Sedimentary Processes of River and Flood plain inferred from ancient deposits

1.分析了不同时代和类型的河流沉积体系，探讨了河流沉积体系中保存陆相化石的沉积条件。在每条河流的不同亚环境中都观察到化石层。在河道基底的“滞后”或裂缝状沉积物中积累的化石表明，包括河流上游和周围在内的更广阔的环境。相反，洪泛平原和牛轭湖沉积物中的化石可能表明环境更接近河流。研究表明，沉积物的粒度分布和岩石组成有助于估计沉积物的输运过程，并有助于区分洪泛平原异常高能沉积物。特大洪水事件改变了环境。几个特大洪水沉积物具有相同的沉积特征。泥沙供给和海平面状况对水槽试验推断的洪水沉积的发生和保存可能具有重要意义。

1.I analyze some fluvial depositional systems of different ages and types to consider the sedimentary conditions to preserve terrestrial fossils in a fluvial depositional system.2.Fossiliferous layers are observed in various subenvironments of each river. Fossils accumulated in channel-base 'lag' or crevasse-splay deposits suggest broader environments including the upper reaches and surrounding of the river. Oppositely, fossils in flood plain and ox-bow lake deposits might indicate environment closer to a river.3.This study presents that grain-size distributions and petrologic composition are useful to estimate sediment transport processes and to distinguish unusual high-energy deposits in flood plain.4.Megaflood event changes the surcumcetance. Several megaflood deposits have the same sedimentary feature.5.The sand supply and sea level condition might be important for occurrence and preservation of flood deposits inffred from flume experiments.