Geological and geochemical characteristics and gold enrichment regularity of the Yangpingwan gold deposit in Shiquan,Shaanxi Province

The Yangpingwan gold deposit was found after the discovery of the Huanglong and Luming gold deposits in the northern Shiquan-Hanyin area of the Qinling orogenic belt.The study of regional gold prospecting and gold metallogeny is of great importance.Geological and geochemical characteristics were studied in this paper through field investigation and laboratory experiment.Gold mineralization occurs in schist of the Lower Silurian Meiziya Formation(S_1m).The northern and southern oreforming belts which contain three ore bodies have been delineated.Gold mineralization is characterized by silicon and pyrite.Gold exists mainly as visible gold between mineral grains or in cracks.Gold mineralization is controlled by schist strata intercalated with quartzite layer and shearing structure.Metallogenic temperature of fluid inclusions is 170-220℃,suggesting mesothermal-epithermal mineralization.D and O isotopes show that ore-forming fluids were derived from precipitation and metamorphosed water.S values vary in the range of 7.5‰-11.7‰,implying that metallogenic materials came from strata.Geological and geochemical characteristics indicate that the Yangpingwan gold deposit is a sedimentary-reformation type deposit formed at middle-low temperatures.