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1
Riganti, Angela. "The geology and geochemistry of the north-western portion of the Usushwana Complex, South-Eastern Transvaal." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1005570.
Full textAbstract:
The 2.9 Ga old Usushwana Complex in the Piet Retief-Amsterdam area (south-eastern Transvaal) represents an exposed segment of a layered intrusion. It has the form of a dyke-like body elongated in a northwesterly direction, and extends to an estimated depth of 3000 -5500 m. Lithologically, the Complex consists of a cumulate succession of mafic rocks capped by granitoids and has intruded along the contact between the basement and the supracrustal sequences of the Kaapvaal Craton. Differentiation of an already contaminated gabbroic magma resulted in an ordered stratigraphic sequence comprising progressively more evolved lithotypes, with at least two imperfect cyclic units developed over a stratigraphic thickness of about 700 metres (Hlelo River Section). Meso- to orthocumulate textured gabbros and quartz gabbros grade upwards into magnetite- and apatite-bearing quartz gabbros, interlayered with discontinuous magnetitite horizons. The gabbros in turn grade into hornblende-rich, granophyric granodiorites. The differentiation process is regarded as having been considerably enhanced by the assimilation of acidic material, derived by partial melting of the felsic country rocks at the roof of the magma chamber. Recrystallisation of these rocks gave rise to the microgranites that locally overlie the granodiorites. Mineralogical, textural and geochemical features indicate a relatively advanced fractionation stage, suggesting that the exposed sequence of the Usushwana Complex in the study area represents the upper portion of the intrusion. No significant mineralised occurrences were identified. However, on the basis of similarities between the Usushwana Complex and other mafic layered intrusions which host significant ore deposits, it is suggested that economic concentrations of base metal(Cu-Ni) sulphides, PGE and chromitites are likely to be developed at lower stratigraphic levels.
2
Crous, Stephanus Philippus. "The geology, geochemistry and stratigraphic correlations of the farm Rietfontein 70 JS on the south -eastern flank of the Dennilton Dome, Transvaal, South Africa." Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1005572.
Full textAbstract:
The study area is located between Loskop Dam and the town of Groblersdal, on the southeastern flank of the Dennilton dome, and is underlain by lithologies of the Pretoria Group, Bushveld Complex mafics and ultramafics and acid lavas that resort under the Rooiberg felsites. Field work comprised of geological mapping, soil-, hard-rock- and stream sediment geochemistry, various geophysical techniques and diamond drilling. The rocktypes that resembles the Rustenburg Layered Suite on the farm Rietfontein 70JS is subdivided into a Mixed Zone, Critical Zone and Main Zone, on grounds of geochemical and certain geophysical attributes. The Mixed Zone that overlies the Bushveld Complex floor-rocks, is furthermore separated into an i) Lower-, ii) Middle- and, iii) Upper Unit. The Lower Unit of the Mixed Zone consists primarily of magnetite-gabbros, iron-rich pegmatites, harzburgites and feldspathic pyroxenites. The Fe-rich constituents of this stratigraphic horizon generates a pronounced magnetic anomaly within the study area. On the basis of; amongst other parameters, Zr/Rb and Sr/Al₂0₃ ratios, the magnetite-gabbros are postulated to conform to lithotypes in the vicinity of magnetite layers 8 to 14 of Upper Zone Subzone B in a normal Bushveld Complex stratigraphical scenario. Similarly, it is argued that the feldspathic pyroxenites and norites that display elevated chromium values are analogues to normal Critical Zone rocktypes of the Rustenburg Layered Snite. A more elaborate and precise stratigraphic correlation for the Critical zone was, however, not possible. It is advocated that a volume imbalance was created by the hot, ascending mafic magmas of the intruding Bushveld Complex, resulting in the updoming of certain prevailing basement features such as the Dennilton Dome. In addition to this ideology, it is proposed that the Mineral Range Fragment is in fact a large xenolith underlain by mafics, after being detached from the Dennilton Dome during the intrusion event. Evidence generated by this study unequivocally indicate that the potential for viable PGE's, Ni, Cu and Au within a Merensky Reef- type configuration or a Plat Reef-type scenario under a relatively thin veneer of acid Bushveld Complex roof-rocks on the eastern flank of the Dennilton Dome, appears feasible.
3
Bartman, R. D. (Reynard Dirk). "Geology of the Palaeoproterozoic Daspoort Formation (Pretoria Group, Transvaal Supergroup), South Africa." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/42447.
Full textAbstract:
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. The Palaeoproterozoic
Daspoort Formation (c. 2.1‐2.2 Ga) forms part of the Pretoria Group on the Kaapvaal craton. This
sandstone‐ and quartzite‐dominated lithological formation covers an elliptical geographical area
stretching from the Botswana border in the west to the Drakensberg escarpment in the east, with its
northern limit in the Mokopane (Potgietersrus) area and Pretoria in the south; altered outliers are also
found in the overturned units of the Vredefort dome in the Potchefstroom area. Deposition of the
Daspoort Formation was in a postulated intracratonic basin which applies equally to the entire
Transvaal Supergroup succession in the Transvaal depository. Various characteristics from the
formation, such as sedimentary architectural elements (e.g., channel–fills etc.), maturity trends and
distribution of lithofacies assemblages across the preserved basin give insight into the developing
conditions during deposition and genesis of the Daspoort Formation. Subordinate evidence from basic
geochemistry, ripple mark data and optical microscope petrology studies support the sedimentary
setting inferred for this Palaeoproterozoic deposit. Fluvial and epeiric marine conditions prevailed
during the deposition of the Daspoort clastic sediments into the intracratonic basin. This shallow
epeiric sea was fed by fluvial influx, predominantly from the west when a transgressive regional
systems tract led to the filling of the basin, evolving into the deeper marine Silverton Formation
setting, laid down above the Daspoort. Transgression from the east (marine facies predominate) to the
west (fluvial facies) is supported by cyclical trends, palaeoenvironmental and palaeogeographical
interpretations. Accompanying poorly preserved microbial mat features contribute to the postulated
shallow marine environment envisaged for the eastern part of the basin whereas ripple marks and
grain size distribution support a fluvial setting for the west, with lithofacies assemblages accounting for
both areas’ depositional interpretation.Dissertation (MSc)--University of Pretoria, 2013.
tm2014
Geology
Unrestricted
4
Brennan, Michael Brendan. "The genesis of ilmenite-rich heavy mineral deposits in the Bothaville/Delmas area, and an economic analysis of titanium, with particular reference to the Dwarsfontein deposit, Delmas district." Thesis, Rhodes University, 1991. http://hdl.handle.net/10962/d1005561.
Full textAbstract:
A number of ilmenite-rich heavy mineral deposits occur along the northern margin of the intracratonic Karoo basin, and are hosted by the fluvio-deltaic Middle Ecca Group. Coastal reworking of delta front sands within a regressive, microtidal shoreline may be considered as a depositional model for the development of the heavy mineral deposits. An economic analysis of titanium suggests long term positive demand, and sustained high prices for this commodity. An evaluation of the Dwarsfontein ilmenite-rich heavy mineral deposit, using available data, indicates how important it is for deposits of this type to be situated close to an upgrading plant or export harbour.
5
Latorre-Muzzio, Gina. "The influence of geological, genetic and economic factors on the ore reserve estimation of Kwaggashoek east iron ore deposit." Thesis, Rhodes University, 1993. http://hdl.handle.net/10962/d1005584.
Full textAbstract:
Tectonics plays an important role in the genesis and subsequent mlnlng development of the Kwaggashoek East ore body. Lithological key units control the effectiveness of the ore forming processes, affecting the in situ ore reserve, The Kwaggashoek East deposit is the product of primary and secondary processes. A genetic model focussed on the source, migration and deposition of iron suggests a possible original source of iron as the product of very dilute hydrothermal input into deep ocean waters, with subsequent migration through structural conduits. Supergene processes account for the upgrading of the ore and the phosphorus redistribution. A good correlation between samples in a preliminary geostatistical study reflects the effectiveness of this process in the high grade ore zone. A broad overview of the economic issues which affect the commercialization of iron, indicates a balanced supply-demand situation for the five next years. The reserve estimation procedure requires accurate scientific terminology and appropriate methodology. Documentation is essential and should be detailed enough to allow for future reassessment. The results of three estimation methods in Kwaggashoek East differ by less than 5%. The accuracy of the final results depends more on geological interpretation and assumptions than on the method applied. Although optimization of grade and tonnage in the Kwaggashoek East deposit seems to be met with the actual cut-off grade used in the Thabazimbi mine district, the grade-quality concept introduced in this thesis indicates a decrease in the estimated reserves for the deposit
6
De, Bever Johannes Nicolaas. "An overview of the early-proterozoic, auriferous Black Reef placer in the Transvaal Basin." Thesis, Rhodes University, 1997. http://hdl.handle.net/10962/d1005596.
Full text
7
Polteau, Stéphane. "Stratigraphy and geochemistry of the Makganyene formation, Transvaal supergroup, Northern Cape, South Africa." Thesis, Rhodes University, 2001. http://hdl.handle.net/10962/d1005616.
