These lavas form the bottom layer of the ventersdorp supergroup. A late archean layer rich in sandsized spherules of former silicate melt in the monteville formation transvaal supergroup, south africa has ir concentrations as high as 6. Lowlatitude glaciation in the palaeoproterozoic era nature. Griqualand west sequence of the transvaal supergroup were investigated by beukes 1980, 1983, who introduced a new stratigraphic subdivision, based mainly on borehole core data. The name transvaal refers to the provinces geographical location to the north of the vaal river. The sequence is preserved in areas historically known as the transvaal basin in the central kaapvaal craton, and the griqualand west basin in the western part of the craton fig. The lower part of the supergroup was named ghaap group and subdivided into the schmidtsdrif, campbellrand, asbesheuwels, and koegas subgroups beukes, 1983. The transvaal supergroup south africa records evidence of trace oxygen production in late neoarchaean strata, approximately 200 million years before the great oxidation event goe which is recorded within the palaeoproterozoic duitschland formation. Although ventersdorp supergroup rocks were encountered in drill holes, the full distribution of these rocks is uncertain due to their weak geophysical. Jones, journaljournal of the south african institute of mining and metallurgy, year2018, volume118, pages671680 m. The prekaroo geology of the southern portion of the.
Apr 27, 2020 transvaal, former province of south africa. General stratigraphy of the transvaal supergroup and the bushveld complex the bushveld complex comprises the voluminous, bimodal intrusive magmas of mafic and felsic characteristics into predating transvaal supergroup sediments and rooiberg group volcanics. The angular unconformity below the ventersdorp supergroup represents a major time gap across the kaapvaal craton. Geology of the palaeoproterozoic daspoort formation. This thesis examines the geology of the daspoort formation pretoria group, transvaal supergroup of south africa, with the accent on describing and interpreting its sedimentology. Highlights for the volcanosedimentary succession of the. The palaeoproterozoic transvaal supergroup floor to the bushveld complex comprises protobasinal successions overlain by the black reef formation. Pdf an overview of the geology of the transvaal supergroup.
Paleomagnetism of a neoarcheanpaleoproterozoic carbonate. Instead, the craton was covered by several thousand of meters of sediments of the transvaal supergroup, underlain by clastic sedimentary and volcanic rocks of the ventersdorp supergroup, deposited in the socalled protobasinal basins e. Deconstructing the transvaal supergroup, south africa. It is delimited by the witwatersrand basin 2,700 mya and the bushveld igneous. Jun 29, 2006 an impressive array of morphological diversity has been recorded in numerous archaean units. This area includes mainly neoarchean and proterozoic sedimentary rocks partly uncomfortably covered by uppermost paleozoic and lower mesozoic rocks and tertiary to. The malmani dolomites are just one rock formation in this sequence, and they are of interest to us because it is in the dolomites that we find the historic lime.
The supergroup is made up of basal protobasinal rocks, upon which followed the black. On our way to prieska, on the farms elandsfontain and koupoort south of griekwastad. Because of the importance of the transvaal supergroup for economic e. The iron and manganese deposits of the transvaal supergroup formed as a result of the rapid increase of free oxygen in theformed as a result of the rapid increase of free oxygen in the earths atmosphere. An overview of the geology of the transvaal supergroup dolomites south africa article pdf.
A regional map of central and northeastern south africa showing the transvaal and griqualand west depositional basins in which the transvaal supergroup is preserved. Pdf the transvaal supergroup and its precursors researchgate. This area includes mainly neoarchean and proterozoic sedimentary rocks partly uncomfortably covered by uppermost paleozoic and lower mesozoic rocks and tertiary to recent soils and sands. A griqualand west in the southwest and b transvaal in the northeast. Petrography and geochemistry of iron formations of the paleoproterozoic koegas subgroup, transvaal supergroup, griqualand west, south africa. Considerable volumes of groundwater are stored within the dolomitic aquifers of the malma.
Neoarchaean tectonic history of the witwatersrand basin. The three huronian glacial units, penetrated and capped by the nipissing diabase, predate the makganyene diamictite in the transvaal. The penge iron formation of the transvaal supergroup of the bushveld complex, was. Geochemical evidence for an impact origin for a late archean. Fitzpatrick author of the outspan london william heinemann 1899 written august, 1896.
