Abstract:
:Comparison geochemical characteristics of granite from northern Chifeng, Inner Mongolia with various type of granite at home and abroad and the discrimination show that most of the Chifeng granite belongs to Ⅰ-type granite, and a small number of A-type with.It is with the characteristic of high-K and alkali.The trace elements is rich in Ba, Th, K and other large ion lithophile elements (LILE), while the high field strength elements (HFSE) Nb, Ti, etc.are relatively depleted, which appear strongly depleted in Sr and P.LREE fractionation significantly, no significant fractionation of heavy rare earth.Significant negative Eu anomalies (
δ Eu between the 0.3-0.843), REE patterns show significant Eu anomalies for the right-wing pedigree.Integrating the outcome of this paper and previous studies, we infer that the granite formed under the stretching and thinning environment.In this process, reducing the pressure and the upwelling of asthenosphere partial melting of the crust plays a role, so as to provide the conditions for the formation of granite.