Abstract:

The virtual geomagnetic poles (V. G. P) in Late Paleozoic for the Junggar block are not distinct obviously from those of the Tarim and the Kazakhstan blocks but the observed paleolatitudes close to the expected values calculated from paleopoles of Kazakhstan block. Therefore the Junggar and the Kazakhstan blocks were a coherent geotec-tonic unit in the Late Paleozoic. The paleomagenetic data show that the Junggar ocean in the Devonian was closed in late Carboniferous at Urlunqur River area. The tectonic evolution of Tarim and Kazakhstan blocks underwent an almost the same course as that of Siberian platform which is representative of eastern Laurasia. Siberian platform has moved northwestward from lower to higher latitudes from Late Paleozoic to early Meso-zoic and migrated southeastward since Jurassic.

Key words: Junggar block, Paleomagnetism, Laurasia, Tectonic evolution

摘要：

新疆准噶尔二台地区晚古生代古极点位置与塔里木、哈萨克斯坦地块同时代极点位置无显著差别。实测古纬度更接近于用哈萨克斯坦极点计算得到的预期古纬度。因此,晚古生代准噶尔地块与哈萨克斯坦地块已是统一的整体。泥盆纪准噶尔地块内的准噶尔洋盆于晚石炭世闭合于乌伦古河一带。西伯利亚板块、塔里木、哈萨克斯坦地块等组成东部劳亚大陆的块体,尽管其运动演化有所差异,但都遵循了以西伯利亚板块为主体大致相同的总的运动演化过程,即晚古生代至中生代早期,由低纬度向高纬度的NW向运动和侏罗纪以来的SEE向运动。

关键词: 准噶尔地块, 古地磁, 劳亚大陆, 构造演化