The Contrast Of Geological Feature Between Getiaowan And Anba Gold Deposit In The Yangshan Gold Belt

The Yangshan gold belt is structurally located within the Mian-Lue suture zone in the West Qinling orogen. There are six gold deposits in the Yangshan gold belt from west to east, which have a total resource of350t, and90%of these come from Anba gold deposit. In order to make certain the reason of distribution imbalance of the huge amounts of gold, assess the metallogenetic potentiality of the other deposits in Yangshan gold belt, we make a detailed contrast of geological feature between Anba and Getiaowan gold deposit in this paper.The study on the metallogenic geological environment shows that Getiaowan and Anba deposit have a similar geological environment:the stratum of Devonian Sanhekou Group is the primary ore-bearing horizon, which is also the source of ore-forming fluid and metallogenic material; Anchanghe-Guanyinba shear zone and its NEE-trending secondary faults control the output and distribution of ore bodies; the small-scale acidic dikes have a close space relation with ore bodies, but the genetic relationship is not clear.The study on the geological feature of two deposits shows that they have the similar ore structure, mineralization style, wall rock alteration and stage of mineralization, but there are some evident difference:the ore bodies of two deposits spread with a NEE-trending on the whole, while some of Getiaowan gold deposit present NEE-trending; the wall rock alteration of carbonatation appear more widely, there are more calcite veins in the stratum.The study on the characteristics of ore forming fluid shows that the ore forming fluid of both of the deposits have the same feature of mesothermal temperature, low salinity, CO2-rich and Na+-Cl-(SO42-)-H2O-CO2system, which are typical orogenic type gold ore fluid. The initial ore-forming fluid is metamorphic hydrotherm, and the meteoric waters interfuse the fluid system with the mineralization process. The lower value of main phase δ18OW-SMOW and δD of Getiaowan gold deposit shows that there are more meteoric waters join in the fluid system, which are caused possibly by the shallower metallogenic depth, lower surrounding rock pressure and greater degree of opening of the fluid system.Through the comparative study, we confirm the dominant factors that control the distribution imbalance of the huge amounts of gold:lithological characters and geological structures.The contrast of two deposits shows that the Getiaowan gold deposit has a good metallogenic potential, and they have prospecting potential in the deep due to the shallow denudation.