The concept, characteristics and significance of fluvial fans

摘要

The concept and characteristics of fluvial fan are elucidated through literature review and case analysis. Firstly, the concept and terminology of fluvial fan are introduced. Secondly, the progress and controversy on the formation mechanism, analysis methods and sedimentary models of fluvial fan are elaborated, and fluvial fan is compared with alluvial fan, river and lacustrine delta. Finally, ten identification signs of the fluvial fan are proposed. It is found through the study that development and scale of fluvial fan are affected by external factors such as climate, tectonic, provenance and wind field. The facies and lithofacies association inside the fan are controlled by the activity of the internal channel. It is pointed that fluvial fans are widely distributed in the world not only today but also in the geological history. The occurrence of fluvial fan will change the traditional continental deposition system dominated by alluvial fan-river-lacustrine. Meanwhile, the research of fluvial fan will be of great significance in the fields of sedimentology and oil and gas exploration.