Tectonic Implications of Paleomagnetic Results From Upper Silurian Series Along the Hexi Corridor, Gansu, China

<正> Characteristic directions of remanent magnetization of 38 samples from Upper Silurian Series （Hanxia Formation） along the Hexi Corridor passed fold test at a 99% confidence level. The corresponding paleopole is located at 45.1°N, 5.5°E (A95= 4.7°, κ=25.1), close to the Late Permian pole for this area (41.4°N, 358.6°E; A95= 4.3°, κ=26.6). However, there appears an obvious difference between paleolatitudes for these two stages （6°±）. Based on paleomagnetic data, it can be deduced that the Hexi Corridor had probably been the western extension of the North China Block by the time of Late Silurian and kept being tectonically mobile compared with the principal parts of the North China Block. In addition, paleomagnetic data reveal that the Hexi Corridor experienced a southward displacement of about 600 km during the Late Paleozoic Era.