Facility Support: Multi-User Facility for U-Th-Pb Geochronology Utilizing a Laser-Ablation Multicollector ICPMS

EAR-0443387 Gehrels该奖项支持U-Th-Pb地质年代学实验室(亚利桑那州激光计时中心)的开发和运营，该实验室使用多采集器电感耦合等离子体质谱仪(来自GV仪器)和193 nm准分子激光器(来自新浪潮研究公司)。这些仪器能够利用10到50微米的束流尺寸，以2-3%(2-sigma)的精度快速产生U-Th-Pb年龄(每小时40岁)。这种快速的吞吐量对于需要生成大型数据集(例如，碎屑锆石来源研究)的应用程序来说是最佳的。激光烧蚀提供的空间分辨率也为解开火成岩和变质地体中常见的复杂生长/扰动历史提供了强有力的工具。该实验室目前能够对石榴石颗粒中的锆石、辉石、独居石和独居石包裹体进行常规的U-Th-Pb年龄测定，并正在努力开发分析磷灰石、金红石和辉石的分析方法。我们预计每年产生约50,000个U-Th-Pb年龄，以支持约50个不同的项目。鼓励学生使用该设施，并提供资金支持学生参与。我们还鼓励在教室环境中使用该仪器，因为它可以远程操作，同时显示激光挖掘和年龄计算。

EAR-0443387GehrelsThis award supports the development and operation of a U-Th-Pb geochronology lab (the Arizona LaserChron Center) that utilizes a multicollector ICP mass spectrometer (from GV Instruments) coupled with a 193 nm excimer laser (from New Wave Research). These instruments are capable of generating U-Th-Pb ages rapidly (40 per hour), with a precision of 2-3% (2-sigma), utilizing a beam size of 10 to 50 microns. This rapid throughput is optimal for applications that require generation of large data sets (e.g., detrital zircon provenance studies). The spatial resolution provided by laser ablation also provides a powerful tool for unraveling complex growth/disturbance histories commonly encountered in igneous and metamorphic terranes. The laboratory is presently able to routinely conduct U-Th-Pb age determinations on zircon, sphene, monazite, and monazite inclusions in garnet grains, and efforts to develop analytical methods for analysis of apatite, rutile, and xenotime are ongoing. We anticipate generating ~50,000 U-Th-Pb ages per year in support of ~50 different projects. Students are encouraged to use the facility, and funds are available to support student involvement. We also encourage use of the instrument in a classroom setting as it can be operated remotely with simultaneous displays of laser excavation and age calculation.