Geochronology and geochem-ical characteristics of the Chaganhadayinhengga strongly peraluminous granites in East Ujimqin Banner of Inner Mongolia and their geological significance

The Chaganhadayinhengga strongly peraluminous granites in East Ujimqin Banner of Inner Mongolia are located in the Xing-Meng fold belt along the central and eastern section of Central Asia-Mongolia orogenic belt between the North China plate and the Siberia plate. The main rock type is garnet-bearing two-mica monzonitic granite. Based on zircon U-Pb isotopic dating, geochemical analysis and tectonic environment discrimination in combination with regional correlation, the authors have reached the following conclusions:The source area of the Chaganhadayinhengga rock mass might have been related to the partial melting of meta-morphosed mudstone; during Late Paleozoic period, before the formation of strong peraluminous granite, even Erlian-East Ujimqin Banner area underwent collisional orogeny, and then after collision, the evolution entered into the post orogenic extension-expan-sionl period. Studies show that the Chaganhadayinhengga rock mass belongs to the Carboniferous-Early Permian typical post colli-sional high temperature type peraluminous granites rarely reported by previous researchers.