Temporal evolution of the giant Salobo IOCG deposit, Carajás Province (Brazil) : constraints from paragenesis of hydrothermal alteration and U-Pb geochronology
Gustavo H. C. de Melo, Lena V. S. Monteiro, Roberto P Xavier, Carolina P. N. Moreto, Erika S. B. Santiago, S. Andrew Dufrane, Benevides Aires, Antonio F. F. Santos
ARTIGO
Inglês
The giant Salobo copper-gold deposit is located in the Carajás Province, Amazon Craton. Detailed drill core description, petrographical studies, and U-Pb SHRIMP IIe and LA-ICP-MS geochronology unravel its evolution regarding the host rocks, hydrothermal alteration and mineralization. Within the...
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The giant Salobo copper-gold deposit is located in the Carajás Province, Amazon Craton. Detailed drill core description, petrographical studies, and U-Pb SHRIMP IIe and LA-ICP-MS geochronology unravel its evolution regarding the host rocks, hydrothermal alteration and mineralization. Within the Cinzento Shear Zone, the deposit is hosted by orthogneisses of the Mesoarchean Xingu Complex (2950 ± 25 and 2857 ± 6.7 Ma) and of the Neoarchean Igarapé Gelado suite (2763 ± 4.4 Ma), which are crosscut by the Old Salobo granite. Remnants of the Igarapé Salobo metavolcanic-sedimentary sequence are represented by a quartz mylonite with detrital zircon populations (ca. 3.1–3.0, 2.95, 2.86, and 2.74 Ga). High-temperature calcic-sodic hydrothermal alteration (hastingsite-actinolite) was followed by silicification, iron-enrichment (almandine-grunerite-magnetite), tourmaline formation, potassic alteration with biotite, copper-gold ore formation, and later Fe-rich hydrated silicate alteration. Myrmekitic bornite-chalcocite and magnetite comprise the bulk of copper-gold ore. All these alteration assemblages have been overprinted by post-ore hematite-bearing potassic and propylitic alteration, which is also recognized in the Old Salobo granite. In the central zone of the deposit the mylonitized Igarapé Gelado suite rocks yield an age of 2701 ± 30 Ma. Zircon ages of 2547 ± 5.3 and 2535 ± 8.4 Ma were obtained for the Old Salobo granite and for the high-grade copper ore, respectively. A U-Pb LA-ICP-MS monazite age (2452 ± 14 Ma) from the copper-gold ore indicates hydrothermal activity and overprinting in the Siderian. Therefore, a protracted tectono-thermal event due to the reactivation of the Cinzento Shear Zone is proposed for the evolution of the Salobo deposit
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FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP
2009/18371-0; 2013/25659-5
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ
573733/2008-2; 481969/2013-6; 308365/2014-3
COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES
fechado
Temporal evolution of the giant Salobo IOCG deposit, Carajás Province (Brazil) : constraints from paragenesis of hydrothermal alteration and U-Pb geochronology
Gustavo H. C. de Melo, Lena V. S. Monteiro, Roberto P Xavier, Carolina P. N. Moreto, Erika S. B. Santiago, S. Andrew Dufrane, Benevides Aires, Antonio F. F. Santos
Temporal evolution of the giant Salobo IOCG deposit, Carajás Province (Brazil) : constraints from paragenesis of hydrothermal alteration and U-Pb geochronology
Gustavo H. C. de Melo, Lena V. S. Monteiro, Roberto P Xavier, Carolina P. N. Moreto, Erika S. B. Santiago, S. Andrew Dufrane, Benevides Aires, Antonio F. F. Santos
Fontes
Mineralium deposita: international journal of geology, mineralogy, and geochemistry of mineral deposits (Fonte avulsa) |