Paleomagnetism and chronology of B-1 marginal sills of the Bushveld Complex from the eastern Kaapvaal Craton, South Africa
AbstractThe Rustenburg Layered Suite (RLS) of the Bushveld Complex in South Africa is the largest mafic–ultramafic-layered complex on Earth. The RLS is associated with marginal sills that penetrate into the ~2.2 billion-year-old sedimentary strata of the Pretoria Group. These sills are in contact and share some geochemical similarities with different zones of RLS and are classified in terms of chemical composition, which suggests their derivation from distinct parental magma compositions (so-called B-1, B-2 and B-3 parental magmas). Existing paleomagnetic constraints for the Bushveld Complex originate from the upper Critical to Upper zones of the RLS, which are associated with B-2 and B-3 marginal sills. Geochemically, verified B-1 marginal intrusions are here used as a proxy for constraining the paleomagnetism and chronology of the Lower and lower Critical zones of the RLS. We identified a dual-polarity magnetic component with a paleopole (Latitude = 13.1°N, Longitude = 44.0°E, A95 = 14.3, N = 7) that is...