Record Details
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 |