Tectonics from topography: constraining spatial and temporal landscape response rates to Teton fault activity using low-T thermochronology, quantitative geomorphology, and limnogeologic analyses

Abstract

Understanding how landscapes respond to tectonic and climatic forcing over a range of timescales remains a top priority for studies in tectonics, geomorphology, and geodynamics. To examine this, we are attempting to separate signals that define uplift, drainage incision, and sediment flux at multiple timescales (10⁷ to 10² yrs). The Teton Range serves as an ideal natural laboratory for filtering this interplay due to its comparatively small size and consistent along-strike climatic variation. Recent studies indicate that Teton fault motion first initiated near Mount Moran at ~13 Ma in the northern portion of the range and slip onset gets younger to the south. No major climatic variations occur along strike, so tectonic forcing is interpreted to be the primary driver of landscape evolution. To test this hypothesis, we are evaluating ‘lag’ between fault slip onset and incision of drainages using AHe techniques combined with quantitative landscape analysis to constrain long-term response and analyzing seismic reflection and core data from range front lakes to determine sediment volume flux over shorter intervals. Preliminary data from a seismic survey completed in August 2018 reveals multiple depocenters in Jackson Lake. Results from the seismic survey and AHe analysis should be available in Spring 2019.

Featured photo by Gideon Rosenblatt on Flickr. https://flic.kr/p/2XjzYH