Timing of Incision of the Salmon River, West-Central Idaho, Using (U-Th)/He Analysis of Apatites

California Institute Of Technology, Pasadena CA

Investigators

Abstract

9909453 Wernicke The upward motion of rock masses relative to the earth's surface has been documented for most major mountain belts, but because of compensating erosion, it is difficult to determine if significant topographic elevation developed and when in the tectonic cycle it occurred. This project will utilize a relatively new method for estimating the age of topographic uplift in the Salmon River-Clearwater Mountains of Idaho, an area analogous to the Sierra Nevada further south in the cordillera, where paleoelevation has been shown to start during the Cretaceous. Results will help determine the spatial pattern of elevation development in the Cordillera and will provide a further test or validation of the method.