GEOPHYSICS OF THE ELANG CU-AU PORPHYRY DEPOSIT, INDONESIA, AND COMPARISON WITH OTHER CU-AU PORPHYRY SYSTEMS

摘要

Elang is a large Cu-Au porphyry deposit situated about 70 km cast of Batu Hijau in Sumbawa, Indonesia. The deposit is associated with a series of tonalite porphyry intrusions that are hosted by andesitic volcanics. Mineralisation is associated with potassic alteration (chlorite-magnetite±biotite) which grades outward to propylitic alteration. This system is overprinted by intermediate argillic alteration, and there is an advanced argillic lithocap, up to 200m thick, covering much of the deposit.