乌雷库-克朗岩体正长花岗岩和花岗闪长岩中锆石的LA-ICP-MS U-Pb年龄分别为(404±2.7)Ma(MSWD=0.24)和(410.5±2.1)Ma(MSWD=0.3),属早泥盆世早期岩浆活动的产物,为阿尔泰造山带在400Ma有一次强烈的岩浆侵入活动提供了新依据,限定了康布铁堡组时代早于410Ma.岩石具高硅(72.22%~78.33%)、高碱(5.76%~9.24%)、高Al2O3(12.07%~14.30%)、低P2O5(0.02%~0.1%)和FeO+MgO(0.33%~3.50%),高A/NCK值(1.04~1.47),低CaO/Na2O值(均值<0.3)特点,属过铝质花岗岩.富Rb、Th、U、K,贫Ba、Sr、P、Ti,高场强元素Nb、Ta的含量偏低.亲Fe元素(V、Co)的含量低,也指示岩体分异演化程度高.岩石的轻稀土富集,并具有Eu(δEu=0.05~0.67)的显著负异常,显示了岛弧花岗岩的地球化学特征.结合阿尔泰的区域地质背景综合分析,推测岩体形成于活动大陆边缘环境,由泥质沉积物和少量变质杂砂岩组成的地壳物质部分熔融形成,源区残留有富钙的斜长石、钛铁矿和磷灰石等.%LA-ICP-MS zircon U-Pb ages and whole rock geochemical data about the Wuleiku-Kelang pluton from the Dadonggou area of Altay in Xinjiang have been reported in this paper.Zircons from granodiorite and syenogranite have well-defined oscillatory zoning, which yielded the mean 206Pb/238U ages of (404±2.7)Ma (MSWD=0.24) and (410.5±2.1)Ma (MSWD=0.3), respectively, indicating that the Kangbutiebao Formation was formed prior to 410Ma.The granitoid rocks have high SiO2 (ranging from 72.22% to 78.33%), total alkali (Na2O+K2O) (changing from 5.76% to 9.24%) and Al2O3 (varying from 12.07% to 14.30%), and low P2O5 (ranging from 0.02% to 0.1%) and MgO+FeO (changing from 0.33% to 3.50%).In addition, they are characterized by high A/CNK values (varying from 1.04 to 1.47) and low CaO/Na2O ratios (average ratios are less than 0.3), which have been defined as calc-alkaline peraluminious granitoid rocks.These rocks have obvious negative anomalies of Ba, Sr, P, Ti, Nb,Ta and Eu (δEu=0.05~0.67) and obvious enrichment of LREE, Rb, Th, U and K, resembling that these granitoid rocks were formed in the volcano arc settings.Combined with the tectonic evolution of the southern margin of Altay, it`s suggested that these granitoid rocks were generated by partial melting of the crust in an active continental margin, with the residues of plagioclase, ilmenite and apatite.
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