长江三峡大宁河流域三千年来沉积环境与河床演变初步研究

张家湾遗址T911剖面及双堰遗址T439剖面粒度、磁化率等环境替代指标的测试分析，并结合区域地质、地貌野外调查结果表明：大宁河流域3000年来气候演变过程与中国东部地区存在着较大差异，中国的东部地区在公元初至公元600年为寒冷期，而该区则为温暖期，笔者认为这是由于该区西北面与东南面均有高大山脉包围，这种特殊的地质地貌格局在一定程度上阻挡了来自北方冷空气进入本区的缘故。本区发掘的遗址多为单一时期的文化，其他时期的文化多以扰动层（即含有两个或两个以上历史时期文化遗物的沉积地层）的形式在沉积地层中出现，通过对沉积地层沉积物粒度，张家湾遗、大宁河河漫滩上的汉晋墓群、双堰塘遗址的相对位置及双堰塘生土层以下巨厚的鹅卵石层的比较分析，认为这与大宁河流域频繁发生的洪灾及河道变迁有关，大宁河频繁发生的洪灾及河道的变迁是影响该区人类生存环境的重要因素之一。

Study on sedimentary environment and riverbed evolution in 3000 years of Daning River

Particle size,magnetic susceptibility and geochemical measurement performed on samples together with local investigation on geology and geomorphology show that there exists a remarkable difference of evolution process between the studied region and east part of China in the past 3000 years.This is formed by the characteristics of the regional geomorphology.The northwest part and southeast part of this region are surrounded by high mountains and prevent the invasion of cold and arid wind from north.Excavation results show that most of the archaelolgical sites excavated are of single cultural perild. Other cultural periods are manifested by the disturbed layer,in which the relics of different cultural periods found.particle size analysis and investigation in-situ indicate that these phenomenon are the direct results of the frequent flood and frequent changes of river channel occurred to the Daning River,a tributary of Changjiang River, located at the upstream of the Three Gorges Proiect.