中朝地块与扬子地块在古生代晚期是太平洋古陆的一部分

<正> 目前有愈来愈多的证据表明在环太平洋周边地区存在大小不同的地块,有人研究发现这些地块在古生代晚期—早中生代时,均处于赤道附近的低纬度地带。笔者与马醒华于1980—1981年期间曾同澳大利亚学者合作,共同对中朝地块的山西太原地区及扬子地块的四川峨眉山地区的晚古生代—早中生代的古地磁进行研究。结果表明两地块在二叠纪晚期也是处于赤道附近的低纬度地带,从而在环太平洋的周边又找到一个太平洋古陆碎块的证据。

SINO-KOREAN BLOCK AND YANGTZE BLOCK AS PART OF THE PACIFICA CONTINENT IN THE LATE PALEOZOIC

The paleo-continents and oceans of the Late Paleozoic are traditionally reconstructed into two continents called Laurasia and Gondwana. The concept of the Pacifica continent was suggested by A. Nur (1978) and he believes that as part of Pangea it connected with the eastern part of Gandwana.The author accepts the term Pacifica continent, but has different opinions on its location and breakup model. During the Late Paleozoic, there existed three Palaeocontinents i. e., Laurasia in the north, Gondwana in the south and Pacifica in the centre.The Pacifica continent was situated near the equator in the west Pacific ocean. We can identify that areas around the Pacific ocean were within the low latitude belt based not only on a lot of paleo-magnetic data of these regions but also the distribution of biota.The Sino-Korean and Yangtze blocks were located in the low latitude belt near the equator as part of the Pacifica continent during the Late Paleozoic. From the, Triassic period, they drifted towards the north and during the Late Triassic-Early Jurassic (i. e. the Indo-Sinian movement) collided with the Siberian block along the central Asian-Mongolian fold system and the Qinling fold system as well.