The geological characteristics, geochemical signature and geophysical expression of porphyry copper-(gold) deposits in the circum-Pacific region

Abstract

Porphyry deposits of the circum-Pacific region contain a large amount of the world’s copper, molybdenum and gold. These deposits are formed from calc-alkaline and potassic magmas characterized by varying oxidation states (fO2), which contribute to different ore mineral assemblages and contrasting relationships to hydrothermal alteration zones. Gold-rich porphyry copper deposits are typically characterized by hydrous and highly oxidized causal magmas. Variations in the styles of geology and mineralization contribute to differing geochemical expressions and geophysical signatures of the porphyry deposits. Exploration programs that integrate high-quality geological mapping and drill-core logging with a three-dimensional understanding of geochemical and geophysical data will facilitate the path to discovery.