Acquisition of a Laser Ablation Single Collector High Resolution Inductively Coupled Plasma Mass Spectrometer

这笔赠款通过重大研究仪器(MRI)计划，为佐治亚州立大学地质学系购买配备激光烧蚀微探头的磁扇区电感耦合等离子体质谱仪(以下称为LA-HR-ICP-MS)提供部分支持。与佐治亚州目前不再制造的四极仪器相比，新的高分辨率仪器提高了分析溶液中或烧蚀颗粒中所含痕量元素的灵敏度和检测下限。在深紫外光(193 nm波长)下运行的准分子激光系统将与相对半透明的矿物(即石英)进行更好的耦合，提供更精细的光斑尺寸和更稳定的光束宽度能量分布，并提供对激光光束进行光栅化的能力。LA-HR-ICP-MS系统有可能大大提高流体包裹体中所含微量元素丰度的测量质量和数量，这是佐治亚州这一小组的专长。新的电感耦合等离子体质谱设施还将延续长期开放使用的传统，作为一种分析设施，服务于美国东南部，既满足学术需求，也供总部位于亚特兰大的朗讯技术公司的工业合作者使用。这种学术和产业的合作使佐治亚州地质部和朗讯科技之间建立了共生关系，朗讯为实验室的运营提供资金支持，为学生提供教育经验，佐治亚州为朗讯的员工提供训练有素的毕业生。将利用这一新设施的地球科学领域的具体研究项目包括：研究伊朗暴露的特提斯蛇绿岩的岩石成因，以更好地了解大洋地壳形成过程；研究伟晶岩矿物赋存的流体包裹体的稀土元素，以揭示水-岩相互作用及其在成矿作用中的作用；高压实验电荷中的微量元素分配，以阐明暴露的变质相的地球化学演化；以及对美国东南部沿海平原含水层的地下水样品进行微量元素分析，以此作为农业和市政需求过度开采淡水资源造成的有问题的咸水侵入的指示。**

0079721GhaziThis grant, made through the Major Research Instrumentation (MRI) Program, provides partial support of the costs of acquiring a magnetic sector inductively coupled plasma mass spectrometer equipped with a laser ablation microprobe (hereafter referred to as LA-HR-ICP-MS) for the Department of Geology at Georgia State University. The new high resolution instrument offers increased sensitivity and lower detection limits for the analysis of trace elements in solution or contained in ablated particulates than the current and no longer manufactured quadrupole-based instrument at Georgia State. An excimer laser system operating in the deep UV (193 nm wavelength) will provide for better coupling with relatively translucent minerals (i.e. quartz) than do Nd-YAG lasers, offers a finer spot size and more stable energy profile across the beam width, and offers the ability to raster the laser beam. The LA-HR-ICP-MS system offers the potential to substantially improve the quality and quantity of measurements of trace element abundances contained within fluid inclusions, the specialty of this group at Georgia State. The new ICP-MS facility will also continue a long standing tradition of open use as an analytical facility serving the southeastern U.S. both for academic needs and use by industrial collaborators from Atlanta-based Lucent Technologies. This academic-industrial collaborative effort has resulted in a symbiotic relationship between the Georgia State Geology Department and Lucent Technologies, with Lucent providing financial support for operation of the lab and educational experiences for students and with Georgia State providing trained graduates for Lucent's workforce. Specific research projects in the geosciences that will utilize this new facility include: studies of the petrogenesis of Tethyan ophiolites exposed in Iran to better understand the process of oceanic crustal formation; rare earth element studies of pegmatite mineral-hosted fluid inclusions to shed light on water-rock interaction and its role in the formation of metalliferous deposits; trace element partitioning in high pressure experimental charges to elucidate the geochemical evolution of exposed metamorphic facies; and trace element analysis of groundwater samples from coastal plain aquifers of the southeastern U.S. as indicators of problematic salt-water intrusions caused by over pumping of fresh groundwater resources for agricultural and municipal needs.***