Full textAbstract:
The Makganyene Formation forms the base of the Postmasburg Group in the Transvaal Supergroup of the Northern Cape Province. The Makganyene Formation has diamictite as the main rock type, but siltstone, sandstone, shale, and iron-formations are also present. A glacial origin has been proposed in the past due to the presence of dropstones, faceted and striated pebbles. Typically, the Makganyene Formation contains banded iron-formations interbedded with clastic rocks (shale, siltstone, sandstone and diamictites) at the contact with the underlying iron-formations. This transitional zone is generally overlain by massive or layered diamictites which contain poorly sorted clasts (mainly chert) within a shaly matrix. Striated pebbles have been found during field work, and dropstones have been observed in diamictites and banded iron-formations during the study. The top of the Makganyene Formation contains graded cycles interbedded with diamictites and thin layers of andesitic lavas from the Ongeluk Formation. The basal contact of the Makganyene Formation with the underlying Koegas Subgroup was described as unconformable by previous workers. However field work localised in the Rooinekke area shows a broadly conformable and interbedded contact with the underlying Koegas Subgroup. As described above, banded iron-formations are interbedded with the clastic rocks of the Makganyene Formation. Moreover, boreholes from the Sishen area display the same interbedding at the base of the Makganyene Formation. This suggests that no significant time gap is present in the whole succession between the Ghaap and Postmasburg Group. The Transvaal Supergroup in the Northern Cape displays the following succession : carbonates-BIFs-diamictites/ lava-BIFs-carbonates. The Makganyene Formation is thus at the centre of a symmetrical lithologic succession. Bulk rock compositions show that the diamictites have a similar composition to banded iron-formation with regard to their major element contents. Banded iron-formations acted as a source for the diamictites with carbonates and igneous rocks representing minor components. Differences in bulk composition between the Sishen and Matsap areas emphasize that the source of the diamictite was very localised. The Chemical Index of Alteration (CIA) has been calculated, but since the source dominant rock was iron-formation, this index cannot be usefully applied to the diamictites. ACN, A-CN-K, and A-CNK-FM diagrams confer a major importance in sorting processes due to the separation between the fine and coarse diamictites. The interbedded iron-formations display little clastic contamination indicating deposition in clear water conditions. However, dropstones are present in one borehole from the Matsap area, indicating that iron-formation took place under ice cover, or at least under icebergs. Stable isotope studies show that the iron-formations, interbedded towards the base of the Makganyene Formation, have similar values to the iron-formations of the Koegas Subgroup. As a result of the above observations, new correlations are proposed in this study, relating the different Transvaal Supergroup basins located on the Kaapvaal Craton. The Pretoria Group of the Transvaal Basin has no correlative in the Griqualand West Basin, and the Postmasburg Group of the Northern Cape Basin has no lateral equivalent in the Transvaal Basin. These changes have been made to overcome problems present in the current correlations between those two basins. The Makganyene Formation correlates with the Huronian glaciations which occurred between 2.4 and 2.2 Ga ago in North America. Another Precambrian glaciation is the worldwide and well-studied Neoproterozoic glaciation (640 Ma). At each of these glaciations, major banded iron-formation deposition took place with associated deposition of sedimentary manganese in post-glacial positions. The central position of the Makganyene Formation within the Transvaal Supergroup in the Northern Cape emphasizes this glacial climatic dependence of paleoproterozoic banded iron-formation and manganese deposition. However these two Precambrian glaciations are interpreted in paleomagnetic studies as having occurred near to the equator. The controversial theory of the Snowball Earth has been proposed which proposes that the Earth was entirely frozen from pole to pole. Results from field work, sedimentology, petrography and geochemistry were integrated in a proposed depositional model of the Makganyene Formation occurring at the symmetrical centre of the lithologic succession of the Transvaal Supergroup. At the beginning of the Makganyene glaciation, a regression occurred and glacial advance took place. The diamictites are mostly interpreted as being deposited from wet-based glaciers, probably tidewater glaciers, where significant slumping and debris flows occurred. Any transgression would cause a glacial retreat by rapid calving, re-establishing the chemical sedimentation of banded iron-formations. These sea-level variations are responsible for the interbedding of these different types of rocks (clastic and chemical). The end of the Makganyene glacial event is characterised by subaerial eruptions of andesitic lava of the Ongeluk Formation bringing ashes into the basin. Banded iron-formation and associated manganese accumulations are climate-dependant. Glacial events are responsible for the build up of metallic ions such as iron and manganese in solution in deep waters. A warmer climate would induce a transgression and precipitation of these metallic ions when Eh conditions are favourable. In the Transvaal Supergroup, the climatic variations from warm to cold, and cold to warm are expressed by the lithologic succession. The warm climates are represented by carbonates. Cold climates are represented by banded iron-formations and the peak in cold climate represented by the diamictites of the Makganyene Formation. These changes in climate are gradual, which contradict the dramatic Snowball Earth event: a rapid spread of glaciated areas over low-latitudes freezing the Earth from pole-to-pole. Therefore, to explain low-latitude glaciations at sea-level, a high obliquity of the ecliptic is most likely to have occurred. This high obliquity of the ecliptic was acquired at 4.5 Ga when a giant impactor collided into the Earth to form the Moon. Above the critical value of 54° of the obliquity of the ecliptic, normal climatic zonation reverts, and glaciations will take place preferentially at low-latitudes only when favourable conditions are gathered (relative position ofthe continents and PC02 in the atmosphere).
8
Field, Matthew. "The petrology and geochemistry of the upper critical zone of the Bushveld complex at the Amandelbult section of Rustenberg Platinum Mines Limited, Northwestern Transvaal, South Africa." Thesis, Rhodes University, 1987. http://hdl.handle.net/10962/d1007499.
Full textAbstract:
A study of petrological and geochemical variations through the upper Critical Zone of the Bushveld Complex at Amandelbult section of R.P,M. was undertaken. The sequence at this locality may be divided into seven "units" two of which appear to be complete, possessing the sequence harzburgite-pyroxenite-norite-anorthosite. The other five Units lack basal, intermediate or upper members. Considerable lateral variations are apparent in this sequence, but these are restricted to the Lower Pseudo Reef-Merensky Reef interval, tne same portion of the succession which is affected by pothole structures. The single most important petrographic feature of genetic significance is the occurrence of annealed, recrystallized anorthosite immediately underlying ulstramafic layers. This, together with the undulatory nature of the contact between the two rock layers, suggests that the ultramafic layer was emplaced as a hot liquid over a pre-existing, crystalline anorthosite floor, and that some remelting of this layer occurred. Variations in the chemical make-up of constituent silicate minerals reveal a number of significant processes which may have been operative in the magma chamber prior to crystallization, Olivine grains, for instance, exhibit extremely wide chemical variations both within single layers and from one layer to the next. These variations are best explained by re-equilibration processes with spinel and base metal sulphides, rather than by wide variations in original liquidus compositions. It appears that the compositions of the initial liquids from which each basal olivine-bearing layer crystallized, were approximately similar. Variations in the iron-magnesium ratio of ortho-pyroxenes indicate well defined continuous fractionation trends in units which are considered to be complete. Magnesian compositions are recorded in ultramfic members, while increasingly iron-enriched values are recorded upwards through the sequence pyroxenite-norite-antorthosite. Plagioclase grains exhibit less well defined fractionation trends, but it is clear that an upward increase in An is encountered through indivitual Units. This is in direct contrast to the trend exhibited by orthopyroxene. A further feature of plagioclase grains is the considerable degree of chemical zonation exhibited by them. In cumulus grains this is commonly manifested as strongly reversed rims, while in intercululus grains normal zoning is ubiquitous. Whole-rock chemical variations through the succession indicate that cyclical variations occur through successive Units, but that these merely reflect changes in modal mineralogy and not liquid fractionation trends. Such trends can be shown for selected element ratios, where these elements are known to partition into a single mineral phase. Rations of pyroxene components such as the nickel/scandium ratio, exhibit a saw tooth pattern through successive Units, while ratios of plagioclase components such as the strontium/alumina ratio have unique, fairly constant values for each individual Unit but different values for successive Units. The latter type of cyclicity is not always strictly confined to lithologically recognized boundaries between Units, and a slight overlap into overlying ultramafic layers is apparent. An investigation of variations in trace element levels in a single layer in five widely separated boreholes revealed that there is some evidence for a lateral fractionation trend from the southwest (more primitive) to the northeast (more evolved), although the small number of data points available preclude definite conclusions. There exists in the data some evidence that the Giant Mottled Anorthosite differs chemically from the other anorthosites in the study section, and that it more closely resembles rocks of the Main Zone. This evidence is particularly apparent in variations of the chromium/aluminium ratio of orthoyroxene grains, and in the An content of plagioclase grains, both of whose trends exhibit distinct inflections at the base of this member. The features of the succession at Amandelbult are best explained by the model of Eales et al. (in press, a), which visualizes the input of a number of pulses of new, hot liquid into a magma chamber containing the fractionated residua of previous influxes. At a critical point in time, just prior to the mafic Merensky Reef input, a large input of gabboic liquid was intruded at high levels in the chamber. The lower portions of this liquid mixed with the residua of earlier mafic inputs, which in turn mixed with new inputs of mafic, typical Critical Zone liquids. Thus the lower portions of the study section represent mixtures of new Critical Zone liquids with the residua of previous such influxes, while the upper portions have the added complication of mixture with a Main Zone-type liquid. The unique chemical character of the Giant Mottled Anorthosite appears to be a direct manifestation of the influence of the Main Zone liquid.KMBT_363
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Tinney, Christopher Bruce. "The surface geology of the Lavino Chrome Mine of the farm Grootboom 336KT, eastern Transvaal." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1013404.
