巴彦淖尔国家地质公园汉代黄河古河道与临戎古城位置的考证

Research on the Location of Palaeo Channel of the Yellow River and the Linrong Ancient City in Han Dynasty in Bayannur National Geopark

黄河流域古河道的变迁对文化遗址形成的影响,是黄河文化研究的重要科学问题之一。内蒙古巴彦淖尔国家地质公园位于黄河中上游的河套盆地,公园内汉代临戎古城遗址的位置一直存在争论,确定黄河古河道与其相对位置关系是关键。通过对临戎古城遗址周边10 km范围进行网格化槽型钻取心,利用钻孔数据构建三维粒度属性模型与沉积结构模型,对隐伏的古河道位置进行了较为精准地确定;并通过钻孔岩心沉积相分析与年代学测试,对古河道的沉积结构与年代进行了验证。结果表明,临戎古城遗址西3 km处存在(2.39±0.24) ka~(1.36±0.05) Cal ka BP的黄河古河道,自南向北流经临戎城西。以此确定的黄河与朔方郡各属县治城的相对位置符合史料的记载。本研究从沉积学角度为巴彦淖尔国家地质公园临戎古城遗址位置的考证提供了地质科学依据。

The influence of the changes of ancient river channel on the cultural sites in the Yellow River Basin is one of the important scientific issues in the study of the Yellow River culture.Bayannur National Geopark in Inner Mongolia is located in the Hetao Plain in the middle and upper reaches of the Yellow River.The location of the Linrong ancient city in the park has been debated for decades.The relative position of the ancient Yellow River channel to the Linrong ancient city is a key to locate the ancient city.The grid groove drilling was carried out within 10 km around the Linrong ancient city in Bayannur National Geopark.Three-dimensional grain size model and sedimentary structure model were constructed to visualize the hidden ancient channel based on the borehole data.Then the structure and age of the ancient channel are verified through analyzing the sedimentary facies of the drilled cores and by the chronology data.The results show that the ancient Yellow River channel which flow from south to north from 2.39±0.24 ka to 1.36±0.05 Cal ka BP is located 3 km to the west of Linrong ancient city in Bayannur National Geopark.The relative position of ancient Yellow River and the towns in Shuofang County are consistent with the historical documentation.This study provides geological evidence for locating the Linrong ancient city in Bayannur National Geopark based on the study of sedimentology.