青藏高原晚新生代磁性地层研究

STUDY ON MAGNETOSTRATIGRAPHY IN QINGHAI-TIBETAN PLATEAU IN LATE CENOZOIC

本文较详细的论述了青藏高原晚新生代晚期的２０多个地层剖面或钻孔的磁性地层极性期，得出了一批地层年代数据。如昆仑山口羌塘组为３．１ＭａＢＰ～０．６５ＭａＢＰ，在该组中发现的三趾马化石为２．０８ＭａＢＰ；定日县贡巴组为２．３ＭａＢＰ～１．９ＭａＢＰ；札达盆地札达组和香孜组为６．１５ＭａＢＰ～３．４ＭａＢＰ，３．４ＭａＢＰ～１．２５ＭａＢＰ；理塘甲洼组为１．２４ＭａＢＰ～０．４３ＭａＢＰ，还得出吉隆三趾马化石年代约为５．０ＭａＢＰ及第四纪早冰期年代，为研究青藏高原隆升的时间、幅度和古环境的变化提供年代学的尺度。

In this paper,the polarity epochs of some twenty and more sections or boreholes in Qinghai Tibetan plateau in Late Cenozoic are discussed in detail,and thence we have the ages of the sediments involved. The Qiangtang Formation at Kunlun pass has an age of 3 1MaBP^0 65MaBP, the Hipperion sp. contained in it being of an age of 2 08MaBP.The Gongba Formation at Dingri county 2 31MaBP^1 90MaBP,the Zhada Formation and Xiangzi Formation in the Zhada Basin 6 15MaBP^3 40MaBP and 3 40MaBP^1 25MaBP respectively, and Jiawa Formation at Litang 1 24MaBP^0 43MaBP. And the age for the Hipperion guizhongensis sp. from Jilong is 5 0MaBP. The age of early Quaternary glaciation is obtained as well. Thus a chronological scale is provided for the study of the time,and rate of the uplifting of the Plateau as well as the consequent environmental changes.