| Dongzhongla ore deposit located in the middle reches of Yarlung Zangbo River valley in the south of Tibet. The deposit located in the south margin of se ri rong –ga ba rift basin in middle east of Gan gdise-Nyanqêntanglha plate.the plotting scale in the deposit area and the route of this area had confirmed that the Dongzhongla ore deposit form from the south margin towards north overturned nappe structure system of Se Ri Rong –Ba Ga Neopaleozoic rift basin,it is a typical Secondary lead-zinc polymetallic deposits. In recent years, some research units in the Dongzhongla ore deposit carry out basic geological and ore prospecting work. But to the lack of understanding of regional geochemical characteristics and the viewpoint is not unified. Based on collection and management of the regional geological data, the predecessor research results,Dongzhongla Pb-Zn deposit is due to intense magmatic activities in late Yanshan and Himalayan mountain early, the Indian plate and the Eurasian plate strong collision. In a tectonic setting of the extensional transition. Large-scale melting occurred in late Yanshan movement, the depth of the earth in the local area, intermediate acid magmatic, intrusion of magma, and Middle Permian Noba pile group(P2l) carbonate contact, ore bearing solution metasomatism. Ore bodies are mainly the dew formation of Upper Carboniferous Lower Permian series Gu group sandstone and slate(C2P1l), Permian system Noba pile group of limestone(P2l), loose rock quartz schist. Ore body mainly exist in limestone area, is mainly controlled by the fold in the area and the core of the fracture system, major minerals are galena, sphalerite, chalcopyrite, visible pyrite.the latest exploration achievements and 1:10000 stream sediment survey, to filtrate, analyze and summarize the collection data of main ore-forming element and classic companion elements. The methods of probability distribution whether to fit the normal distribution; The methods of element abundances coefficient, variation coefficient and skewness to analyze the Cu Pb Zn element data structure. The abnormal iteration methods to caculate 3 elements of regional background value and anomaly threshold, and according this data to divided into three-level concentration zoning of the traditional geochemical and catchment basins geochemical.Rock geochemical data structure triangle and geochemical data structure diagram shows the Dongzhongla Pb Zn ore deposit mine rock geochemical samples as a whole is given priority to with Pb, Zn elements. Geochemical maps and geochemical anomaly map all showed that lake on both sides of the anomaly scale larger, concentration limits, irregular shape. Three ore bodies are located in three distinct areas, which furtherverified the geochemical map and geochemical anomaly map of ore prospecting significance. Finally, Cu,Pb,Zn in the delineation of elements of the integrated anomaly geochemical prospecting areas 5. |
