thumbnail

Southern Appalachian hillslope erosion rates measured by soil and detrital radiocarbon in hollows

Geomorphology

By:
, ,
DOI: 10.1016/j.geomorph.2011.08.030

Links

Abstract

Understanding the dynamics of sediment generation and transport on hillslopes provides important constraints on the rate of sediment output from orogenic systems. Hillslope sediment fluxes are recorded by organic material found in the deposits infilling unchanneled convergent topographic features called hollows. This study describes the first hollow infilling rates measured in the southern Appalachian Mountains. Infilling rates (and bedrock erosion rates) were calculated from the vertical distribution of radiocarbon ages at two sites in the Coweeta drainage basin, western North Carolina. At each site we dated paired charcoal and silt soil organic matter samples from five different horizons. Paired radiocarbon samples were used to bracket the age of the soil material in order to capture the range of complex soil forming processes and deposition within the hollows. These dates constrain hillslope erosion rates of between 0.051 and 0.111mmyr-1. These rates are up to 4 times higher than spatially-averaged rates for the Southern Appalachian Mountains making creep processes one of the most efficient erosional mechanisms in this mountain range. Our hillslope erosion rates are consistent with those of forested mountain ranges in the western United States, suggesting that the mechanisms (dominantly tree throw) driving creep erosion in both the western United States and the Southern Appalachian Mountains are equally effective. ?? 2011 Elsevier B.V.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Southern Appalachian hillslope erosion rates measured by soil and detrital radiocarbon in hollows
Series title:
Geomorphology
DOI:
10.1016/j.geomorph.2011.08.030
Volume
138
Issue:
1
Year Published:
2012
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
121
Last page:
129
Number of Pages:
9