, SE Brazil, is dominated by shear zone system established between Ediacarano and Cambriano and characterized by brittle-ductile to ductile shear zones. The Taxaquara Shear Zone (TSZ) was one of the first transcurrent structures of regional relevance identified in the Ribeira Belt, having been attributed to it great importance in the tectonic compartmentation of this tectonic entity. The deformational mechanisms of the shear zones, tectonic models and the period in which this system was installed are still subject of debate in the scientific literature. In spite of the importance attributed to it, the ZCT has been little studied since its definition, which makes it an interesting target to be reevaluated in the light of new concepts and techniques of investigation in microtectonics, structural geology and geochronology.The present Masters proposal, linked to the FAPESP Thematic Project (2015/03737-0), will continue the studies developed by the candidate in two FAPESP projects (IC 2016/22051-4 and BEPE-IC 2017/08919-4). The main objective is to investigate the deformation conditions (temperature and mechanisms) of the milonitic rocks, the tectonic system responsible for the genesis of the SE Brazilian Shear Zone System and the period in which it was active. For this, microstructural and crystallographic analyzes (via EBSD), quantitative analyzes of the deformation (finite strain) and thermochronological analysis (40Ar / 39Ar) will be carried out. The results will be added to others to compose a discussion about the thermo-tectonic evolution of the ZCT. (AU)

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)

RIBEIRO, V, B.; MULDER, J. A.; FALEIROS, F. M.; KIRKLAND, C. L.; CAWOOD, P. A.; O'SULLIVAN, G.; CAMPANHA, G. A. C.; FINCH, M. A.; WEINBERG, R. F.; NEBEL, O.. Using apatite to resolve the age and protoliths of mid-crustal shear zones: A case study from the Taxaquara Shear Zone, SE Brazil. LITHOS, v. 378, DEC 15 2020. (18/00320-9, 18/10012-0, 15/03737-0, 18/16307-1)

RIBEIRO, V, B.; LAGOEIRO, L.; FALEIROS, F. M.; HUNTER, N. J. R.; QUEIROGA, G.; RAVEGGI, M.; CAWOOD, P. A.; FINCH, M.; CAMPANHA, G. A. C.. Strain localization and fluid-assisted deformation in apatite and its influence on trace elements and U-Pb systematics. Earth and Planetary Science Letters, v. 545, SEP 1 2020. (18/10012-0, 18/00320-9)

RIBEIRO, B. V.; FALEIROS, F. M.; CAMPANHA, G. A. C.; LAGOEIRO, L.; WEINBERG, R. F.; HUNTER, N. J. R.. Kinematics, nature of deformation and tectonic setting of the Taxaquara Shear Zone, a major transpressional zone of the Ribeira Belt (SE Brazil). TECTONOPHYSICS, v. 751, p. 83-108, JAN 20 2019. (18/10012-0, 15/04487-7, 18/00320-9, 16/22051-4, 17/08919-4)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

RIBEIRO, Bruno Vieira. Deformational, crystallographic and petrochronological analyses of the mylonites from Taxaquara shear zone in Ribeira Belt (São Paulo). 2019. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Geociências (IG/BT) São Paulo.