A chronostratigraphic framework for the north-central Kaapvaal craton, the Bushveld Complex and the Vredefort structure

Structural analysis of the collar of the Vredefort Dome, South Africa—Significance for impact‐related deformation and central uplift formation

“…These supracrustal rocks range in age from 3.07 Ga to ∼2.1 Ga (Armstrong et al 1991) and comprise two volcanic sequences (the 3.07 Ga Dominion group and the 2.71 Ga Ventersdorp supergroup) intercalated with two major sedimentary sequences (the 2.9-2.71 Ga Witwatersrand supergroup and the 2.6-2.1 Ga Transvaal supergroup). In addition to several small alkali granite intrusions, mafic and ultramafic sills associated with the extrusive 2.71 Ga Ventersdorp event (Pybus 1995;Reimold et al 2000) and the intrusive 2.06 Ga (Walraven et al 1990) Bushveld magmatic event occur in the collar rocks.…”

Volcanism of the Palaeoproterozoic Bushveld Large Igneous Province: The Rooiberg Group, Kaapvaal Craton, South Africa

“…The majority of isotopic ages (single-grain zircon Pb-evaporation) determined from samples of the Rooiberg Group and the Bushveld Complex range from 2061±2 to 2052±48 Ma (Table 1) (e.g., Walraven et al, 1987Walraven et al, , 1990Walraven, 1997;Buick et al, 2001). More recently, Buchanan et al (2004) determined Rb-Sr ages of 2071+94/-65 Ma for the Dullstroom and Damwal Formations.…”

New techniques for estimation of source parameters: Applications to airborne gravity and pseudo-gravity gradient tensors

“…In the collar rocks, they are concentric with widths greater than 50 m and lengths about 10 km (Grieve and Therriault, 2000). Walraven et al (1990) estimated the age of these granophyre dikes at 2.016±0.024 Ga. Kamo et al (1996) dated the impact event at 2.023±0.004 Ga based on the estimated age of pseudotachylite in the core region. Stepto (1990) subdivided the Archean basement into three concentrical units; an inner zone of granulite facies mafic and felsic gneisses, known as Inlandsee Leucogranofels (ILG), an outer amphibolite facies granitoids composed of granite, granodiorites, tonalities and adamellites, known as Outer Granite Gneiss (OGG) and finally Steynskraal Formation (SF).…”