Geology and geochemistry of the Phu Lon copper-gold skarn deposit at the northern Loei Fold Belt, Northeast Thailand

Abstract

The Phu Lon deposit in northeast Thailand (Nong Khai province) is the best known skarn copper-gold deposit in the Palaeozoic-Cenozoic Loei volcano-plutonic belt (Loei Fold Belt). The research project documented herein comprises a detailed study of the deposit geology, providing the basis for calc-silicate mineral chemistry and sulphur isotope and fluid inclusion investigations. This is the first result of analysis of the fluid chemistry at Phu Lon and strongly supports a direct relationship between magmatic fluid and mineralisation. This research also summarises the salient features of the Phu Lon deposit to compare with other world-class copper-gold skarns. This comparison suggests that the Phu Lon skarn deposit may represent an oxidised end-member of gold enriched types.