Paleomagnetic Constraints From 925 Ma Mafic Dykes in North China and Brazil: Implications for the Paleogeography of Rodinia

Hu，Yuyang1,2; Zhao，Xixi3; Peng，Peng4; Yang，Fengli1,2; D'Agrella-Filho，Manoel S.5; Chen，Weiwei1,2; Xu，Mingchen1,2

2022-09-01

10.1029/2022JB025079

JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH   Impact Factor & Quartile

2169-9313

2169-9356

Coeval Neoproterozoic mafic dykes with a well-constrained isotopic age of 925 Ma are distributed in the North China Craton (NCC) of China and São Francisco Craton (SFC) of Brazil. Several recent studies favor the hypothesis that these two cratons were connected during 925 Ma and constituted building cratons for the supercontinent Rodinia. However, the paleo-positions of the two cratons in Rodinia have not yet been paleomagnetically resolved. This paper presents the paleomagnetic results of these dykes in both NCC and SFC. Detailed thermal and alternating-field demagnetization revealed that these dykes record stable components of magnetization with unblocking temperatures below the Curie temperature of magnetite. Rock magnetic results and scanning electron microscope analysis further confirm that the major magnetic minerals in dyke samples are pseudo-single domain titanomagnetites. The mean directions of the characteristic remanent magnetization (ChRM) of the dykes are distinct from those of rocks of different ages in the sampling localities, and are supported by positive baked contact tests, indicating primary remanent magnetization. The ChRM of the SFC dykes also exhibits dual polarity. Our results suggest that the NCC and SFC were in the moderate to high paleolatitudes of the Southern Hemisphere during approximately 925 Ma, suggesting a possible paleogeographic connection between the two cratons. A new paleogeographic reconstruction of both cratons during 925 Ma is proposed, which is supported by other geological evidence.

mafic dykes North China Craton Paleomagnetism Rodinia supercontinent São Francisco Craton

SCI

English

NI Journal Papers

Corresponding

National Natural Science Foundation of China[41890833];National Natural Science Foundation of China[No. 41874076];National Natural Science Foundation of China[No. 92158207];

WOS:000861868500001

GEOSCIENCES

2-s2.0-85139149854

Scopus

1.School of Ocean and Earth Science,Tongji University,Shanghai,China
2.State Key Laboratory of Marine Geology,Tongji University,Shanghai,China
3.Department of Ocean Science and Engineering,Southern University of Science and Technology,Shenzhen,China
4.Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing,China
5.Instituto de Astronomia,Geofísica e Ciências Atmosféricas,Universidade de São Paulo,São Paulo,Brazil

Hu，Yuyang,Zhao，Xixi,Peng，Peng,et al. Paleomagnetic Constraints From 925 Ma Mafic Dykes in North China and Brazil: Implications for the Paleogeography of Rodinia[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2022,127(9).

Hu，Yuyang.,Zhao，Xixi.,Peng，Peng.,Yang，Fengli.,D'Agrella-Filho，Manoel S..,...&Xu，Mingchen.(2022).Paleomagnetic Constraints From 925 Ma Mafic Dykes in North China and Brazil: Implications for the Paleogeography of Rodinia.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,127(9).

Hu，Yuyang,et al."Paleomagnetic Constraints From 925 Ma Mafic Dykes in North China and Brazil: Implications for the Paleogeography of Rodinia".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 127.9(2022).