Petrografia e mineralogia do furo SPD-120 do depósito de Au-Pd-Pt de Serra Pelada, Curionópolis, Pará

Abstract

The Serra Pelada Au-Pd-Pt deposit is situated near the homonymous community, in the municipality of Curionopolis, Pará. It is located in the Carajás Mineral province, in the eastern portion of the Amazonian craton. The deposit is hosted by hydrothermally altered metasedimentary rocks of Águas Claras formation, of Neoarchean age, formed from sediments deposited in a fluvial-marine environment. The Serra Pelada deposit area is composed of meta-dolomitic sandstones, gray metasiltstones, red metasiltstones, a mafic dike and a dioritic intrusion. Some important studies about the deposit have been done, however, some questions about its origin still remain. Thus, this work aimed at characterizing petrographically and mineralogically the metasedimentary rocks from Serra Pelada. Therefore, petrographical analysis, as well as Scanning Electron Microscope (SEM) with Energy Dispersive X-Ray Spectrometry (EDS) analysis were performed in samples collected from the drill cores from the SPD-120 drill hole, provided by Cooperativa de Mineração dos Garimpeiros de Serra Pelada (Coomigasp), so this work could get more answers for the remained questions about Serra Pelada deposit origin. The lithologies identified and characterized in this work are: 1) meta-quartz sandstones; 2) meta-silicified sandstones; 3) carbon-rich metasiltstones; 4) iron-rich metasiltstones; and 5) kaolinitic mudstones. These metasedimentary rocks show sedimentary and metamorphic features, preserving evidence of hydrothermal activities that affected them.