Disseminated Ores of the Darasun Gold Deposit (Eastern Transbaikalia) and Their Genesis

摘要

The large Darasun deposit was considered a classical superdeep gold deposit for a long time [1,2, and others]. In accordance with the well-known classification proposed by Lindgren [3], the Darasun deposit corresponds to the typical mesothermal deposits. However, based on several indicators, the authors of [3, 4] demonstrated that this deposit differs from the typical mesothermal deposits and resembles porphyry copper deposits or fluid-magmatic systems associated with the shallow granitoid intrusions [4, 5]. One of the major distinctions from the mesothermal deposits is represented by the discovery of relicts of high-temperature chloride brines that participated in the formation of high-grade ores. The new interpretation of the nature of mineralization also opens new perspectives for exploitation of the deposit. In particular, only ore veins were extracted so far by the underground mining technique in the deposit and low-grade disseminated ores were considered unfeasible for exploitation. However, porphyry copper deposits differ primarily from the vein deposits by the large volumes of commercial disseminated ores that can be exploited by the open mining technique.