|
Breves |
|
|
Para, Brazil |
| Main commodities:
Cu Au Ag W
|
|
 |
|
|
 |
Super Porphyry Cu and Au
|
IOCG Deposits - 70 papers
|
All papers now Open Access.
Available as Full Text for direct download or on request. |
|
|
The Breves Cu-Au-(Ag-W-Bi-Sn) deposit lies within the Carajás copper-gold belt, in Para state, Brazil.
For details of the regional tectonic and geological setting of the deposits see the Carajas IOCG Province record.
The Breves ore is hosted by sandstones and siltstones of the >2,681±5 Ma Aguas Claras Formation, and in the roof zone of a complex, highly altered granitoid intrusion, and comprises disseminated mineralisation in a greisenised zone, resulting from alteration of probable monzogranites and syenogranites.
The ore bearing greisen contains abundant xenomorphic quartz associated with Fe-chlorite and muscovite. The gangue assemblage includes fluorite, tourmaline, and minor monazite, xenotime, chlorapatite, thorite, zircon, calcite, siderite and bastnaesite. The dominant copper mineral is chalcopyrite, with associated pyrite, arsenopyrite, pyrrhotite and molybdenite. Gold, which is in equilibrium with native bismuth, is a common inclusion in chalcopyrite. The greisen also contains sub-economic tungsten and niobium that are related to the presence of ferberite, qitianlingite and Nb-rutile. The host granites yields ages of 1878 ±8 and 1880 ±9 Ma for two phases, and a combined age of 1879 ±6 Ma. Dating of monazite and xenotime grains in late- to post-mineralisation veins gives a combined age of 1872 ±7 Ma, indistinguishable from the ages of the granites. This suggests Breves, like Alvo 118, Águas Claras, Gameleira and Estrela, is related to the ~1.88 Ga large igneous province of the Carajás region, as described in the the Carajas IOCG Province record, rather than the ~2.7 Ga age of many of the other key IOCG deposits of the province, such as Salobo and Cristalino.
The deposit contains:
50 Mt @ 1.22% Cu, 0.75 g/t Au, 2.4 g/t Ag, 0.12% W, 70 ppm Sn, 0.0175% Mo and 75 ppm Bi.
For detail consult the reference(s) listed below.
The most recent source geological information used to prepare this decription was dated: 2004.
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
|
|
|
|
Bucco Tallarico F H, McNaughton N J, Groves D I, Fletcher I R, Ribeiro Figueiredo B, Beatriz Carvalho J, Luzimar Rego J, Rossetto Nunes A 2004 - Geological and SHRIMP II U-Pb constraints on the age and origin of the Breves Cu-Au-(W-Bi-Sn) deposit, Carajas, Brazil: in Mineralium Deposita v39 pp 68-86
|
Pollard, P.J., Taylor, R.G., Peters, L., Matos, F., Freitas, C., Saboia, L. and Huhn, S., 2019 - 40Ar-39Ar dating of Archean iron oxide Cu-Au and Paleoproterozoic granite-related Cu-Au deposits in the Carajas Mineral Province, Brazil: implications for genetic models: in Mineralium Deposita v.54, pp. 329-346.
|
|
Porter GeoConsultancy Pty Ltd (PorterGeo) provides access to this database at no charge. It is largely based on scientific papers and reports in the public domain, and was current when the sources consulted were published. While PorterGeo endeavour to ensure the information was accurate at the time of compilation and subsequent updating, PorterGeo, its employees and servants: i). do not warrant, or make any representation regarding the use, or results of the use of the information contained herein as to its correctness, accuracy, currency, or otherwise; and ii). expressly disclaim all liability or responsibility to any person using the information or conclusions contained herein.
|
Top | Search Again | PGC Home | Terms & Conditions
|
|
