Cosmogenic Nuclides Applied to Fault-Scarp Dating

9980535对地质上最新的断层进行时间测定对许多新构造和环境项目是至关重要的，但很难确定断层运动是否发生在有记录的历史之前。断裂地表的断层通常会由于不同的垂直运动而留下陡峭的山崖。粗略地说，年轻的断层崖陡峭且边缘尖锐，而较老的断层崖已被侵蚀，因此它们不那么陡峭和光滑。试图利用这一关系更定量地估计陡坎“扩散率”，以校准年龄与断层陡坎地貌的关系。然而，这项技术和其他技术都有很大的误差，这对所获得的断层活动年龄产生了负面影响。该项目将尝试使用宇宙成因的氯-36积累在几个已知年龄的断层周围，以改进对断层陡坎扩散率的估计。结果应该有助于减少使用断层陡坎形态的错误，并降低准确估计断层运动年龄的成本。

9980535PhillipsTiming of geologically recent faults is crucial to many neotectonic and environmental projects, but is difficult to determine if the fault movements occurred prior to recorded history. Faults that break the surface commonly leave a scarp due to differential vertical movements. Crudely, young fault scarps are steep and have sharp edges, whereas older ones have been eroded so that they are less steep and smoothed. Attempts to use this relationship more quantitatively estimate a scarp "diffusivity" to calibrate the age vs. fault scarp geomorphology relationship. However, this and other techniques have large errors which negatively impacts the ages of fault movement obtained. This project will attempt to use cosmogenic chlorine-36 accumulation around several faults of known age to refine estimation of fault scarp diffusivity. Results should help reduce errors in using fault scarp morphology and lower the costs of accurately estimating the age of fault movements.