Gold mineralization in the Serra de Jacobina region, Bahia Brazil: tectonic framework and metallogenesis

Autor: Johildo Salomão Figueiredo Barbosa, S. S. Iyer, Maria da Glória da Silva, Carlos Eduardo Silva Coelho, Carlson de Matos Maia Leite, Jorge André Braz de Souza, Valter Mônaco Conceição Filho, João Batista Guimarães Teixeira, Maísa Bastos Abram
Rok vydání: 2001
Předmět:
Zdroj: Mineralium Deposita. 36:332-344
ISSN: 1432-1866
0026-4598
Popis: Gold deposits in the Serra de Jacobina region in Bahia, northeastern Brazil, occur in a belt of siliciclastic metasedimentary rocks intercalated with mafic and ultramafic rocks, and underlain by a tonalite–trondhjemite–granodiorite gneiss-dominated (TTG) basement. The siliciclastic sequence probably represents the remnants of a sedimentary basin, which formed in an Archean passive margin-type setting. The basin was subsequently subjected to a complex history of deformation, metamorphism, and hydrothermal activity, as a result of oblique collisional events in Late Archean and Paleoproterozoic. The majority of the auriferous occurrences in the area are hosted by quartz-pebble conglomerates, and have been noted to resemble placer-type deposits. However, structurally-controlled hydrothermal orebodies, and the formation of gold occurrences also in quartzites and mafic and ultramafic rocks, support an epigenetic model for the mineralizing event. Gold mineralization is interpreted to be an integral part of the late (~1.9 Ga) tectonothermal evolution of the Serra de Jacobina region. It was roughly coeval with the emplacement of large volumes of post-collisional type, peraluminous granitic magmas, during a regional strike-slip regime.
Databáze: OpenAIRE
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