It has become common in the sedimentological literature to distinguish between sedimentationrates (sediment thickness per unit time) and accumulation rates (solid sediment mass per unit area and time), particularly in papers dealing with modern sediments and the results of ocean drilling (e.g., Van Andel 1983; Ehrmann and Thiede 1985). This discrimination is important when sediments of different porosities are compared, and it is indispensable for any kind of sediment budget.