SOME PALEOMAGNETIC RESULTS ON NORTH CHINA, QINLING AND YANGTZE BLOCKS
Liu Yuyan Yang Weiran (China University of Geosciences,Wuhan 430074) Morinaga Hayao (Himeji Institute of Technology ,Japan 671-22) Adachi Yasuhisa Yaskawa Katsumi (Osaka College,Japan) (Kobe University ,Japan 657) Yang Zhihua (Xi' an College of Geology ,Xi' an 710054)
This paper describes paleomagnetism of 474 specimens from 70 sites in North China Block ,Qinling Orogenic Belt and Yangtze Block. We isolated primary magnetic components from 112 specimens of 16 sites and obtained apparent polar wonder paths (APWP) and variations in paleomagnetic declinations and paleolatitudes of the three zones since the Cambrian. As the result, we demonstrate the following conclusions : ( 1 )The three zones were situated in the present order from the geographic north since the Cambrian : North China Block ,Qinling Orogenic Belt and Yangtze Block ;(2)In the Cambrian period,there was a paleo-ocean on both the northern and the southern sides of paleo-Qinling terrane; (3)At the time,North China Block was situated about 1 060km away in the north from Yangtze Block ; (4 )The three zones moved to the north with tectonic rotation since the Cambrian and were fused together during a period between the Triassic and the Cretaceous.