Discovery of A-type Granite Zone and Its Geodynamic Significance in the Western Kunlun Mts., China

There is a distinct zone of A-type granite in western Kunlun Mts. with the scope corresponding to the Kudi mantle steps. The A-type granites generated in late Indosinian, intergrowthing with late Hercynian I-type granites. The characteristics of A-type granitic rocks are enrichment in alkali, LREE, Y, Nb, Zr, lean in Al, Mg, Ca, Ba and Sr transition elements, and extended Si02 contents, which are quite similar to those of A-type granite in Chaelundi, Australia. The research results indicate that the studied granites belong to A2-type which formed in late orogenic extension environment and intruded in the process of the lithospheric delamination.