Mathematical approach to sedimentary component partitioning of polymodal sediments and its applications

Most continental sediments are composed of overlapped components, whose gra in-size follows a type of distribution function. The components and the fun ction type of a sample are determined on frequency and cumulative curves of grain-size distribution so as to designate the function formula. The funct ion parameters can be estimated by fitting designated function to measured grain-sized data of the sample, which simultaneously achieves numerical par titioning of the components. Genetic analysis of hydraulic and aeolian sedi ments demonstrates the following environmental implications. Fluvial sedime nt is composed of isolated saltation and suspension component. The sediment in drainage closed lakes is dominated by suspension silt-clay component, w ith little portion of saltatory sand. Fine sand component makes up a majori ty of desert sand overlapped with small portion of fine dust. Loess is comp osed of overlapped short-suspending silt component and long-suspension fine component. Long-suspension fine dust is the unique component of deep-sea a eolian sediment. The fine component shows constant grain-size distribution and genetic connection from desert sand, loess of Northern China to Norther n Pacific Ocean, which is transported mainly by westerly stream and dispers ed in whole stratosphere to form the background dust.