Chapter 23 Continental shelves as sediment capacitors or conveyors: source-to-sink insights from the tectonically active Oceanside shelf, southern California, USA

Abstract

AbstractContinental shelves are the key interfaces between terrestrial sediment source areas and deep-sea depositional systems, promoting the transfer of sediment across continental margins. Work on shelves in the context of entire continental-margin sediment-routing systems has focused on their importance as capacitors of sediment during several to tens of thousands of years of post-glacial shoreline transgression and sea-level highstand. We demonstrate that the tectonically active Oceanside shelf offshore southern California has served as an efficient conveyor of sediment from land to the deep sea during millennia of significant climatic fluctuations. This conveyance is a result of littoral drift of sediment to canyon heads at narrow segments of the shelf. We compare insights from the Oceanside shelf to other shelves across the tectonically active Pacific margin of the United States, and demonstrate the importance of shelf width, climatic forcings and timescale of observation in assessing the role of shelves as sediment capacitors or conveyors.