Acquisition of (U-Th)/He Thermochronology Laboratory

9902988米勒这笔赠款为建造一个新的(U-Th)/He热年代学实验室提供部分支持，以补充斯坦福大学现有的40Ar/39Ar和裂变径迹(FT)热年代学实验室。术语热年代学指的是使用天然放射性衰变“时钟”来重建岩石经历的时间-温度历史。由于温度通常可以作为埋藏深度的替代指标，这些方法可以用来帮助重建挖掘、造山和变形历史。不同的温度计时器在不同的温度区间内是灵敏的，因此在不同的深度也是如此。在矿物磷灰石中，He和FT系统具有很强的互补性，其灵敏度区间分别约为40-85℃(约1.5-3公里深)和80-125℃(约3-5公里深)。新设施的初步工作将针对一系列研究，包括：调查旧金山湾区圣安德烈亚斯断裂系统的晚新生代挤压和造山作用，以帮助了解该系统的运动学和地震危险性评估；重建内华达州和犹他州北部盆地和山脉省的第三纪伸展历史；重建中亚中新生代造山和变形历史；利用裂变径迹外部探测器铀显微填图方法和SHRIMP-RG离子探针元素显微填图方法，评估U和Th分带对(U-Th)/He年龄精度的影响。

9902988MillerThis grant provides partial support for the costs of constructing a new (U-Th)/He thermochronology laboratory to compliment existing 40Ar/39Ar and fission track (FT) thermochronology laboratories at Stanford University. The term thermochronology refers to the use of natural radioactive decay "clocks" to reconstruct the time-temperature histories experienced by rocks. Because temperature can commonly be used as a proxy for burial depth, these methods may be used to help reconstruct exhumation, mountain building, and deformational histories. Different thermochronometers are sensitive within different temperature intervals and thus at different depths. In the mineral apatite, the He and FT system are highly complementary in that their sensitivity intervals are about 40 to 85 degrees C (about 1.5 to 3 km depth) and 80-125 degrees C (about 3 to 5 km depth), respectively.Initial work in the new facility will be directed toward a range of studies including: investigating late Cenozoic transpression and mountain building along the San Andreas fault system in the San Francisco Bay Area to contribute toward kinematic understanding of the system and to seismic hazard assessment; reconstructing the history of Tertiary extension in the northern Basin and Range Province in Nevada and Utah; reconstructing Mesozoic and Cenozoic mountain building and deformational histories in central Asia; and using fission track external detector uranium micromapping methods and SHRIMP-RG ion microprobe element micromapping methods to assess the effects of U and Th zoning on the accuracy of (U-Th)/He ages.***