“北京人”化石产地洞穴堆积物的古地磁学研究

我国是世界上古人类化石和遗迹最丰富的国家之一,北京人化石产地周口店又是至今世界上人类化石发掘最为完整的一个地点。搞清北京人的堆积物的地质时代,对进一步了解人类发展的历史和第四纪地质年代学具有重要意义。1976年1月-4月期间,我们对周口店第一地点的洞穴主要堆积物进行了古地磁地层学的研究,对北京人的年代问题提出我们的粗浅认识,供有关方面讨论。

A PALAEOMAGNETIC STUDY ON THE CAVE-DEPOSITS OF ZHOUKOUDIAN (CHOUKOUTIAN), THE LOCALITY OF SINANTHROPUS

This paper gives the results of palaeomagnetic study on the main cave-deposits (the fourth to the tenth layers) of Zhoukoudian (Choukoutien), the locality of Sinan-thropus. The major conclusions are as follows.1. The remanence of 28 oriented samples were measured by a IAM-24 type astatic magnetometer. In order to remove the secondary magnetization, magnetic cleaning was done in a 150 Oe. A. C. field. Before and after the demagnetization all samples show normal polarity.2. By comparing the available data to the Geomagnetic Time Scale, it is suggested that the age of Sinanthropus is less than 0.69 m.y.3. The direction of remanence measured from these samples are: D, = 7°7′, Jr = 54°50′. The ancient north magnetic pole was located near 82°50′ N, 241°46′ E. Hence at the time of Sinanthropus existence Zhoukoudien was located at 35°21′ N latitude, much further south than that of to-day.