Acquisition of a Noble Gas Thermochronometry Laboratory at Berkeley Geochronology Center

这项重大研究仪器(MRI)计划拨款支持在伯克利地质年代学中心建立一个惰性气体热计时实验室(NGTL)。NGTL将重点研究辅助相的(U-Th)/He和4He/3He年龄，以确定它们的低温(200摄氏度)热历史。将购买的设备包括一台双筒显微镜，用于构建气体提取系统的组件，包括半导体激光器和超高真空激光提取室，用于构建超高真空气体净化系统的组件，以及四极质谱仪。激光加热气体提取和净化系统将被用来从样品中释放出氦，然后在四极质谱计上进行分析。在气体分析之后，回收的样品将被溶解，溶液将被添加到现有校外设施中通过电感耦合等离子体质谱分析进行U和Th浓度的同位素稀释测量。NGTL对200摄氏度以下岩石热历史的定量评估能力将用于建立在类地行星最上面几公里处发生的过程的时间尺度和速率。将促进一系列PI和合作研究，包括：(1)量化山区景观中的折返、侵蚀和构造作用的速度和时间尺度，并测试气候变化对地形可能产生的影响；(2)限制近地表行星撞击的温度和时间尺度以及火星陨石在火星上的长期停留温度；(3)量化地球表面的化学风化的时间尺度和速率；(4)限制地球表面样品的长期停留时间尺度，以及(5)研究惰性气体在不同材料中的扩散动力学，以促进对固态扩散的基本了解，并可能确定惰性气体在地球和行星科学中的新应用。研究生和博士后研究人员将接受低温热时研究方法的培训，国际和平研究所的计划旨在招募妇女和少数民族获得研究生和博士后奖学金。*

0618219ShusterThis Major Research Instrumentation (MRI) Program grant supports establishment of a noble gas thermochronometry laboratory (NGTL) at the Berkeley Geochronology Center. The NGTL would focus on (U-Th)/He and 4He/3He dating of accessory phases to establish their low temperature ( 200 degrees C) thermal histories. Equipment to be purchased includes a binocular microscope, components to a build gas extraction system including diode laser and ultrahigh vacuum laser extraction chamber, components to build an ultra high vacuum gas purification system and a quadrupole mass spectrometer. The laser heated gas extraction and purification system would be used to liberate He from samples which would subsequently be analyzed on the quadrupole mass spectrometer. Following gas analysis, recovered samples would be dissolved and solutions would be spiked for isotope dilution measurements of U and Th concentrations via ICP-MS analysis at available off campus facilities. NGTL capabilities for quantitative evaluation of the thermal histories of rocks below 200 degrees C will be used to establish timescales and rates of processes taking place in the uppermost few kilometers of terrestrial planets. A range of PI and collaborative research will be facilitated including: (i) quantifying the rates and timescales of exhumation, erosion and tectonism in mountainous landscapes and testing possible influences that climate variability has on relief, (ii) constraining the temperatures and timescales of near-surface planetary impacts and long-duration residence temperatures of the Martian meteorites while on Mars, (iii) quantifying the timescales and rates of chemical weathering at Earth's surface, (iv) constraining long-term residence timescales of samples near Earth's surface, and (v) studying noble gas diffusion kinetics in different materials to advance basic understanding of solid-state diffusion and potentially identify novel applications of the noble gases to the Earth and planetary science. Graduate and postdoctoral researchers will be trained in low-temperature thermochronometry research methods and the PI's plan targeted recruitments of women and minorities for graduate and postdoctoral fellowships.***