And get this the file didnt even show up when i stopped the activity. Chapter 3 state of the environment consists of sedimentary deposits from the dwyka group, ecca group and beaufort group as illustrated in figure 1. Karoo system, geologic system of rocks outcropping over a 1,560,000squarekilometre 600,000squaremile area of africa from the equator south to the cape of good hope. The karoo supergroup has evolved from two distinct tectonic regimes sourced from the southern and the northern margin of gondwana. All four of those groups of rocks are part of the karoo supergroup a term used by geologists.
Overall, the karoo supergroup across the kalahari karoo basin reflects a transition from a glaciation period through to deltaic and swampy periods ultimately turning arid before the extrusion of. These reflect the progressive infilling of the karoo basins, the changing tectonic framework as well as the migration of gondwana from polar to tropical latitudes. Lower karoo sediments are preserved in deep vallyes. The karoo is partly defined by its topography, geology, and climate above all, its low rainfall, arid air, cloudless skies, and extremes of. The karoo supergroup is the most widespread stratigraphic unit in africa south of the kalahari desert. Modelling of distribution and geometry of lithological. Sedimentation in an intracratonic extensional basin. Pdf the karoo supergroup of the kalahari basin researchgate. A provisional basin analysis of the karoo supergroup. The karoo supergroup is renowned for its fossil wealth.
Meal key bb bed and breakfast dbb dinner, bed and breakfast. Jurassic karoo supergroup 4604 m dolerites karoo dolerites jd crystalline sills and dykes permian karoo supergroup 4604 m beaufort abrahamskraal pa mudstone, sandstone and thin chert beds karoo supergroup 4604 m ecca waterford pw dark grey carbonaceous shale fort brown pf shale rythmite ripon pr mottled grey sandstone and shale. The karoo supergroup as a whole thus spans the period ca 320 ma to ca 120 ma. Late palaeozoic palynomorph assemblages from the karoo supergroup and their potential for biostratigraphic correlation, kalahari karoo basin, botswana. How to see karoo files from your pc karoo user forums. The karasburg basin is situated in southern namibia and preserves a heterogeneous succession of karoo supergroup strata up to m thick. The uppermost preserved succession in this basin is the amibberg formation which is 250m thick and consists of intervals of sandstone, siltstone and mudstone. From an age perspective, the dwyka group is of late carboniferous to early permian age woodford and chevallier 2002, while the ecca group is of permian age and the beaufort group of triassic age. Because of the abundance of fossil tetrapods in the rocks of the karoo supergroup, they have been used to divide the rock succession into fossil zones, called biozones. In southern africa, rocks of the karoo supergroup cover almost two thirds of the present land surface, including all of lesotho, almost the whole of free state, and large parts of the eastern cape, northern cape, mpumalanga. In geological terms, the karoo supergroup refers to an extensive and geologically recent 180310 million year old sequence of sedimentary and igneous rocks, which is flanked to the south by the cape fold mountains, and to the north by the more ancient ventersdorp lavas, the transvaal supergroup and waterberg supergroup. The karoo supergroup succession along the lebombo monocline is highlighted in figure 1. These three groups are part of the karoo supergroup.
The stratigraphy of the karoo supergroup is presented in table 1. There is no exact definition of what constitutes the karoo, and therefore its extent is also not precisely defined. The first comprehensive map of the pre karoo geology, focusing particularly on the distribution of witwatersrand supergroup rocks, was compiled by r. Petrography and geochemistry of sandstone samples of vischkuil formation, karoo supergroup, south africa, journal of petroleum exploration and production technology, 2016, pp. Karoo in namibia were maximum thicknesses of 700 m are reported from the waterberg area, 520 m from the mt. Thegroupisbestdeveloped in the eastern part of soutpansberg, where the maximum preserved thickness is about 5 000 m.
The gemsbok subbasin is situated in the southwestern corner of the kalahari karoo. The karoo basin is located in central south africa and spans an area of more than 200,000km2 figure 1 aarnes et al. The sills are exposed in metrewide water drainage tunnels at depths of approximately. This has enabled the biozones to be correlated with equivalent sequences elsewhere in the world and forms the basis of reconstructing global patterns of diversity.