Full textAbstract:
A mapping project of the surface geology of the Lavino chrome mine and its surroundings was initiated in order to establish the surface geological relationships in the area. In so doing the chromitite layer presently being mined has been identified and potential exploration targets in the area have been outlined. The Lavino Chrome mine field area is situated within the eastern lobe of the Bushveld Igneous Complex. The area is bounded by in the north by the Steelpoort Lineament, in the west by the Dwars River fault and in the east by the contact with the Transvaal Sequence floor rocks. Layered igneous rocks (pyroxenites, norites and anorthosites) of the Rustenburg Layered Suite dominate the geological landscape at the Lavino mine. The fact that outcropping igneous rocks of the Critical Zone abut directly against the quartzite floor rocks on the mine property makes this area unique in the Bushveld Complex. The hills in the field area are capped by mafic/ultramafic iron-rich sheet - like bodies. Extensive strike-slip faulting is seen in outcrop in the area to the north/northwest of present mining operations. On the basis of field relationships, the main chromitite layer presently being mined at Lavino is identified as the Middle Group chromitite layer MG 1. Three other prominent chromitite layers stratigraphically associated with MG 1 are identified as the Middle Group chromitites MG 2, MG 3 and MG 4. Several other less prominent outcropping chromitite layers are tentatively identified as those belonging to the Lower and Upper group of chromitites. The disconformable nature of the contact between the layered igneous rocks and the Transvaal Sequence floor rocks has resulted in the development of a wedge of undifferentiated pyroxenites in the north of the field area. The economically important LG 6 chromitite layer may be developed in subcrop within this wedge.
10
Badenhorst, Jaco Cornelis. "The precambrian iron-formations in the Limpopo belt as represented by the magnetite quartzite deposits at Moonlight, Koedoesrand area, Northern Transvaal." Thesis, Rhodes University, 1991. http://hdl.handle.net/10962/d1013309.
Full textAbstract:
This dissertation is based largely on data that was accumulated during the execution of an exploration program by Iscor Ltd in the Northern Transvaal. The program included geological mapping, geophysical surveys and drilling, on Precambrian iron-formations in the Central Zone of the Limpopo Belt. The structure, stratigraphy, metamorphism, and economic importance of the magnetite quartzites and associated lithologies of the Moonlight prospect are discussed. The lithologies underlying the Moonlight prospect area consist of various pink- and grey-banded gneisses and pink granulite, together with a variety of metasedimentary supracrustal rock-types and concordant serpentinite bodies. The gneissic rock-types consist of chlorite-quartz-feldspar gneiss, chlorite-quartz-feldspar augen gneiss, hornblende-quartz-feldspar gneiss, biotite-quartz-feldspar gneiss, felsic and mafic granulite, and foliated amphibolite. The metasedimentary lithologies are represented by calc-silicates and marble, white quartz-feldspar granulite, magnetite quartzite, metaquartzite and garnet-bearing granulite and gneiss (metapelites). The concordant ultramafic bodies consist of serpentinite with lesser amphibolite, dunite, and chromitite. Intrusive pegmatites and diabase dykes are also present in the prospect area. Metamorphism reached granulite-facies, and more than one retrqgrade metamorphic event is recognized . Amphibolite-facies assemblages are present, but it is uncertain whether they represent another retrograde event . Polyphase deformation has produced intense and complex folding , resulting in irregular magnetite quartzite orebodies. The high metamorphic grades have resulted in medium- grained recrystallization of the magnetite-quartzites with a loss of prominent banding often associated with these rock-types . The magnetite quartzite occurs as three seperate but related ore zones, consisting of one or more ore-bands seperated by other lithologies. All three zones form poor outcrops and suboutcrops in a generally flat lying and sand covered area. · Although representing a low-grade iron ore (32% total Fe), the magnetite quartzite deposits at Moonlight are regarded as potentially viable due to the large opencast tonnages available at low stripping ratios, and the relatively cheap and easy beneficiation process needed to produce a magnetite concentrate with 69-70% total Fe.
11
Rafuza, Sipesihle. "Carbonate petrography and geochemistry of BIF of the Transvaal supergroup : evaluating the potential of iron carbonates as proxies for palaeoproterozoic ocean chemistry." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1018611.
Full textAbstract:
The subject of BIF genesis, particularly their environmental conditions and ocean chemistry at the time of deposition and their evolution through time, has been a subject of much contentiousness, generating a wealth of proposed genetic models and constant refinements thereof over the years. The prevailing paradigm within the various schools of thought, is the widespread and generally agreed upon depositional and diagenetic model(s) which advocate for BIF deposition under anoxic marine conditions. According to the prevailing models, the primary depositional environment would have involved a seawater column whereby soluble Fe²⁺ expelled by hydrothermal activity mixed with free O₂ from the shallow photic zone produced by eukaryotes, forming a high valence iron oxy-hydroxide precursor such as FeOOH or Fe(OH)₃. An alternative biological mechanism producing similar ferric precursors would have been in the form of photo-ferrotrophy, whereby oxidation of ferrous iron to the ferric form took place in the absence of biological O₂ production. Irrespective of the exact mode of primary iron precipitation (which remains contentious to date), the precipitated ferric oxy-hydroxide precursor would have reacted with co-precipitated organic matter, thus acting as a suitable electron acceptor for organic carbon remineralisation through Dissimilatory Iron Reduction (DIR), as also observed in many modern anoxic diagenetic environments. DIR-dominated diagenetic models imply a predominantly diagenetic influence in BIF mineralogy and genesis, and use as key evidence the low δ¹³C values relative to the seawater bicarbonate value of ~0 ‰, which is also thought to have been the dissolved bicarbonate isotope composition in the early Precambrian oceans. The carbon for diagenetic carbonate formation would thus have been sourced through a combination of two end-member sources: pore-fluid bicarbonate at ~0 ‰ and particulate organic carbon at circa -28 ‰, resulting in the intermediate δ¹³C values observed in BIFs today. This study targets 65 drillcore samples of the upper Kuruman and Griquatown BIF from the lower Transvaal Supergroup in the Hotazel area, Northern Cape, South Africa, and sets out to explore key aspects in BIF carbonate petrography and geochemistry that are pertinent to current debates surrounding their interpretation with regard to primary versus diagenetic processes. The focus here rests on applications of carbonate (mainly siderite and ankerite) petrography, mineral chemistry, bulk and mineral-specific carbon isotopes and speciation analyses, with a view to obtaining valuable new insights into BIF carbonates as potential records of ocean chemistry for their bulk carbonate-carbon isotope signature. Evaluation of the present results is done in light of pre-existing, widely accepted diagenetic models against a proposed water-column model for the origin of the carbonate species in BIF. The latter utilises a combination of geochemical attributes of the studied carbonates, including the conspicuous Mn enrichment and stratigraphic variability in Mn/Fe ratio of the Griquatown BIF recorded solely in the carbonate fraction of the rocks. Additionally, the carbon isotope signatures of the Griquatown BIF samples are brought into the discussion and provide insights into the potential causes and mechanisms that may have controlled these signatures in a diagenetic versus primary sedimentary environment. Ultimately, implications of the combined observations, findings and arguments presented in this thesis are presented and discussed with particular respect to the redox evolution and carbon cycle of the ocean system prior to the Great Oxidation Event (GOE). A crucial conclusion reached is that, by contrast to previously-proposed models, diagenesis cannot singularly be the major contributing factor in BIF genesis at least with respect to the carbonate fraction in BIF, as it does not readily explain the carbon isotope and mineral-chemical signatures of carbonates in the Griquatown and uppermost Kuruman BIFs. It is proposed instead that these signatures may well record water-column processes of carbon, manganese and iron cycling, and that carbonate formation in the water column and its subsequent transfer to the precursor BIF sediment constitutes a faithful record of such processes. Corollary to that interpretation is the suggestion that the evidently increasing Mn abundance in the carbonate fraction of the Griquatown BIF up-section would point to a chemically evolving depositional basin with time, from being mainly ferruginous as expressed by Mn-poor BIFs in the lower stratigraphic sections (i.e. Kuruman BF) to more manganiferous as recorded in the upper Griquatown BIF, culminating in the deposition of the abnormally enriched in Mn Hotazel BIF at the stratigraphic top of the Transvaal Supergroup. The Paleoproterozoic ocean must therefore have been characterised by long-term active cycling of organic carbon in the water column in the form of an ancient biological pump, albeit with Fe(III) and subsequently Mn(III,IV) oxy-hydroxides being the key electron acceptors within the water column. The highly reproducible stratigraphic isotope profiles for bulk δ¹³C from similar sections further afield over distances up to 20 km, further corroborate unabatedly that bulk carbonate carbon isotope signatures record water column carbon cycling processes rather than widely-proposed anaerobic diagenetic processes.
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Bowen, Michael Peter. "The petrogenesis of the volcanic rocks of the Witwatersrand triad in the Klerksdorp area, Transvaal." Thesis, Rhodes University, 1985. http://hdl.handle.net/10962/d1001569.
