Upgrade of noble gas facility for (U-Th)-He capability

我们计划升级我们现有的VG 5400惰性气体质谱仪和提取线，现在只用于氩-氩地质年代学，以允许从磷灰石和锆石等矿物中分析氦，用于（U-Th）-He测年。 现有的质谱仪不仅用于氩和氦同位素分析，而且还用于广泛的其他惰性气体;然而，我们需要一个专用的提取线，用于从矿物颗粒中释放和纯化氦，用于（U-Th）-He测年。 （U-Th）-He测年方法产生关于岩体最后一次冷却到75摄氏度的温度的信息（例如，在山脉后期隆起和侵蚀期间，或在火山岩单元冷却期间）或最后被加热到这些相对较低的温度以上（例如，在通过加热的含金属流体的流入形成矿物存款的过程中）。 因此，在过去的十年中，它已成为热年代学研究的一个非常重要的工具，即，研究山带的热历史、火山序列和矿床。 加拿大只有另外一个实验室（达尔豪西大学）目前有能力进行（U-Th）-He测年。 在年轻的造山带（如加拿大西部的科迪勒拉）中，（U-Th）-He测年方法有着非常广泛的令人兴奋的应用，在不列颠哥伦比亚省大学获得进行此类工作的能力将对不列颠哥伦比亚大学和加拿大西部其他研究机构的众多研究人员的研究产生重大影响。

We plan to upgrade our existing VG5400 noble gas mass spectrometer and extraction line, which is now used only for argon-argon geochronology, to permit analysis of helium from minerals such as apatite and zircon for use in (U-Th)-He dating.  The existing mass spectrometer is designed for not only argon and helium isotopic analysis but also a wide range of other noble gases; however, we require a dedicated extraction line for liberating and purifying helium from mineral grains for (U-Th)-He dating.  The (U-Th)-He dating method yields information on when a rock mass last cooled through temperatures as low as 75 degrees Centigrade (e.g., during late uplift and erosion of a mountain range, or during cooling of a volcanic rock unit) or was last heated above these relatively low temperatures (e.g., during the formation of a mineral deposit by influx of heated, metal-bearing fluids).  Over the past decade it has therefore become a very critical tool for studies of thermochronology, i.e., research into the thermal history of mountain belts, volcanic successions and mineral deposits.  Only one other laboratory in Canada (at Dalhousie University) presently has the ability to carry out (U-Th)-He dating.  There is a very wide range of exciting applications of the (U-Th)-He dating method within a young orogenic belt such as the Cordillera of western Canada, and acquiring the capability of doing this type of work at the University of British Columbia will have a major impact on the research of numerous researchers at UBC and in other research institutions in western Canada.