A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg in fulfilment of the requirements for the degree of Doctor of Philosophy. June 2016. / The Dicynodon Assemblage Zone (DiAZ) spans the last three million years of the Late Permian (Lopingian) Beaufort Group (Karoo Supergroup). Fluvio-lacustrine conditions covered the entire Karoo Basin during this period, preserved as the rocks of the Balfour, Teekloof, and Normandien formations. However widely separated exposures and few dateable horizons make correlating between lithostratigraphic subdivisions difficult. Here a revised litho- and biostratigraphic framework is provided for the Upper Permian DiAZ. The Balfour Formation’s Barberskrans Member (BM) is renamed due to identifying the Oudeberg Member and not the BM at the current type locality (Barberskrans Cliffs). It is renamed Ripplemead member (RM) after Ripplemead farm 20 km north of Nieu Bethesda where it outcrops. The Teekloof Formation’s Javanerskop member and Musgrave Grit unit in the central Free State Province are regarded mappable units whereas the Boomplaas sandstone (BS) may represent a unit that is a lateral equivalent to the Oudeberg Member. Palaeontological and detrital zircon data suggest none of these locally persistent sandstone horizons correlate temporally. Three index fossils that currently define the DiAZ (Dicynodon lacerticeps, Theriognathus microps, and Procynosuchus delaharpeae) appear below its lower boundary and disappear below the Permo-Triassic Boundary (PTB), coincidentally with the appearance of Lystrosaurus maccaigi. The base of the DiAZ is redefined, with the revived Daptocephalus leoniceps and T. microps re-established as the index fossil for the newly proposed Daptocephalus Assemblage Zone (DaAZ), and is subdivided into two subzones. Da. leoniceps and T. microps’ appearance define the lower and L. maccaigi defines the base of the upper subzone. The same patterns of disappearance are observed at the same stratigraphic interval throughout the basin, despite the thinning of strata northward. Additionally wetter floodplain conditions prevailed in the Lower DaAZ than in the Upper DaAZ which likely reflects climatic changes associated with the Permo-Triassic mass extinction (PTME). Palaeocurrent and detrital zircon data demonstrate a southerly source area, and recycled orogen petrography indicates the Cape Supergroup is the source of Upper Permian strata. Dominant late Permian zircon population supports the foreland nature of the Karoo Basin. Orogenic loading/unloading events are identified by two fining-upward cycles, separated by a diachronous third-order subaerial unconformity at the base of the RM and Javanerskop members. Sediment progradation northwards was out-of-phase with the south and wedge-shaped. Distributive fluvial systems depositing sediment within a retroarc foreland basin best explains these observations. Lithostratigraphic beds and members are recommended for use as local marker horizons only in conjunction with other proxies, such as index fossils or radiometric dates in future studies. / LG2017

Thesis (M. Sc. (Geology)) -- University of Limpopo, 2020 / The Glentig, Alma and Swaershoek Formations were deposited after the emplacement of the Bushveld igneous complex (BIC). The sediments accumulated in what is termed as the proto-basin of the Waterberg Group. The Glentig Formation is an unconformity bounded formation that is overlain by the Swaershoek and Alma Formations of the Waterberg Group. This study revisited the stratigraphy and put perception on the petrography, lithofacies, provenance, paleoweathering, tectonic setting and source rock characteristics of the lower parts of Waterberg Group (Swaershoek and Alma Formations) and Glentig Formation. The methodologies employed in achieving the aforementioned goals include stratigraphical analysis, petrographical and modal composition analyses, lithofacies analysis and geochemical analysis. In the study area (northeast of Modimolle town), the Glentig Formation lies or bounded between the Swaershoek Formation and Schrikkloof Formation of the Rooiberg Group. The Glentig, Swaershoek and Alma Formations attained a maximum thickness of about 400 m, 300 m and 190 m, respectively. Based on the stratigraphical analysis, the Swaershoek, Alma and Glentig Formations can be correlated. The basis for the correlation rests solemnly on the similarities in the lithological characteristics that can be found in the three