Acquisition of a multi-collector, inductively coupled plasma mass spectrometer (MC-ICP-MS)

一台电感耦合等离子体质谱仪（MC-ICP-MS）将被安装在威斯康星大学麦迪逊分校的放射性同位素实验室。新的MC-ICP-MS将取代1999年安装的现有仪器，并将与最近安装的飞秒激光烧蚀系统耦合。新仪器将用于同位素地球化学三个领域的研究：金属稳定同位素、u系列地质年代学、长寿命同位素地质年代学和放射性成因示踪剂。稳定金属同位素的研究将包括Mg、Si和Fe的研究，主要集中在同位素分馏因素的实验测定上。此外，一项重要的工作将涉及太古宙和元古宙带状铁地层、黑色页岩和碳酸盐的原位同位素分析。u系列地质年代学研究将以了解100 kyr火山系统的演化为导向，其中238U-230Th年龄与40Ar/39Ar年龄进行了比较，并提供了广泛的地球化学数据，包括Sr， Nd， Pb和Hf同位素。一项关于火山口复合体的新研究将与早期关于中央喷口/复合火山的研究进行比较。对长寿命地质年代学系统和同位素示踪剂（包括U-Th-Pb、Lu-Hf和Rb-Sr）的研究将包括利用飞秒激光烧蚀技术对U-Pb/Lu-Hf锆石进行原位研究，同时对相同材料进行O和Li同位素研究；项目将包括冥古宙的锆石，以及白垩纪的锆石，这是一个更广泛的时间尺度计划的一部分。此外，将利用飞秒激光烧蚀法对长石进行原位Sr和Pb同位素分析，用于物源研究和火山演化研究；对于前者，Sr和Pb分析将耦合到单晶40Ar/39Ar分析。新的仪器将被威斯康星大学麦迪逊分校的学生和博士后使用，也将接待来自中西部和其他地区的访问科学家。

An Inductively Coupled Plasma Mass Spectrometer (MC-ICP-MS) will be installed in the Radiogenic Isotope Laboratory at the University of Wisconsin - Madison. The new MC-ICP-MS will replace an existing instrument that was installed in 1999, and will be coupled to a recently installed femtosecond laser ablation system. The new instrumentation will be used for research in three areas of isotope geochemistry: metal stable isotopes, U-series geochronology, and long-lived isotope geochronology and radiogenic tracers. Work in stable metal isotopes will include studies involving Mg, Si, and Fe, with a major effort expended on experimental determination of isotope fractionation factors. In addition, a significant effort will involve in situ isotopic analysis of Archean and Proterozoic banded iron formations, black shales, and carbonates. Research in U-series geochronology will be directed towards understanding the evolution of 100 kyr volcanic systems, where 238U-230Th ages are compared with 40Ar/39Ar ages, as well as extensive geochemical data, including Sr, Nd, Pb, and Hf isotopes. A new initiative on caldera complexes will provide comparisons with earlier work on central vent/composite volcanoes. Work on long-lived geochronological systems and isotope tracers, including U-Th-Pb, Lu-Hf, and Rb-Sr, will include in situ U-Pb/Lu-Hf zircon studies by femtosecond laser ablation, coupled with O and Li isotope studies of the same materials; projects will include Hadean zircons, as well as Cretaceous zircons that are part of a broader timescale initiative. In addition, in situ Sr and Pb isotope analyses of feldspars by femtosecond laser ablation will be pursued, both for provenance studies, as well as volcanic evolution studies; for the former, Sr and Pb analysis will be coupled to single-grain 40Ar/39Ar analysis. The new instrumentation will be used by students and post-docs at UW-Madison, and will also host visiting scientists from the Midwest and other areas.