1. Geological Party No. 211, Sino Shaanxi Nuclear Industry Group, Xi'an 710024, China;
2. College of Earth Sciences, Jilin University, Changchun 130061, China

The muscovite granite has been found in Permian ophiolite melange, which intruded into gabbro and diabase dikes as vein in Hongji Mountain, central and western Qiangtang. The authors studied the petrology and geochemistry characteristics, with an emphasis on its petrogenesis and geological implication. Geochemically, the muscovite granite is silica-rich in composition, with high content of alkali (Na₂O+K₂O). It's peraluminous granite that belongs to the calc-alkaline series and is characterized by the enrichment of Th, Sr and the depletion of Nb, Ta, Zr, Ti. The chondrite-normalized REE distribution patterns are characterized by U-shaped pattern with intensely positive Eu anomaly. The petrology, geochemistry, element ratios and tectonic setting of muscovite granite are similar to obduction-type granites. The muscovite granite has low CaO/Na₂O, high Al₂O₃/TiO₂ and low zircon saturation temperatures(T_Zr), indicating it was probably generated by dehydration-melting of muscovite-rich pelite in a condition of low temperature fluid on the continental margin, while the ophiolite melange obducted onto continental crust. The discovery of Hongji Mountain muscovite granite indicates that the Paleo-Tethys had been closed, and north Qiangtang collided and converged with south Qiangtang.