Acquisition of microscope and automated stage system for fission-track analysis

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该奖项为亚利桑那大学地球科学系提供了进行裂变径迹分析的实验室设备。一种广泛应用的年龄测年技术，可提供岩石和矿物低温热史的详细信息。该设备的购置填补了该部门现有地质年代学设施的重大空白。更重要的是，该设施提供了一种独特的内部能力，可以使用铀-铅、裂变径迹和铀-钍-氦定年等互补技术，从单个矿物颗粒（小到沙粒）中获得多个年龄。铀-铅定年法提供了被分析的特定矿物的形成年龄，而裂变径迹法和铀-钍-氦定年法提供了特定矿物在低于250摄氏度到60摄氏度的温度下冷却的时间。了解后一种温度下冷却的时间和速率特别有用，因为它提供了侵蚀速度和时间的信息，并通过代理提供了独特的信息，例如，山脉形成过程、景观形成和沉积物沉积的时间和速率。这种“三重测年”具有独特和创新的潜在应用领域，如了解南极洲的冰川过程，评估涉及气候、气候变化和造山的相互作用，为石油、天然气和矿藏的形成和勘探提供有价值的新信息。进行裂变轨迹分析的潜力有利于亚利桑那大学正在进行的和未来的各种项目，研究各种各样的问题，如沉积来源、现代和古代造山带和景观演化、地质记录中野火的鉴定、以及晚新生代全球冷却和冰川作用对控制活跃的造山活动的作用。此外，将裂变径迹和铀-钍-氦定年与该部门最先进的激光烧蚀多收集器电感耦合等离子体质谱仪相结合，用于铀-铅定年，不仅可以对常用矿物锆石进行三重定年，还可以分析其他更复杂的矿物，如钛矿、磷灰石和单氮石。裂变轨道设施还加强了亚利桑那大学地球科学系的研究和教学基础设施。许多本科生和研究生以及一些博士后正在研究从裂变径迹法的应用中获益良多的问题。这些设施为他们提供了在学习和应用这种方法方面获得实践经验的机会。该设备也构成了正在进行和计划的nsf资助的夏季学生热年代学研讨会在亚利桑那大学举行的重要组成部分。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This award provides the Department of Geosciences at the University of Arizona with the laboratory equipment to carry out fission-track analysis ? a widely applied age dating technique that provides detailed information on the low temperature thermal history of rocks and minerals. The acquisition of this equipment fills a significant gap in the existing geochronological facilities of the department. Of broader significance is that this facility provides a unique in-house capability to obtain multiple ages from single mineral grains (as small as grains of sand) using the complementary techniques of uranium-lead, fission-track, and uranium-thorium-helium dating. Uranium-lead dating provides the age of formation of the particular mineral being analyzed, while fission-track and uranium-thorium-helium dating provide the time that particular mineral cooled through temperatures below about 250 degrees Celsius to 60 degrees Celsius. Knowing the timing and rates of cooling below the latter temperatures is particularly useful as it provides information of rates and timing of erosion, and by proxy, unique information on, for example, the timing and rates of mountain building processes, landscape formation, and sediment deposition. Such "triple-dating" has unique and innovative potential applications in fields such as understanding glacial processes in Antarctica, evaluating interactions involving climate, climate change and mountain building, to providing valuable new information on the formation and exploration of oil, gas, and mineral deposits.The potential to perform fission-track analysis benefits a variety of ongoing and future projects at the University of Arizona investigating problems as diverse as sedimentary provenance, modern and ancient orogenic and landscape evolution, identification of wildfire in the geologic record, and the role of late Cenozoic global cooling and glaciation on controlling active mountain building. Furthermore, combining fission-track and uranium-thorium-helium dating with the departmental state-of-the-art laser ablation multi-collector inductively coupled plasma mass-spectrometer for uranium-lead dating allows not only the triple-dating of the commonly-used mineral zircon, but also the analysis of other more analytically complex minerals such as titanite, apatite, and monazite. Fission-track facilities also enhance the infrastructure for research and teaching in the University of Arizona Department of Geosciences. A number of undergraduate and graduate students as well as a few post-docs are working on problems that benefit greatly from the application of the fission-track method. These facilities provide them with the opportunity to gain hands-on experience in learning and applying this methodology. This equipment also forms a vital part of ongoing and planned NSF-funded summer student thermochronology workshops held at the University of Arizona.