锆石LA-ICP-MS原位微区U-Th-Pb-He双定年方法研究

Zircon in-situ microanalytical U-Th-Pb-He double dating, is essentially a combination of zircon LA-ICP-MS in-situ U-Th-He thermochronology and LA-ICP-MS U-Pb dating. Obtaining both U-Th-He and U-Pb data through in-situ microanalysis, not only increases analytical efficiency, also, more importantly, promotes a tighter coupling between U-Th-He and U-Pb data and improves the reliability of geological interpretation for the data. This project is designed based on the latest development and currently existing issues in zircon in-situ microanalytical U-Th-Pb-He double dating. This project adopts two concentric ablation beams to acquire isotopic data from selected areas away from grain margins and inclusions. Isotopic data collected are used for calculating U-Pb age, and are combined with 4He pit volume to calculate U-Th-He age. The aim of this project is to establish zircon in-situ microanalytical U-Th-Pb-He double dating method.

锆石LA-ICP-MS原位微区U-Th-Pb-He双定年，将锆石LA-ICP-MS原位U-Th-He热年代学和锆石LA-ICP-MS U-Pb定年相结合，同时在微区上获得U-Th-He和U-Pb年龄。该技术不仅大大提高了分析效率，更重要的是，使得两种年龄数据更为紧密地耦合起来，更接近真实地反映矿物热历史，大大增强了年龄数据地质解释的可靠性。本项目针对锆石LA-ICP-MS原位微区U-Th-Pb-He双定年方法的研究现状和目前存在的问题，采用一小一大的两个同心激光斑束，分别剥蚀锆石颗粒上远离矿物颗粒边缘和包体的区域，获得匹配的同位素数据，直接获得U-Pb年龄，并结合4He剥蚀坑体积同时获得原位U-Th-He年龄，建立锆石LA-ICP-MS原位微区U-Th-Pb-He双定年方法。

锆石LA-ICP-MS原位微区U-Th-Pb-He双定年，将锆石LA-ICM-MS原位U-Th-He热年代学和锆石LA-ICM-MS U-Pb定年相结合，同时在微区上获得U-Th-He和U-Pb年龄。该技术不仅大大提高了分析效率，更重要的是，使得两种年龄数据更为紧密地耦合起来，更接近真实地反映矿物热历史，大大增强了年龄数据地质解释的可靠性。本项目针对锆石LA-ICP-MS原位微区U-Th-Pb-He双定年方法的研究现状和目前存在的问题，初步确定锆石LA-ICP-MS原位激光U-Th-Pb-He双定年流程并优化样品制备工艺。