Full textAbstract:
Several hundred chemical analyses of early Proterozoic lavas of the Witwatersrand triad (incorporating the Dominion Group, Witwatersrand Supergroup and Ventersdorp Supergroup) in the Klerksdorp area, have revealed the presence of various distinct magma types. These essentially correspond to formally defined lithostratigraphic units, but several inconsistencies have necessitated the use of informal nomenclature. The lavas have been regionally metamorphosed to low-grade, greenschist facies assemblages. Original igneous textures are preserved, despite a metamorphic overprint. Metamorphism has resulted in a certain degree of random chemical remobilization. Ba, Sr, Rb, K₂0, Na₂0 and CaO have been highly mobile, and their usefulness in petrogenetic modelling is extremely limited. In contrast, Zr, Nb, Y, LREE's, Cr, Ni, Ti0₂ P₂0₅ and Al₂0₃ have remained immobile. Ti/Zr and Ti/P ratios together constitute efficient discriminating variables for characterizing the different magma types. Lava compositions range from primitive Mg-rich tholeiites to rhyolites, the bulk being tholeiitic andesites. Al₂0₃ contents do not exceed 15%, a feature which reflects the tholeiitic, as opposed to calcalkaline, character of these lavas. Two magma-types are present within the Dominion Group, which is a typical example of bimodal volcanism. The Dominion basic lavas are overlain by the Dominion acid porphyries, with a limited amount of interfingering. The basic lava suite is highly fractionated, with compositions ranging from Mg-, Cr- and Ni-rich tholeiites (close to primary mantle melts) to evolved tholeiitic andesites. The most primitive liquids evolved by 45% fractional crystallization of hornblende, followed by a further 70% crystallization of an orthopyroxene-plagioclase assemblage containing up to 3% sulphides. The Dominion porphyries are rhyolitic, display very limited compositional variation, and probably represent a crustal melt related to the same magmatic event which produced the basic lavas. The only lavas from the Witwatersrand Supergroup present in the Klerksdorp area are those of the Crown Formation (Jeppestown amygdaloid). These are tholeiitic dacites which display extremely limited compositional variation, and are unrelated to any of the other magmas of the Witwatersrand triad. The Ventersdorp Supergroup comprises 4 magma-types: The Kliprivierberg Group lavas at the base are subdivisible into 3 sub-types on the basis of Zr contents. (Zr>11Oppm) are the most evolved. They are tholeiitic andesites which display fairly limited compositional variation. It is likely that more evolved compositions are present in other areas where the porphyritic lavas which characterize this unit are better developed. The overlying Orkney lavas are characterized by 110ppm>Zr>90ppm. They are tholeiitic andesites of similar composition to the Alberton lavas, but have lower incompatible element levels, higher siderophile element levels, and are of extremely uniform composition. The uppermost Loraine/Edenville lavas range from magnesian tholeiites to tholeiitic andesites. They are distinguished by Zr< 90ppm, and contain the most primitive magmas af the Witwatersrand triad, with up to 17,5% MgO, 2600ppm Cr, 600ppm Ni and M-values up to 77. The most primitive liquids evolved by 38% fractional crystallization of orthopyroxene ∓ chromite, followed by 35% fractional crystallization of an extract containing clinopyroxene and plagioclase. The absence of olivine precipitation is a result of the inherently high Si0₂ content of the magma. The Loraine/Edenville, Orkney and Alberton lavas do not lie on a common liquid line of descent, but are probably consanguinous. The Platberg Group overlies the Kliprivierberg Group, and has a coarse-clastic sedimentary unit, the Kameeldoorns Formation, at the base. Three petrographically distinct porphyritic lava sequences overlie the Kameeldoorns Formation, namely the informal "Goedgenoeg formation", the Makwassie quartz-feldspar porphyries and the Rietgat Formation. Despite petrographic differences, the Goedgenoeg and Rietgat lavas are chemically indistinguishable and thus form a single magma-type. The Makwassie porphyries are dacitic in composition with a high proportion of feldspar and quartz phenocrysts. Rational variation trends are attributed to a nett loss of Si0₂ during secondary alteration. The porphyries are probably of crustal origin. The Goedgenoeg/Rietgat lavas display unusual chemistry and a broad, irrational compositional spectrum. They contain very high incompatible element levels, high nonnative quartz, as well as high MgO, M-values, Cr and Ni relative to the other tholeiitic andesites of the Witwatersrand triad. It is tentatively suggested that they are hybrid magmas containing both crust and mantle components, the former possibly represented by the Makwassie porphyries. Field evidence suggests that Platberg volcanism commenced directly after Klipriviersberg volcanism ceased, and was accompanied by a period of enhanced tectonic activity. The Platberg lavas thus probably reflect a crustal melting cycle associated with the Klipriviersberg magmatic event. The Allanridge lavas are the youngest rocks of the Witwatersrand triad. They are separated from the Platberg Group by a unit of flat-lying sediments, the Bothaville Formation, which was deposited after an extended period of peneplanation. The Allanridge lavas form a separate magma-type. They are tholeiitic andesites of similar composition to the Alberton lavas, but have higher incompatible element levels and are not consanguinous. The compositional similarities amongst the basic magma-types of the Witwatersrand triad suggests that all were generated in an hydrous mantle. Interelement ratio differences between the various magma-types nevertheless support the concept that the mantle was chemically heterogeneous during the early Proterozoic.
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Land, Jarred. "Genesis of BIF-hosted hematite iron ore deposits in the central part of the Maremane anticline, Northern Cape Province, South Africa." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1020905.
Full textAbstract:
The Paleoproterozoic Transvaal Supergroup in the Northern Cape Province of South Africa is host to high-grade BIF-hosted hematite iron-ore deposits and is the country’s most important source of iron to date. Previous work has failed to provide a robust and all-inclusive genetic model for such deposits in the Transvaal Supergroup; in particular, the role of hydrothermal processes in ore-genesis has not been adequately clarified. Recent studies by the author have produced evidence for hydrothermal alteration in shales (Olifantshoek Supergroup) stratigraphically overlying the iron-ore intervals; this has highlighted the need to reassess current ore-forming models which place residual supergene processes at the core of oregenesis. This thesis focuses on providing new insights into the processes responsible for the genesis of hematite iron ores in the Maremane anticline through the use of newly available exploration drill-core material from the centre of the anticline. The study involved standard mineralogical investigations using transmitted/reflected light microscopy as well as instrumental techniques (XRD, EPMA); and the employment of traditional whole-rock geochemical analysis on samples collected from two boreholes drilled in the centre of the Maremane anticline, Northern Cape Province. Rare earth element analysis (via ICP-MS) and oxygen isotope data from hematite separates complement the whole-rock data. Iron-ore mineralisation examined in this thesis is typified by the dominance of Fe-oxide (as hematite), which reaches whole-rock abundances of up to 98 wt. % Fe₂O₃. Textural and whole-rock geochemical variations in the ores likely reflect a variable protolith, from BIF to Fe-bearing shale. A standard supergene model invoking immobility and residual enrichment of iron is called into question on the basis of the relative degrees of enrichment recorded in the ores with respect to other, traditionally immobile elements during chemical weathering, such as Al₂O₃ and TiO₂. Furthermore, the apparently conservative behaviour of REE in the Fe ore (i.e. low-grade and high-grade iron ore) further emphasises the variable protolith theory. Hydrothermally-induced ferruginisation is suggested to post-date the deposition of the post-Transvaal Olifantshoek shales, and is likely to be linked to a sub-surface transgressive hydrothermal event which indiscriminately transforms both shale and BIF into Fe-ore. A revised, hydrothermal model for the formation of BIF-hosted high-grade hematite iron ore deposits in the central part of the Maremane anticline is proposed, and some ideas of the author for further follow-up research are presented.
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Clarke, Lee Brian. "The geology of the Kruidfontein Volcanic Complex, Transvaal, S. Africa." Thesis, University of Leicester, 1989. http://hdl.handle.net/2381/27558.
Full textAbstract:
The Proterozoic Kruidfontein Volcanic Complex (KVC) is a collapsed carbonatitic caldera structure, preserved as a high-level feature within Transvaal Sequence sediments. An outer ring of hills contains silicate pyroclastic rocks composed of lithic and pumice fragments, crystals and recrystallized matrix. These rocks are the products of co-ignimbrite lithic breccias and partially welded ignimbrite flows. An inner caldera was filled with recrystallized carbonatitic bedded volcaniclastic rocks. Relic pyroclastic carbonate fragments, such as droplet and armoured lapilli, containing juvenile calcite laths, are present. Well preserved primary structure sequences indicate emplacement by pyroclastic flow, surge and air-fall. Together with some reworking and debris flow deposits. The volcanism spans from early eruption of phonolitic material, from ring vents associated with caldera collapse, to smaller volume carbonatitic eruptions, producing intracaldera deposits. The processes operating during emplacement of carbonatitic pyroclastic material are essentially the same as those of silicate tuffs. As well as numerous fragments of phonolitic pumice in the silicate tuffs, there are unusual banded fragments composed of alternating silicate and carbonate compositions which appear to have been originally magmas separated by liquid immiscibility. The fragments show replacement of Al by Fe, and have also been K-feldspathized. Sovite and alvikite carbonatite dykes show that variation between CaO, MgO and FeO is consistant with fractionation from sovite to Fe-rich alvikites. All the carbonatites are strongly enriched in REE. The alvikites are enriched in the incompatible elements La, Ce, Nd, Y, Th, compared with the sovites, but are depleted in Sr, P, Ti, because of early fractionation of Sr-rich calcite, apatite and Ti-Fe oxides. The alvikites also have more positive δ18O and less negative δl3C compositions compared with the sovites, with values trending away from "mantle" compositions. This interpretation is consistant with a carbonatite magma chamber beneath the KVC which fractionated to produce the carbonatites seen at the present day surface. The few, highly altered, KVC nephelinitic rocks have trace-element distributions suggesting that they are parental to the phonolites. Fractionation from nephelinites, to phonolites, to trachytes satisfactorilly accounts for the incompatible trace element distributions. Some of the rocks have suffered secondary alteration, but have retained their trace element signatures. Zr and Nd are residual, whilst crystal fractionation involving feldspar, magnetite, and apatite have depleted some rocks in P, REE, and Sr. The fractionation from phonolite to trachyte, which is the reverse of normally observed trends, is ascribed to increasingly high F contents in the fractionating KVC magma. Three types of fluorite mineralization are recognised at KVC: 1) Replacement and disseminated deposits, 2) Fluorite veins and fracture fillings, 3) Fluorite-rich carbonatite and related dykes. Only Type 1) deposits are of economic importance at Kruidfontein. Fluorite selectively replaces calcite rather than ankerite in the KVC rocks, with ankeritization preceeding and inhibiting fluorite mineralization. Shallow dipping ankeritic tuffs form the host rock for a large (Tilde with hyphen below 5xl06 tonnes) sub-economic horizontal stratiform fluorite orebody, emplaced after inward sag of the bedding.
