Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Densmore, A. L. Articles by Guidon, R. Search for Related Content GeoRef GeoRef Citation

What sets topographic relief in extensional footwalls?

¹ Department of Earth Sciences, ETH Zürich, CH-8092 Zürich, Switzerland
² Department of Earth and Environmental Sciences, Tulane University, New Orleans, Louisiana 70118, USA
³ Department of Earth Science and Engineering, Imperial College, London SW7 2AZ, UK
⁴ Department of Earth Sciences, ETH Zürich, CH-8092 Zürich, Switzerland

We use three large normal fault arrays in the northeastern Basin and Range Province, western United States, to document catchment development and relief production during fault growth. Fault slip and slip rates increase systematically along strike from zero at the fault tips. Catchment relief and across-strike range width both increase as slip accumulates but reach maximum values at a distance of 15 km from the fault tips and remain uniform along strike over much of the footwalls. Catchment outlet spacing also increases away from the fault tips but does not reach a uniform value and may vary by a factor of 5–6 along strike. We infer that catchments first elongate in the across-strike direction as slip accumulates and the range half-width increases. Once the half-width reaches its maximum value, continued catchment growth is possible only by along-strike capture, which increases outlet spacing but not relief. The close correspondence between catchment relief and range half-width suggests that geomorphically limited hillslope and channel gradients are achieved within the 15 km tip zone. Thus, the limiting factor in footwall development is the width of the range, which is controlled by two external agents: the geometry and spacing of the major faults, and the elevations of base level on both flanks.

Key Words: normal faults • topography • tectonic geomorphology • landscape evolution • Idaho • Montana

This article has been cited by other articles:

				P. A. Allen Time scales of tectonic landscapes and their sediment routing systems Geological Society, London, Special Publications, January 1, 2008; 296(1): 7 - 28. [Abstract] [Full Text] [PDF]