二次离子质谱第四纪锆石年代学:台湾金瓜石英安岩定年  

Quaternary zircon geochronology by secondary ion mass spectrometry:A case study of the Chinkuashi dacite from northeastern Taiwan.

作　　者：高钰涯[1] 李献华[1] 李秋立[1] 锺孙霖[2] 

机构地区：[1]中国科学院地质与地球物理研究所岩石圈演化国家重点实验室,北京100029 [2]台湾大学地球科学系

出　　处：《地学前缘》2010年第2期146-155,共10页Earth Science Frontiers

基　　金：中国科学院知识创新工程重大项目(KZCX1-YW-15-2);岩石圈演化国家重点实验室基金项目(Z0806)

摘　　要：高精度第四纪年代学是第四纪研究的基础,对了解地球演化和发展非常关键。大型二次离子质谱(SIMS)锆石U-Th-Pb定年方法,集高空间分辨率、高精度、高效率和近无损分析等优势于一体,可以提取矿物微区中记录的丰富地质信息,在第四纪年代学研究中具有很大的应用潜力。文中对SIMS第四纪锆石原位微区年龄测定的基本原理、分析校正方法进行介绍,并报道我们测定台湾第四纪金瓜石英安岩锆石U-Pb年龄的结果((1.166±0.020)Ma)。Precise age determination of geological events throughout the Quaternary period is fundamental for Quaternary studies and paramount for understanding the Earth＇s evolution.Large radius secondary ion mass spectrometry（SIMS）has increasingly been used in Quaternary geochronology due to its high-resolution,high-precision, high-efficiency,and non-destructive nature.When applied to U-Pb zircon geochronology the micrometer-scale spatial resolution and high mass resolving power（MRP）of SIMS make it possible to extract complex geologic information preserved within micron-sized minerals that would otherwise be obscured or over-looked using other methods.In this paper,we introduce the principles,analytical techniques and correction methods of SIMS in-situ U-Pb dating for Quaternary zircons,and report a SIMS U-Pb zircon age of（1.166±0.020）Ma for the Quaternary Chinkuashi dacite from northeastern Taiwan.

关 键 词：二次离子质谱 第四纪锆石 U-PB定年 不平均U-系定年 

分 类 号：P597.3[天文地球—地球化学]