These boreholes indicated that to the northwest of the site portion 81 the karoo sedimentary succession is directly underlain by conglomerate reefs of the witwatersrand supergroup. The prekaroo geology of the southern portion of the. The southern tectonic regimes are believed to be related to processes of subduction and orogenesis along the panthalassan paleo pacific margin of gondwana, this resulted in the formation of a retroarc foreland. Predrill groundwater geochemistry in the karoo basin. Upb zircon shrimp ages for the lebombo rhyolites, south. The beaufort group is represented by the yellow key on the map.
The strata were deposited in glacial, deep marine including turbidite, shallow marine, deltaic, fluvial, lacustrine and aeolian environments. Files are available under licenses specified on their description page. Karoo succession is thought to have been responsible for triggering the early toarcian extinction event hesselbo et al. The karoo basins of southcentral africa university of alberta. Gsa data repository 2017154 earliest triassic in the karoo. Chapter 12 the foreland karoo basin, south africa m. Diamictites and associated glacigenic rocks of the tshidzi formation represent the permocarboniferous dwyka group karoo supergroup in the karoo age basins, i. Magnetostratigraphic constraints on the age of the lower. Stratigraphy and palynostratigraphy, karoo supergroup permian and triassic, midzambezi valley, southern zambia.
The karoo supergroup of the kalahari basin report on a field visit to exposures in the kalahari karoo basin of botswana benson n. Petrography and geochemistry of sandstone samples of vischkuil formation, karoo supergroup, south africa, journal of petroleum exploration and. Abstractthe karoo supergroup in southern africa occurs in the areally extensive main karoo and kalahari basins as well as 3n a number of subsidiary basins. Sample base samples analyzed were collected in 1996.
Pdf on feb 1, 2002, bruce rubidge and others published the karoo supergroup find, read and cite all the research you need on researchgate. Therefore the bedrock outcrops are extremely rare, limited in size and a low number of boreholes drilled in this vas area ca. The rocks are flatlying, undeformed and unmetamorphosed, and appear to be unjointed when seen in in. A simplified geological map of the outcrops of karoo supergroup rocks in southern africa. What follows is an open file report to the community and all other interested parties on the initial results from the borehole.
In the south of namibia, the karasburg and kalahari. Introduction to the bushveld complex, south africa the bushveld complex, of palaeoproterozoic age, is located in the central. The term karoo was extrapolated from the main karoo basin of south africa, to describe the sedimentary. Karoo supergroup sedimentary stratigraphy was deposited in basins related to epeirogenic flexuring of the subcontinent associated with the breakup of. Tshipise, tuli, northern lebombo, ellisras and springbok flats, that are situated north of the main karoo basin of south africa. The karoo supergroup ranges in age from late carboniferous to early jurassic.
The rocks overlying the natal group is a thick unit of tillite that was deposited in a glacial environment by retreating ice sheets about 300 million. Notice that the karoo is either pale khaki the outside or darker khaki the center and that lesotho is also two coloured. This basin extended across much of southern gondwana and records 120 million years of geological history. Geological setting university of the witwatersrand. Original paper exploration geology petrography and geochemistry of sandstone samples of vischkuil formation, karoo supergroup, south africa a. Karoo bridge cookbook introduction karoo bridge is a sip session border controller developed by oss software solutions. Current bio and lithostratigraphic subdivision of the. Karoo supergroup sediments, and are intruded by karoo dolerites.
