Metallogenic Model And Prospecting Prediction Of Xiaodushan Tungsten Deposit In Gansu Province

Xiaodushan tungsten deposit is a quartz-vein type of scheelite deposit, located in northwest of Dunhuang, Gansu province.In this paper, the geological features of ore deposit, ore-controlling structures, ore genesis, ore-controlling factors, metallogenic regularity are studied by collecting relevant information, conducting a geological survey and doing some test.By analyzing the geotectonic background and tectonic evolution history of the deposits. It is considered that the ore bearing fractures is tensional at first, and then became shear joint.In terms of ore genesis, Xiaodushan tungsten deposit is a post-magmatic hydrothermal quartz vein scheelite deposit. W element is from the late intrusive acid rock of the edge of deep mine, and Ca element is probably from the wall rock of ore veins.There is acid rock body in mining area and surrounding area, such as granite, granite-porphyry, moyite and granodiorite. It is belived that the formation of the deposit is related to late intrusive granite body, and the rock may be homologous but invaded in different times by analysis of rare earth elements.The veins in I belt are basically the same occurrence. Whether the veins of II belt exposed at the surface and the length along the strike is related to cutting action by EW faults. There may still exist northwest-weins in the deep zoon of the southeast and northwest of II belt.Metallogenic material is from concealed rock body in the north of mining area. The ore solution filled from northwest to southeast and from below, it leads to the metallogenic belt has the lateral trending to northwestwards.There is a strong positive correlation among Sn,Bi and W enement. Sn,Bi element can be used as ore indicator elements. There is a large anomaly belt has been irised out in the north of mining area by using geophysical prospecting, this anomaly may be caused by concealed basic body or skarn rock.