According to field investigation,the Yingfeng rapakivi granite is formed in mid-Proterozoic and located between shear belts as a lentiform in the structural belt of north margin of Qaidam basin.There are also diabase dyke and quartz diorite digoclase trondhjemite vein of the same time,which show a character of bimodal magmatic association.In the granite body,pyterlitic texture is very common,and,ovoid megacrystal composed by K-feldspars which has a megacryst content of 50% to 60%,size about 2cm to 3cm,agg...