Record Details

Aspect-dependent variations in regolith creep revealed by meteoric ¹⁰Be

ScholarsArchive at Oregon State University

Field Value
Title Aspect-dependent variations in regolith creep revealed by meteoric ¹⁰Be
Names West, Nicole (creator)
Kirby, Eric (creator)
Bierman, Paul (creator)
Clarke, Brian A. (creator)
Date Issued 2014-06 (iso8601)
Note This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the Geological Society of America and can be found at: http://geology.gsapubs.org/.
Abstract Although variations in insolation and emergent feedbacks among soil moisture,
vegetation, and soil cohesion are commonly invoked to explain topographic asymmetry that
depends on aspect, few studies have directly quantified the efficiency of regolith transport along
hillslopes of opposing aspect. We utilize meteoric ¹⁰Be concentrations in regolith (n = 74) to
determine mass flux along equatorial- and polar-facing hillslopes in three forested, upland
watersheds in and adjacent to the Susquehanna Shale Hills Critical Zone Observatory (SSHO) in
central Pennsylvania. In combination with regolith depth measurements and high resolution
topography, these fluxes allow us to evaluate transport rate laws and the efficiency of regolith
creep. Concentrations of meteoric ¹⁰Be in regolith along six separate transects imply that regolith
flux is similar along all hillslopes, despite differences in topographic gradient and regolith
thickness. Comparison of flux with regolith depth and topographic gradient reveals that transport
depends on regolith depth, and that regolith creep is twice as efficient along low-gradient, south-facing slopes with thin regolith as compared to steep, north-facing slopes mantled with thicker
regolith. We suggest that the observed topographic a symmetry in these watersheds has evolved
over geologic time as a result of differences in the frequency of freeze-thaw events between
hillslopes of opposing aspect.
Genre Article
Identifier West, N., Kirby, E., Bierman, P., & Clarke, B. A. (2014). Aspect-dependent variations in regolith creep revealed by meteoric ¹⁰Be. Geology, 42(6), 507-510. doi:10.1130/G35357.1

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