2015-03-132015-03-132013-12VELOSO, Ângela Suélem Rocha; SANTOS, Márcio Dias; RIOS, Francisco Javier. Evolução dos fluidos mineralizantes e modelo genético dos veios de quartzo auríferos em zona de cisalhamento do depósito Ouro Roxo, Província Tapajós, Jacareacanga (PA), Brasil. Brazilian Journal of Geology, São Paulo, v. 43, n. 4, p. 725-744, dez. 2013. Disponível em: <http://ppegeo.igc.usp.br/pdf/bjg/v43n4/11.pdf>. Acesso em: 10 mar. 2015. <http://dx.doi.org/10.5327/Z2317-488920130004000011>.2317-4889https://repositorio.ufpa.br/handle/2011/6416The Ouro Roxo gold deposit, located near Jacareacanga, Tapajós Gold Province, southwestern Para, Brazil, comprises a hydrothermal system of sulfide quartz veins that was hosted by the calc-alkaline mylonite granitoid Tropas Intrusive Suite of Paleoproterozoic age and controlled by the N-S trending ductile-brittle oblique Ouro Roxo-Canta Galo, crosscutting the granitoid Tropas. Three kinds of fluids were identified as sources of mineralization in the Ouro Roxo deposit: 1) an aqueous fluid within the H2O-NaCl-MgCl2-FeCl2 system, with low-to-middle salinity and homogenization temperature (Th) = 180-280°C; 2) Cu and Bi-bearing H2O-NaCl-CaCl2 brines, with Th = 270-400°C, genetically related to a magmatic event coeval to shearing, which underwent dilution by mixing with meteoric water; 3) gold bearing middle-salinity aquocarbonic fluid, with Th = 230-430°C, which was interpreted as ore fluid related to shearing. The T-P conditions of ore formation, estimated by chlorite geothermometer and fluid inclusion isochors, range from 315 to 388°C and 2,0 to 4,1kb. The two main mechanisms for gold deposition in transtensional sites of the shear zone were: 1) Mixing of aquocarbonic fluid and magmatic brines induced an increasing of fO2 and decrease of pH; 2) interaction between fluids and feldspars and ferromagnesian minerals of the hoster granitoid which reduced fO2 and fS2 during hydrolysis and sulfidation reactions, with precipitation of iron sulfides together with gold. The orogenic environment, the veining style, the structural control by shearing, the hydrothermal alteration (propylitic+philic+carbonatization), the metallic association (Au+Cu+Bi), the association of aquocarbonic ore fluid with magmatic brines in ore deposition, are all consistent with an orogenic model for genesis of the Ouro Roxo deposit with magmatic participation.porAcesso AbertoPetrografiaCisalhamentoOuro roxoProvíncia Aurífera do Tapajós - PAJacareacanga - PAPará - EstadoAmazônia brasileiraArtigo de Periódico