Stable isotope systematic applied to the characterization of the hydrothermal paleo-systems of the Alvo Bacaba and Alvo Castanha, Carajás Mineral Province, PA.

• Grant number: 09/02747-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2009
• End date: August 31, 2010
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Lena Virginia Soares Monteiro
• Grantee: Andre Luiz Silva Pestilho
• Host Institution: Instituto de Geociências (IG). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

This project proposes the application of the stable isotope systematic on the study of hydrothermal haloes and evolution of the hydrothermal paleo-systems associated with the genesis of the Alvo Castanha and Alvo Bacaba deposits. These deposits represent satellite targets in relation to the iron oxide-copper-gold Sossego deposit, which was the first opened copper mine in the Carajás Mineral Province. The Alvo Castanha and Alvo Bacaba deposits have similar paragenetic evolution represented by sodic and potassic alterations, chloritization, sericitization, and specially, extensive scapolitization zones. In both deposits, the copper mineralization was late and similar ore signatures were recognized, despite the different host rocks in each deposit (volcanic rock at Alvo Castanha and felsic intrusive rock at Alva Bacaba). However, the ore mineral association indicates distinct fO2 e fS2 conditions associated with the mineralization stage in these deposits (pirrhotite-chalcopyrite-pyrite in Alvo Castanha deposit and chalcopyrite-bornite in the Alvo Bacaba). Zinc enriched ore zones, recognized only at Alvo Castanha, are also distinctive. The isotopic study objectives: (1) characterization of the distribution of hydrothermal alteration zones and of paragenetic, structural and metallogenetic relationships; (2) identification of the nature of fluid, metals, and sulfur sources, as well as the relative contribution of those sources in the formation of different ore deposits in the province; and (3) identification of the processes responsible for the evolution of the hydrothermal paleo-system and ore deposition. Petrography, scanning microscope studies and geochemistry of stable isotope (O, H, C, and S) will be carried out on representative mineral phases of the paragenetic evolution in both deposits.

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)

SILVA PESTILHO, ANDRE LUIZ; SOARES MONTEIRO, LENA VIRGINIA; COELHO DE MELO, GUSTAVO HENRIQUE; MORETO, CAROLINA PENTEADONATIVIDADE; JULIANI, CAETANO; FALLICK, ANTHONY EDWARD; XAVIER, ROBERTO PEREZ. Stable isotopes and fluid inclusion constraints on the fluid evolution in the Bacaba and Castanha iron oxide-copper-gold deposits, Carajas Mineral Province, Brazil. ORE GEOLOGY REVIEWS, v. 126, NOV 2020. (09/02747-0)

Academic Publications

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

PESTILHO, Andre Luiz Silva. Stable isotope systematic applied to characterization of the hydrothermal systems associated with the Alvo Bacaba and Alvo Castanha copper deposits, Carajás Mineral Province, PA. 2011. Master's Dissertation - Universidade Estadual de Campinas (UNICAMP). Instituto de Geociências Campinas, SP.