Evolution of Fluvial Systems on the Colorado Plateau

The Colorado River system and its tributaries serves as a unique opportunity to explore how fluvial erosion and structure interact in an arid environment. Our work focuses on the history of the Colorado Plateau itself as well as how the Plateau can be used as a natural laboratory for understanding the development of drainage networks in bedrock-erosive landscapes. This includes both timing and rates of fluvial incision in addition to the processes which control drainage initiation on dipping surfaces.

This research focuses on the effects of fluvial systems on landscape evolution. Currently, we are using cosmogenic radionuclides in gravel terraces to explore the history of incision and deposition along the central San Juan River. Using high-resolution topographic data created from UAV surveys, we relate geomorphic surfaces downstream of the Raplee Ridge monocline to understand how existing structures may have affected incision rate and timing of deposition. Raplee Ridge also serves as a natural laboratory for exploring if channel initiation and drainage expansion mechanisms which have been developed in soil-mantled landscapes can be applied to exclusively bedrock-erosive features. Using the spacing of drainages along Raplee Ridge’s dipping face, we are exploring the processes which initiated channels as well as building conceptual models for how lithologic variation can affect drainage development. 

In addition, we are exploring how provenance can be used to constrain drainage evolution over Paleogene timescales. Shifting river dynamics can cause rapid abandonment of large cobbles as incisional processes become dominant, leaving a record of drainage geometry long after the fluvial system has shifted. This work is centered around constraining the age of Grand Canyon incision using fluvial deposits on the Shivwits Plateau to determine if a south-to- north drainage existed at 6 Ma.