【摘要】 南天山北缘库米什地区铜花山南部黄尖石山岩体高 Na、Mg 和 Fe、准铝或过铝质（ACNK=0.91～1.35）,它们相对富集 K、Rb、Th,贫 Zr、Hf 等 HFSE,略亏损 Nb、Ta 和 P,具典型岛弧钙碱性Ⅰ型花岗岩的元素地球化学特征。其锆石 U-Pb 年龄为423Ma,ε_Nd（t）=-3.70～-7.32,t_2DM=1.45～1.75Ga,表明它们是早古生代早志留纪晚期由先存中元古代幔源基性地壳物质熔融的产物。岩体的 Ba、Sr 和 P 等弱亏损,Nb 和 Y 丰度及 Rb/Zr 比值中等则指示是活动大陆边缘俯冲带岛弧演化到正常大陆弧环境的产物。因此,该岩体的形成标志着南天山洋盆于晚志留世时期已进入俯冲消减的活动大陆边缘演化阶段。更多还原

【Abstract】 The Huangjianshishan granitic intrusions in north margin of southern Tianshan are characterized by the high Na,Mg,Fe and metaluminous-peraluminous features.They are relatively enriched in K,Rb and Th,poor in Zr and Hf and depleted in Nb,Ta and P,showing typical characters of calc-alkaline I-type granite in island arc.The zircon U-Pb age of 423Ma has been obtained.Their ε_Nd（t）are from-3.70 to-7.32,and t_2DMfrom 1.45 to 1.75Ga.These indicate that the intrusion is the product formed by the partial melting of Mesoproterozoic mantle-derived basic materials.In addition,their slightly depletion of Ba,Sr and P and moderation of Nd and Y contents and Rb/Zr ratio demonstrate that they were produced in the normal island are of active continental margin.Thus, occurrence of Huangjianshishan intrusion marked the evolutional period of active continental margin in southern Tianshan during the late Silurian.更多还原