User:Tillman/Serra Pelada geology

Notes and refs: Very* preliminary cut at this!

• http://www.portergeo.com.au/database/mineinfo.asp?mineid=mn347 Short article summarizing the geology of the article. Unfortunately, as I know next to nothing about this area, it's not that much help to me.

• http://www.mindat.org/loc-21632.html -- seems to collect most of the refs

• http://link.springer.com/article/10.1007/s001260100201 Absract: The Serra Pelada Au-PGE deposit, Serra dos Carajás. Entire article is posted to Research Gate as a PDF, see Google. I have a copy.

• http://econgeol.geoscienceworld.org/content/97/5/1127 Serra Pelada, Reconnaissance Mineralogy and Chemistry of Very High Grade Palladian Gold Mineralization, Abstract only

• http://www.canmin.org/content/40/5/1451.abstract PALLADIUM AND PLATINUM MINERALS FROM THE SERRA PELADA Au–Pd–Pt DEPOSIT, CARAJÁS MINERAL PROVINCE, NORTHERN BRAZIL

• http://link.springer.com/article/10.1007/s001260100178#page-1 Abstract + pp1-2, Gold deposits of the Carajás mineral province: deposit types and metallogenesis. Mineralium Deposita, July 2001, Volume 36, Issue 3, pp 300-33. Full text: https://www.academia.edu/8065509/Gold_deposits_of_the_Caraj%C3%A1s_mineral_province_deposit_types_and_metallogenesis

• http://docplayer.net/4004000-Technical-report-on-recent-exploration-at-the-serra-pelada-gold-platinum-palladium-project-in-para-state-brazil-for-colossus-minerals-inc.html Nice details and cross sections of Serra Pelada deposit. Deposit hosted in red metasiltstone, Rio Fresco Formation, 2.68 Ga. Gold-PGE minztn comtinues downdip from the old open pit.

The majority (>75%) of the ore is hosted in the black, carbon-rich, lower part of the carbonaceous and calcareous meta-siltstone.

Estimated resource: in the unmined portion of the deposit, is 56 t Au, 15 t Pd and 7 t Pt, grading 15.20 g/t Au, 4.09 g/t Pd and 1.89 g/t Pt (CVRD, 1998). Original pre-mining resources have been estimated at ~110 t Au, ~35t Pd and ~18 t Pt, although the uncertainty of these figures is high. (Porter report)

Gold-PGE mineralisation is associated with the formation of magnetite- and hematite-rich hydrothermal breccias, massive zones of hematite metasomatism, intense sericite (white mica)-kaolin metasomatism, siderite veining and a jasperoid envelope of amorphous silica alteration hosting rare disseminated pyrite.

Virtually all of the Au-PGE ore-related mineral assemblages have undergone intense weathering to hydrated Fe-oxides and secondary clay minerals. The geochemistry of the primary Au-PGE ores at Serra Pelada displays many similarities to that of Fe-oxide Cu-Au deposits within the Carajás Mineral Province, in terms of metal association (eg. Co, Ni, Cu, U), LREE enrichment and accompanying Fe-metasomatism. (Porter report)