新疆东准噶尔A型花岗岩的锆石Hf同位素初步研究  

PRIMARY Hf ISOTOPIC STUDY ON ZIRCONS FROM THE A-TYPE GRANITES IN EASTERN JUNGGAR OF XINJIANG,NORTHWEST CHINA

作　　者：唐红峰[1] 赵志琦[2] 黄荣生[2] 韩宇捷[1,3] 苏玉平[1,3] 

机构地区：[1]中国科学院地球化学研究所地球深部物质与流体作用地球化学研究室,贵州贵阳550002 [2]中国科学院地球化学研究所环境地球化学国家重点实验室,贵州贵阳550002 [3]中国科学院研究生院,北京100049

出　　处：《矿物学报》2008年第4期335-342,共8页Acta Mineralogica Sinica

基　　金：国家自然科学基金项目(批准号:4077204440773006)

摘　　要：新近在New Wave UP-213型激光器（LA）和Nu plasma多接收电感耦合等离子体质谱仪（MC—ICPMS）上建立了一种锆石Hf同位素分析方法，以这种新建的方法对新疆东准噶尔A型花岗岩首次开展锆石Hf同位素研究。结果表明，东准噶尔A型花岗岩有高的正εHf（T）值，变化范围为10．3-13．7。综合考虑这些花岗岩的地质背景和地球化学组成，我们认为它们的源岩主要是具亏损地幔Hf-Nd同位素组成的年轻玄武质洋壳，并在源区混人了少量陆源大洋沉积物。本文的Hf同位素结果为阐明东准噶尔地区A型花岗岩的起源提供了新的证据。Reported in this paper are a new method of Hf isotope analysis on zircons, which has been recently established by using New Wave UP-213 laser plus Nu plasma MC-ICPMS, and the results of the first Hf isotopic study on the zircons from the A-type granites in eastern Junggar of Xinjiang. The results showed that the A-type granites have relatively high εHf（T） values ranging from 10. 3 to 13.7. From the geological setting in which the A-type granites were formed and their geochemical compositions, it is suggested that the source materials of the A-type granites come mainly from young basaltic oceanic crust which is similar to the depleted mantle and some marine sediments from the continents in Hf and Nd isotopic compositions. The results of Hf isotopic analysis in this study provide new evidence for the origin of the A-type granites in eastern Junggar of Xinjiang.

关 键 词：HF同位素 LA-MC-ICPMS A型花岗岩 东准噶尔 新疆 

分 类 号：P588.12[天文地球—岩石学] P597[天文地球—地质学]