Study On Characteristics And Mineralization Mechanism Of Carboniferous Volcanic Rocks Of Chilongfeng Iron Deposit In The Eastern Tianshan,Xinjiang

Chilongfeng iron deposit is located in Bailingshan ore field which belongs to the south of Jueluotage tectonic metallogenic belt in eastern Tianshan, Xinjiang. Bailingshan ore field is an important Fe-Cu-Au polymetallic metallogenic zone. The ore field has attracted great attention of geologists because of its unique mineralization geological condition and rich iron ore resources. It has found many of the molding deposits in this region, such as Hongyuntan iron deposit, Tieling iron deposit, Bailingshan iron deposit and Chilongfeng iron deposit, it also associated with copper mineralization. In recent years, numerous scholars have launched extensive geological work on multiple iron deposit in this metallogenic belt, analyzed typical iron deposits and made rich achievements. They think that regional volcanism has a close relationship with mineralization.By fully collecting predecessors’ research data and combinating the field geological work, this paper discussed volcanic geological and geochemical characteristics of Dikan’er Formation in Chilongfeng iron deposit, and Chilongfeng iron deposit was also analyzed. The major findings were as following:Carboniferous volcanic rocks are widely distributed in this area. It has multiple types of rocks. The lithology of Dikan’er Formation mainly includes basalt, andesite, rhyolite and tuff, it is dominated by intermediate-acid rocks with small amount of basic rock. Geological and geochemical characteristics show the rocks are formed in an island or continental marginal arc. The evolution of the volcanic rocks is mainly controlled by partial melting of the mantle which is caused by subducting slabs,and mixed in minor crustal contamination.Carboniferous volcanic activity is one of the biggest magmatic events. The formation of ore deposits in this area is closely related to the magma-hydrothermal activities. Deep volcanic magma system provides ore-forming material to formation of the deposit. Fractured zones in volcanic vent and volcanic mechanism are the important guiding mine and host structure of the deposits, and provided pathway to migration of ore-forming fluid.Chilongfeng iron deposit is hosted by volcanic of Carboniferous Dikan’er Formation. The ore body is obviously controlled by strata, and it is in conformable contact with the strata. Ore minerals are mainly consisted of hematite(specularite), and with minor magnetiteand limonite,while gangue minerals are consisted of chlorite, quartz, calcite and pyrite. Ore structure mainly occur as banded, thin vein, massive and powder, whereas ore textures dominantly display as aphanitic- particle and leaf shaped. Wall-rock alteration mainly includes chloritization, silicification and sericitization. By comparing different type of volcanic ore deposits and other deposits in the area, it is considered that this mineralization type belong to the marine volcanic hydrothermal-sedimentary origin.Through analyzing and studying on the regional background, ore-forming materials, ore-forming hydrothermal and tectonic conditions, it is considered that it has a good metallogenic potential in this area. We should pay more attention to prospecting in deep and external area.