formations. Six facies were identified based on lithofacies analysis. The lithofacies are grouped into 2 facies association (FA1 and FA2). The two facies associations are FA1: Conglomerate and massive sandstone, and FA2: Cross-bedded sandstone, and planar cross-bedded sandstone. Sedimentological characteristics of the identified facies associations are interpreted as debris flow, and longitudinal and transverse bars (fluvial channel deposits). Petrography and modal composition analyses indicate that the detrital components of the sandstones are dominated by monocrystalline quartz, vi feldspar and lithic fragments. The sandstones of the Swaershoek, Alma and Glentig Formations can be classified as subarkosic arenite and lithic arkosic arenite. Also, provenance analysis indicates that the sandstones are derived from both felsic igneous provenance and intermediate igneous provenance. The modal composition analysis and geochemical tectonic setting discrimination diagrams show that the sediments are from both the passive and active continental margin tectonic settings. Also, the geochemical data of major and trace elements suggested that the studied formations have been derived from the same provenance source area. The indices of weathering indicated that the studied rocks have been subjected to moderate to the high degree of chemical weathering. / Mining Qualification Authority (MQA)

Thesis (MSc) -- Stellenbosch University, 1973. / The Marble Delta is an area of approximately 40 sq. km in Natal (30°22' Long., 30°40' Lat.), occupied by Precambrian marble and associated granites. The deeply dissected country was geologically mapped on a scale of I : 6 000. A new lithostratigraphic classification of the metasediments is proposed. The base of the lowermost Le Joncguet Formation (composed of dolomitic marble and siliceous beds) is not exposed. This is followed by the predominantly ca.lcitic Oribi Formation with interbedded dolomite and graphitic layers. The marble is unconformably overlain by the Cherrywillingham Formation which comprises mainly amphibolite and granulite. The .three formations together constitute the Marble Delta Group. The main petrological units are calc-silicate marble, metaquartzite, dolomite marble, cluster serpen~ine marble and ce,lcite marble. Graphite layers are considered to have originated in situ from organic remains; there is occasional evidence of ionic transfer of carbon from this graphite by magmatic fluids. The common mineral assemblages are diopside + calcite + dolomite, tremolite + calcite + diopside + quartz, calcite + quartz + dolomite, forsterite + calcite + dolomite, plagioclase + cordierite + garnet + quartz, amphibole + clinopyroxene + plagioclase, hornblende + clinopyroxene + calcite, wollastor~te + calcite + diopside. Other minerals are graphite, antigorite, chrysotile, sphene, spinel, clinohumite, chondrodite, zoisite, clinozoisite, hedenbergite, phlogopite, ilmenite, hercynite, dravite, cummingtonite, talc, apatite, microcline, saponite. The mineral assemblages resulted from regional metamorphism and polyphase contact metamorphism.

Thesis (PhD (Geology))--University of Stellenbosch, 1997. / 1123 leaves printed on single pages, preliminary pages and numbered pages 1-286. Includes bibliography, list of figures and tables and explanation of abbreviations used. / Digitized at 600 dpi grayscale to pdf format (OCR), using a Bizhub 250 Konica Minolta Scanner. / ENGLISH ABSTRACT: This first comprehensive study of the petroleum geochemistry of the Bredasdorp Basin, and the adjacent Southern Outeniqua Basin, documents the characteristic large number of hydrocarbon shows and the four regionally distinctive marine source rocks. Detailed correlation of reservoired hydrocarbons with source rock bitumens shows that two source rocks have expelled oil in commercial quantities and two others have expelled commercial quantities of wet gas/condensate. In contrast with earlier studies which indicated that thermal 'gradualism' prevailed, this study indicates that the post-rift thermal history of the basin is very complex. Post-rift cool-down is punctuated by periods of rapidly increasing heat flow resulting in much of the maturation being localised in time. These periods of increased heating coincide with regional plate tectonism. The associated thermal uplift and downwarp effects govern the periods of trap formation and control the hydrocarbon migration direction. Migration distances of