The Petrology Characteristics Of The Paleozoic Granite In Sonidzuoqi Area Of Inner Mongolia

The study area is located in the northwest region of Inner Mongolia Sonidzuoqi,tectonic location belonging to the eastern Central Asian orogenic belt-Xinmeng orogenic belt. The study division of tectonic units belongs to the northern orogenic belt of Xingmeng orogenic belt. Its south boundary is Erlianhot-Hegenshan fault zone and the North belongs to the Siberia active continental margin. The Chagan Obo- Arun Qi deep Fracture across the zone from east to west. The area belonged to the ancient Asian Ocean tectonic domain in the Paleozoic, while in the Mesozoic, it belonged to the West Paleozoic tectonic domain.The layers of study area included the Carboniferous first section of Baoligaomiao group clastic rock, the Cretaceous Baiyingaolao volcanic rocks and Cretaceous Damoguaihe group, the Paleogene Yierdingmanha group and the Quaternary Sand and gravel. The Baiyin gaolao group erupted unconformably aroud the alkali feldspar granites.The granitoids combination in the study area are alkali feldspar granites, adamellite and granodiorite mainly. The alkali feldspar granites is the main object of study.The alkali feldspar granites batholith exposed in the area of Zhunheremuyin sumu of the northern Chagan Obo- Arun Qi fracture, invaded by the porphyritic granodiorite in the area of Chututaolegai. Dikes of porphyritic granodiorite and biotite monzonitic granite invaded in the rock mass, spreading WE.The alkali feldspar granite zircon U-Pb isotopic dating analysis obtained weighted average age: 312.2Ma ± 7.4Ma(MSWD = 6.67), belonging to the Late Carboniferous. The results of geochemical elements show that rocks are high silica and alkali-rich, indicating the geochemical features of the calc-alkaline series. A/CNK=1.01~1.12,A/NK=1.05~1.40,belonging to the metaluminous-weakly peraluminous rocks. fractional degree of HREE and LREEare not apparent,and the negative Eu anomalies is obvious, being typical of the "Flying Seagull". The study area Moyite trace element primitive mantle normalized spider diagrams show that incompatible elements Ba, Nb, Ce, Sr, Ti and the others loss more strongly,but compatible elements Rb, U, Th and others enriched more strongly, showing that the magma source is crustal.The study area granite 10000 Ga / Al trace elements Zn, Zr, Y and Ce diagram and the A-type granites classification diagram displayed that the carboniferous granite rock category in the study area is A2 subclass of A-type granites. The Moyite sample race element data structure discern diagram in the study area display that the investment points all fall into the same area of Gollision Granite and Volcanic Arc Granite area,belonging to the Volcanic Arc environment.