The Geological And Geochemical Characteristics And Metallogenic Characteristics Of The A're Mass In Shangri-La County,Yunnan Province

Based on the detailed field geological survey, through petrography, geochronology and geochemistry of A're intrusions rock differential Research, and eastern belt the Pulang intrusive rock mass and its adjacent area Chundu intrusive body formation through the comparison between the mechanism and rock mineral composition, reveal the intrusive rock mass of the thermal of the magma origin, magma properties and magmatic processes and tectonic setting.According to the basic principles of geology, petrography theory as a theoretical basis for determining the A're intrusive rock mass of the characteristics of emplacement, on A're invasion between rock mass and rock erosion relation are studied in detailed, emplaced in Tu Mugou formation sandstone and slate which, output in the form of rock strain, flaser body less. The rock with the massive structure, porphyritic structure, rock xenoliths are relatively developed, no obvious zonation.According to the principles of geochemistry, isotope set methods in the theory and the method of A're southern and Northern Rock chronology and geochemical characteristics of system research. U-Pb isotopic study shows hot southern and Northern Rock rock era respectively 228 Ma and 219 Ma, belonging to the Late Triassic to the early stage of subduction of oceanic crust, resulting in slab melting, magma invasion after the contamination crystallization formation. Geochemical characteristics show that heat Arab intrusive rock and Chundu, Pulang intrusive rock lithology differences exist, before the two intrusive rock lithology of basic fall into the monzonite and syenite classes, Pulang intrusions into the granite flash diorite, monzonite and alkaline series, Pulang rock ALK content relatively lower than Chundu pluton, were lower than that of the thermal mass. A're intrusive body is a kind of high potassium and calcium alkaline magmatic rock, which is related to the formation of the environment and the quasi orogenic uplift and the related. A're rock in North and South have I type granite type characteristics, and related characteristics of adakite geochemistry. Has the consistency and belongs to peraluminous rock, the spring.Mineralogical characteristics show that the A're rock in northern relative southern rock erosion change degree is relatively small, also shows that the southern rock in the formation times closer to the magma action peak full hydrothermal effect has a close relationship. Plutons in A're forming process have experienced the transition process of oceanic island arc, confirms the regional plate subduction resulted in the change of ancient tectonic environment. In the process of crystallization, the relative temperature and pressure condition of the rock mass in the northern part of the rock is stable in the south rock mass.A're rocks into the process of rock in the presence of partial melting of the sandstone, which and the Pulang rock has strong similarities, but with different partial melting Chundu rock mudstone, show that A're and Pulang area in oceanic crust subduction of the ancient tectonic environment is similar, but Chundu area exist some differences. In the process of intrusion, the magma is not affected by external melt or fluid, and the different rock types belong to the same magma. The forming environment of the intrusive rock mass in A're area is closer to the stress range of the collision zone. Chundu area of geochemical characteristics of rocks, showed characteristics of crust mantle type, and there are different degrees of crustal contamination effects, Pulang pluton showed by interaction of crust and crust mantle mixing. The formation of the granites in the area is accompanied by the evolution of the volcanic arc with partial melting and non separation and crystallization. In terms of geochemical contrast can be seen in the Chundu porphyry copper ore loading rock mass relative o hot regions in the more alkaline and A're Arab Northern Rock and intrusive body characteristics and Chundu area closer, with certain favourable metallogenic conditions.