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Bowen, Teral Barbara. "The geochemical stratigraphy of the volcanic rocks of the Witwatersrand triad in the Klerksdorp area, Transvaal." Thesis, Rhodes University, 1985. http://hdl.handle.net/10962/d1004932.
Full textAbstract:
This study lias initiated with the aim of identifying the existence of any geochemical criteria which may be used to distinguish between the various volcanic formations within the Witwatersrand triad. The Witwatersrand triad comprises three sequences: the Dominion Group at the base, the Witwatersrand Supergroup in the middle, and the Ventersdorp Supergroup at the top. It is underlain by Archaean basement rocks, and covered by rocks of the Transvaal sequence. The Dominion Group consists of the sedimentary Rhenosterspruit quartzite Formation at the base, overlain by a bimodal component of the Syferfontein Porphyry succession of lavas. Basaltic lavas are the major component of the Rhenosterhoek Formation, while the overlying Formation consists primarily of dacitic porphyries. Intercalations of one lava type within the other are common, however, so each formation is not the exclusive domain of only one lava type. The Witwatersrand Supergroup, a predominantly argillaceous and arenaceous sequence, contains two narrow volcanic horizons, one of wbich, the Jeppestown Amygdaloid (now Crown Formation), consisting of tholeiitic andesites, occurs in the study area. The overlying Ventersdorp Supergroup has, at its base, the basaltic Klipriviersberg Group, of which four out of six formations are present in the study area, namely, the Alberton, Orkney, Loraine and Edenville Formations. This group is succeeded unconformably by the PIatberg Group, consisting of the sedimentary Kameel doorns Formation, followed by the (informal) Goedgenoeg, Makwassie Quartz Porphyry and Rietgat Formations. The Goedgenoeg and Rietgat Formations are basaltic, whil e the Mawassie rocks range from basaltic to dacitic, the majority being tholeiitic andesites and andesites . The Pniel sequence at the top of the Ventersdorp Supergroup consists of the sedimentary Bothaville Formation, and the Allarridge Formation, the lavas of which are basaltic with some andesitic tendencies. A well-defined geochemical stratigraphy was found to exist. From the eleven volcanic formations examined, nine distinct geochemical units emerged, as the Loraine and Edenville Formations were found to have the same geochemical characteristics, as did the Goedgenoeg and Rietgat Formations. Despite having undergone law-grade greenschist facies metamorphism, very clear variation patterns with height are displayed by the immobile elements Ti, P, Kb, Zr and Y, and the light rare earth elements La, Ce and Nd. In contrast, much scatter was observed in the variation patterns of Na, K, Mn, Ba and Rb. Three techniques were employed to effect discrimination between formations - orthosonal discrimination, interelement and ratio vs ratio plots, and discriminant analysis. Confidence limits placed on normal probability plots served to isolate outlier samples for further examination by the various discrimination techniques. A successful test of the efficacy of the discrimination techniques was afforded when fourteen samples from an unknown succession were positively identified as representative of the Klipriviersberg Group
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Foster, Michael Benedict John. "Geological control of aquifer properties of the Chuniespoort Group in the Klip River Valley and Natalspruit Basin, Transvaal." Thesis, Rhodes University, 1988. http://hdl.handle.net/10962/d1013338.
Full textAbstract:
The aquifer of the study area occupies an escarpment and low lying limestone plain, and exhibits a Vaal River type karst. The four dolomitic formations present fall into two distinct aquifer forming types; chert poor units and chert rich units. The chert poor units of the Oaktree and Lyttelton Formations were deposited in a subtidal environment and were probably dolomi tised in a migrating schizohaline environment during basin subsidence and shoreline trangression. The chert rich units of the Monte Christo and Eccles Formations were deposited in the shallow subtidal to supratidal zones and the interbedded chert and dolomites may result from minor cyclical marine trangressions and regressions or be a geochemical response to the periodic flooding of freshwater carbonate and flats and tidal deltas. These fundamental geological differences are reflected in correspondingly different development of karst. Transmissive zones in the chert poor units are generally discrete solution features in massive dolomite, 1 m to 2 m thick. Transmissive zones in the chert rich units comprise thick (up to 60 m) and extremely weathered chert with a high void content resulting from the dissolution of carbonate material. The relative importance of various geological features to the development of the karst was assessed using information from two extensive hydrogeological investigations of the area. From the results it bas been concluded that lithostratigraphy, including the occurrence of palaeokarstic horizons, is the major control of aquifer properties. All other geological features are of lesser importance but may nevertheless be associated with enhanced transmissivi ties in any given unit. Faults and lineaments are the structural features most widely associated with highly transmissive zones. The knowledge gained in this study is applicable elsewhere as the principal hydrogeological characteristics of the study area are common to many of the Chuniespoort Group aquifers in the Pretoria - Witwatersrand - Vereeniging Region.
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Carruthers, Jane. "Game protection in the Transvaal 1846 to 1926." Thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/23736.
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Faure, Kevin. "A stable isotope study of the Kaap Valley Tonalite, Barberton Mountain Land, South Africa." Master's thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/15849.
Full textAbstract:
Bibliography: pages 100-109.The Kaap Valley Tonalite (KVT) was a homogenous hornblende+ biotite tonalite that had been subjected to overail propylitic and potassic alteration. Petrographic studies reveal that carbonate alteration and increased proportions of hydrous minerals occur along the KVT and Barberton greenstone belt contact zone, and along major shear zones within the KVT.
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Kriel, Lize. "'N Vergelyking tussen Colin Rae en Christoph Sonntag se weergawes van die Boer-Hananwa-oorlog van 1894." Pretoria : [S.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-10192005-111653.
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Teigler, Bernd. "Mineralogy, petrology and geochemistry of the lower and lower critical zones, Northwestern Bushveld Complex." Thesis, Rhodes University, 1991. http://hdl.handle.net/10962/d1005590.
Full textAbstract:
This study of the lower part of the Rustenburg Layered Suite in the Western Bushveld Complex is based mainly on drill core samples from three localities, which are approximately 130 km apart. The NG-sequence, situated in the northwestern sector of the complex (Union Section, R.P.M.) extends from the floor of the complex to the base of the upper Critical Zone. The sequence is ca. 1800 m thick and it comprises mainly ultramafic cumulates, namely pyroxenites, olivine pyroxenites, harzburgites and dunites. Norites and anorthos ites are present only in minor proportion. Within the upper half of the NG-sequence ten prominent chromitite layers are correlated with the LGI MG4-interval. Correlation is also established between published sequences and the two other sequences studied, located 8 km and 55 km, respectively, east of Rustenburg. Whole-rock chemical data (major and trace elements), microprobe and Sr isotope data are presented. Petrographic studies provide modal analyses and measurements of grain size. All petrographic, mineralogical and other geochemical data point to an origin of the cumulates of the NG-sequence by crystallization from liquids of the U-type lineage and derivatives thereof. No evidence is found for the involvement of parental liquids with a distinctly different composition or crystallization order (A-liquids). However, subtle compositional variations of the parental liquids are evident in slight changes of the Cr content in orthopyroxene or in variations of Sr isotope ratio. The NG-sequence is characterized by intervals with reversed fractionation trends caused by repeated influxes of pristine magma (during periods of high magmatic activity) resulting in a high degree of rejuvenation. These intervals are overlain by others with a normal fractionation trend, interpreted as cumulates formed in periods with low or no magmatic activity, in which fractional crystallization controlled bulk composition of the evolving liquid. The Lower Zone in the NG-sequence is dominated by a progressive shift towards more primitive compositions, while in the Critical Zone fractionation was the major operating process in the magma chamber. However, during deposition of the pyroxenitic lower Critical Zone several replenishment events occurred, during which fresh Cr-rich magma was emplaced. Massive chromitite layers were deposited after mixing between the newly emplaced magma and the resident residual liquid shifted bulk compositions into the primary field of chrome-spinel. Cumulus plagioclase crystallized after bulk composition of the residual liquid was driven to the orthopyroxene plagioclase cotectic by continued fractional crystallization; this occurred once in the Lower Zone, yielding a single, thin norite layer, and again in the upper Critical Zone of the NG-sequence. A facies model is proposed based on the stratigraphic and compositional variations along strike in the Western Bushveld Complex. This model explains the variations by means of the position of the sequence with regard to a feeder system. The olivine- and orthopyroxene-rich, but plagioclase-poor NG-sequence represents the proximal facies, while the SF-sequence (poor in ferromagnesian phases, but plagioclase-rich) is developed as a distal facies, close to the Brits graben.
