The assembly of North China Craton (NCC) and Laurentia in the late Mesoproterozoic, and its implication for the formation of Rodinia

A new paleomagnetic study is carried out on ca. 1150 Ma mafic dykes from Shandong Province in the North China Craton (NCC). After stepwise thermal demagnetization, most samples from the dikes yielded consistent high-temperature component (HC). The primary origin of the HC is bolstered by positive baked-contact tests and a reversal test. A paleomagnetic pole calculated from 30 virtual geomagnetic poles is located between the ca. 1220 Ma pole and the pole from the ca. 1110 Ma lower Nanfen formation, and is different from any younger poles of the NCC; it is considered as a key pole of ca. 1150 Ma for the NCC. The new ca. 1150 Ma pole places the NCC in a moderate paleolatitudinal region. The new pole and the reported late Mesoproterozoic to early Neoproterozoic poles of NCC and Laurentia (Swanson-Hysell et al., 2019; Ding et al., 2021) suggest the two continents became an integrated landmass during ca. 11501110 Ma. A late Mesoproterozoic semi-supercontinent including the NCC, Laurentia, Siberia and Australia is proposed. The semi-supercontinent then assembled with Baltica, Amazonia, Kalahari, and other continents to form Rodinia. Reference Swanson-Hysell, N.L., Ramezani, J., Fairchild, L.M., and Rose, I.R., 2019, Failed rifting and fast drifting: Midcontinent Rift development, Laurentias rapid motion and the driver of Grenvillian orogenesis: Geological Society of America Bulletin, v. 131, p. 913940. Ding, J.K., Zhang, S.H., Evans, D.A.D., Yang, T.S., Li, H.Y., Wu, H.C., and Chen, J.P., 2021, North China craton: The conjugate margin for northwestern Laurentia in Rodinia: Geology, v. 49, p. 773778.