| Xincheng gold mine is located in the northwest of north China land mass uplifted Jiaobei Jiaoliao-Jiaolai fault uplift, Yishu fault zone east of jiaojia gold belt. In the Region Archean-Proterozoic metamorphic belts development, magmatic activity frequent and intense, fault structure developments, geological background is complex, and metallogenic conditions is superior.After 31 years of mining, to the end of 2008, Xincheng gold mine reserves resources retained 4549151t, metal quantity 15022Kg, can only service 4.88 years, belong to resources moderate the crisis mines.Xincheng gold deposit is one of the mines to be exhausted in China .In order to solve problems of prospecting predication and exploration, reserches have been carried out by analizing the regional ,local geology and characteristics of geochemistry comprehensively, especially the ore controling factors and prospecting signs. On the basis of the work, conclusions and achievements are obtained as following:1,Precambian metamorphic rocks are the source bed of the gold mines. Linglong and Guojialing super-unit offer ore-forming material sources for mineralization, and Guojialing super-unit is the wall rock of the gold ore deposits.2,Ore bodies controlled by the faults is hosted by the lower wall of the gouge,which is developed on the main fault surface,indicating that gouge obstruct the hydrothermal migration. Fractured and alteration zone located in the is favourable to migration, enrichment and deposits of the ore forming fluid. Orebodies occur in the Lord of the tectonic fractures ups and downs in the shape of large slow sites. Due to the ore-controlling fracture superposition many inheritance activities, so contributed to the main tectonic fracture surface of the ups and downs, and the outward in fractures ups and downs of prominent part is orebodies occur mainly favorable positions.3,Controlled by the tectonic altered rocks, in a strong position tectonic activity of mineralized zone of enrichment, rock altered degree is high, fracture, porosity, permeability, is conducive to mineral liquid penetration, diffusion, and accountability. This site altered function repeatedly superposition easily form rich ore body, Orebody from prolific in the pyrite ore phyllic cataclasite zone and pyrite phyllic granodioritic cataclasite zone.4,Geochemical anomaly shows that Au,Ag,Cu,Pb,Zn are anormal in inner-middle zone,and middle-outter anormalous zone is reflected by the Post-ore halo elements, including Hg,As,Sb,Bi and W, or with the end of halo indicator elements Mo, Co abnormalities coexist, indicating that the ore body extension to deep is still very great.5,Xincheng gold mine in the formation controlled compoundly by three ore-controlling factors such an the Precambrian metamorphic basement as the main body of jiaodong groups and JingShan group, NE, NNE faults, Yuan ancient remelting type of magmatic rocks and Mesozoic yanshan magmatite. In addition, ductile shear zone, hydrothermal altered and ore-forming fluid played an important role to the enrichment of gold. This article obtained six gold predicted targets through to analysis and research the ore-forming geological conditions of the mine, the geochemical characteristics, ore-controlling factors and metallogenic regularities. |
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