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Schutz, Christopher John. "Site relationships for Pinus patula in the Eastern Transvaal escarpment area." Thesis, University of Oxford, 1990. http://hdl.handle.net/10413/9535.
Full textAbstract:
The largest area of commercial timber plantations in southern Africa is
situated along the Eastern Transvaal Drakensberg Escarpment north of
Nelspruit. The site requirements of tree species in this area are poorly
understood. The purpose of this study was to examine site-tree relationships
in the region and the implications of such relationships for the science of
forestry. Pinus patula Schiede & Deppe in Schlecht. & Cham. was selected for
the study as it is the most widely planted species in the region.
In Chapter 1 the geology, geomorphology, climate, soils and vegetation of the
study area are described. A geological map was compiled. Soil descriptions
were based on 439 soil pits distributed so as to cover the range of site
conditions in the area.
The regression techniques used to identify key environmental factors and to
model their relationships with tree parameters are described in Chapter 2, in
which site-growth relationships specifically are investigated. In mature
stands of P. patula 159 plots were established in such a way as to cover the
widest variation in both site conditions and tree growth. The relationship
between site index (mean top height at 20 years) and 100 site plus 10 stand
parameters recorded at each plot was modelled by means of best-subsets,
multiple and ridge regression. Several candidate models were compared on the
basis of coefficient of determination and validation using independent data.
The best model predicted the site index of the validation plots within 60 cm
of the measured site index. The possible roles of the site variables
identified by the models are discussed.
In Chapter 3 site-foliar nutrient relationships are described. A close
relationship was found between foliar and soil nutrient levels for the six
major geological substrates. Site index was more accurately predicted from
concentrations of individual foliar nutrients than from ratios of these
nutrients. The Diagnosis and Recommendation Integrated System (DRIS),
however, appeared to have greater potential for nutrient diagnosis.
Provisional ORIS norms for P. patula were computed.
In Chapter 4 the excessive accumulation of litter in P. patula stands was
examined. Undecomposed litter layers were greater than 15 cm in thickness on
nearly 25% of the 159 sites studied. Average litter layers contained greater
amounts of nutrients than the underlying topsoil. Due to the colonization of the litter by tree roots, the degree of immobilization of nutrients in litter
is not known. Environmental factors associated with variation in litter
thickness were identified by models which explained up to 73% of the total
variation. These factors are considered to act indirectly by promoting or
retarding decay organisms. The possible implications of litter accumulation
for the maintenance of site productivity are discussed.
In Chapter 5 relationships between site and some wood properties are
described. Although between-tree variation was larger than between-site
variation, some important relationships with site were identified. 10% of all
trees on the 159 plots had severe stem bumps. Most of the variables in a
model to predict the severity of bumps could be interpreted as being
associated with stem stability or exposure. The conclusion was that wind is
probably the major cause of this defect.
The findings of the study are summarized in Chapter 6. Particular attention
is given to a synthesis of the possible roles of site factors in their
relationships with the tree parameters investigated. There were strong
relationships between tree parameters and mainly rainfall, altitude, soil
wetness, exchangeable bases, effective rooting depth, slope position and
geology. The single most deficient nutrient element appeared to be calcium.
The implications for both research and management are outlined.Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1990.
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Scoon, Roger N. "Discordant bodies of postcumulis, ultramafic rock in the upper critical zone of the Bushveld complex : iron-rich ultramafic pegmatite bodies at Amandelbult and the Driekop platiniferous ultramafic pipe." Thesis, Rhodes University, 1986. http://hdl.handle.net/10962/d1004912.
Full textAbstract:
From the abstract: In the layered sequence of the Bushveld Complex a number of distinct, but possibly genetically related groups of transgressive, postcumulus, ultramafic and mafic rock are recognised. The main part of this thesis investigates a suite of postcumulus rocks for which the name iron-rich ultramafic pegmatite is proposed. The majority of iron-rich ultramafic pegmatite bodies examined are from the upper critical zone of the layered sequence at Rustenburg Platinum Mines Amandelbult Section, in the northern sector of the western Bushveld Complex. Field relationships imply that the iron-rich ultramafic pegmatites should be considered as an integral feature of the layered sequence, even though they transgress the cumulates. Consequently, this thesis also includes a study of the cumulate sequence at Amandelbult. A second group of postcumulus, ultramafic rocks which is investigated comprises latiniferous ultramafic pipes; the Driekop pipe has been selected as a case study. This thesis is presented in four sections, namely, an introduction and verview, and studies on the Driekop pipe, the cumulate sequence at mandelbult and the iron-rich ultramafic pegmatite suite. A new classification scheme of discordant bodies of postcumulus, ultramafic rock in he Bushveld Complex is proposed (see also Viljoen & Scoon, in press). In he scheme presented here, two main varieties of postcumulus, ultramafic rock re recognised, namely, non-platiniferous magnesian dunites and iron-rich ltramafic pegmatites.
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Maier, Wolfgang Derek. "Geochemical and petrological trends in the UG2-Merensky unit interval of the upper critical zone in the Western Bushveld Complex." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1005563.
Full textAbstract:
One of the most remarkable features of the layered sequence of the Bushveld Complex is its lateral consistency in lithology. This work has established a geochemical and lithological correlation along 170 km of strike of the interval between the UG2 chromitite and the Merensky Reef within the Upper Critical zone of the western limb of the Bushveld Complex. The correlation is based on geochemical investigations of 10 borehole intersections and lithological comparisons of more than 20 borehole intersections around the western lobe of the complex. The basic data presented include 123 whole-rock analyses for major and 12 trace elements, 97 analyses for ' 12 trace elements, and ca. 5500 microprobe analyses of all major phases. Patterns of cryptic variation are established. Some layers (the UG2 chromitite and pyroxenite) show considerable consistency with regard to geochemistry and lithology. Others can be traced along most of the investigated strike length, such as the Lone Chrome Seam, the Footwall Marker anorthosite and the immediate anorthosite footwall to the Merensky Unit. Most of the distinguishable members within the study section, however, show great variation along strike (i.e., the Lower and Upper Pseudoreef Markers, the central noritic sequence in the southern arm of the western limb and parts of the immediate Merensky Reef footwall succession). Several models have been evaluated to interpret the geochemical and lithological data. The author comes to the conclusion that the degree of lithological consistency depends on the variability of magmatic parameters within different parts of the chamber. The most important of these parameters are: (i) the size of fresh primitive influxes and consequently the heat flux, (ii) the composition of the residual liquid, and (iii) the frequency of the influxes. Fresh influxes of more or less similar composition thus spread out along the floor if the residual liquid was less dense than the fresh primitive liquid, but intruded the chamber as a plume where plagioclase had crystallized for some time and the residual liquid had become relatively dense. The size of the influx may be regarded as a measure of the amount of heat flux from the feeder into the chamber. A large influx created uniform physicochemical conditions in the chamber whereas a smaller influx created a strong lateral gradient of physicochemical parameters in the chamber, with subsequent differences in viscosity, density, convection currents, yield strength and thus different mixing behaviour of different liquids. Furthermore, a persistent heat flux from the feeder may have delayed crystallization of successive phases in those parts of the chamber proximal to the feeder . Therefore, new influxes would have been deposited on a footwall of varying thickness and lithology in response to different degrees of crystallization and accumulation along strike. The development of a normal cyclic unit (chromititeharzburgite-pyroxenite-norite (+anorthosite?)) may thus have been interrupted at various stages in different parts of the chamber. The ability to correlate anorthosites over great strike distances implies that their formation did not follow entirely random processes but was dependent on specific magmatic conditions which prevailed over laterally extensive portions of the chamber at certain stages during the evolution of the crystallizing liquid.
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"Die geologie van die Krokodilrivierfragment, Transvaal." Thesis, 2014. http://hdl.handle.net/10210/13109.
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Pienaar, Jacobus Conradie. "Die geologie van die Alldays omgewing in Noord-Transvaal." Thesis, 2014. http://hdl.handle.net/10210/10133.
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Clendinin, C. W. "Tectonic influence on the evolution of the Early Proterozoic Transvaal sea, southern Africa." Thesis, 2015. http://hdl.handle.net/10539/16515.
Full textAbstract:
The epeiric Transvaal Sea covered the Kaapvaal Craton of
southern Africa during the Early Proterozoic and its remnant
strata represent one of the oldest known carbonate depositories.
A genetic stratigraphic approach has been used in this research
on the evolution and syndepositional tectonics of the Transvaal
Sea; research also emphasized the development of basement
precursors, which influenced the Transvaal Sea. Eight subfacies
were initially recognized and their interrelationships through
Transvaal Sea time and space were used to identify ten
depositional systems. Paleogeographic reconstructions indicate
that the depositional systems developed on morphological
variations of a distally-steepened carbonate rarp and that the
depositional character of each was simply a function of water
Backstripping of the depositional systems indicates that the
Transvaal Sea was compartmentalized; three compartments are
preserved on the Kaapvaal Craton. Backstripping also indicates
that the depositional center of the Transvaal Sea lay over the
western margin of an underlying rift. Rifting had developed a
major, north-south-trending structure, and its geographical
interrelationships with the east-west-trending Selati Trough
created the compartment architecture of the basement.
Interpretation of syndepositional tectonics suggests that
six stages of subsidence influenced the Transvaal Sea. Early
subsidence consisted of mechanical (rift) subsidence followed by
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Van, Schalkwyk John Francois. "Metamorphism of ultramafic rocks during the Limpopo orogeny : evidence for the timing and significance of CO2-rich fluids." Thesis, 2014. http://hdl.handle.net/10210/11669.
