Unravelling the allogenic and autogenic influences on fluvial architecture is challenging because of the large scale of outcrops required to capture sufficient data to test conceptual models. Using a suite of lidar data collected from a helicopter, Rittersbacher et al. explore controls on the large-scale architecture of fluvial sediment bodies in the nonmarine Blackhawk Formation of eastern Utah. Helicopter-based laser scanning provide data to quantify the geometry and continuity of channel bodies on a scale large enough (>10 km) to account for migration and avulsion of a fluvial system. The data reveal almost 400 independent channel bodies. The stacking patterns and spatial evolution the dimensions of the channel bodies are interpreted to represent a succession of deposits of a large prograding distributary fluvial system. Analyses reveal that the key control on channel architecture is the distance of a channel to the contemporary shoreline, contrasting with previous interpretations that accommodation rate of the floodplain was the main controlling factor on accumulation.
Analysis of fluvial architecture in the BlackhawkFormation, Wasatch Plateau, Utah, U.S.A. using large 3D photorealistic models by Andreas Rittersbacher, John A. Howell, and Simon J. Buckley