The Erosional Signature of Drainage Divide Motion Along the Blue Ridge Escarpment
Name
JGR Earth Surface - 2022 - Stokes - The Erosional Signature of Drainage Divide Motion Along the Blue Ridge Escarpment.pdf
Description
Published version
Size
12.99 MB
Format
Adobe PDF
Checksum (MD5)
f38c657a9ab0b48c7b5db10513a9d448
Author(s)
Stokes, Maya F
Larsen, Isaac J
Goldberg, Samuel L
McCoy, Scott W
Prince, Philip P
Perron, J Taylor
Date Issued
December 14, 2022
Journal
Journal of Geophysical Research: Earth Surface
Publisher
American Geophysical Union
Citation
Stokes, M. F., Larsen, I. J., Goldberg, S. L., McCoy, S. W., Prince, P. P., & Perron, J. T. (2023). The erosional signature of drainage divide motion along the Blue Ridge Escarpment. Journal of Geophysical Research: Earth Surface, 128, e2022JF006757.
Version
Final published version
Abstract
The planform rearrangement of river basins is recognized as an important process for landscape evolution. The boundaries of river basins can shift either through gradual drainage divide migration or discrete river captures, but the methods for identifying these processes often rely on topographic evidence that remains otherwise untested. Moreover, efforts to understand the relative importance of either process are hampered by a lack of age constraints on river captures. We use 10Be-derived erosion rates to test whether, and how, divide motion is occurring at three locations along the Blue Ridge Escarpment in the Appalachian Mountains. In the Pee Dee River basin, we find that the escarpment is migrating inland up to 45 m/Myr, consistent with topographic evidence for gradual divide migration. In the Dan River basin, erosion rates support the topographic evidence for river capture, and we use a forward model of river incision to estimate that the capture likely occurred in the past 12.5 Myr. In the South Fork Roanoke River basin, where the presence of a knickzone has been interpreted as evidence that a river capture initiated a pulse of faster erosion, we instead measure nearly uniform tributary erosion rates above and within the mainstem knickzone. Simulations show that river incision into a more erodible layer of rock, with or without a river capture, could produce the observed topography and erosion rates in the South Fork Roanoke River. Our results show how multiple lines of evidence can illuminate the rates and mechanisms of river basin reorganization.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution
Persistent DSpace Link
DOI of Published Version
10.1029/2022jf006757
