地质科技情报2018，Vol.37Issue(3)：28-37,10.DOI:10.19509/j.cnki.dzkq.2018.0304
北昆仑奥依亚依拉克岩体锆石LA-ICP-MS U-Pb定年及其地质意义
LA-ICP-MS Zircon U-Pb Dating of Aoyiyayilake Intrusive Rocks in Northern Kunlun and Its Geological Significance
摘要
Abstract
The analysis of the major and trace elements of the Aoyiyayilake rock in Northern Kunlun reveals that the content of SiO2 ranges from 66.62％to 72.36％, and the total alkali content (Na2O+K2O) is 7.82％-8.83％;and that rittmann combination index (σ) is 2.13-3.36 and the ratio of K2 O/Na2 O is1.63-1.84.This proves the rock belongs to high-K calc-alkaline or potassium-phonolitic tephrite series magma.Aluminum saturation index (A/CNK) is 1.0-1.2.By combining rock type, the diagram (ACF) is judged to belong to aluminum-oversaturated-strongly peraluminous rock S-type granite.The total quantity of rare earth elements is large.The ratio of heavy and light rare earth elements is 9.64-15.6 and (Ce/Yb) N=7.62-15.20.The curve is tilted right, belonging to light rare earth elements enrichment.δEu is centralized between 0.33 and 0.69.The europium possesses obviously negative anomaly.Microelement is represented as the strong enrichment of Rb and Th and deficit of Zr, Hf and Yb.This suggests that the forming environment is post collision by combining the structural environment.According to the characteristics of its main and trace elements, and CaO/Na2 O value 0.42-0.76, larger than 0.3, it is supposed that the material composition in source region is main greywacke.With the ratio of Rb/Sr 0.79-1.82, by combining comprehensive analysis of structural environment, this paper suggests that the main source of magma is partial melting of incompletely mature continental crust.Through zircon U-Pb dating, the surface age weighted average value of 206 Pb/238 U is (423.99±0.91) Ma, which indicates the age of protolith crystal.关键词
二长花岗岩/U-Pb测年/北昆仑/奥依亚依拉克Key words
monzonitic granite/U-Pb dating/north Kunlun/Aoyiyayilake分类
天文与地球科学引用本文复制引用
桑明帅,杨有生,陈邦学,刘良文..北昆仑奥依亚依拉克岩体锆石LA-ICP-MS U-Pb定年及其地质意义[J].地质科技情报,2018,37(3):28-37,10.基金项目
中国地质调查局项目"昆仑-阿尔金成矿带地质矿产调查"(1212011220640) （1212011220640）