these hydrocarbons are described and show inter alia that oil migrates no more than -7-10 km but gas migrates regionally. Two regional episodes of meteoric water flushing reduce sandstone cementation in palaeo-highs forming potential reservoirs at specific times. The unusually low salinity of remnants of this water in some sandstones help characterise these two main migration conduits. A highly detailed hydrocarbon correlation scheme derived from gas, light oil and biomarker data has been established which differentiates products of the four active source rocks and helps characterise the oil-oil, oil-source and source-source pairs. It is evident from these correlations that two periods of migration and reservoiring occurred at 50-60 Ma and 0-10 Ma. As a result, source-reservoir plays which characterise certain areas of the basin as predominantly oil or gas prone can be described. These correlations also highlight areas where mixtures of hydrocarbons are common and where some of the early reservoired oil has been displaced to new locations, constituting potential new exploration plays. Source rocks for some of the analysed hydrocarbons have yet to be found and may not even have been drilled to date. One such source rock appears to be located in the Southern Outeniqua Basin, making that area a potential target for further exploration. This study resolved the common heritage of the source rocks and reservoir sandstones which form part of the Outeniqua petroleum system. The hydrocarbon volumes available to this system show that by world standards it is indeed significant. / AFRIKAANSE OPSOMMING: Die groot aantal koolwaterstof voorkomste asook vier streekskenmerkende mariene brongesteentes word in hierdie eerste omvattende studie van die petroleumgeochemie van die Bredasdorp-kom en die aangrensende Suidelike Outeniqua-kom saamgevat. Gedetaileerde korrelasies van die opgegaarde koolwaterstowwe met brongesteente bitumen, dui daarop dat twee van die vier geidentifiseerde brongesteentes olie in kommersiele hoeveelhede uitgeset het. Die ander twee het kommersiele hoeveelhede nat gas-kondensaat uitgeset. In teenstelling met vroeer studies wat daarop gedui het dat termale 'gradualisme' voorgekom het, dui hierdie studie daarop dat die na-riftermale geskiedenis van die kom baie meer kompleks is. Verskeie periodes van versnelde toename in hittevloei het voorgekom in die na-rifse verkoeling. Dit het daartoe gelei dat veroudering plaaslik binne 'n beperkte tydsverloop plaasvind. Hierdie periodes van hittetoename stem ooreen met die regionale plaattektoniek. Die geassosieerde termiese opheffing en afwaartse vervormingseffek, beheer die totstandkoming van opvanggebiede en die migrasierigting van die koolwaterstowwe. Migrasie-afstande van die koolwaterstowwe word bespreek en wys inter alia daarop dat olie nie verder as -7-10 km beweeg nie, maar gasmigrasie vind regionaal plaas. Twee kort episodes van meteoriese wateruitsetting, het sandsteensementasie in palaeohoogsliggende gebiede verminder wat potensiele reservoirs gevorm het op spesifieke tye. Die ongewone lae soutvlakte van oorblyfsels van die water in sekere sandstene help om die twee vernaamste migrasieroetes te kenmerk. 'n Hoogs omvattende koolwaterstof-korrelasieskema wat van gas, ligte olie en biomerkerdata verkry is, is opgestel. Die skema het onderskei tussen produkte van die vier aktiewe brongesteentes en help om die olie-olie, olie-bron en bron-bron pare te karakteriseer. Dit is duidelik van die korrelasies dat twee periodes van migrasie en opgaring plaasgevind het ongeveer teen -50-60 Ma en 0-10 Ma. Gevolglik kan bronreservoir omskrywings wat sekere dele van die kom karakteriseer as grotendeels olie of gas-ontvanklik beskryf word. Hierdie korrelasies beklemtoon ook areas waar mengsels van koolwaterstowwe algemeen voorkom en waar sekere van die vroeer opgegaarde olie verplaas is na nuwe lokaliteite, wat nuwe eksplorasieteikens daarstel. Brongesteentes vir sekere van die ge-analiseerde koolwaterstowwe, moet nog gevind word en is tot op hede nog nie raakgeboor nie. Een so 'n brongesteente kom voor in die Suidelike Outeniqua-kom, wat daardie area 'n potenslele teiken vir verdere eksplorasie maak. Die studie het die gesamentlike oorsprong van die brongesteente en reservoirsandsteen, wat deel is van die Outeniqua Petroleumsisteem, geidentifseer. Die koolwaterstofvolumes wat beskikbaar is vir die sisteem wys dat, gemeet teen wêreldstandaarde, dit wel beduidend is.

