To provide important insights into the petrogenesis of the Early Cretaceous intermediate-acidic magmatic rocks in middle-lower Yangtze River region,it carried out a detailed investigation of Li-Sr-Nd isotopes and geochemistry for the Wushan granodiorite porphyry,quartz diorite porphyry and the basic dyke. The Wushan granodiorite porphyry samples are characterized by the high concentrations of SiO2,MgO,and K2O and low concentration of Na2O,respectively,enrichment in LREEs and LILEs,and relative depletion in Y and Yb. They exhibit isotopic values of (87Sr/86Sr)i=0.7030-0.7074,εNd(t)=-5.1--4.6,and δ7Li=+0.9‰-+3.2‰,respectively,which are between the isotopic values of crustal and mantle end-members,revealing a crust-mantle mixing process between felsic melts from a juvenile lower crust and mafic melts from an enriched mantle source. They were subsequently subjected to weakly fractional crystallization of pyroxene and hornblende and minor crustal contamination during the ascent and emplacement. The Early Cretaceous intermediate-acidic magmatic rocks and related deposits in middle-lower Yangtze River region could be related to upwelling of asthenospheric mantle caused by the subduction of the Paleo-Pacific plate and its induced reactivation of sub-continental lithosphere.
middle-lower Yangtze River regionWushanintermediate-acidic magmatic rockgeochemistryLi-Sr-Nd isotope
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