The decomposition of polymodal settling velocity distributions for a comprehensive sedimentological description of sand-sized samples



The composition of sediment samples and/or the influence of current activity on the sediment can be easily determined using the dissection of settling velocity distributions. A new dissection method for the analysis of settling velocity distributions has been developed. The initial settling velocity distribution is decomposed by means of settling velocity distributions of the main biogenic constituents, three planktic and three benthic foraminifera species. A divergence from the natural size distribution of a foraminifera species can be attributed to current influence. Thus, negative or positive skewness of current-affected foraminifera populations indicate erosional or depositional sediment influence. The dissection of Holocene samples from the northern North Atlantic demonstrates the advantages of this method in the interpretation of sand-size material.