|Peter C. Lightfoot, Leon Bagas, and Feng-Jun Nie report that China is currently positioned as the largest global producer of gold with a 2014 production of 450 t from predominantly epithermal deposits, which places it well ahead of production from other countries, according to the U.S. Geological Survey. Despite this strong position as a producer, China has gold reserves that are much smaller, on the order of 33,000 t of gold in global reserves, but only 1,900 t is in China.|
Zhang et al. (in press) report on a study of the history and economics of gold mining in China, and their work reports reserve figures from Xu (2012), which are compliant with Chinese rule sets on classifications following the National codes on classification of mineral reserves and resources. There is no exact alignment of categories in the JORC and Chinese codes as yet, so the comparisons must be treated with commensurate caution.
Continued production of gold in China depends on continued exploration success, and this success is rooted in the technical excellence in discovery that is underpinned by sound geological principles and new knowledge. For example, epithermal deposits are formed from meteoric hydrothermal with varying proportion of magmatic hydrothermal fluids, which are commonly driven by the magma-heat energy.
Such deposits are generally formed in the Earth crust at shallow depths with temperatures of less than 400 degrees C and depths of about 2 km. Epithermal deposits have been classified as low sulfide-type, high sulfide-type and alkaline-type, alunite-kaolinite type (or acidic sulfate type) and adularia-sericite type (Bonham, 1986, and others). The tectonic setting for these epithermal gold deposits include continental-margin arcs and island-arcs, and back-arcs located above subduction zones (e.g. Sillitoe, 2000, and others).
An outstanding review of current models of gold mineralization. Read on ...