Andesite-hosted copper sulphide-bitumen mineralization in a back arc andean basin, North Central Chile

摘要

A marked spatial relationship between copper sulphide and bitumen exists within a narrow horizon of andesites in North Central Chile. Temporal relationships indicate that the bitumen probably acted as a reductant template for the copper sulphides and other metal ineralization which occurs within the andesite. Whole oil gas chromatography indicates that the bitumen was an oil which has experienced various degrees of biodegradation. Fluid inclusion studies within calcite and quartz suggest the presence of at least two phases of oil migration within the andesites.