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This paper presents an experimental study on the local bed morphology and grain size characteristics around an impermeable spur dyke.A series of experiments are conducted with different types of sedime... 相似文献
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SHOJI FUJII NORIYUKI NASU ALEC J. SMITH NORIO FUJI YOSHIHIKO MIZUTANI MISABURO SHIMAKURA KENJI KONISHI CHIAKI IGARASHI JUNRYO MURAMOTO TOSHIO TAKEMURA TAKASHI SHIMODA SAM BOGGS JR. KANTARO FUJIOKA HARUNA MAPPA HOTAKA KAWAHATA YONG SAE KONG TAKEO TANAKA 《Boreas: An International Journal of Quaternary Research》1986,15(4):265-277
Remnants of a submerged ancient forest have been found on the continental shelf of NW Japan off the Kurobe alluvial fan in Toyama Bay. The remains, standing tree stumps and roots, are located at depths between 20 and 40 m and ages of 8,000 years B.P. to 10,000 years B.P. have been determined by the 14 C method. Alnus and Salix are the most commonly preserved genera and the trees grew on the now sub-merged seaward margin of the alluvial fan. Pollen analysis permits an estimate of palaeo-temperatures 2°C to 4°C lower than at present. Diatoms give some indication of salinity variations at the time of forest development and suggest brackish water, possible lagoonal conditions. The distribution of the stumps and roots suggests that there were probably two separate forests which were overwhelmed by rising sea-level and flash flood deposits. The present day submarine exposures may be due to recent submarine erosion related to the seaward movement of flood waters which passed from the fan into the upper reaches of the Toyama submarine canyon system. 相似文献
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