Experimental study of estimation for paleohydraulic conditions based on grain-size of deposits

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Many methods for the estimation of paleohydraulic condition have been proposed based on grain-size composition of deposits. In this research project I tried to clarify the phenomena using by experimental approaches.There is no universal size-distributions induced by transport, and instead, that the size distributions are strongly governed by the size distribution of the sand used in the experiments. Relationships between the grain-size distributions of individual transport modes and the texture of the "original sand" are best demonstrated by normalizing data with the size distribution of the "original sand". The results of normalizing of experimental data suggest that there is rather strict selection as to grain size whether a grain can be suspended. But the suspension process does not prefer a peculiar size among the grains which can be suspended ; i.e., grains of every size present in the suspended load are represented in the same proportion as in the "original sand". Moreover, turbidites deposited in flume show a same size pattern to suspended sands obtained from the normalizing. Avalanching and saltating sands, however, have their characteristic grain-size distributions modified even by short-distance transport.In conclusion we can not estimate the paleohydraulic condition directly from the information of grain-size compositions of deposits!