MRI: Acquisition of a Thermal Ionization Mass Spectrometer for High-Precision Geochronology and Isotope Geology

确定千年到十亿年时间尺度上的地质过程的速率需要在广泛的地球材料上以非常高的精度确定同位素比率。精确和准确的放射性和成因同位素测量为地质年代学提供了基础，除了其他类型的同位素数据外，地质年代学还可用于揭示诸如质量灭绝、气候变化、生物进化速度等事件的因果关系和巧合，并提供对驱动板块构造和火山喷发的质量和热传输物理的更详细了解。这笔核磁共振成像赠款提供资金，用于在普林斯顿大学地球科学系购买热电离质谱仪(TIMS)，其重点是测量高精度的同位素比率，这对于确定地球物质的年龄和了解地质过程的速率至关重要。这一新工具将补充由Pi Schoene管理的现有TIMS。新的TIMS提供的增强能力将使该实验室能够扩大其研究重点，并确保Schoene和合作者Pi Higgins的研究计划之间的联系，以及系内和广泛的地球科学界内的其他教员之间的联系。新的TIMS将用于1)增加世界级U-Pb实验室的能力，以容纳和培训来自包括文理学院在内的广泛大学的内部和外部用户；2)将更多的时间用于探索和开发新的同位素系统；3)进一步提高这些技术的精确度和准确度，使地质年代学和同位素地质学社区受益；4)扩大Schoene和Higgins对整合研究和课堂工作的投入；5)建立在Higgins领导的现有项目的基础上，让当地城市社区参与并教育当地城市社区，了解环境和人类造成的铅污染的危险及其背后的科学。这笔核磁共振成像赠款提供资金，用于在普林斯顿大学地球科学系购买一个新的TIMS，由Pi Schoene和联席PiHiggins管理，这将补充目前由Schoene管理的现有TIMS。新仪器将被安置在毗邻最先进的地球化学设施的现有空间，得到现有清洁实验室的支持，用于样品制备，并补充由希金斯领导的现有ICPMS设施的研究能力。TIMS和ICPMS的现有设施在满足广大地球科学界对地质年代学和同位素数据的需求方面取得了良好的成绩；它们还投入大量时间建立技术和工作流程，以确保常规方法的精确度和准确度，并使新的科学成为可能。目前TIMS的重点是铀-铅地质年代学的大量应用；新仪器将扩大这些能力，并将时间用于测量稳定的和放射性成因的锶和钙同位素。新仪器还将允许私人投资机构接待更多的外部用户，从而扩大实验室的影响，并向可能没有基础设施容纳类似实验室的大学的广泛用户提供急需的高精度地质年代学和同位素数据。有针对性的地球科学研究项目包括：了解大陆和火山系的演化；通过地层区段的地质年代学校准过去深处的气候变化率；将冰芯记录用于跟踪超过100万年前的大气成分；测量洪水玄武岩喷发的通量并了解其对环境的影响；以及提高月球样本地质年代学的精确度和准确度。

Determining the rates of geologic processes over thousand to billion year time scales requires the determination of isotopic ratios with very high precision on a wide range of Earth materials. Precise and accurate measurements of radioactive and radiogenic isotopes provides the basis for geochronology, which in addition to other types of isotopic data, can be used to unravel ties between causation versus coincidence in events such as mass extinctions, climate change, the pace of biotic evolution, and provide a more detailed understanding of the physics of mass and heat transfer that drive plate tectonics and volcanic eruptions. This MRI grant provides funds to purchase a thermal ionization mass spectrometer (TIMS) in the Department of Geosciences at Princeton University, which focuses on measuring high-precision isotope ratios that are essential for determining the age of Earth materials and understanding the rates of geologic processes. This new instrument will supplement an existing TIMS managed by PI Schoene. The enhanced capacity provided by the new TIMS will permit the lab to broaden its research focus and secure ties between the research programs of Schoene and co-PI Higgins, as well as other faculty in the department and within a broad geoscience community. The new TIMS will serve to 1) increase the capacity of a world-class U-Pb lab to host and train internal and external users from a broad spectrum of universities, including liberal arts colleges, 2) devote more time to exploring and exploiting new isotopic systems, 3) further increase the precision and accuracy of these techniques to benefit the geochronologic and isotope geology communities, 4) expand the devotion of Schoene and Higgins towards integrating research and class work, and 5) build on existing programs led by Higgins to engage and educate local urban communities in the dangers of, and science behind, environmental and anthropogenic Pb contamination. This MRI grant provides funds to purchase a new TIMS in the Department of Geosciences at Princeton University to be managed by PI Schoene and co-PI Higgins, which will supplement an existing TIMS currently managed by Schoene. The new instrument will be housed in an existing space adjacent to state-of-the-art geochemistry facilities, be supported by existing clean labs for sample preparation, and also supplement the research capabilities of existing ICPMS facilities led by Higgins. The existing TIMS and ICPMS facilities have developed a track record of serving the demand for geochronologic and isotopic data within a broad geoscience community; they also devote substantial time to establishing techniques and workflows that both ensure the precision and accuracy of routine methods and enable new science. The focus of the current TIMS is on the numerous applications of U-Pb geochronology; the new instrument will expand those capabilities and also devote time to measuring stable and radiogenic Sr and Ca isotopes. The new instrument will also permit the PIs to host more external users, thus broadening the impact of the laboratories and providing much-needed high-precision geochronologic and isotopic data to a wide-range of users from Universities that may not have the infrastructure to host similar laboratories. Targeted Geoscience research projects range from understanding the evolution of continents and volcanic systems, calibrating rates of climate change in the deep past through geochronology of stratigraphic sections, extending the reach of ice-core records for tracking atmospheric composition beyond a million years ago, measuring the flux of flood basalt eruptions and understanding their environmental impact, and increasing the precision and accuracy of geochronology of Lunar samples.