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

基于沉积物粒度估算古水文条件的实验研究

基本信息

批准号：
07454127
负责人：
MASUDA Fujio
金额：
$ 3.01万
依托单位：
KYOTO UNIVERSITY (1996)Osaka University (1995)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07454127/
关键词：
flume experiment grain size paleo-hydraulic condition deposits 地層

项目摘要

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!

已经提出了许多基于沉积物粒度组成的古水文条件估计方法。在这个研究项目中，我试图通过实验方法来阐明这一现象。运输引起的普遍尺寸分布不存在，相反，尺寸分布很大程度上取决于实验中使用的沙子的尺寸分布。通过使用“原始砂”的粒度分布对数据进行归一化，可以最好地证明各个传输模式的粒度分布与“原始砂”的质地之间的关系。实验数据归一化的结果表明，对于颗粒大小是否可以悬浮有相当严格的选择。但悬浮过程并不偏好可悬浮颗粒中的特定尺寸；即，悬浮负载中存在的各种尺寸的颗粒的比例与“原始沙子”中的比例相同。此外，沉积在水槽中的浊积岩显示出与正火获得的悬浮砂相同的尺寸模式。然而，即使通过短距离运输，崩塌和盐化的沙子也会改变其特有的粒度分布。总之，我们不能直接根据沉积物的粒度组成信息来估计古水文条件！