Study On The Steeped Landform In The Yangtze Gorges Area

The Yangtze River originates from north Tanggula of the Tibetan Plateau is one of the largest river in the world, the length is 6380km. The river flows eastward through three major China topographies, entering into the East China Sea. It is special note that the Yangtze Gorges, linking the upper rocky valley and the lower river channel on fluvial plain is located in the second transitional belt. So this Gorges area had been formed by intense episodic tectonic movement and river down-cutting. The transfixion of the Yangtze Gorges is a very important event in the history of the Yangtze evolution process. The early studies proposed that the timing of Yangtze River that thought the Three Gorges area occurred in the Tertiary period. In recent decades, many scholars tried to find the evidence of the Yangtze Gorges evolution with terrace or water system evolvement or the Flood-alluvial Fan in Jianghan basin. Especial, in recent years, the uplifting process of the Tibetan Plateau which is associated with the evolution of the Yellow River has been better understood. Although some geomorphologists tend to believe the linking-up ages of the Three Gorges ranging from 3.0 to 0.2 Ma B.P.. However, due to the congruence of the construct uplifting after the Yanshanian orogeny and humid climate at semi-tropical, the landform becomes very fragmentation and the earth soil erosion is acute.In this paper, by the way of description of large-scale topographic maps and field investigation by route, geomorphic mapping to typical region, author attempt to analyses the topographic surface feature and base on the lately dating, and timing and cause of the Yangtze Gorges.