Please cite this article in press as: Pisarevsky, S.A., et al., Paleomagnetism and U–Pb age of the 2.4 Ga Erayinia mafic dykes in the south-western Yilgarn, Western Australia: Paleogeographic and geodynamic implications. Precambrian Res. (2014), http://dx.doi.org/10.1016/j.precamres.2014.05.023 ARTICLE IN PRESS G Model PRECAM-4000; No. of Pages 10 Precambrian Research xxx (2014) xxx–xxx Contents lists available at ScienceDirect Precambrian Research jo ur nal homep ag e: www.elsevier.com/locate/precamres Paleomagnetism and U–Pb age of the 2.4 Ga Erayinia mafic dykes in the south-western Yilgarn, Western Australia: Paleogeographic and geodynamic implications Sergei A. Pisarevsky a,b,c,∗ , Bert De Waele c,d , Sarah Jones e , Ulf Söderlund f,g , Richard E. Ernst h,i,j a Australian Research Council Centre of Excellence for Core to Crust Fluid Systems (CCFS), Australia b The Institute for Geoscience Research (TIGeR), Department of Applied Geology, Curtin University, GPO Box U1987, Perth, WA 6845, Australia c School of Earth and Environment, University of Western Australia, Crawley, WA 6009, Australia d SRK Consulting (Australasia) Pty Ltd., P.O. Box 943, West Perth, WA 6872, Australia e St Barbara Limited, PO Box 1161, West Perth, WA 6872, Australia f Department of Geology, Lund University, Sölvegatan 12, 223 62 Lund, Sweden g Laboratory for Isotope Geology, Swedish Museum of Natural History, Box 50 007, SE-104 05 Stockholm, Sweden h Department of Earth Sciences, Carleton University, Ottawa K1S5B6, Canada i Ernst Geosciences, 43 Margrave Avenue, Ottawa K1T3Y2, Canada j Faculty of Geology and Geography, Tomsk State University, 36 Lenin Avenue, Tomsk 634050, Russia a r t i c l e i n f o Article history: Received 3 February 2014 Received in revised form 18 May 2014 Accepted 28 May 2014 Available online xxx Keywords: Paleomagnetism U–Pb TIMs age Paleoproterozoic Yilgarn Craton Mafic dykes Supercontinent a b s t r a c t We present results from a paleomagnetic study of the previously undated Erayinia dykes intruding the south-western Yilgarn Craton. The U–Pb TIMs baddeleyite age of these dykes is now 2401 ± 1 Ma, which is about 10 m.y. younger than the 2418–2410 Ma Widgiemooltha dyke swarm. The paleomagnetic study isolated a stable primary remanence with steep downward direction, and the paleomagnetic pole (22.7 ◦ S, 150.5 ◦ E, A 95 = 11.4 ◦ ) is similar, but not identical to that of the previously studied Widgiemooltha dykes. We interpret this difference as the result of the movement of the Yilgarn Craton toward the pole at ∼1 ◦ /m.y. angular speed, which is comparable with tectonic plates’ velocities during the Phanerozoic. Paleomagnetic polarities of Widgiemooltha and Erayinia dykes suggest that at least one geomagnetic reversal occurred between these two magmatic events. The estimated amplitude of geomagnetic secular variations at c. 2400 Ma is slightly higher than predicted by the existing models for the last 5 m.y. at the c. 64 ◦ latitude. The paleomagnetic data and patterns of c. 2.6–2.1 Ga mafic dyke swarms permit the recently suggested reconstruction of the Paleoproterozoic supercontinent. © 2014 Published by Elsevier B.V. 1. Introduction The popular hypothesis of supercontinental cycles (e.g. Condie and Aster, 2010; Nance and Murphy, 2013 and references therein) predicts the assembly of a supercontinent in Siderian time (2.5–2.3 Ga). This supercontinent is usually called Kenorland (Williams et al., 1991), but Bleeker (2003) suggested the existence of the Sclavia supercraton, while another supercraton, Superia, which included the Superior, Karelia and Hearne cratons, has been postulated by Bleeker and Ernst (2006). Söderlund et al. (2010) ∗ Corresponding author at: School of Earth and Environment, University of Western Australia, Crawley, WA 6009, Australia. Tel.: +61 8 6488 5076. E-mail addresses: Sergei.Pisarevsky@uwa.edu.au, Sergei.Pisarevskiy@curtin.edu.au (S.A. Pisarevsky). provided some evidence that the Zimbabwe and Yilgarn cratons could also have formed part of Superia. On the other hand, Condie et al. (2009) demonstrated that the global distribution of U–Pb ages of subduction-related granitoids and of detrital zircon sug- gest slowing down or even cessation of the plate tectonics between 2.45 and 2.20 Ga. If true, this would be inconsistent with the formation of a supercontinent during the Siderian time. As pale- omagnetism is the only method for quantitatively formulating and verifying pre-Mesozoic continental reconstructions, and the only tool for analysing the ancient geomagnetic field, any new paleo- magnetic data from well-dated Siderian rocks provide important clues for a better understanding of the abovementioned models. However, Early Proterozoic paleomagnetic data are scarce. Evans and Pisarevsky (2008) included only five reliable 2500–2300 Ma paleomagnetic poles from four cratons (Dharwar, Karelia, Yilgarn and Superior) into their synthesis. http://dx.doi.org/10.1016/j.precamres.2014.05.023 0301-9268/© 2014 Published by Elsevier B.V.