Rates of delta progradation during highstands: consequences for timing of deposition in deep-marine systems

Estimated times required for 24 modern river systems to form a shelf-edge delta range from 8.5 ka to 116.5 ka, depending on fluvial sediment supply, delta width, shelf volume and shelf transport rates. These values indicate that transport of sand into deep-marine systems is likely to be significant during third-order highstands of relative sea-level. Factors such as shelf transport dynamics may slow delta progradation while submarine canyons cutting the shelf may reduce the time before deep-marine deposition occurs. Interpreting ancient sand-rich deep-marine strata as lowstand deposits without sufficient palaeogeographic information may not therefore always be appropriate.