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Courtnage, Paul Michael. "Post-Transvaal deformation between the Johannesburg dome and the Bushveld complex." Thesis, 1995. https://hdl.handle.net/10539/24288.
Full textAbstract:
A dissertation submitted to the Faculty of Science, University or the Witwatersrand, for the
degree of Master of Science.The study of an area north of the Johannesburg Dome has revealed that the rocks of the Transvaal Supergroup have been affected by widespread deformation, as well as metamorphism to the greenschist facies. Thermal modelling suggests that the metamorphism, and hence porphyroblast growth, can probably be attrIbuted to the thermal effect of the Bushveld Complex. Thus, textural relationships between porphyroblasts and cleavage microstructure in slates could be utilized to establish the relative timing of ductile deformation events in the area. (Abbreviation abstract)
AC 2018
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Bosch, P. J. A. "Die geologie van die Wolkberg Groep tussen die Abel Erasmuspas en Graskop, Oos-Transvaal." Thesis, 2014. http://hdl.handle.net/10210/11709.
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Clay, Andrew Neil. "The geology of the Malmani Dolomite Sub-Group in the Carletonville area, Transvaal." Thesis, 2015. http://hdl.handle.net/10539/16934.
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Boer, Rudolf Hans. "Physico-chemical conditions of mineralization in the Sabie-Pilgrim's Rest Goldfield, Eastern Transvaal." Thesis, 2016. http://hdl.handle.net/10539/20867.
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A dissertation submitted to the Faculty of Science, University of the
Witwatersrand, Johannesburg, for the Degree of Doctor of Philosophy
Johannesburg, 1995A different class of mesothermal gold deposit at Sabie-Pilgrim’s Rest is described which is probably associated with the Bushveld igneous event in South Africa. Pressure and temperature estimates indicate that the ore-fluids of the Sabie-Pilgrim's Rest Goldfield, which occurs within the early Proterozoic Transvaal Supergroup, were similar to those of mesothermal gold deposits. [Abbreviated abstract. Open document ot view full version]
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Wabo, Hervé. "Paleomagnetism of post-Transvaal sill complexes, selected dykes and the Uitkomst Complex - relation to the Bushveld Complex." Thesis, 2014. http://hdl.handle.net/10210/8790.
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Ph.D. (Geology)The Paleoproterozoic (i.e. 2500 Ma to 1600 Ma) apparent polar wander path (APWP) for the Kaapvaal craton (KC) is not well constrained, due to the lack of reliable paleopoles and absence of numerical ages for existing poles. In addition, the duration of emplacement, and timing of remanence acquisition of the Rustenburg Layered Suite (RLS) and other units of the Bushveld Large Igneous Province (LIP) are still unclear. During the present paleomagnetic study, samples were collected from the small intrusions that occur around the RLS and that are believed to be related to the Bushveld LIP for the establishment of new paleomagnetic and virtual geomagnetic poles. In addition, samples from post-Transvaal sills and dykes were targeted for U-Pb dating and geochemical analyses. Geochronological and geochemical data helped to constrain the timing of the newly defined paleopoles. These paleopoles were used in conjunction with previously published ones from KC to evaluate the APWP for this craton during the Paleoproterozoic. Two of the studied post-Transvaal sills in the eastern KC revealed U-Pb ages that are identical to the age recently reported from the Marginal Zone of the RLS. Geochemical signatures of sill samples were in very good agreement with the newly obtained ages. New ages and geochemical data provided constraints on the magnetic components recorded by the sills. The results confirm the existence of B1 Bushveld magma-related sills on KC as well as pre and post-Bushveld sills as previously suggested. Particularly, dataset from the B1 Bushveld magma-related sills allowed for understanding the magnetic history of the RLS at the early stages (Marginal Zone) of its formation. Paleomagnetic sampling of the Uitkomst Complex provided constraints on the remanence acquisition of this complex and also helped to understand the timing of the Bushveld magmatism outside of the main complex. Paleomagnetic data from a post-Transvaal dolerite dyke swarm near Lydenburg revealed a complex magnetic history. Characteristic magnetic components constrained by geochemical analyses were not similar to the RLS, but indicate probable relationship to other units of the Bushveld LIP. The new ages generated in this study coupled to those previously obtained from the upper layers of the RLS suggested that this suite emplaced within a time period of at least 4 million years. Paleomagnetic results from the B1 Bushveld magma-related sills and available data from the upper layers of the RLS reveal that during the RLS emplacement, the Earth’s magnetic field reversed at least eight times. These results, together with data from the Lydenburg dykes, further indicate a minimum of nine changes in polarity of the Earth’s magnetic field during the formation of the Bushveld LIP. During the present study, new pole positions of different reliability were added to the existing paleomagnetic database for the KC. Paleopoles from the Paleoproterozoic database of the KC (including those generated in the present study) were used to propose a new APWP for this craton from ~2200 Ma to ~1800 Ma. Particularly, poles from the B1 Bushveld magma-related sills and Uitkomst Complex provide the information to identify striking features in the APWP of the Paleoproterozoic KC.
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Els, Barend Gerhardus. "The auriferous Middelvlei reef depositional system, West Wits Line, Witwatersrand Supergroup." Thesis, 2014. http://hdl.handle.net/10210/9563.
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Vorster, Cornelis Johannes. "Geologie van die Klein-Letabagebied, Noord-Oos-Transvaal met spesiale verwysing na die granitiese gesteentes." Thesis, 2014. http://hdl.handle.net/10210/10553.
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Pretorius, Stephanus Johannes. "Die geologie in die omgewing van Swartwater en die westelike deel van die distrik Messina in die sentrale sone van die Limpopo-gordel." Thesis, 2014. http://hdl.handle.net/10210/10556.
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Coetzee, Louis Lodewyk. "Genetic stratigraphy of the paleoproterozoic Pretoria Group in the Western Transvaal." Thesis, 2009. http://hdl.handle.net/10210/1954.
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M.Sc.The sedimentary succession of the Paleoproterozoic Pretoria Group is very important for understanding Earth’s ancient history. It represents a time of extreme environmental changes on Earth, from global ice-ages to hot-houses. However, the genetic stratigraphy of the succession is poorly understood so that the stratigraphic relationships between the events remain uncertain. This dissertation provides a genetic stratigraphic model of the succession by utilising an integrated sedimentological and geochemical approach which culminates in a new sequence stratigraphic subdivision of the Pretoria Group. The study focuses on the Potchefstroom area in the western part of the Transvaal depository. The Pretoria Group commences with the Rooihoogte Formation which overlies the Chuniespoort Group with erosional contact. New stratigraphic data indicates that the Rooihoogte Formation is a correlative of the Duitschland Formation in the eastern Transvaal. The succession was deposited in a foreland basin. An important new finding is that a diamictite at the base of the formation contains striated and bull-nosed pebbles and is of glacial origin. The discordantly overlying Timeball Hill Formation is composed of a coarsening upward carbonaceous shale – hematite oolite-bearing quartzite unit overlain by a second carbonaceous shale, capped by a second glacial diamictite (the well known Rietfonteindam diamictite). The oolitic ironstones in the quartzites suggest that they formed in a warm oxidizing environment. The shales display mature chemical indices of alteration which supports this theory. ä13Corganic values increase from –35‰ to –24‰ from the bottom to the top of the Timeball Hill Formation indicating net carbon burial, which translate to a decrease in atmospheric CO2 and colder climates as deposition evolved. In turn this can be linked to the presence of the glacial Rietfonteindam diamictite in the upper part of the Timeball Hill Formation. The Rietfonteindam diamictite is overlain by conglomerate, quartzite and shale of the Boshoek Formation, which were deposited as an upwards fining transgressive sedimentary unit following on post-glacial eustatic sea-level rise. It is in turn overlain by the 2.22Ga. Hekpoort basalt. This basalt is metasomatically altered, but has remained virtually unaffected by regional metamorphism, as shown by detailed SEM petrographic analyses. Excellent examples of zeolite- filled amygdales are preserved in the lavas. The Hekpoort lavas are overlain by fluvial red beds of the Dwaalheuwel Formation. A lateritic paleosol (Hekpoort paleosol) is developed below the red bed succession. The red beds are overlain with sharp gradational contact by the carbonaceous shelf mudstone of the Strubenskop Formation which grades up into the shallow marine Daspoort quartzite. The Silverton Formation, mainly composed of carbonaceous shale, overlies the Daspoort Formation with sharp gradational contact and grades upwards into shallow marine Magaliesberg quartzite. ä13Corganic values decrease from –25‰ to –29‰, from middle to top of the Silverton Formation, most probably indicating carbon input into the atmosphere and therefore rising atmospheric temperature. The Machadodorp lava, which was previously thought to be restricted to the eastern part of the Transvaal basin, was found to be present in the Potchefstroom area as well. Five unconformity-bounded sequences are present in the succession. Estimates are that they were deposited in time intervals of 60m.y. each.
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Brandt, R. T. "The Geology Of Certain Igneous Intrusive Rocks In The Far East Rand, Transvaal, South Africa." Thesis, 2015. http://hdl.handle.net/10539/16428.
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"Alteration and gold mineralisation in the Roodepoort Goldfield, Pietersburg Granite-Greenstone Terrane." Thesis, 2014. http://hdl.handle.net/10210/12896.
