Acquisition of microsampling equipment and peripherals to create the NAU Earth Materials Microanalytical (EMMA) Facility

0450977 Reid这笔赠款支持购买设备，用于研究天然材料中痕量元素、放射性成因和稳定同位素成分的微尺度不均一性。北亚利桑那大学地质学系将购买一台ND-YAGUV激光和去溶解雾化器样品导入系统，该系统将与现有的多收集器电感耦合等离子体质谱仪(MC-ICP-MS)、微型钻头和连续流动系统对接，将与现有的稳定同位素比质谱仪(SIRMS)配对。这些外围设备将允许对微克大小的样品进行微米级采样，这些样品可以直接引入质谱仪。UV激光消融系统和去溶喷雾器将支持对地壳岩浆室的停留时间和化学演化的研究，这些研究需要放射性同位素年代学(例如U系列不平衡)和微尺度的微量元素分析，以及辅助相(例如锆石和尿安石)的同心生长边缘。微钻探和连续流动系统将支持活动边缘构造力驱动的地壳流体的路径和地球化学演化的研究。将得到支持的其他研究包括：北美大陆元古代地壳组合的重力调查；美国西部第四纪冰盖的地层对比和远端范围的评估；以及放射性尘埃的运输和命运的“法医”研究。

0450977ReidThis grant supports acquisition of equipment for research on microscale heterogeneity in trace element, radiogenic, and stable isotopic compositions of natural materials. The Department of Geology at Northern Arizona University will acquire a Nd-YAG UV laser and desolvation nebulizer sample introduction systems to be interfaced to an existing multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS), a microdrill, and a continuous flow system to be mated to an existing stable isotope ratio mass spectrometer (SIRMS). These peripherals will allow for micron-scale sampling of microgram sized samples that can be directly introduced into the mass spectrometers. The UV laser ablation system and desolvation nebulizer will support research on the residence time and chemical evolution of crustal magma chambers that requires radiogenic isotope geochronologic (e.g., U-series disequilibria) and trace element analysis of microscale, concentric growth rims of accessory phases (e.g., zircon and allanite). The microdrill and continuous flow system will support research on pathways and geochemical evolution of crustal fluids driven by tectonic forces at active margins. Additional research that would be supported include: themobarometric investigations of the Proterozoic crustal assembly of the North American Continent; stratigraphic correlation and evaluation of the distal extent of Quaternary tephras in the Western U.S.; and "forensic" studies of the transport and fate of radioactive fallout.***