Chapter 7 Epithermal Gold Deposits of China—An Overview

Abstract

Abstract Reported epithermal deposits in China contain a total resource of at least 1,460 tonnes (t) Au. Approximately 550 t Au are in Mesozoic deposits in eastern China, related to the widespread Mesozoic Yanshanian magmatism produced by Pacific Plate subduction. Quaternary deposits in Taiwan (>500 t Au), Paleozoic deposits in north-western China (~150 t Au), and scattered deposits elsewhere of Yanshanian and late Paleozoic age (~260 t Au) also contribute to the total. Tertiary deposits are recorded in southwestern China, but currently known ones are mainly small and not abundant. We summarize information from the Chinese and Western literature for 64 deposits that have been described as epithermal; however, we recognize that some deposits probably have been incorrectly classified as epithermal. Thirty-five low-sulfidation deposits, as well as six low-sulfidation alkalic deposits, are included in this group. Five of the low-sulfidation deposits contain combined resources of ~305 t Au, and four of the low-sulfidation alkalic deposits contain resources of ~55 t Au. We interpret 17 deposits to be intermediate sulfidation, with eight containing combined resources of ~240 t Au. Five high-sulfidation deposits are reported, and two of these, Jinguashi on Taiwan and Zijinshan in southeastern China, contain combined resources of >800 t Au. Considering all known epithermal deposits, 10 contain ≥30 t Au, seven contain between 10 and 30 t Au, and the remainder have <10 t Au each or have no reported resource. This apparently skewed size distribution highlights a peculiarity of mineral resources in China, such that only deposits investigated by professional exploration/mining groups report significant resources. Most deposits are mined on an ad hoc basis by individuals or groups lacking technical resources. Consequently, there is an excellent opportunity for discovery of new deposits or expansion of known deposits in all regions of China by groups with a sound knowledge of the characteristics of epithermal deposits. Recognition of the presence of low-sulfidation alkalic deposits may indicate excellent potential for important discoveries of this type of deposit.