Objective Previous studies on adakitic rocks with high Sr/Y and La/Yb ratios have established that such rocks may form in a variety of tectonic settings through different petrogenetic processes including:(1)partial melting of subducted young(<25 Ma),hot and hydrated oceanic slab;(2)partial melting of thickened lower crust;(3)assimilation and fractional crystallization processes involving basaltic magma;(4)partial melting of delaminated lower crust;and(5)partial melting of hydrous garnet peridotite.The various origins for
