Yanshanian Magmatism And Mineralization Of The Tianjingshan Area From South Anhui Province

The Tianjingshan gold field is located in the eastern Jiangnan Uplift, south Anhui Province, development in the secondary fault zone of prov.Anhui, Zhengjiang and Jiangxi:Huangmao-sanyang-tunxi ductile shear belt.The magmatic activities around the Tianjingshan gold field are mainly concentrated in Jingningian and Yanshanian, the granite of Jingningian is Lingshan pluton, accounts for about two-thirds of the Tianjingshan gold field, Lingshan pluton is in the south east of the area. Most of the Yanshanian granite porphyry invatrudes between Jingtian wall rock and Lingshan pluton in rock shoot and dike output.The Qingshan-Changgai magmatic rocks on the regional tectonic geological background and mineralization is closely related to the Tianjingshan gold field. The Tianjingshan gold field is located in the contact zone of Lingshan pluton and surrounding rock.The ore body is lenticular and vern distribution, the major ore type is quartz vern type and altered rock type.Ore minerals are natural gold and sulfide, alteration types mainly include silicification, chloritization and sericitization.Quartz vein of temperature of fluid inclusions in 286～380℃, and salinity is between 3.0%～6.12% NaCleq.H, O isotopes in magmatic water, the Tianjngshan gold field is magmatic hydrothermal type gold deposit.Qingshan-Changgai magmatic rocks band for the I type grante, high potassium with weakly peraliminous calc-alkaline series.Qingshan pluton (QS001-1) is (150.3±1.7) Ma, Changgai pluton (14QC001-1) is (140.3±2.6) Ma, Changgai pluton (14QC002-5) is (141.0±2.4) Ma, Guzhu pluton (14QC004-1) is (141.0±3.0) Ma, Shimenxiang (Zaoshan) pluton (14QC005-2) is (140.6±2.2) Ma, Dalingjiao pluton (14QC006-1) is (141.0±2.0) Ma, formed in Yanshanian during late Jurassic to early Cretaceous. This series of magmatic rocks is relatively light rare earth elements and heavy rare earth elements relatively flat type right allocation model,Qingshan-Changgai magmatic rocks have the characteristics of crust-mantle mixed molten rock on the basis of zircon Hf isotope.Qingshan-Changgai magmatic rocks underwent hornblende, apatite, sphene and felsic minerals such as the separation of crystal, the magmatic rocks are derived from the Mespproterozoic and Neoproterozoic basement of the south Anhui Province, early magma generated continental island arc environment, the late magmatic was in extensional tectonic background, tectonic background of the transformation was the paleo-pacific plate to Eurasia plate subduction.