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Vermaakt, Deon Tobias. "Die Suikerbosverskuiwing." Thesis, 2014. http://hdl.handle.net/10210/13085.
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Obbes, August Murray. "The structure, stratigraphy and sedimentology of the Black Reef-Malmani-Rooihoogte succession of the Transvaal supergroup south-west of Pretoria." Thesis, 2014. http://hdl.handle.net/10210/12713.
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Van, Wyk Jacob Pieter. "Die geologie van die gebied Rooinekke-Matsap-Wolhaarkop in Noord-Kaapland met spesiale verwysing na die Koega-subgroep, Transvaal-supergroep." Thesis, 2014. http://hdl.handle.net/10210/10796.
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Schaefer, Markus Olaf. "Paleoproterozoic Mississippi Valley-Type Pb-Zn deposits of the Ghaap Group, Transvaal Supergroup in Griqualand West, South Africa." Thesis, 2009. http://hdl.handle.net/10210/1969.
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Nel, Brian Philip. "Petrography and geochemistry of iron formations of the Paleoproterozoic Koegas Subgroup, Transvaal Supergroup, Griqualand West, South Africa." Thesis, 2013. http://hdl.handle.net/10210/8762.
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M.Sc. (Geology)Nel, B.P. (2013). Petrography and geochemistry of iron formations of the Paleoproterozoic Koegas Subgroup, Transvaal Supergroup, Griqualand West, South Africa. MSc thesis (unpublished), University of Johannesburg, Aucklandpark, pp. 133. The Early Paleoproterozoic Koegas Subgroup comprises a succession of siltstone, mudstone, iron-‐formation, chert and carbonate rocks that overlies the iron-‐formations of the Asbestos Hills Subgroup with sharp contact. It is overlain with erosional unconformable contact by glaciogenic diamictites of the Makaganyene Formation. This study focused on the lithostratigraphy, mineralogy and geochemistry of the iron-‐ formations of the Koegas Subgroup based on fresh diamond drill core samples obtained during the Agouron scientific drilling project in South Africa in 2004. The iron formations the Koegas Subgroup are represented by a few important lithotypes, occurring in distinct sedimentary facies, which formed in unique depositional and diagenetic environments. The iron formations consist essentially of four facies, namely silicate lutite, mixed silicate-‐siderite lutite, siderite lutite and siderite peloidstone A repetitive sedimentary cycle consisting of fine-‐grained chemical lithotypes grading upward into reworked chemical lithotypes is evident throughout the Koegas Subgroup iron formations. Silicate lutite formed in deep water settings well below the wave base along a chemocline. Siderite lutite formed in shallower parts of the basin through transformation of primary ferric iron precipitate by iron respiration in presence of organic carbon. Peloidstone formed above normal wave base in shallow water by reworking of earlier siderite lutite deposits. The REE geochemistry provides important clues as to the depositional environment of the iron formation as follows. Depletion in LREE and enrichment in HREE combined with positive Y are typical of ocean water indicate that the iron formations were deposited in a marine environment. Positive Eu anomaly suggest the presence of a hydrothermal component in the ocean water from which the iron formations were deposited. Negative Ce anomalies indicate that somewhere in the marine system Ce3+ was oxidized to Ce4+ oxide, probably in the presence of free oxygen in the ocean water column (Bau and Dulski, 1996). The negative Ce anomalies seen in the Koegas iron formations are the oldest currently known from iron formations. As such the Ce anomalies most probably signify an increase in the oxygenation state of the ocean immediately prior to the rise of atmospheric oxygen as defined by Guo et al. (2009).
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Van, Wyk Catharina Johanna. "Die mineralogie en geochemie van sedimentêre siklusse in die Kuruman- en Griquatown-ysterformasies van die Transvaal-Supergroep in Griekwaland-Wes." Thesis, 2014. http://hdl.handle.net/10210/11922.
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"Sedimentologie en palinologie van die permiese Vryheid formasie in die Greenside-steenkoolmyn, Witbank-steenkoolveld, Suid-Afrika." Thesis, 2014. http://hdl.handle.net/10210/12768.
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Schouwstra, Robert Pieter. "Kontroles van goudmineralisasie by die Sheba-goudmyn, Barberton-distrik." Thesis, 2014. http://hdl.handle.net/10210/9259.
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M.Sc. (Geology)The Main Reef Complex (MRC) section is developed in the Zwartkoppie and Sheba Formations of the Onverwacht and Fig Tree Group respectively. The section is represented by three shear zones, associated with a prominent anticlinal structure, locally known as the Birthday No.2 anticline. This tight isoclinal structure is marked by a chert unit, with a core of green quartz-carbonate schist, and is overlain and surrounded by greywackes and shales of the Sheba Formation. At depth the main mineralized fracture occurs to the south of, and parallel to the Birthday No.2 chert bar. Above the crest of the anticlinal structure gold mineralization is associated with three shear zones (which transgress the bedding of the greywackes and shales) known as the No .. I, No. 2 and No. 3 Fractures. Pyrite and arsenopyrite are the main ore minerals, with minor amounts of chalcopyrite, sphalerite, tetrahedrite and pyrrhotite. Pyrite mineralization is ubiquitously developed along the shear zones, while arsenopyrite mineralization is restricted to certain areas. Assay data of the greywackes and shales show that there is a correlation between gold contents and the abundance of arsenopyrite. Gold has been observed in association with all the sulphide minerals present, and as inclusions within pyrite and arsenopyrite. Electron microprobe analyses have revealed significant levels of gold in arsenopyrite, probably as submicroscopic inclusions.
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Kruger, Petrus Johannes. "'n Verbruikersprofiel van voetslaners in Transvaal." Thesis, 2015. http://hdl.handle.net/10210/14529.
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Davies, S. J. "The importance of browse in late dry season and early wet season diets of cattle and goats in a communal area of the Eastern Transvaal lowveld." Thesis, 1993. http://hdl.handle.net/10539/21651.
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A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg, 1991.The contribution of browse and grass to the diets of cattle and goats was assessed in relation to the total biomass of woody foliage and grass available in the study area. Livestock made less use of browse during the dry season than was shown by studies conducted in the Sahel and Nylsvley, northern Transvaal. Goats fed more selectively, utilised newly flushed foliage more and fed upon a greater variety of woody plant species than did cattle. Browse contribute nore to goat diets than to cattle diets although goats were less often supplied with browse. For goats, feeding on standing browse, 'supplied browse and leaf litter occupied 34.7 % of observation time before the tree/shrub flush and 8.3 % post-flush; for cattle the contributions were 14.7 % and 5.8 %, respectively. Fruits, flowers and bark were utilised only during the pre-flush period and only by goats. Goats spent significantly more time grazing and more time browsing than did cattle during the post-flush period. Agave sisalana (sisal) contributed to cattle diets during the preflush and post-flush periods, and to goat diets during the pre-flush period. Since relatively little standing woody foliage is accessible to the animals (16.6 % preflush and 30.7 % post-flush of the wet season maximum), lopping of woody foliage by herders substantially increases the amount of food accessible to livestock, and supplied browse was eaten wherever it was encountered. Aerial cover of grass averaged less than 20 %, grass biomass ,less than 120 kgDM.ha·t and biomass concentration of grass less than 553.5 gDM.m"3 for catena toplands, catena bottomlands and drainage line thickets. The low contribution of browse to livestock diets during this study was due to the scarcity of accessible, palatable forage, exacerbated by the late flush 011 woody plants. In addition, local people harvesting live wood for fuel may compete with foraging livestock. To increase the supply of food for livestock further the rollowing practices could be encouraged: storage of woody foliage litter until the late dry season, use of chemicals to increase the nutritional value of poor quality browse and establishment of woodlots of palatable, perhaps leguminous, evergreen woody species for use as livestock fodder.
GR2017
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Grobler, Johannes Theodorus Wessels. "Die bestuurstaak van die provinsiale administrasieklerk in die skool." Thesis, 2014. http://hdl.handle.net/10210/9808.
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M.Ed. (Education Management)The subject of this investigation is the management function of the provincial administration clerk in the school. The investigation is limited to schools within the ambit of the Transvaal Education Department and has been aimed, primarily, at determining the responsibilities and position of the administration clerk in the effective functioning of the school. As the administration office forms the nerve-centre of the school's activities and due to its staff consistence of administration clerks, a clear indication of their duties and responsibilities is an essential management function of the school principal. The investigation in regard to the functions of the senior provincial administration clerk demonstrated that the school principal as the management leader, must possess a thorough knowledge of administrative matters. This is essential as he, being the in-service trainer, has to suitably equip the senior provincial administration clerk with the required knowledge and skills in order that she, in tum, can easily perform as management leader of the school's administrative section. In order to keep pace with change and modernisation, the school principal and administration clerks must be prepared to attend in-service training courses. Moreover, they must gain knowledge on their own accord through the reading of circular letters, catalogues, manuals and also keep abreast of technological development such as the modern micro computer, word processor as well as facsimile and duplicating machines. The services of a good administration clerk are indispensable to the school principal as well as the educator. Qualities which the administration clerk must possess include reliability, loyalty, responsibility, willingness to help, tact, courtesy, charm, enterprise and patience. AIthough the educator cannot be relieved of all administrative responsibilities, the school principal must nevertheless reflect seriously about administrative responsibilities that should not really be undertaken by the educator. By entrusting responsibilities such as the processing of marks, compiling of class lists, raising of funds, transport arrangements, controlling of stock, duplicating work...