摘要
本文从现代洪水事件作用可以形成大片不对称流水波痕入手，“将今论古”，发现古代地层剖面中也有大量水下至水上的沉积旋回序列，每个旋回单元与下伏岩层为突变接触。水下沉积环境富含不对称流水波痕，水上则为富含泥裂，它们系为洪水事件沉积产物。这些洪水事件具有不同的规模和级别，在地学上具有重要意义。
The asymmetrical current ripple marks occur over a wide range of scales in the Meso- zoic and Cenozoic continental fluvial and lacustrine sedimentary environments in China. They may exhibit diverse morphologies:very wide or very narrow,indicating a permanent shallow-water environment or an ephemeral overbank environment.The results of re- search in this paper have disclosed that within the ancient stratigraphic sections,there are many subaerial and subaqueous sedimentary cyclic sequences,each of which show sharp contacts with the underlying strata.The subaerial environments abound in asymmetrical current ripple marks,whereas the subaqueous ones in desiccation cracks.This implies that the current ripple marks resulted from the flood event deposition.These flood events of varying sizes may have important geological implications.
关键词
陆相
流水波痕
事件沉积
地质意义
洪水事件
asymmetrical current ripple mark
event deposit
geological implication
