Sipan |
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Peru |
Main commodities:
Au
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Super Porphyry Cu and Au
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IOCG Deposits - 70 papers
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All papers now Open Access.
Available as Full Text for direct download or on request. |
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The Sipán epithermal gold deposit is located ~40 km NW of Cajamarca and 30 km from the Yanacocha mine, at an altitude of ~3500 m above sea level (#Location: 6° 54' 51"S, 78° 46' 32"W).
The deposit was discovered in 1992 and was mined by Cía Minera Sipán of the Hochshild Group from 1997 to closure in 2001.
Regional and District Setting
Sipán is one of a number of epithermal and porphyry style deposits that define a broad halo around the Yanacocha cluster.
For details of the regional setting, see the separate Peruvian Andes record, and for the district setting, the Yanacocha, Kupfertal, La Quinua record.
Geology, Mineralisation and Alteration
Sipán is a high sulphidation epithermal Au-Ag deposit that is genetically related to the Miocene Chicche stratovolcano. The volcanic cone and surrounds are composed of pyroclastic rocks, dislocated by faults and radial fractures and overprinted by hydrothermal alteration and gold mineralisation. The economic gold mineralization occurred as a strip that had a strike length of 950 m and a width that varied from 30 to 230 m. Mineralisation has been dated at between 11.5 and 10. 9 Ma (Turner, 1997), and extends to a depth of 250 m, with the enclosing rocks predominantly oxidised (Candiotti and Guerrero 2,000). It is structurally controlled by transverse NE aligned faulting.
The primary mineralised assemblage is composed of pyrite and enargite, locally accompanied by chalcocite, covelite and native sulphur. Alteration occurs as strips the nucleii of which are intensely silicified and leached to "vuggy silica", flanked by a quartz-alunite alteration which grades into an outer argillic zone.
Sipán and La Zanja lie beneath a shallowly west dipping high-elevation peneplain similar to, and apparently contiguous with that at Yanacocha and Tantahuatay. At Sipán and La Zanja, this surface is at an elevation that is ~400 m lower than at Tantahuatay and Yanacocha which are 30 to 40 km to the east. Sipán and La Zanja also differ from Yanacocha in that they are structurally controlled and caldera related, whereas mineralisation at Yanacocha has a greater reliance on brecciation, lithological control and resurgent magmatic-hydrothermal activity (Turner, 1999).
The deposit yielded 16 Mt @ 2.0 g/t Au (Cardozo 2006).
The most recent source geological information used to prepare this decription was dated: 2007.
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.
Sipan
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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.
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