College of Earth Sciences, Jilin University, Changchun 130061, China

Sandaowanzi gold deposit is a typical gold telluride minerals deposit, located at the northern edge of the Xiao Xing'an range, NE China. In order to reveal the ore-forming geological setting, the authors recently conducted studies on geochronology and geochemistry of volcanic rocks hosting the deposit. The results show that the zircon U-Pb ages of the trachydacite porphyry from the syn ore-forming geological bady and basaltic trachyandesite porphyry from ore-forming rock are (124.2±0.9)Ma (MSWD=0.5, n=18) and (118.9±2.3) Ma(MSWD=0.5, n=6); Volcanic rocks from the basaltic trachyandesite and trachydacite porphyry are high in SiO₂ (52.75%��62.30%), and the K₂O and Na₂O are 2.02%��2.85% and 3.96%��4.24%, respectively; Rittman index (δ) is between 0.85 and 3.67, which belongs to the high-K calc-alkaline to calc-alkaline series; the dike of basaltic trachyandesite porphyry formed after mineralization is with SiO₂ of 51.53%��52.32%, K₂O of 2.30%��2.36%, Na₂O of 3.78%��4.14%, and Rittman index (δ) is between 4.05 and 4.86; these rocks are characterized by enrichment in large ion lithophile elements (LILEs, such as Cs, K, Rb, Ba, and LREEs) and depletion in high field strength elements (HFSEs, such as Nb, Ta, Zr, Hf, and HREEs), especially the features of strong positive Th, U, Nb, and Ta, which is similar to the calc-alkaline island arc basalt. It is concluded that the Sandaowanzi gold deposit formed in the Early Cretaceous (124��119 Ma) or Late Mesozoic post-collision extensional setting. The source may be the oceanic lithosphere mantle, which was mixed with crustal material in magma evolution, and the mineralization is closely related to the Early Cretaceous subalkalic volcanic-rocks.