Modes of extensional faulting controlled by surface processes
Abstract
We investigate the feedbacks between surface processes and tectonics in an extensional setting by coupling a 2-D geodynamical model with a landscape evolution law. Focusing on the evolution of a single normal fault, we show that surface processes significantly enhance the amount of horizontal extension a fault can accommodate before being abandoned in favor of a new fault. In simulations with very slow erosion rates, a 15 km thick brittle layer extends via a succession of crosscutting short-lived faults (heave < 5 km). By contrast, when erosion rates are comparable to the regional extension velocity, deformation is accommodated on long-lived faults (heave >10 km). Using simple scaling arguments, we quantify the effect of surface mass removal on the force balance acting on a growing normal fault. This leads us to propose that the major range-bounding normal faults observed in many continental rifts owe their large offsets to erosional and depositional processes.
Additional Information
© 2014. American Geophysical Union. Accepted manuscript online: 26 Sep 2014. Manuscript Accepted: 22 Sep 2014. Manuscript Revised: 19 Sep 2014. Manuscript Received: 12 Aug 2014. Article first published online: 9 Oct 2014. The authors wish to thank Don Forsyth, Brian Yanites, and Eric Mittelstaedt as well as Taylor Perron and his group for fruitful discussions. This work was supported by NSF grants OCE-1154238 and EAR-1010432. Input files and scripts used for the numerical simulations are available upon request by emailing the corresponding author at jaolive@mit.edu. The Editor thanks Phaedra Upton and one anonymous reviewer for their assistance in evaluating this paper.Attached Files
Published - grl52166.pdf
Supplemental Material - Auxiliary_Material_Ts01.docx
Supplemental Material - Auxiliary_Material_fs01.pdf
Supplemental Material - Auxiliary_Material_readme.docx
Supplemental Material - Auxiliary_Material_text.docx
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Additional details
- Eprint ID
- 53008
- Resolver ID
- CaltechAUTHORS:20141218-093500529
- OCE-1154238
- NSF
- EAR-1010432
- NSF
- Created
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2014-12-18Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field