从晋北地区地貌演化看桑干河的古流向

The Ancient Flow Direction of Sanggan River in the Landform Evolution for Northern Shanxi Province

第三纪 ,恒山 -小五台山、管涔山和坝缘山地逐渐隆起。源于该山地的桑干河、洋河等河流全部汇入洋河谷地中。第四纪 ,大同 -阳原等盆地形成 ,逐渐吸引桑干河等河流向东流入该盆地。洋河仍循原河道。始成现在的水系格局。

Mt. Heng-Xiaowutai, Mt. Guancen and the southern edge mountainous land of Inner Mongol Plateau upheaved gradually in the Tertiary Period. Sanggan River and Yang River and other ones originating from the mountainous land all flew together into the Valley of Yang River. During the Quaternary period, Datong-Yangyuan basin and other basins had been formed, which gradually attracted the River System of Sanggan River to flow eastwards into this basin, while Yang River followed former river course again. The present pattern of the river system had been formed.