安比拉事件在中国存在的证据  

GEOLOGICAL EVIDENCE FOR THE PRESENCE OF THE EMPEROR EVENT IN CHINA

作　　者：葛同明[1] 樊利民[1] 刘坚[1] 

机构地区：[1]地质矿产部广州海洋地质调查局

出　　处：《地质学报》1992年第4期381-389,共9页Acta Geologica Sinica

摘　　要：黄土地层、珠江口盆地第四纪地层以及雷州半岛英利火山岩的古地磁学研究表明,布容极性时出现有反极性地磁场。英利火山岩的K—Ar同位素年代测定值为0.58±0.13Ma。据气候地层学和生物地层学资料确定,黄土地层和珠江口盆地第四纪地层的反极性层段的年代分别为0.45Ma和0.47—0.48Ma。这些反极性层段的年代相当于安比拉事件的年代。从中国不同地区、不同地层揭示的这一事件证实了安比拉事件为全球性极性倒转,并非极性漂移。安比拉事件的确定将为中、晚更新世地层的划分提供磁极性的依据。Palaeomagnetic study on Quaternary loess deposits in China, Quaternary strata in the Pearl River Mouth Basin and Cenozoic volcanic rocks on the Leizhou Peninsula indicates the presence of the reversal of the geomagnetic field in the Brunhes Chron. The magnetostratigraphic data of the loess deposits at three localities reveal that the samples of the strata showing the features of remanence of reversed polarity are located within the fifth loess layer (L_3). Polarity-reversed intervals of three boreholes in the Pearl River Mouth Basin lie within the layer below the 0.46 Ma LAD of the nannofossil P. locunosa. The K-Ar isotopic dating of polarity-reversed volcanic rocks in Yingli of the Leizhou Peninsula reveals an age of 0.56+0.13 Ma. With the help of climatostratigraphic and biostratigraphic data, the strata of reversed polarity of the loess deposits and Quaternary strata in the Pearl River Mouth Basin are determined to be 0.47—0.48 Ma in age according to the accumulation rate of the sediments, The above-mentioned similarity in age suggests the same reversal event equivalent to the age of the Emperor Event named by Ryan. This reversal event revealed in different regions, rocks and strata in China proves that the Emperor Event is a global event rather than polar wandering. The confirmation of the Emperor Event will permit a precise definition of Middle and Late Pleistocene strata.

关 键 词：布容极性时 安比拉事件 地磁学 

分 类 号：P318[天文地球—固体地球物理学]