2013 Fiscal Year Final Research Report
Supercritical flow sedimentation of flash floods and its preservation potential in rock records
| Project/Area Number |
21540474
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Geology
|
|---|
| Research Institution | Osaka City University |
|---|
Principal Investigator |
MAEJIMA Wataru 大阪市立大学, 理学(系)研究科(研究院), 教授 (20173700)
|
|---|
| Project Period (FY) |
2009-04-01 – 2014-03-31
|
| Keywords | 射流 / 反砂堆 / 堆積作用 / 堆積環境 / 堆積構造 / 堆積相 / シート洪水流 |
|---|
| Research Abstract |
Studies of several sedimentary successions revealed that records of supercritical flow sedimentation are well preserved in flash flood deposits. The form of internal stratification of supercritical flow deposits shows wide variability, especially in its amplitude/wave length ratio. This variability in stratification is attributed to the morphological differences in antidune bedforms. The flume experiments show the amplitude/wave length ratio of antidunes is dependent with flow depths; shallower the flow depth, higher the amplitude/wave length ratio. Comparison of forms of internal stratification of in-channel flood deposits and sheet flood deposits in the Neogene Kunimi Formation revealed that the values of amplitude/wave length ratio of anidunes in the latter are consistently larger than the values in the former. This result is compatible with the results of the flume experiments.
|
