二次离子质谱第四纪锆石年代学:台湾金瓜石英安岩定年

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)。

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

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 overlooked 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.