1. College of Earth Sciences, Jilin University, Changchun 130061, China;
2. Tianjin Branch of China National Offshore Oil Corporation, Tianjin 300459, China;
3. China Nonferrous Metal(Guilin) Geology and Mining Co., Ltd., Guilin 541004, Guangxi, China

This study presents the petrology and geochemistry of volcanic rocks from the Middle Jurassic Hurige Formation, in Tuquan Basin of Middle Great Xing'an Range, NE China, to resolve their petrogenesis, magmatic origin and geological implication. The Hurige Formation volcanic rocks are intermediate to acidic, mainly comprised by trachyandesite, andesite and rhyolite. The geochemical characteristics of the rocks display a typical high-K calc-alkaline series with an average ��REE of 74×10^-6, 90×10^-6 and 63×10^-6,average(La/Yb)_N of 8.64, 9.33 and 2.72, and average ��Eu of 0.95, 0.89 and 0.11, respectively. All the rocks show the similar geochemical characteristics of significant enrichment in Rb, K(LILE), Th,U(HSFE)and LREE, depletion in Nb, Ta, P and Ti (HSFE), indicating a crustal magmatic genesis. The volcanic rocks are likely derived from partial melting of a thickened lower crust induced by mantle material intrusion, under the compressional structural background. Combined with the Mesozoic tectonic evolution in the Great Xing'an Range from the Middle Jurassic to Early Cretaceous, the volcanic rocks in the Tuquan Basin were formed in the collisional tectonic setting of Mongol-Okhotsk.