Geochronology and geochemistry of Hutouya monzonitic granite of Qimantage,Qinghai

The geochemical features of the monzonitic granite in Qimantage Hutouya deposit area , Qinghai , in respect to the mineralization , suggest that this granite belongs to weak peraluminous and high-k calc alkaline rock series .The REE of the samples show right slope with obvious LREE /HREE differentiation and negative Eu abnormity.The trace elements show enrichment of LILE (Rb, Th, U, La, Nd), and deleption of Ba, Sr, Nd, P, Ti.The Sr-Nb isotopic data indicate that the magma source is mainly aluminosilicate lower crust with a small amount of new crustal materials .The weighted mean zircon U-Pbage of the Hutouya monzonitic granite is 221 ± 1.7 Ma, belonging to Late Triassic .The Hutouya monzonitic granite was formed in the tectonic setting of transi -tion from compression to extension during Middle-Late Triassic.