Petrografia e mineralogia do furo de sondagem SPD-146 do depósito de Au-Pd-Pt de Serra Pelada, Curionópolis- Pará

Abstract

The Serra Pelada Au-Pd-Pt deposit is located in Curionópolis/PA, approximately 150 km from Marabá/PA, southeastern of the Amazon Craton, northeastern portion of the Carajás Mineral Province (PMC), which is known worldwide for your metallogenetic potential, making the southeastern region of the state a great investment zone in mineral exploration. This deposit is hosted by an Archean metassedimentary sequence (Águas Claras formation), which is tectonically overlying the metavulcano-sedimentary rocks of the Rio Novo group. This sequence is subdivided into three informal units: I) “Milharina” meta-sandstones; II) Red beds “Sangue de Boi” (reds meta-siltstones) and; III) Grey meta-siltstones, which were observed and described in the SPD-146 drill hole provided by the Cooperativa de Mineração dos Garimpeiros de Serra Pelada (COOMIGASP). In the SPD-146 hole, aim of this work, three lithologic types were describeds having the base-top sequence: gray metasiltstone, with 88.00 thick meters, mineralogically composed by quartz and sericite and impregnated at various intervals by iron oxyhydroxides and clay-minerals incipient orientation and sericite, undulating extinction quartz and still recrystallized edges quartz suggesting low grade metamorphism; Ferrified metasiltstone, 13.50 thick meters, mineralogically composed of quartz, hematite and kaolinite, having intense silicification locally probably caused by hydrothermalism; Again a range of the gray metasiltstone, 13.00 thick meters, mineralogically composed by quartz and kaolinite and pyrite traces, and finally, gray yellowish metasandstone mineralogically composed by undulating extinction and recrystallized edges quartz and iron oxide of 10.00 thick meters. No traces mineralization were found in these rocks.