The Study On Geochemistry Feature Of Dong Jun Ergun Lead-zinc-silver Deposits

Dong Jun lead-zinc-silver mine area geotectonic position belongs to the southeastern margin of the Siberian Plate, in the contact position of Ergun Xingkai geosyncline fold belt and Nan Xigui Tuqi china force geosyncline fold belt. There is a close relationship between the structural development and Siberia plate margin hyperplasia. Ore-forming position belongs to the southeastern margin of the Siberia plate of Mongolia-Greater Khingan Range orogenic belt, and in the South East of Derbugan deep fault and the north of GenHe deep fault. Using geochemical theory and method to study the geochemical feature of deposit and investigate the material source, ore-forming type, ore-forming geochemical feature, ore-forming temperature, and the change regularity of ore-forming elements etc. Then, guide the prospecting direction.The stratum of mining area is relatively simple and is mainly middle Jurassic Tamulan group and Quaternary Holocene. The fault structure developed, the linear structure is the most obvious. The main ore controlling structures is the tensile fracture of NE and NEE. The wall rock alteration is widespread development, and the alteration types that closely related to ore-forming are mainly silicification, sericitization, kaolinization. Ore(mineralized) belt of mining area most located in the alteration belt Internal. And the trend and alteration belt are basically the same, Ore bodies mainly occur in Middle Jurassic Andesitic basalt and Rhyolitic tuff, and surrounding rock boundaries is obvious, thickness change is relatively stable, and grade is uniform. By the influence of tectonic fracture belt, the occurrence is relatively steep. The ore types are lead zinc ore and lead zinc silver ore, ore structures are mostly vein structure and disseminated structure, mineral structures are mostly euhedral-subhedral structure and xenomorphic granular structure.The main elements analysis indicates that the volcanic rocks in the mining area belong to high potassium calc alkaline series volcano rock, have the feature of Alkalis enrichment, Aluminum supersaturated and relatively rich in sodium. Trace elements analysis indicates that the volcanic rocks in the mining area rich Rb, Ba, Th, U other large ion lithophile elements, and loss Ta, Nb, Ti and high field strength elements. Rare earth element analysis indicates that the volcanic rocks in the mining area have high REE total content, and have the feature of LREE riched and HREE lost, and strong fractionation between LREE and HREE, δEu values ranged between 0.17~0.93 and showed the evolution of obvious negative anomaly to weak anomaly. Sr, Nd isotopes analysis indicates that the diagenetic material in the mining area mainly come from the mantle, and mixing may occur with oceanic crust of subduction invade into the mantle. The Ore geochemical feature and feature of fluid inclusions analysis indicates that there are mutiperiodic mineralization in DongJun lead zinc silver deposits, and the ore-forming temperature is not high, and the deposits belongs to the shallow low, medium low temperature hydrothermal deposit. Combining the geological features of deposit, geochemical features of deposit and geochemical anomalies features of deposit, and establishing the metallogenic prediction criterion, then conducting mining area metallogenic prediction and guiding the Prospecting.