In situ U-Pb dating of titanite by LA-ICPMS

作     者：SUN JinFeng 1,2,YANG JinHui 1,WU FuYuan 1,XIE LieWen 1,YANG YueHeng 1,LIU ZhiChao 1,2 & LI XianHua 1 1 State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China 2 Graduate University of the Chinese Academy of Sciences,Beijing 100049,China 

出 版 物：《Science Bulletin》 (科学通报(英文版))

年 卷 期：2012年第20期

页      面：2507-2529页

学科分类：070902[理学-地球化学] 0709[理学-地质学] 07[理学] 

基　　金：supported by the National Natural Science Foundation of China(40925007) State Key Laboratory of Lithospheric Evolution(Zhuan0809) 

主　　题：In situ titanite U-Pb dating LA-ICPMS single spot line raster scan matrix effect 

摘      要：Titanite is an ideal mineral for U-Pb isotopic dating because of its relatively high U,Th and Pb ***,we developed a technique for U-Pb dating of titanite using the 193 nm ArF laser-ablation system and Agilent 7500a *** of titanite (BLR-1 and OLT-1) and zircon (91500 and GJ-1) were dated using single spot and line raster scan analytical *** check the matrix effect,titanite (BLR-1) and zircon (91500) standards were analyzed as the external *** weighted mean 206 Pb/238 U ages of OLT-1 titanite are 1015±5 Ma (2,n=24) and 1017±6 Ma (2,n=24) by single spot and line raster scan analyses,respectively,using BLR-1 titanite as the external *** ages are consistent with its reference age of about 1014 ***,using 91500 zircon as the external standard,the weighted mean 206 Pb/238 U ages are 917±4 Ma (2,n=24) and 927±5 Ma (2,n=24) for BLR-1 titanite,and 891±4 Ma (2,n=24) and 901±5 Ma (2,n=24) for OLT-1 titanite by single spot and line raster scan analyses,*** is evident that these ages are ～12% younger than their reference *** results reveal that significant matrix effect does exist between different kinds of minerals during LA-ICPMS U-Pb age determination,whereas it is insignificant between same ***,same mineral must be used as the external standard for fractionation corrections during in situ LA-ICPMS U-Pb age *** addition,we determined U-Pb ages for titanites from the Early Cretaceous Fangshan pluton,which indicates a rapid cooling history of this pluton.