The Origin Of Quaternary Deposit And Its Environmental Significance In Three Gorges Of The Yangtze River

Since the beginning of the Quaternary, with the uplift of Tibetan Plateau, the Asian monsoon was established and became the controlling factor of the climate and environmental change of China. Quaternary loess deposit of China is brought by wind force from the origin area to the deposit area in the arid climate condition. Its origin area is the northern China where is becoming drought caused by Tibetan Plateau uplift. The Asian monsoon, which were caused by the uplift of the Tibet Plateau, brought the dust to the depositional area. In another word, Quaternary loess deposit perfectly embodied Tibetan Plateau uplift and Asian monsoon system evolution. Therefore the loess research is the very important key to know the China climate and environment past, now and future. There have 46% national territory in China under the influence of Asian monsoon system, and this area is the gravity of economy, culture and politics of China. So the loess research not only has the profound significance to the climate and environment of China, also relate to the development of the economy, society and culture of China directly. Furthermore, the recent research proved the information that the eolian loess of China contained is in accordance with the deep-sea deposit research and the ice-core record. So the eolian loess deposit of China also have the significant meaning of the globle change research.In this paper, our research site is Wushan county, which is located at the Three Gorges of the Yangtze River. We collected hundreds of bulk samples from five sections of which 3 were from the Wangtianping mountain and 2 from the banks of Yangtze River respectively. We defined them as Wangtianping-1, 2, 3 section and Jiangbian-1, 2 section. Throngh the grain-size analysis of these samples, we find the grain-size of Wangtianping-1, 2 section concentrated in 4-16 μm and the Jiangbian-1,...