| My paleomagnetic research has concentrated on studying the accretionary history and tectonic evolution of Permian Tethys in Northwest China, within the global continental context of Pangaea. Accretionary ages of terranes in Northwest China become younger from north to south. The Altay Terrane forms an early Paleozoic accretionary complex around the Siberian Craton in the north, whereas the accretion of the Tarim Terrane took place during Permian times in the south. Lottes and Rowley (1990) critically evaluated continental reconstructions, and conclude that an Early Jurassic assembly of Pangaea, based upon sea floor spreading data, is appropriate for Permian times as well. The northern continents of Laurasia within the Pangaean reconstruction were separated from the southern continents of Gondwana by the Tethyan Ocean.;New Permian and Late Carboniferous paleomagnetic results from the Tarim, Junggar and Yili Terranes of Northwest China allow for terrane paleogeographic reconstructions within this Tethyan domain. Shallow Late Carboniferous magnetic inclinations, and Cathaysian Province coral fauna may place the Yili Terrane in tropical latitudes, perhaps as an integral part of northernmost Gondwana. Angaran Province flora, and steep paleomagnetic inclinations recorded in Late Permian foreland lacustrine sediments of South Junggar, however, suggest an affinity of the Junggar Terrane with Laurasia. The calc-alkaline volcanic arc complex of the Borohoro-Bogda Mountains along the southern margin of the Junggar Basin most likely marked the south, active boundary of Permian Laurasia, beneath which Tethyan oceanic lithosphere subducted. An Early Permian collision of the Tarim Terrane with Junggar is suggested by paleomagnetic directions from Lower Permian sediments and volcanics, which impose a latitudinal proximity of Northwest Tarim with South Junggar.;Post-Permian relative motions between terranes presently comprising most of Eurasia are substantial, and are well documented in the paleomagnetic record. Northward demise of Tethyan oceanic lithosphere through subduction zones transported Cathaysian tectonic elements such as Tarim and Yili from south to north. With each successive continental collision, subduction of Tethyan oceanic lithosphere migrated south. Ancestral suture zones and bounding faults have been rejuvenated through most of the Mesozoic and Cenozoic with each additional terrane accretion, culminating in the collision of the Indian Continent during Tertiary times. |
