Study On Ore-forming Geological Conditions And Metallogenic Regularities Of Dongtian Lead-Zinc Deposit In Mohe County,Heilongjiang Province

Dongtian lead-zinc deposit is located in Yilin forestry station of Amuer forestry bureau in Daxing'anling,Heilongjiang province.The studied area belongs to the south edge of the upper Heilongjiang trapping zone which is in the north of the NNE Dongtian-Jiaolushan volcanic rocks in late Jurassic of the main ridge volcanic rock zone Greater in Daxing'anling Range.The mining area is located in the gold and nonferrous metal metallogenic belt in Eergu'Na,one of the key prospecting areas in the Page Suoku-orakei gold metallogenic prospect area.A systematic survey was Carried out in the area in order to reveal the resource potential of lead-zinc mine in this area.The main findings obtained are as follows:(1)Through geological survey,Tamulangou group of Upper Jurassic of Mesozoic as well as Guanghua group of lower Cretaceous are closely related to mineralization in the studied area.The N-E trending fault structure and the secondary fracture are the ore control structure.(2)Two subterranean concealed high polarizable anomalies have been found by excitation sounding which were caused by sulfide containing sulfide through drilling.(3)Through the 1:20000 soil geochemical survey,11 anomalies were delineated.Among these anomalies Ht-11 has a large area and good identity of concentration centres.According to the results of the later verification,Ht-11 was caused by ore deposit.(4)Four mineralized alteration zones have been found on the surface through implementation of geophysical and geochemical,the grade of lead is 0.225-0.73%,and the grade of zinc is 0.316-1.329%.exploration anomaly trenching engineering.Silicification,epidotization,carbonatation,sericitization,chloritization and kaolinization are developed around the ore bodies.The main metal minerals in the ore are pyrite,followed by sphalerite,galena,and limonite,and then magnets and chalcopyrite.The useful industrial minerals of the ore body are sphalerite and galena.According to the above results,it is believed that the formation of the Dongtian lead zinc deposit is related to the Mesozoic tectono volcanic eruption and the shallow magmatism.The formation of the Dongtian Lead-Zinc Deposit is under the condition of the tectonic-magma multi-phase activity.The North East trending fault provides the conditions for the circulation and transport of ore bearing hydrothermal fluid.The fracture structure and structural fracture zone provide a place for the diffusion filling and precipitation of ore bearing hydrothermal fluid.The mineralization of lead and zinc in the studied area was formed under the action of volcanic hydrothermal fluid.This paper is a summary of the geological and mineral background,metallogenic geological conditions,geochemistry and Geophysics for a theoretical basis for further geological prospecting in this area.