【摘要】 浙西地区地处下扬子陆块东南缘,区内中生代岩浆侵入活动强烈,与成矿作用关系密切。与锡成矿作用有关的双溪口花岗岩锆石LA-ICP-MS U-Pb定年结果显示,成岩年龄为130.4±1.1 Ma。岩石具有富SiO₂,高Ga、Zr、Nb和Y,贫Al₂O₃、Sr、Ba、Ti和P,Eu强烈负异常(δ_Eu=0.08⁰.42)的地球化学特征,Zr饱和温度为848⁸87℃,属铝质A型花岗岩。锆石Hf同位素ε_Hf（t）变化范围集中在-4.66^-2.50之间,二阶段模式年龄t_DM2变化于1192¹311 Ma之间,暗示其源区物质主要来自中元古代地壳。结合区域地质矿产资料综合分析,认为浙西地区与锡相关的成矿事件发生于132¹27 Ma之间,受控于早白垩世伸展环境下壳幔岩浆的相互混合作用。更多还原

【Abstract】 The Mesozoic magmatism in the western Zhejiang province, i.e., the southeastern margin of the Yangtze Block, is widespread and commonly associated with ore mineralization. LA-ICP-MS zircon U-Pb dating of the Shuangxikou granite yielded an age of 130.4±1.1 Ma. The granite intrusion is characterized by metaluminous, showing features of high-K calc-alkalic series. The granites have low Al₂O₃, Sr, Ba, Ti, P contents, obvious negative Eu anomalies(δ_Eu=0.08-0.42), and high contents of SiO₂, Ga, Zr, Nb, and Y. The crystallization temperature estimated by "Zr saturation temperature" is 848-887 ℃, reflecting the character of A-type aluminous granite. Zircon Hf isotopic compositions(ε_Hf（t） of-4.66--2.50, and t_DM2 of 1.19-1.31 Ga) indicate that the source of the Shuangxikou granite was dominated by the Mesoproterozoic crust material. On the basis of an integrated study of geological survey and mineral exploration in the western Zhejiang, we conclude that the tin mineralization occurred in 132-127 Ma controlled by the crust-mantle interaction in the extensional environment in the Early Cretaceous.更多还原