摘要
EPITHERMA Au-(Cu) deposits occur largely in volcano-plutonic arcs (island arcs as well as continentalarcs) associated with subduction zones, with ages similar to those of volcanism. These deposits form atshallow depth,【1 km, and are hosted mainly by volcanic rocks. Modern volcanic-hydrothermal systems provide an analogue to the environment for the ancient intrusion-related and volcanic epithermal deposits. Recent studies also indicate that the volcanic epithennalore deposits are formed from magmatic fluids, although the magmatic signatures have been largely erasedby meteoric water. At depth (fig. 1), the magmatic fluid from the high-level intrusive magma will result in the formation of intrusion-related deposits (e.g. porphyry Cu, Au, Mo deposits). Detailed studies of fluid inclusions and stable isotopes indicate that the hydrothermal system that form these deposits are initially
