Isolating Bank Strength Controls on River Terrace Evolution: Implications for Sediment Delivery to Marine Depositional Basins
Limaye, Ajay B. S. and Lamb, Michael P.
Fluvial terraces are unique and ubiquitous landscape features which record millennial trends in river aggradation and degradation. Consequently, interpretations of the river terrace record tie strongly to the history of sediment delivery to marine depositional basins in the Quaternary. Though fluvial terraces are commonly interpreted to record step changes in base level or climatic forcing, which may impact sediment budgets regionally, the degree to which autogenic meandering processes imprint the river terrace record remains uncertain. This challenge results in part from computational difficulties in modeling spatial differences in bank strength, which can steer channel migration. Consequently, we have developed a numerical model for landscape evolution in meandering-influenced environments that overcomes previous dependence on landscape grid resolution. We apply this new framework to assess autogenic versus allogenic influences on terrace formation frequency and geometry, and make quantitative comparisons to terraces at field sites including the Colorado River, Texas; Wind River, Wyoming; and Clearwater River, Washington.
AAPG Search and Discovery Article #90162©2013 Pacific Section AAPG, SPE and SEPM Joint Technical Conference, Monterey, California, April 19-25, 2013