西北地质2017，Vol.50Issue(2)：37-48,12.
新疆阿尔泰大东沟乌雷库-克朗岩体LA-ICP-MS锆石U-Pb年龄、地球化学特征及其地质意义
LA-ICP-MS Zircon U-Pb Age,Geochemistry of the Wuleiku-KelangPluton from the Dadonggou Area of Altay in Xinjiang and Its Tectonic Implications
摘要
Abstract
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.关键词
花岗岩/锆石U-Pb年龄/地球化学/乌雷库-克朗岩体/阿尔泰Key words
granite/LA-ICP-MS U-Pb zircon dating/geochemistry/Wuleiku-Kelang Pluton/Altay分类
天文与地球科学引用本文复制引用
曾祥武,刘家军..新疆阿尔泰大东沟乌雷库-克朗岩体LA-ICP-MS锆石U-Pb年龄、地球化学特征及其地质意义[J].西北地质,2017,50(2):37-48,12.基金项目
中国地质调查局"西北华北重点地区地质矿产调查评价"(12120113071900)项目 （12120113071900）
