中文摘要：

位于新疆西天山北缘的博罗科努晚古生代岛弧带出露有大量的中酸性侵入体分布有一系列与斑岩-夕卡岩型铁铜多金属矿床，本文对该岛弧带中部阔库确科夕卡岩型铁铜矿区与成岩相关的花岗岩和闪长岩进行了元素地球化学、矿物化学和锆石U-Pb同位素年代学研究。岩体富si和K，A／CNK〈1．1，属于准铝质一弱过铝质I型花岗岩。岩石富集轻稀土和大离子亲石元素，亏损重稀土和高场强元素，具有明显的Eu负异常，表现出俯冲带岩浆作用特征。岩石Nb／Ta比值（9．8-13．3）、黑云母MgO质量分数（9．45％-10．99％）和角闪石凹值（0．73-0．85）均介于壳源型和幔源型之间，表明其形成具有壳幔源物质参与。锆石LA-ICP-MSU-Pb同位素定年结果显示，花岗岩和闪长岩形成时代相近，二者加权平均年龄分别为（362．3±2．8）Ma和（565．4±3．7）Ma．Rb．（Yb＋Nb）和Rb-（Yb＋Ta）图解显示岩石几乎都为火山弧花岗岩，（Sr／Y）-Y和（La／Yb）N-YbN图解显示它们均属经典岛弧岩石，说明岩体形成于晚泥盆世板块俯冲的大地构造背景下。锆石饱和温度（705-760℃）和黑云母形成温度（710～750℃）显示岩体为下地壳部分熔融的产物，Th／Ce-Sr／Th和Th／Yb-Sr／Yb的关系反映成岩流体来自于沉积物脱水，Harker图解以及Ba、Sr、P、n和Eu等元素的显著亏损，暗示结晶分异作用的发生。我们认为，晚泥盆世时期，在北天山洋向伊犁板块俯冲的构造背景下，俯冲带沉积物脱水产生的流体引发下地壳发生部分熔融，伴随着地幔物质的加入以及一定程度的结晶分异作用，形成了阔库确科矿区岩体。

英文摘要：

The Late Paleozoic Boluokenu island arc belt, located at the north margin of the West Tianshan Mountain, Xinjiang Autonomous Region, China, hosts abundant mineral resources and intermediate-acid intrusions. In this paper, geochemistry of rock and mineral as well as U-Pb isotopic chronology studies on granites and diorites in Kuokuqueke skarn-type Fe-Cu deposit which lies in the middle of the are behwere carried out. The rocks are enriched in SiO2 and K20 with A/CNK〈 1.1, belonging to I-type granite of high-K calc-alkaline series. They are enriched in LREE and LILE with clear negative Eu anomalies, and are depleted in HREE and HFSE.The Nb/Ta ratio（9. 8-13.3）, MgO contents in biotite（9.45%-10.99% ） and the M valuesof amphibole（0. 73-0. 85 ）all belong to the type between crust-derived type and mantle type. LA-ICP-MS U-Pb isotopic dating on zircons from Kuokuqueke granite and diorite yielded similar ages of 362.8 ± 2.8 Ma and 363.4 ± 3.7 Ma, respectively. The Rb-Yb ＋ Nb and Rb-Yb ＋ Ta diagrams indicate that most of the rocks belong to volcanic arc granitoids. The Sr/Y-Y and （La/Yb）N-YbN diagrams show all of them are island-arc rocks. Above geochronological and geochemical data suggest that Kuokuqueke intrusion formed under the tectonic setting of subduction during the Late Devonian. Zircon saturation temperature （705 ± 760℃ ）and biotite formation temperature（710±750 ℃ ）suggest that the magma originated from partial melting of the lower crust.Th/Ce-Sr/Th and Th/Yb-Sr/Yb diagrams show that the diagenetic fluid is from dehydration of sediments. Harker diagram and the strong depletion of Ba, Sr, P, Ti and Eu indicate that the rocks have undergone crystallization differentiation. It is thus suggested that Kukuqueke granite mainly formed from partial melting of the lower crust caused by dehydration of the subduction zone when the North Tianshan Mountain ocean subducted to the Yili plate during the Late Devonian, accompanying with the addition of mantle materials and crystallization dif