Structural control and genesis of auriferous quartz veins from the Serra do Cavalo Magro, Sete Barras (São Paulo State), southern Ribeira Belt

• Grant number: 16/11584-1
• Support type: Scholarships in Brazil - Master
• Effective date (Start): November 01, 2016
• Effective date (End): October 31, 2018
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Frederico Meira Faleiros
• Grantee: Isaac Siles Malta
• Home Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

This project aims to investigate the structural control and genesis of auriferous quartz veins of the Serra do Cavalo Magro, Sete Barras (São Paulo State), southern Ribeira Belt. The mineralized veins are hosted by Calymmian metasedimentary rocks from the Votuverava Group and Ediacaran rocks from the Agudos Grandes Granite along a ductile shear zone. The activities to be undertaken include fieldwork with geological mapping and collection of geological and structural data, systematic sampling, including mineralized veins and host rocks, petrographic and microstructural analyses and fluid inclusion studies. The specific objectives are to: (a) produce detailed geological maps, (b) characterize the geometry of the mineralized veins at the macroscopic and microscopic scales and their relationships with other regional and local structural elements; (c) determine the composition and trapping temperature and pressure conditions of fluids involved in the formation and deformation of the veins using fluid inclusion studies; (d) characterize the metamorphic conditions of the immediate vein host rocks by means of petrographic and microstructural studies and using applicable geothermobarometers. It is intended to answer the following questions: (a) what are the pressure and temperature conditions of vein formation? (b) are the veins genetically related with major structures like regional folds and shear zones or are they related with the Agudos Grandes Granite intrusion? (c) was the gold mineralization formed during the veins crystallization or during a late episode of deformation and fluid circulation? Although the study target is within an area protected by environmental laws, the work should contribute with the elaboration of descriptive and genetic models for the mineralization, which may assist in the search for similar deposits in the central and meridional portions of the Ribeira Belt. (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)

MALTA, ISAAC S.; FALEIROS, FREDERICO M.; MONTEIRO, LENA V. S.; ANDRADE, MARCELO B.; COLDEBELLA, BRUNA; ESTEVES, MELINA C. B. P-T-fluid-deformation regime of the Ediacaran Serra do Cavalo Magro orogenic gold deposit, Ribeira Belt, Brazil. ORE GEOLOGY REVIEWS, v. 120, MAY 2020. Web of Science Citations: 0.