New Palaeoproterozoic palaeomagnetic data from the Kaapvaal Craton, South Africa
Shawn Letts, Trond H. Torsvik, Susan J. Webb, Lewis D. Ashwal, 2011. "New Palaeoproterozoic palaeomagnetic data from the Kaapvaal Craton, South Africa", The Formation and Evolution of Africa: A Synopsis of 3.8 Ga of Earth History, D. J. J. Van Hinsbergen, S. J. H. Buiter, T. H. Torsvik, C. Gaina, S. J. Webb
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Palaeomagnetic data from the well-dated 2060.6±0.5 Ma Phalaborwa Complex in South Africa (Kaapvaal Craton) are of excellent quality. High unblocking components are carried by magnetite and single polarity remanence directions (mean declination 5.0°, inclination 57.3°, α95 = 5.2°) yield a palaeomagnetic pole (latitude 27.7°N, longitude 35.8°E, A95 = 6.6°) that overlaps with existing poles from the near coeval 2054.4±1.3 Ma Bushveld Complex. The Phalaborwa and Bushveld complex poles, along with poles from the well-dated Vredefort impact (2023±4 Ma) and Post-Waterberg Dolerites (1874.6±3.9 Ma), define the most reliable poles for the Kaapvaal Craton during this time interval (c. 2060–1875 Ma) and witness low rates of Mid-Palaeoproterozoic apparent polar wander. Poorly dated NE–NNE-trending dyke swarms that intrude the Phalaborwa and Bushveld complexes both yield dual-polarity remanence components that share a common mean at the 95% confidence level. Primary palaeomagnetic poles (Phalaborwa dykes pole latitude 7.6°, longitude 12.1°, A95 = 11.8°; Bushveld dykes pole latitude 12.6°, longitude 24.1°, A95 = 10.8°) suggest that they are of the same age as the Post-Waterberg dolerites (c. 1875 Ma). They could also be as old as the Phalaborwa and Bushveld Complexes, however; high-precision geochronology is required to resolve this issue and to enlarge the number of Palaeoproterozoic key poles for the Kaapvaal Craton.