Laser Microsampling and High Resolution Geochronology Using MC-ICPMS

9526344 Halliday该项目将开发ICP磁扇区多接收器质谱法（MC-ICPMS）新技术，用于岩石学和地球化学两个相关领域--高分辨率地质年代学和精确的原位同位素测量。 MC-ICPMS结合了非常高效的等离子体电离的优点和多收集器磁扇区质谱的精度。 激光器的增加有助于需要空间分辨率的研究。 P.I.将把他们的开发工作集中在新技术上，这些技术提供了其他方法无法很好地复制的能力。 特别是，低230 Th/232 Th样品的高灵敏度U-Th测量，小样品的Hf同位素研究和高精度激光原位Sr，Pb和Hf同位素测量将与MC-ICPMS。 在第一个实例中，P.I.s建议使用这些方法进行流体包裹体的Sr和Pb同位素研究，使用高精度原位同位素测量阐明岩浆历史，火成岩系统的U-Th不平衡研究，锆石的Hf同位素研究和使用显微矿物包裹体确定P-T时间路径。

9526344 Halliday This project will develop the new technique of ICP magnetic sector multiple collector mass spectrometry (MC-ICPMS) for application in two areas of relevance to petrology and geochemistry - higher resolution geochronology and precise in situ isotopic measurements. MC-ICPMS combines the advantages of very efficient plasma ionization with the precision of multiple collector magnetic sector mass spectrometry. The addition of a laser facilitates studies for which spatial resolution is needed. The P.I.s will focus their development work in new techniques that provide a capability not well duplicated by other methods. In particular, high sensitivity U-Th measurements on low 230Th/232Th samples, Hf isotopic studies of small samples and high precision in situ laser Sr, Pb, and Hf isotopic measurements will be made with MC-ICPMS. In the first instance the P.I.s propose using these methods for Sr and Pb isotopic studies of fluid inclusions, elucidating magmatic histories using high precision in situ isotopic measurements, U-Th disequilibrium studies of igneous systems, Hf isotopic studies of zircons and the determination of P-T-time paths using microscopic mineral inclusions.