Fission-Track Thermochronologic Investigation of Basement Uplifts and Basin Fill in the Rocky Mountain Foreland

怀俄明州西部落基山前陆风河山脉的裂变径迹热年代学表明，有可能测量渐新世/始新世时期发生的构造抬升的时间和速率。PI将使用裂变径迹热年代学来：1)确定落基山脉前陆以基底为核心的隆起的开始时间和表观隆起速率；2)估计相关盆地的盆地充填深度；以及3)如果断层存在于其他范围的核心中，如在风河中，则识别断层。此外，还将进行实地研究，以确定这种核心断裂的年龄以及它是挤压还是伸展的。这个项目的意义在于它对根本原因的影响。大多数前陆变形理论与法拉隆板块的水平俯冲和/或科罗拉多高原的旋转有关。然而，缺乏具体的约束，因为我们对变形时间的理解只是一般性的，我们的几何模型不包括岩心的年轻隆起，我们不确定伴生盆地的充填深度。这项研究旨在提供具体的时间和几何信息，以支持落基山脉前陆变形理论。

Fission track thermochronology in the Wind River Range in the Rocky Mountain foreland of western Wyoming has shown the potential to measure the timing and the rates of tectonic uplift that occurred in Oligocene/Eocene time. The PI will use fission-track thermochronology to: 1) determine time of uplift initiation and apparent uplift rate for basement-cored uplifts in the Rocky Mountain foreland; 2) estimate depth of basin fill in the associated basins; and 3) indentify faulting if it is present in the cores of other ranges as it is in the Wind Rivers. In addition, field studies will be conducted to determine the age of this core faulting and whether it is compressional or extensional. The significance of this project lies in its implications concerning fundamental cause. Most theories for foreland deformation relate to horizontal subduction of the Farrallon plate and/or rotation of the Colorado Plateau. However, specific constraints are lacking inasmuch as our understanding of the timing of deformation is only general, our models of the geometry do not include young uplift of the cores and we are not sure how deep the associate basins were filled. This study is designed to provide the specific temporal and geometric information needed to constrian theories of Rocky Mountain foreland deformation.