LATE PALEOZOIC PALEOMAGNETISM AND TECTONIC IMPLICATION FOR NORTHEAST JUNGGAR BLOCK, XINJIANG UYGUR AUTONOMOUS REGION, CHINA

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.