Thesis (DSc) -- Stellenbosch University, 1967. / INTRODUCTION: This dissertation aims to illuminate some surprises which the deceptively uncomplicated Table Mountain sandstone had long been harbouring in its kloofs and cliffs . The major contributions of this first systematic investigation of an extensive portion of the Table Mountain sandstone are the discovery of diagnostic marine fossils by means of which the first direct dating of the deposit is effected and important sedimentological conclusions drawn...

Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The southern portions of the Early- to Mid-Archaean Barberton granitoid-greenstone terrain of South Africa consists of a high-grade metamorphic granitoid-gneiss terrain that is juxtaposed against the low-grade metamorphic supracrustal sequence of the Barberton Greenstone Belt. The boundary of the two different crustal domains corresponds to the Theespruit Formation, an amphibolite-facies, highly tectonized mélange of metabasites, felsic volcanics and rare, aluminous clastic sediments that occurs along the granitoidgreenstone margins. Amphibolite-facies lithologies in the Theespruit Formation are characterized by strongly prolate mylonitic fabrics that formed in a constrictional tectonic regime. Away from the granitoid-greenstone margin and towards the central parts of the greenstone belt, these rocks grade to, and are overprinted by, greenschist-facies S-L mylonites that formed during non-coaxial deformation. Both peak and retrograde minerals define, and are aligned parallel to, the fabrics in these rocks, indicating that shearing was initiated under peak metamorphic conditions and continued during retrogression. S-C’ fabric relationships indicate that shearing occurred in an extensional tectonic regime and that, during deformation, the gneiss terrain was uplifted relative to the greenstone belt. Peak metamorphic assemblages of grt-st-bt-chl-pl-qtz and ky-st-btms- pl-qtz in metasediments and grt-ep-hbl-pl-qtz in amphibolite constrain peak metamorphic conditions of 7.4 ± 1.0 kbar and 560 ± 20 ºC that were attained during the main accretionary episode in the Barberton terrain at 3229 ± 25 Ma. Peak assemblages in all rocks are pre-tectonic and were deformed and re-equilibrated during retrogression, resulting in these being minimum estimates of peak metamorphic conditions. Petrographic evidence and retrograde pressure-temperature estimates indicate that retrogression involved near-isothermal decompression of ca. 4 kbar prior to cooling into the greenschist-facies. The style and timing of metamorphism in the Theespruit Formation is similar to that of the granitoid-gneiss terrain, suggesting that the Theespruit Formation shares a geological history with the gneiss terrain and that it is allochtonous to the greenstone belt. The main deformational and fabric-forming event exhibited in the Theespruit Formation occurred during the exhumation of the granitoid-gneiss terrain subsequent to peak metamorphism. Consequently, the juxtaposition of this terrain againstthe greenstone belt was achieved by tectonic underplating and core complex formation at ca. 3.23 Ga. The occurrence of high-grade constrictional mylonites that are overprinted by low-grade non-coaxial mylonites as well as extension in an overall compressional tectonic regime is consistent with exhumation by extensional orogenic collapse. Burial of the high-grade terrain to depths of 25 – 30 km is only possible in a relatively cold and rigid crustal environment, while the extremely low apparent geothermal gradients of ca. 20 ºC/km preserved in this terrain suggest that