Download limit exceeded you have exceeded your daily download allowance. Source and age of upper transvaal supergroup, south africa. Timing and tempo of the great oxidation event pnas. The 25002100 ma transvaal sequence of south africa comprises 15,000 m of relatively. In this threefold subdivision of the transvaal supergroup, the lowermost sequences eastern. The lower zone occurs as separate compartments, each of alternating bronzitite, harzburgite, and.
Geology of the palaeoproterozoic daspoort formation pretoria. Since its discovery in 1886 this deposit yielded more thansince its discovery in 1886 this deposit yielded more than 5050 000000 t of gold, or about 40% of all the gold ever mined by mankind. The rustenburg layered suite is subdivided from bottom to top into the lower, critical, main, and upper zones fig. Remaining gold resources are about 36000 t or 40% of the worlds total gold. Subsidence of the intrusion produced the present lopolithic geometry fig. Aug 09, 2005 proposed correlation of the huronian supergroup and the upper transvaal supergroup. The 2,650 to 2,100 myr transvaal supergroup rests unconformably on the. Banded ironformation bif is a rock of precambrian age. South african suidafrikaanse journal of geology tydskrif. Transvaal definition and meaning collins english dictionary.
Both transvaal and bushveld rocks are extensively mineralized, the former containing large deposits of iron, manganese, asbestos, andalusite. The prekaroo geology of the southern portion of the kaapvaal. Ghaap group, transvaal supergroup, of the kaapvaal craton reveals a complex series of viscous and thermochemical magnetic overprints. It was bounded by mozambique and swaziland to the east and by cape province to the west. An impressive array of morphological diversity has been recorded in numerous archaean units. Report on the annual meeting of the transvaal working. The transvaal supergroup is located in the transvaal basin in south africa, and rests on the northern and western parts of the kaapvaal craton. The transvaal basin is one of three basins of the transvaal supergroup on the kaapvaal craton. Geological setting university of the witwatersrand. Paleomagnetism of a neoarcheanpaleoproterozoic carbonate ramp and carbonate platform succession transvaal supergroup from surface.
The protobasinal successions comprise predominantly mafic lavas and pyroclastic rocks, immature alluvialfluvial braidplain deposits and finer. The archaeanpalaeoproterozoic transvaal supergroup on the kaapvaal craton in south africa is, however, exceptionally well preserved, and is thus. The sedimentary and tectonic setting of the transvaal. Deposition started with the schmidtsdrif subgroup, which is probably oldest in the southwestern part of the basin, and which contains stromatolitic carbonates, siliciclastic sediments and minor lava flows. Field observations together with ar chronology support multiple pseudotachylite forming events in the vredefort dome, with at least a few occurrences clearly pre or postdating the impact event. Rocks enriched in pge, which occur near the contact of the bushveld complex with older transvaal supergroup sedimentary rocks, may contain. Mineralogy and petrology of the contact metamorphosed. Pdf virgin rock temperatures and geothermal gradients in. The transvaal from within a private record of public affairs by j. Little is known about plate tectonic reconstruction of the kaapvaal craton in southern africa during the early paleoproterozoic, in particular for the period between 2. Gly 163 earth history the transvaal supergroup nils lenhardt earth history transvaal supergroup. The study area of the present thesis is located in southwest of the prieska subbasin, transvaal supergroup, south africa.
Petrography and geochemistry of iron formations of the. The transvaal supergroup is a stratigraphic unit in northern south africa and southern botswana, situated on the kaapvaal craton, roughly between 23 and 29 degrees southern latitude and 22 to 30 degrees eastern longitude. Pdf in the neoarchaean intracratonic basin of the kaapvaal craton, between approximately 2640. Report on the annual meeting of the transvaal working group. Transvaal supergroup however has shown that the unconformity below the transvaal still falls within the neoarchean eon walraven and martini, 1995. There is significant potential for mining at least one of. Msc thesis unpublished, university of johannesburg, aucklandpark, pp. Locality map, showing the distribution of the major subdivisions of the transvaal supergroup within the transvaal, griqualand west and kanye basins in south africa and southern botswana. This supergroup is divided into the chuniespoort group and the pretoria group.
