New ca.1150 Ma paleomagnetic results of North China Craton (NCC) its paleogeographic and tectonic implications

Abstract

A new paleomagnetic study is carried out on the ca. 1150 Ma mafic dykes from the North China Craton (NCC). After stepwise thermal demagnetization, most samples yielded two components. The low-temperature component directs north and down with intermediate inclination, which is interpreted as a viscous remanent magnetization of the present magnetic field. The high-temperature component (HC) directs east and down with steep inclination. Positive baked-contact tests and a reversal test suggest the HC is primary. Combined with the relevant paleomagnetic data previously published (Hou et al., 2009; Wang et al., 2020), a new pole is calculated from more than thirty high-quality virtual geomagnetic poles. The pole has averaged out the paleo-secular variation and is different from any younger paleomagnetic poles of the NCC. The pole places the NCC in a mid-latitude region. Combined with the reported 1230-780 Ma paleomagnetic poles from NCC and Laurentia, the new results suggest the two continents assembled during ca. 1150–1110 Ma at high-latitude region. They then together moved to low-latitude region and merged with Amazonia, Baltica, Kalahari to become a part of Rodinia.