Constraining rates of thrusting and erosion: Insights from kinematic thermal modeling
- 1Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- 2Department of Geosciences, Idaho State University, Pocatello, Idaho 83209, USA
Abstract
We present a thermal model of a simple thrust system that can be used to determine thrust rates and erosion rates from low-temperature thermochronology. Unlike previous models, this model incorporates the effects of erosion both during and after thrusting. In particular, we examine the modeled evolving thermal structure and pressure-temperature-time evolution of hanging-wall rocks that undergo fault-bend folding due to transport over a blind footwall ramp. In all cases, rocks cool as they move over the footwall ramp, potentially providing a common pinpoint for determining thrust rates. In the simplest case, low-temperature thermochronology of minerals that pass through their closure temperature over the ramp will yield details on thrust kinematics (thrust rate, timing of initiation, and duration of thrusting). Additional cooling ages of a more comprehensive sample suite can capture cooling due to erosion. In these latter cases, model results can place limitations on erosion rates.
Footnotes
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↵GSA Data Repository item 2006105, modeled structural, topographic and thermal evolution of a nominal thrust system, no vertical exaggeration, is available online at www.geosociety.org/pubs/ ft2006.htm, or on request from editing{at}geosociety.org or Documents Secretary, GSA, P.O. Box 9140 Boulder, CO 80301-9140, USA.
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- Accepted 12 February 2006.
- Received 11 November 2005.
- Revision received 8 February 2006.
- The Geological Society of America, Inc.
