Birth, Life and Death of Paleoriver systems: Insights from the Stratigraphic Record
G27, Wills Memorial Building, University of Bristol
A special talk by Benjamin Meaker Visiting Professor Rebecca Dorsey.
We often think of large rivers in terms of well studied modern examples, rivers that are currently “alive”. But continent-scale rivers are not permanent. They form in response to various types of climatic and tectonic forcing (often due to major plate-boundary reorganizations), they may persist for 10’s of Myr, and eventually are terminated by processes such as regional uplift and deformation. Thus the life cycle of a paleoriver system offers insights into long-term changes in regional topography and underlying processes of crustal and mantle deformation that control topography through time. The stratigraphic record provides an excellent tool for studying paleoriver evolution. We can apply concepts in sequence stratigraphy (e.g., interplay between sediment supply and accommodation space) to interpret the tectonic, climatic and eustatic controls on river behavior over a wide range of timescales. This presentation will explore the stratigraphic record of processes that govern initiation and evolution of paleoriver systems through time, with examples from the Colorado River (SW U.S.), Eocene Tyee Formation in western Oregon, and the UK region.