Constraining lateral bedrock erosion rates of the Buffalo National River, Arkansas

How are wide bedrock river valleys created? How does climate, hydrology, vegetation and tectonism influence the rate of valley widening? To understand this, we need to measure the rate of erosion of bedrock channel walls.

Clay Robertson, PhD candidate at Kansas State University, is researching the influence of talus piles on the evolution of wide bedrock valleys. Talus piles can protect the valley wall from lateral erosion, thus slowing the rate at which valley widening takes place.  He is using both sediment and rock surface OSL dating to estimate the residence time for talus blocks sitting along the valley walls of both wide and narrow valleys in the Buffalo National River in northwest Arkansas. In this study, he aims to better constrain the rates at which valleys widen and shed light on the processes required to create wide bedrock valleys, a common geographic feature whose genesis is not yet understood.