Formational types of porphyry copper deposits and their ore-magmatic systems

Abstract

Two individual ore-formational types have been identified within the porphyry copper family: the gold-copper-porphyry and molybdenum-copper-porphyry ones. The fundamental difference between them lies in their geotectonic position that determines the origin and composition of fertile magmatic source, as well as other features the composition of ore-bearing porphyry intrusions, the mineralogical and geochemical features of ores, and the pattern of metasomatic and ore zonation. In this study, we investigated porphyry copper ore-magmatic systems with complex metallogeny, or complex porphyry copper systems (CPCS), where porphyry copper deposits constitute the core elements spatially associated with mineralization of other ore-formational types. Based on a set of conjugated and combined types of ore mineralization we established the differences between diorite-related gold-copper-porphyry CPCS, formed in basaltic volcano-plutonic belts, and granodiorite-monzonite-related molybdenum-copper-porphyry CPCS, formed in andesite belts. These differences confirm the validity of the distinction of the two ore-formational types of deposits of the porphyry-copper family.