分析长江三峡及其邻区第四纪气候特征及可能的影响因素。在前人研究基础上,通过对万州、奉节、巫山和宜昌等地第四纪地貌特征,以及保存在夷平面、阶地、扇三角洲和湖相沉积中沉积物特征的综合分析研究表明:①三峡在早更新世为温暖潮湿环境,在0.11 Ma B.P.左右发生气候转变,之后直至全新世为干燥寒冷环境;宜昌地区第四纪气候变化趋势与三峡地区相同。②三峡在早更新世到0.3 Ma B.P.以来,沉积记录主要显示为暖湿气候;在0.3 Ma B.P.以前,三峡基本不具备发育第四纪冰川的条件。导致三峡及宜昌地区在0.11 Ma B.P.左右发生明显的沉积物差异和气候变化的原因,与发生在0.15 Ma B.P.的青藏高原共和运动具有密切的关系。
英文摘要:
Comprehensive analysis of planation surfaces, terraces, fan deltas and lake sediments in the Three Gorges of the Yangtze River and its adjacent areas is carried out in order to study the characteristics and its affecting factors of Quaternary climate. It shows that it was warm and humid in the Early Pleistocene in the Three Gorges area and the climate changed in 0.11 Ma B.P. and became cold and dry until Holocene. It was warm and humid in the early Pleistocene in the Three Gorges area until 0.3 Ma B.P., so it is impossible for the development of Quaternary glaciers in the Three Gorges before 0.3 Ma B.P. The Gonghe Movement of Tibet in 0.15 Ma B.P. is considered to be responsible for the difference of sediments and change of climate in the Three Gorges and Yichang area in 0.11 Ma B.P.