Characterisation of hypogene covellite assemblages at the Chuquicamata porphyry copper deposit, Chile, Section 4500N.

摘要

This thesis was planned as a first step towards the characterisation of covellite, attempting to develop practical criteria for the differentiation of hypogene from supergene covellite in the Chuquicamata porphyry copper deposit, Chile. Approximately 120 samples of ore were collected from 3 drillholes that intersect the major alteration zones (e.g. potassic, quartz-sericitic, chloritic), within the 4500N coordinate section, recommended by mine staff to be representative of the deposit. The petrology and mineralogy of the samples were studied using reflected light microscopy, x-ray diffraction, and the electron microprobe.;Hypogene covellites from Chuquicamata contain significant Fe, which varies systematically from 0 to ;The hypogene sulphide assemblages were studied in the context of experimentally-determined sulphide phase equilibria to pose constraints on temperatures of ore deposition. Assemblages from within the potassic zone of alteration in the 4500N section at Chuquicamata can be constrained to a temperature range of approximately 400 to 600