矿床地质2009，Vol.28Issue(4)：481-492,12.
LA-MC-ICP-MS锆石微区原位U-Pb定年技术
In situ U-Pb zircon dating using laser ablation-multi ion counting-ICP-MS
摘要
Abstract
High resolution in situ U-Pb zircon geochronology on zoned grains can obtain isotope signatures from multiple growth or thermal events. We present a method using laser ablation-multicollector-inductively coupled plasma-mass spectrometry (LA-MC-ICP-MS) to overcome complications associated with intricately zoned zircon crystals through in situ sampling of zircon volumes as small as 12μm, 25 μm and 40 μm in diameter by about 10 μm in depth. High precision U-Pb age of a series of zircon standard covering a wide age range of 30 to 1 065 Ma was acquired using LA-MC-ICP-MS. The precision of measured Pb/U ratios in homogeneous zircon is about 2% (2a), resulting in routinely achieved precision of U-Pb ages obtained by external calibration of ～ 1 % (2σ) or better. All masses of interest can be simultaneously recorded with a multi-ion counting system (MIC) operating in static mode, and the short ablation required to achieve such precision results in spatial resolution that is superior to comparable U-Pb zircon analyses by single collector ICP-MS. The resulting present U-Pb age for five zircon reference samples and two geological samples show an excellent agreement with the previously reported ID-TIMS or SHRIMP data.关键词
地球化学/锆石/LA-MC-ICP-MS/U-Pb年代学Key words
geochemistry/ zircon/ LA-MC-ICP-MS/ U-Pb geochronology分类
天文与地球科学引用本文复制引用
侯可军,李延河,田有荣..LA-MC-ICP-MS锆石微区原位U-Pb定年技术[J].矿床地质,2009,28(4):481-492,12.基金项目
本研究得到国土资源部公益性行业科研专项经费(200811114)、国土资源大调查项目(1212010816039)和公益性科研院所基本科研业务费(K2007-2-3,Ywf060712)的联合资助 （200811114）