burial and exhumation occurred rapidly, within a time-span of ca. 15 – 20 Ma. These parameters strongly suggest that metamorphism occurred in response to a lateral plate tectonic process that was operational in the Barberton terrain at 3230 Ma. / AFRIKAANSE OPSOMMING: Die suidelike dele van die Vroeg- tot Middel-Argaïese Barberton graniet-groensteen terrein van Suid-Afrika bestaan uit ‘n hoë-graad metamorfe graniet-gneiss terrein wat die lae-graad metamorfe groenstene van die Barberton Groensteen Gordel begrens. Die grens tussen die twee verskillende kors-domeine hang saam met die Theespruit Formasie, ‘n amfiboliet-fasies, getektoniseerde melange van metabasiete, felsiese vulkaniese gesteentes en skaars, alumineuse klastiese sedimente wat langs die graniet-groensteen kontakte voorkom. Amfiboliet-fasies gesteentes in die Theespruit Formasie word gekenmerk deur sterk prolaat milonitiese maaksels wat in ‘n vernouende tektoniese omgewing gevorm het. Hierdie rotse word weg van die graniet-groensteen kontak en na die sentrale dele van die groensteen gordel oordruk en vervang deur groenskis-fasies S-L miloniete wat tydens nie-koaksiale vervorming gevorm het. Beide piek en retrograad minerale definieer, en is georienteer parallel aan, die maaksel in die rotse, wat daarop dui dat skuifskeur onder piek metamorfe toestande begin het en volgehou het tydens retrogressie. S-C’ maaksels dui daarop dat skuifskeur in ‘n verlengende tektoniese omgewing plaasgevind het en dat die gneiss terrein opgehef is relatief tot die groensteengordel tydens vervorming. Piek metamorfe versamelings van grt-st-bt-chl-plqtz en ky-st-bt-ms-pl-qtz in metasedimente en grt-ep-hbl-pl-qtz in amfiboliet bepaal piek metamorfe toestande van 7.4 ± 1.0 kbar en 560 ± 20 ºC wat bereik is gedurende die hooffase van akkresie in die Barberton terrein teen 3229 ± 25 Ma. Die piek metamorfe versamelings in alle rotse is pre-tektonies en is vervorm en geherekwilibreer tydens retrogressie, wat maak dat die beramings minimum skattings van piek metamorfe toestande is. Petrografiese getuienis asook druk-temperatuur beramings dui daarop dat retrogressie gepaard gegaan het met byna-isotermiese drukverligting van naastenby 4 kbar voor afkoeling tot in die groenskis-fasies. Die styl en tydsberekening van metamorfose in die Theespruit Formasie is vergelykbaar met metamorfose in die granietgneiss terrein, wat daarop dui dat die Theespruit Formasie ‘n geologiese geskiedenis met die gneiss terrein deel en allochtoon is tot die groensteen gordel. Die hooffase van vervorming en maakselvorming in die Theespruit Formasie het plaasgevind gedurende die herontbloting van die graniet-gneiss terrein na piek metamorfose. Gevolglik is dieteenplasing van dié terrein teen die groensteen gordel vermag deur tektoniese onderplasing en kernkompleksvorming teen ongeveer 3.23 Ga. Die verskynsel van hoëgraadse vernoude miloniete wat oordruk word deur lae-graadse nie-koaksiale miloniete asook verlenging in ‘n algeheel saamdrukkende tektoniese omgewing dui daarop dat herontbloting plaasgevind het deur middel van verlengende orogenetiese ineenstorting. Die begrawing van die hoë-graadse terrein tot dieptes van 25 – 30 km is net moontlik in ‘n relatief koel en star kors-omgewing, terwyl die uitermate lae geotermiese gradiente van ongeveer 20 ºC/km wat in die terrein behoue gebly het daarop dui dat begrawing en herontbloting vinnig geskeid het, binne ‘n tydsverloop van ongeveer 15 – 20 Ma. Hierdie beperkings is ‘n sterk aanduiding dat metamorfose plaasgevind het as gevolg van ‘n laterale plaattektoniese proses wat werksaam was in die Barberton terrein teen 3230 Ma.

