Study On The Igneous Rocks Series In Xuemisitan, Xinjiang

The author chose xinjiang west Junggar, Xuemistan volcanic belts as the study area in the area, the late Paleozoic volcanic series development as the research object. Over a very large number of collecting on previous based on the related geological data for the region, and emphatically that uranium-beryllium ore deposits occur in associated the volcanic region are detailed field geological survey. The area is conducted on the various volcanic microstructure appraisal and systematically collection, collection and experimental analyses different kinds of geochemical and volcanic isotope-dating data. The author basis for all kinds of large data analysis of the causes of volcanic rock did, and then discussed the volcanic region of xinjiang Xuemistan late Paleozoic in tectonic setting.Through the comprehensive research, Xuemistan area of the exposed rocks mainly has the devonian, Marine, the lower carboniferous paralic sedimentary clastic rock, intermediate-basic rock, intermediate-acidic volcanic rocks and volcanic clastic rock; The continental carboniferous-lower Permian in acid-acidic volcanics and pyroclastic rocks.Rock geochemistry indicate high content that NaO,K2O, (K2O= 3.42%-9.85%; making.0=0.48%-5.30%), alkalinity of high potassium higher, calcium alkaline volcanic rock series, the source of magma mixing mainland may be dyed shells make.Different volcanic zircon SHRIMP 87Rb/86Sr dating and Pb isotope and U-isotope-dating concluded that the study area except flow lines rock 422.5 Ma SIMS age value is the main volcanic age value in the 230~260 Ma,;Different volcanic rare-earth standardization mode and the trace element analysis show that early Permian volcanic rocks and volcanic post-Hercynian potassium to pledge granite belong to the silicon aluminium shell of molten rock type, belong to the same homologous but not synchronous.Comprehensive above material, Xuemistan volcanic area near the island when output devonian mainland side of the basalt; Early carboniferous for island is almost more stable continental side and mainland basalt; Because of early Permian, stress later crashing plates to pull zhang environment by extrusion, in its structure transformation with produced the inland of intermediate-acidic volcanic rocks.