They are extensively intruded by dolerite sills and dykes which, in collusion with predominantly basaltic volcanism etendeka plateau and a number of subvolcanic com. The supergroup consists of a sequence of units of nonmarine origin, deposited between the late carboniferous and early jurassic, a period of about 120 million years. Folded and thrust faulted rocks of the upper cape supergroup will be examined and we cross the algoa basin cretaceous at uitenhage on the way. Something is wrong here, some process is holding the file open and its not showing up to the file system. The main karoo basin constitutes a retroarc foreland basin, while the rest are intracratonic sag basins or rift basins. Gaps within the ka karoo unconformities in nwnamibia and their tectonic implications 1a. Media in category karoo supergroup the following 10 files are in this category, out of 10 total. The supergroup consists of a sequence of units, mostly of nonmarine origin, deposited between the late carboniferous and early jurassic, a period of about 120 million years. Hydrothermal deposits considerable amount of copper produced from vein type deposits, e. In geological terms, the karoo supergroup refers to an extensive and geologically recent 180310 million years old sequence of sedimentary and igneous rocks, which is flanked to the south by the cape fold mountains, and to the north by the more ancient ventersdorp lavas, the transvaal supergroup and waterberg supergroup. Hydrochemical and hydrogeological impact of hydraulic.
The dwyka group forms the lowermost and oldest deposit in the karoo supergroup basin. Petrography and geochemistry of sandstone samples of vischkuil formation, karoo supergroup, south africa a. Basin karoo rocks have been subdivided into four main formations. Four of the five main stratigraphic groups which comprise the karoo of south africa are recognised in namibia.
I had to reboot the karoo for the fit file to show up. The karoo supergroup in southern africa occurs in the areally extensive main karoo and kalahari basins as well as in a number of subsidiary basins in south africa, namibia, botswana, zimbabwe and mozambique. The permian ecca group, karoo supergroup is a sedimentary sequence that accumulated between the late carboniferous dwyka group and the late permianmiddle triassic beaufort group. Rubidge d a department of earth and atmospheric sciences, university of alberta, 126 earth sciences building, edmonton, alta. Daly skip to main content accessibility help we use cookies to distinguish you from other users and to provide you with a. Exposures of the karoo supergroup occur in the northern and southern portions of malawi, south central africa. Large areas of the southern african continent are covered by the karoo supergroup.
The karoo supergroup is the largest stratigraphic unit in southern africa, covering almost two thirds of the present land surface, including central cape province, almost all of orange free state, western natal, much of southeast transvaal, zambia, zimbabwe and malawi. The evolution of marginalmarine systems of the amibberg. The prekaroo geology of the southern portion of the kaapvaal. The beaufort group is the third of the main subdivisions of the karoo supergroup in south africa. This cuhninated with extensive karoo flood basalt volcanism in the early jurassic. The karoo is a palaeontological wonderland karoo space.
A palynological biozonation has proved feasible for the permian strata in some of the karoo basins. Due to present energy shortfall in south africa, the requirement for new energy sources have gained new momentum and part of this new focus is on shale gas in karoo type formations. Formations present are part of the karoo supergroup. Basin and extends south from the kgalagadi district of botswana into the. Modie report on a field visit to exposures in the kalahari karoo basin of botswana contents summary 1 1 introduction 2. Chapter 12 the foreland karoo basin, south africa sciencedirect. Palynofacies patterns of the highveld coal deposits karoo.
The time span of the karoo system extends from the carboniferous and permian periods about 359 million to 251 million years. Continued exploration has shown that the metasediments of the damara orogeny have been thrusted over the southern edge of the congo craton basement. Samples collected at bethulie were keyed to a measured section quite close to the one presented in smith 1995 with the 0 m datum at the level of the caledon river. Ug nda rwanda burundi 80 of congo tanzania lake victoria geology pemba zanzibar kaolin mafia indian ocean mozambique cretaceous to recent marine and. Lithostratigraphy of the kookfontein formation ecca group. The palaeozoic palynostratigraphy of the karoo supergroup and. Karoo supergroup the karoo is a palaeontological wonderland to palaeontologists, the karoo supergroups rocks and fossils hold the key to understanding the early. The stratigraphic sequence of the ecca group in the eastern cape province consists of dark grey shale, sandstones and mudrocks with subordinate chert and yellow. In southern africa, rocks of the karoo supergroup cover almost two thirds of the present land surface, including all of lesotho, almost. Rocks of the beaufort group karoo supergroup outcrop over approximately 300 000 km2 in south africa smith 1990 and are renowned for their wealth of terrestrial tetrapod fossils, which have enabled the present eightfold biostratigraphic subdivision of this succession rubidge et al. Stratigraphy of the karoo supergroup in southern africa. The type area of the karoo supergroup is the great karoo in south africa, where the most extensive outcrops of the sequence are exposed. The karoo strata in this region are covered unconformably by sands of the kalahari beds upper cretaceous recent.
