“泥河湾层”的古地磁学初步研究

自本世纪二十年代以来,中外的地质和古生物学者曾对桑干河谷两岸出露的所谓“泥河湾层”进行过不少工作。1954年我国地质界正式提出把“泥河湾层”划归早更新世,从此“泥河湾层”就成为我国华北地区这一时期的标准地层。

A PRELIMINARY PALEOMAGNETIC SURVEY OF THE NIHEWAN BED

Paleomagnetic method is used to date the Nihewan Bed, a type for Early pleistocene in North China. Accoring to the magnetic polarity zones the ages of three sections (Hong’ya, Xiaodukou and Hutouliang) have been evaluated as follows. Hong’ya section, disconformable with the underlying beds (the Hipparion red clay), may be lain down between 2.60-1.60 m.y.; the exposed bottom layer at Xiaodukou section may be formed about 3.00 m.y. ago, the lower part at Hutouliang section may be compared with the lower part at Xiaodukou, belonging to the Gauss Normal Epoch ending in 2.43 m.y. ago. Remebering that the basal Yuanmou Formation was formed approximately 3.12 m.y. ago, one should point out that all the above type sections of Early Pleistocene are older than 3.00 m.y., and that is worthy of notice to both geologists and paleoanthropologists.