关键词: 平流沉积物, 古洪水, 年代分析, 大比降河段, 高山峡谷

Abstract:

To advance the ancient flood research and enrich the research results, taking a river reach with high gradient ratio in canyon region as the object of study, we carried out field survey and laboratory analysis on the slack water deposits of ancient flood. It was found that the sedimentary environment include the backwater zone of the tributaries, rock niches and so on; the sedimentary particles are coarser than usual; the heavy minerals are more prone to be affected by the local concentrated mineral; the coarser granular mainly contains sand without clay and is well sorted; the fine particles only settle in rock niches; the age analysis illustrates that the effective carbon is easily affected by the surrounding environment. The research results provide some reference for the research of the slack water deposits and the improvement of ancient flood identification.

Key words: slack water deposits ;ancient flood , age analysis, river reach of high gradient ratio, canyon