Weeks To Saddle Bridge Gold Ore-controlling Regularity And Metallogenic Prediction Research

Maanqiao gold deposit is located in Zhouzhi county, Shaanxi province. It is on the north edge of Vaviscian fold belt in Qinlin. Ore-bearing stratohorison is Tongyusi group of late Devonian system and ore-bearing rock is minute clastic rock formation. In the area, magma action is strong, metamorphism and hydrothermal action is evident. Wallrock alternation is wide spread. The tenor of gold is low.There are three parts in mine-east, middle and west. Faults are wide spread in the area. The orebodies controlled by ductile shear zone, which are lenticular and bedded, are in interlayer fault zone between Devonian system and Carboniferous system. The enrichment of gold is under the control of polyfactor-the outspread of the ore bed is controlled by the regional ductile shear zone, the rich orebody is controlled by the accessorial ductile-brittle shear zone, and the succedent brittle shearing formation break the mineral to some extent, also has some favorable function to the enrichment of gold. Strong transformation of geology is the main reason of the gold deposit' formation. The ductile shear zone is not only the ore-leading and ore -controlling structure , but also the ore-bearing structure.In the gold deposit which belongs to the ductile shear zone, there is rich gold deposit not only in the zone where there is strong transformation or where the ductile of fault shear zone changes to the brittle shear zone, but only in the belt where there is weak transformationThe dissertation is on the basis of collecting predecessors' achievement, and brings to success by field autoptical and studies in doors. By researching geology condition and geology background, it is concluded that the main ore-controlling ore-leading structure is The accessorial formation of Xufenzi-Huangshiban, which is to the north of Banfangzi-Xiaowangjian, which is in the fault belt between Shaliangzi-Shuangmiaozi and Miaogou-Xiaowangjan.It is also concluded that the ore bed in the depths of K20, K19 and K25 are rich. It is predicted that it is difficult to forming ore beds in the depth of K19 because the index of wallrock alternation decreases. A lot of iron pyrites in the meddle of 1430 near ore bed in Dayagou can be found , which is the next foreground of finding ore.At the same time, the dissertation has also made a discuss about the genesis of the ore bed and brings forward a new idea that partial aurum of the gold deposit comes from the mantle.