Mechanics of thrust fault formation
Abstract
Thrust faults in layered materials follow stepped trajectories comprised of alternating flats (layer-parallel segments) and ramps (segments oblique to layering). New thrust faults generally form in the footwalls of active thrust. By examining the evolving stress fields in the footwalls of active stepped thrusts, a mechanical model for the formation of thrust surfaces is developed. Analysis of displacements and sheet lengths for some natural duplexes finds a clear correlation between displacement and length of the underlying thrust sheet, suggesting that this is the environment in which most of the imbricates form. A similar correlation for imbricate active thrust sheets produces a topographic low in a similar position. Further support for the model is provided by the periodic nature of displacement variations.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1987
- Bibcode:
- 1987PhDT........15W
- Keywords:
-
- Geological Faults;
- Mathematical Models;
- Morphology;
- Pressure Effects;
- Stress Distribution;
- Displacement;
- Erosion;
- Topography;
- Geophysics