NORTH CHINA CRATON: THE CONJUGATE MARGIN FOR NORTHWESTERN LAURENTIA IN RODINIA

The position of the North China Craton (NCC) in Rodinia is still ambiguous. In this study, new paleomagnetic results have been attained from fifteen ~775 Ma mafic dikes in eastern Hebei Province, NCC. Complete stepwise thermal demagnetization revealed two components from the samples. The low temperature component was determined below 400 ºC, and could be a viscous remanent magnetization. The high temperature component (HC) has unblocking temperatures up to 580 ºC, which is directed northeast or southwest with shallow inclinations. The primary origin of the HC is bolstered by a reversal test and indications of a positive baked-contact test. The paleomagnetic pole is determined by averaging the 15 virtual geomagnetic poles from each dike, located in the western Pacific region. It is not similar to any published younger poles of the NCC and considered as a key pole. The new ~775 Ma pole places the NCC in an equatorial region. Matching the late Mesoproterozoic to early Neoproterozoic (~1110-775 Ma) apparent polar wander paths of the NCC and Laurentia suggests that the NCC and the western Laurentia could have a long-lived connection in Rodinia.