EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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Resultados da Pesquisa
Item Magmatic-hydrothermal fluids leaching older seafloor exhalative rocks to form the IOCG deposits of the Carajás Province, Brazil : evidence from boron isotopes.(2021) Melo, Gustavo Henrique Coelho de; Monteiro, Lena Virginia Soares; Hunger, Raphael Bianchi; Toledo, Poliana Iara Freitas; Xavier, Roberto Perez; Zhao, Xin-Fu; Su, Zhi-Kun; Moreto, Carolina Penteado Natividade; Jesus, Silvandira dos Santos Goes Pereira deThe notable group of iron oxide-copper–gold (IOCG) deposits at the Carajas Province (Amazonian Craton, Brazil) contain remarkable copper reserves due to a complex Neoarchean metallogenetic evolution. The overlay of diachronic hydrothermal-mineralizing events is revealed by two clusters of boron isotope compositions of hy- drothermal tourmaline obtained in IOCG deposits (Salobo, Igarap ́e Bahia, GT-46, Grota Funda and Furnas) with (i) high δ11B (+8.2 to +17.2‰) and (ii) low δ11B (+3.4 to +9.8‰) values. The isotopically heavy boron sig- natures, recorded in tourmaline cores, are inherited from the volcano-sedimentary sequences of the ca. 2.76 Ga Itacaiúnas Supergroup, which includes exhalative tourmaline and spilites formed in extensive exhalative systems prior to the IOCG formation. During the main IOCG event at ca. 2.55 Ga, the regional circulation of magmatic- hydrothermal boron-rich fluids originated tourmaline rims and new crystals with lower δ11B values. We describe the critical role of an older volcano-sedimentary as a source for boron and likely metals leached by magmatic- hydrothermal fluids to form the IOCG deposits of the Carajas ́ Province.