...because if the study's authors are claiming that the entire sediment load is being deposited terrestrially (above sea level), then they need to go back to school. By far the majority of sediments in a delta system are deposited along the prograding delta front - below sea level. An amazing amount of silt is taken far out into the ocean basin. Furthermore, deltas are notorious for subsiding. The more sediment is added, the more they slump and slide deeper into the basin. Also, the weight of sediment can depress the crust they are being deposited upon, allowing more sediment without adding to above sea-level height. Deltas grow out and down, not up (relatively). If the study is correct, then this delta, in the abscence of sea-level rise, should be getting higher every year.

I caution you on hanging your hat on this one, Tom, until we see the original study.