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？一种广泛应用的年代测定技术，提供岩石和矿物低温热历史的详细信息。购置这一设备填补了该部现有地质年代学设施的一个重大空白。更广泛的意义是，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-氦定年的补充技术，从单个矿物颗粒（小到沙粒）获得多个年龄。铀-铅年代测定提供了被分析的特定矿物的形成年龄，而裂变径迹和铀-钍-氦年代测定提供了特定矿物冷却到250摄氏度至60摄氏度以下的时间。了解低于后者温度的冷却时间和速度特别有用，因为它提供了侵蚀速度和时间的信息，并通过代理，提供了关于造山过程、景观形成和沉积物沉积的时间和速度的独特信息。这种“三重定年法”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，评估气候、气候变化和造山运动的相互作用，提供关于石油、天然气、和矿藏。核裂变的潜力-径迹分析有利于亚利桑那大学正在进行和未来的各种项目，这些项目调查的问题多种多样，如沉积物的来源，现代和古代造山和景观演化，在地质记录中识别野火，以及晚新生代全球冷却和冰川作用对控制活跃的造山作用的作用。此外，将裂变径迹和铀-钍-氦定年与部门最先进的激光烧蚀多接收器电感耦合等离子体质谱仪结合起来进行铀-铅定年，不仅可以对常用矿物锆石进行三重定年，还可以分析其他分析更复杂的矿物，如钛铁矿，磷灰石和独居石。裂变跟踪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。一些本科生和研究生以及一些博士后正在研究从裂变径迹方法的应用中受益匪浅的问题。这些设施使他们有机会获得学习和应用这一方法的实际经验。该设备也是正在进行和计划中的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.