Thesis (MSc (Earth Sciences))--University of Stellenbosch, 2009. / Fan 3 is one of four basin-floor fans that form part of the Tanqua Karoo Fan Complex in South Africa. It can be subdivided into several sandstone lobes, based on the presence of thin-bedded siltstone intervals above and below major sandstone packages. Six lobes are identified in the mid fan section, as well as two older groups of thin, low-volume turbidite deposits at the base. Some of the lobes are further divided into an upper and lower lobe-element based on depositional behaviour. The volumetrically and spatially larger lobes have a finger-like appearance in plan view, which is attributed to multiple lobe-scale axial zones. This is especially visible towards the eastern margins of Lobes 2, 4 and 5. The stratigraphy and facies distribution are presented on several 2D panels. Computer generated isopach maps are presented for each lobe, lobe-element and interlobe unit. Autogenic control on the depositional pattern of the Fan 3 lobe complex was inferred from the palaeoflow patterns of the composing lobes and lobe-elements. The majority of the lobes show a north-eastern palaeoflow direction in the south, with a gradual westward shift in the north. Inferred controls are basin-floor topography, the presence of pre-existing lobes, and characteristics of the depositional flow, such strength, density, sediment load, palaeoflow direction.

<p>This research was aimed at employing the broad use of petrophysical analysis and reservoir modelling techniques to explore the petroleum resources in the sandstone units of deep marine play in the Bredasdorp Basin.</p>

M.Sc. (Geology) / Please refer to full text to view abstract

MSc. (Geology) / The Mesoproterozoic Pilanesberg Alkaline Complex is located in the north central region of the Kaapvaal Craton of South Africa and is one of the largest alkaline intrusive bodies in the world. It is also one of the least studied due to the fact that the dominant exposure of the complex forms part of the Pilanesberg National Park. The Pilanesberg Complex intruded into the western limb of the Paleoproterozoic Bushveld Complex, the complex is a circular structure of 530km2 appearing on the map as a set of concentric rings of different varieties of syenites, capped by extrusive pyroclastic units and lavas. The present study is focused on the petrography and mineral chemistry of the rocks and minerals in an outcrop of mainly lujavrite, which is located in the Ledig nepheline syenite previously referred to as Ledig foyaite, named after an informal settlement by the name of Ledig which is situated approximately a kilometer south of the outcrop. This unit is emplaced in the southern region of the Pilanesberg complex and is believed to be a hybrid of the white nepheline syenite and the green nepheline syenite. A number of different rock types were examined from this outcrop, however, detailed work was only carried out on the lujavrites, in particular the eudialyte bearing lujavrites. The lujavrites consist of porphyroblasts of heterogeneously-sized feldspars, feldspathoids and mafic minerals set within a finer grained material. The bulk rock geochemical data on the Ledig lujavrites indicate considerable variation, but no obvious trends. A selected number of samples collected from the ledig lujavrite outcrop were geochemically analysed, these samples sit within the nepheline syenite field and have a shoshonitic affinity. The samples analysed have a relatively wide range of SiO2 content (20.39% to 52.67%), however the majority of the samples fall between 47.07 and 52.67%, the fluorite rich sample analysed has the lowest SiO2 as well as the lowest alkali content. The lujavrites and tinguaites are silica undersaturated and rich in alkalis. All the samples analysed are alkaline in nature and fall in the ferroan field. There is some variation in the SiO2 content and a large variation in Mg# in the sample population, this appears to be due to different proportions of minerals occurring as phenocrysts. No clear trends emerge, which is in part due to the very large differences in element concentrations within rock types with similar SiO2 content and Mg#. A lack of geochemical variation stemming from Abstract differentiation was expected as the samples were collected from a single outcrop essentially within a single lithology. There are a number of different phases of eudialyte that have been identified and studied from the Pilanesberg, at both the outcrop and in the northern area of the green lujavrites. At the Ledig lujavrite outcrop, there are euhedral magmatic eudialytes, which contain nepheline inclusions as well as post-magmatic eudialytes present in the samples studied. The two textural types have distinctly different chemical compositions. The majority of the feldspars present within the Ledig lujavrites appear, from their texture, to be primary magmatic minerals, however there are also feldspars present within the lujavrites which appear to be a product of secondary unmixing of feldspars as documented by the perthitic textures. Sodalite is present as a magmatic mineral; however, it is most commonly observed in the interstitial spaces and is thought to be an alteration product of nepheline. Analcime occurs in the groundmass, forming in the intergranular reaction rim between mineral phases. The analcime is typically controlled by the shape of the interstices...