1.Introduction A-type granites commonly occur in post-orogenic intraplate tectonic settings and provide information on post-collisional/intraplate extensional magmatic processes within the continental lithosphere as well as the formation of the upper continental crust (Mushkin et al.,2003).Their origins have been attributed to:(1) direct fractionation products of mantle-derived alkaline basalts (Turner et al.,1992);(2) partial melting of crustal materials at high temperature and low pressure (King et al.,1997);(3) hybridization between anatectic granitic and mantle-derived mafic magmas (Bonin,2004);and (4) related to mantle plume (Zhang and Zou,2013).