Geodynamic drivers of canyon incision, Salmon River, Idaho and surrounding regions.
Funding Source: US National Science Foundation
Collaborators: Gene Humphries (co-PI) - University of Oregon, Brian Yanites (co-PI) Indian University, Jonathon Perry-Houts (PhD 2019), Matthew Morris (PhD 2020), Nathan Mitchell (PhD 2021)
GeoScape Team Members: Alison Duvall (lead PI), Seth Williams (graduate student), Philip Schoettle-Greene (PhD 2021)
The Inland Northwest offers a unique opportunity to examine the role that mantle dynamics play in epeiorogeny and landscape evolution.
Overview
The Salmon River watershed shows classic features of a disequilibrium landscape: A greater than one kilometer deep canyon carves through perched surfaces of low relief. Modeling of river knickpoints suggests this landscape experienced broad regional uplift of 1-1.5 km since ~8-10 Ma.
This region of high and transient topography appears to correlate directly with mantle processes interpreted from seismic tomography. From these observations we suggest that both lithospheric foundering and plume driven dynamic uplift play a role in driving recent landscape evolution in the Salmon River watershed.
With our collaborators, we are coupling seismic tomography with surface erosion and exhumation data using numerical models of landscape evolution and upper mantle dynamics. Our goal is to use the river as a recorder of landscape transience and by coupling erosion rate measures averaged over different time scales, link surface processes to mantle dynamics.