The transvaal sequence: an overview

An overview of the geology of the Transvaal Sequence and Bushveld Complex, South Africa

“…1). In general, the Transvaal strata dip at angles up to 20 ~ towards the centrally located Bushveld intrusives, but complex deformation of both units occurred along the Thabazimbi-Murchison lineament on the northern margin of the Transvaal basin and around the Vredefort dome in the south in post Bushveld times (Eriksson et al, 1993). Isolated "fragments" of Transvaal rocks within Bushveld intrusives are found at Rooiberg, Crocodile River, Dennilton, Marble Hall and Makeckaan (Fig.…”

“…','.'.','.'.'.-.'.'.'.'.'.'. '..2 Modified after Meyer and De Beer (1987), Eriksson et al (1991) and Von Gruenewaldt and Harmer (1993) (Button, 1986;Hartzer, 1987), or late-Pretoria to Rooiberg Group synsedimentary tectonism related to central basin thermal doming as Rooiberg lavas ascended through the crust (Eriksson et al, 1993). The Transvaal Sequence and the Bushveld Complex appear to have had an interrelated tectonic history.…”

“…The protobasinal phase of the Transvaal Sequence in the Transvaal basin is thought to reflect ca. 2600 Ma Ventersdorp-type rift-controlled sedimentation and volcanism (Cheney et al, 1990;Bosch, 1992;Eriksson et al, 1993). Subsequent thermal subsidence and reactivation of Ventersdorp Supergroup fault systems were probably responsible for the succeeding widespread chemical sedimentation which covered much of the Kaapvaal craton (Clendenin et al, 1988(Clendenin et al, , 1991Eriksson et al, 1993), and which is now preserved within the three structural basins, Transvaal, Griqualand West and Kanye.…”

“…2600 Ma Ventersdorp-type rift-controlled sedimentation and volcanism (Cheney et al, 1990;Bosch, 1992;Eriksson et al, 1993). Subsequent thermal subsidence and reactivation of Ventersdorp Supergroup fault systems were probably responsible for the succeeding widespread chemical sedimentation which covered much of the Kaapvaal craton (Clendenin et al, 1988(Clendenin et al, , 1991Eriksson et al, 1993), and which is now preserved within the three structural basins, Transvaal, Griqualand West and Kanye. Following a major hiatus in Transvaal deposition, the clastic sedimentary and volcanic rocks of the Pretoria Group and correlates were laid down within a rifted continental setting, possibly a half-graben environment (Eriksson et al, 1988;Eriksson and Clendenin, 1990;Eriksson et al, 1991).…”

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

“…This setting was also affected by relatively gentle regional shortening and folding of Transvaal sedimentary strata as the Eburnean supercontinent, which included the Kaapvaal craton, began to amalgamate . The post-Magaliesberg Formation sedimentary succession points to rapid uplift and tectonic instability related to major and rapid thermal doming as the Rooiberg magmas ascended through the crust (Eriksson et al, 1993Catuneanu and Eriksson, 1999). The uppermost Pretoria Group clastic depositional environment was thus disrupted by Rooiberg volcanism, with emplacement of extensive mafic to felsic lavas, and subordinate volcaniclastic strata and clastic sediments.…”