Lithogeochemical Characteristics Of A-Type Granitoids From Boziguoer, Baicheng County, Xinjiang

Alkaline Granitoids intrusive rock from Boziguoer,Baicheng County,Xinjiang is under observation because of riching useful elements such as Nb,Ta,Zr. The research on characteristics of petrology, petrochemistry, geochemistry, mineralogy and Petrogenesis tectonic background of Alkaline Granitoids intrusive rock from Boziguoer,Baicheng County,Xinjiang is made by means of observation through microscopic , EPMA , X-ray fluorescence spectrometry and ICP-MS. The experiment result shows:1. petrology characteristic of granitoids rocks:Three kinds of granitoids rocks from Boziguoer Aegirine riebeckite quartz monzobiorite,aegirine riebeckite granodiorite,biotite riebeckite quartz monzonite are divided.Granitoids rocks are gray, hypidiomorphic granular texture and granitic texture,massive structure.The essential mineral are quartz(7%²4%),plagioclase(48%⁶2%),kfeldspa(r15%³5%), arfvedsonite(5%²5%), aegirine(acmite)(5%¹2%),biotite (5%¹2%); The content of accessory minerals is 3%⁶%.The accessory minerals are mainly zircon,pyrochlore,thorite,fluorite,monazite,xenotime, ilmenite, magnetite, apatite.2. characteristics of major elements,rare earth element,microelement of granitoids rocks:All three kinds of granitoids rocks exhibit low kalium peralkalic, which is belong to A-Type Granitoids with Medium content of SiO₂. All three kinds of granitoids rocks are outcome from comagmatic and formed in the corresponding period igneous activity possibly.The sequence of magmatic differentiation is that quartz monzobiorite,quartz monzonite,granodiorite.The total quantity of rare earth element is high,while the content of LREE is enrichment and the content of HREE is deficit.V-type curve is possessed of Eu negative anomalous evidently and Ce negative anomalous slimly.The rare earth element is rich in LIL element such as Rb,Cs,Th,U,and Sr,Ba are low grade. In addition to all of the above,the ratios of Rb,Sr and Rb,Ba are high. 3.The characteristic of petrogenetic mineral:Alkali feldspar are mainly orthoclase , microcline and perthite. Alkaline amphibole is arfvedsonite. Alkaline orthopyroxene is aegirine or acmite.The biotite is belong to iron biotite.The chemical composition of biotite belongs to anorogenic period Alkaline Granitoids rocks in FeO^T-MgO-Al₂O₃ triangular plot,which shows that the petrogenesis of Alkaline Granitoids rocks in this location have nothing to do with subduction.4. Granitoids intrusive rock from Boziguoer is belong to peralkalic A-type granites rocks. Formation stress is greater than 4kbar, formation temperature is between 770⁸30℃.The background of geotectonic is intraplate tectonics anorogenic period environment...