During the archaean the ocean waters carried abundance of soluble ferrous iron and any oxygen produced by. South african suidafrikaanse journal of geology tydskrif vir. Transvaal supergroup, situated in the contact metamorphic aureole. In the neoarchaean intracratonic basin of the kaapvaal craton, between approximately 2640 ma and 2516 ma, two successive stromatolitic carbonate platforms developed. The transvaal supergroup moving swiftly ahead, about 2. The black reef formation is the basal lithostratigraphic unit of the late archean to early proterozoic transvaal supergroup els et al. Both transvaal and bushveld rocks are extensively mineralized, the former containing large deposits of iron, manganese, asbestos, andalusite, gold, fluorine. The late archaeanearly proterozoic transvaal sequence is preserved within the transvaal, kanye and griqualand west basins, with the 2050 ma bushveld complex intrusive into the upper portion of the succession within the transvaal basin. Lower and upper limits for viscosity are 1017 pas and 1025 pas, respectively.
This triggered another round of heavy sedimentation and marks the beginning of the transvaal supergroup. Du plessischertfree metallurgical grade dolomite in the southern transvaal. An overview of the geology of the transvaal supergroup. The sedimentary and tectonic setting of the transvaal supergroup. This new age demonstrates that the campbellrandmalmani carbonate platform was deposited during late archean time, and is the oldest extensively preserved carbonate platform known. Deconstructing the transvaal supergroup, south africa core. Ghaap group, transvaal supergroup, of the kaapvaal craton reveals a complex series of viscous and. A volcanic ash bed that crops out 4050 m below the contact between the campbellrand subgroup and the kuruman iron formation, transvaal supergroup, south africa, yields an u pb zircon age of 2521 3 ma. A note on two occurrences of inferred microbial mat features preserved in the c. Cases and solutions an overview of the geology of the transvaal supergroup dolomites south africa p.
It lies unconformably on the volcanosedimentary rocks of the ventersdorp supergroup and the sedimentary. Despite this complex history, a potential primary singlepolarity. Current correlations between the pretoria and postmasburg groups of the transvaal supergroup are shown to be invalid. The quartzpebble conglomerates host erratic concentrations of gold and uranium. The black reef formation is a laterally extensive sedimentary succession at the base of the transvaal supergroup. The uppermost huronian glacial unit, the gowganda fm. Testing models of pregoe environmental oxidation a. Altermann abstract in the neoarchaean intracratonic basin of sitional stages, but mainly during early diagenesis. The bushveld complex in the context of thethe bushveld. The transvaal supergroup south africa records evidence of trace oxygen production in late neoarchaean strata, approximately 200 million years before the great oxidation event goe which is recorded within the palaeoproterozoic duitschland formation transvaal supergroup between 2. Molar tooth structures of the neoarchean monteville formation, transvaal supergroup, south africa.
For this interval, paleomagnetic data for the kaapvaal craton are scarce, and do not allow. Dated samples and results bold are shown in stratigraphic context and collectively, unlock the longheld correlation between the basalts of the ongeluk and hekpoort. Fossil evidence of archaean life pubmed central pmc. The limpopo river marked its border with botswana and zimbabwe to the north, while the vaal river marked its boundary with orange free state province to the south. Provinsie transvaal, commonly referred to as the transvaal.
Textural and rulebased lithological classification of. The intercratonic witwatersrand basin contains the largest known gold deposit on earthdeposit on earth. The origin of the gold and uranium ores of the black reef. It is dated to the boundary between the archean and proterozoic eras, roughly 2,500 mya. The palaeoproterozoic transvaal supergroup floor to the bushveld complex comprises protobasinal successions overlain by the black reef formation, chuniespoort group and the uppermost pretoria group. An overview of the geology of the transvaal sequence and. Textural and rulebased lithological classification of remote. Underexplored extensions of stratabound platinumgroup element pge deposits in the bushveld complex in south africa may contain 65,000 metric tons of platinum, palladium, and rhodium to a depth of 3 km. The transvaal supergroup is a stratigraphic unit in northern south africa and southern. Neoarchaean tectonic history of the witwatersrand basin and.
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