A Palaeomagnetic Investigation of the Neoarchean Pongola Supergroup, South Africa

Chris J. Rowan¹, Nicholas J. Beukes¹, J. Gutzmer¹, and David Evans^2
1Palaeoproterozoic Mineralisation Research Group, Department of Geology, University of Johannesburg, Johannesburg, South Africa
²Yale University, New Haven, CT

Late Archean (~3.0-2.8 Ga) sediments and lavas of the Pongola Supergroup in South Africa represent one of the oldest-known cratonic cover sequences, and also contain diamictites that may represent the earliest recorded glaciations of the Earth’s surface. Despite their age, these sequences have been subjected to only mild deformation and thermal metamorphism. Preliminary paleomagnetic results from these rocks indicate that, in contrast to the correlative Witwatersrand Supergroup, strong thermal overprinting has not completely destroyed an early paleomagnetic signal, which indicates that the Kaapvaal Craton was located at moderate to high paleolatitudes for most of the NeoArchean. We aim to definitively establish the existence of a primary remanence and construct a well-constrained apparent polar wander path for the Kaapvaal Craton, which would which would provide important insights into the character of tectonic processes on the early Earth.

AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery