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Melt and fluid inclusions from volcanic quartz phenocrysts in the Shila gold / base metal ore district, Peru: precursors to ore-forming epithermal solutions?

✍ Scribed by Luminita Grancea; Anne-Sylvie André-Mayer; Michel Cuney; Jacques L. Leroy


Publisher
John Wiley and Sons
Year
2002
Tongue
English
Weight
234 KB
Volume
14
Category
Article
ISSN
0954-4879

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✦ Synopsis


ABSTRACT Despite the close association with volcanic activity, the source of metals and ligands in the epithermal ore deposits is still controversial. In order to explore the magmatic–hydrothermal connection further, silicate melt, saline‐ and water‐rich fluids, and CO~2~ vapours are documented that are trapped as inclusions in quartz phenocrysts from dacitic dykes associated with epithermal gold/base metal mineralization in the Shila district (Peru). Melt inclusion characteristics, and microthermometric and laser Raman fluid inclusion data are presented. The investigation of melt and fluid inclusions reveals that the volatile phase of magmas might represent the precursors to the early chlorine‐rich ore‐forming epithermal solutions. Microthermometric investigations in magmatic quartz crystals and data on quartz mineralized veins suggest that the fluid evolution and ore deposition may be the result of several processes including: release of an evolving magmatic fluid, and/or boiling, and/or mixing.