Report on a field visit to exposures in the kalahari karoo basin of botswana. Dwyka group ice sheets cover gondwana the dwyka group forms the lowermost and oldest deposit in the karoo supergroup basin. The contact relationship between the soutpansberg and waterberg group rocks is a tectonic one, though the latter rocksarebelievedtobeyounger. Geochemistry of sandstones and shales from the ecca group. The karoo sediments in the sbf basin clearly represent the broad spectrum of the same set of palaeo environments that are recognized in the main karoo basin rocks. It occupies a stratigraphic position between the underlying skoorsteenberg formation and the overlying waterford formation, with its regional extent limited to the cutoff boundaries of the skoorsteenberg formation. Borchers in the early 1960s, based largely on borehole records. The karoo supergroup in southern africa occurs in the areally extensive main karoo and kalahari basins as well as in a number of subsidiary basins in south africa, namibia, botswana, zimbabwe and. The most obvious gap between permian and cretaceous strata in the huab area has been used by milner et al. Mitchell, 1986, and extend over a minimum area of 0. Jurassic karoo supergroup, cretaceous sediments, and tertiary to recent sands of the kalahari post karoo intrusives. These consist of a western area, west of the groups, i.
Gondwana glaciation, permian and triassic karoo supergroup rocks were deposited in rift basins in the middle and lower zambezi valley areas. The dominant lithologies in this basin are part of the karoo supergroup, which is a thick package of sedimentary rocks that formed during the late carboniferous to middle jurassic periods figure 2 johnson et al. Supergroup, extensive deep drilling has occurred in the area around the rietfontein site. Thus, karoo bridge is much closer to being a proxy rather than being a switch. No file created for this activity while it was running. Biostratigraphy of the lower burgersdorp formation. The permian kookfontein formation forms part of the upper ecca group in the southwestern part of the main karoo basin of south africa.
Unlike other similar commercial offerings, karoo bridge tries to reconcile the evils of b2bua and the sip standards. Modie 2000 the karoo supergroup of the kalahari basin. Most of the karoo supergroup is located in south africa and the great karoo has an area of more than 600 000 km 2. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a pdf plugin installed and enabled in your browser. Roberts introduction the karoo succession of south africa attained scientific prominence during the 19th century on account of its rich terrestrial vertebrate fauna, dis tinctive glossopteris flora, unrivalled glacial deposits in places. Stratigraphic chart with the major lithostratigraphic subdivisions of the karoo supergroup in the main karoo basin of south africa based on the time scale of. Carboniferous to jurassic karoo supergroup occur in the aranos, huab and waterberg basins, in the southeastern and northwestern parts of the country. Grain size statistics and depositional pattern of the ecca. Kimberlite sills and dykes associated with the wesselton. Lithostratigraphy of the tshidzi formation dwyka group. Karooetendeka unconformities in nw namibia and their.
Proposed development of the malutiaphofung landfill site. Evolutionary rates of midpermian tetrapods from south africa and the role of temporal resolution in turnover reconstruction volume 44 issue 3 michael o. The karoo supergroup itself overlies the earlytomiddle paleozoic cape supergroup, principally composed of quartzose sandstones and subordinate shale that were deformed and metamorphosed during the late permian cape orogeny halbich et al. Petrography and geochemistry of sandstone samples of. Pdf the centrally located kalahari karoo basin of botswana covers more than half the country and comprises a major carboniferous to. Biostratigraphy of the lower burgersdorp formation beaufort.