Acquisition of (U-Th)/He Thermochronology Laboratory

9902988米勒这笔赠款提供部分支持的费用，建设一个新的（U-Th）/He热年代学实验室，以补充现有的40 Ar/39 Ar和裂变径迹（FT）热年代学实验室在斯坦福大学。 热年代学是指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。 由于温度通常可以用作埋藏深度的代理，这些方法可以用来帮助重建折返，造山和变形的历史。 不同的温度计在不同的温度区间内敏感，因此在不同的深度。 在矿物磷灰石中，He和FT系统是高度互补的，因为它们的灵敏度区间约为40至85摄氏度（约1.5至3公里深）和80-125摄氏度新设施的初期工作将针对一系列研究，包括：研究弗朗西斯科海湾地区圣安德烈斯断层系统沿着新生代晚期的平移挤压和造山作用，以有助于对该系统的运动学理解和地震危险性评估;重建了内华达州和犹他州的北方盆岭省第三纪伸展史，重建了中亚中、新生代造山变形史;并利用裂变径迹外探测器铀微图方法和SHRIMP-RG离子微探针元素微测绘方法，以评估U和Th分带对（U-Th）/He年龄准确性的影响。

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.***