Union Section of Rustenburg Patinum Mines is situated in the northwestern part of the Bushveld Complex, some twenty kilometres north of the Pilanesberg Alkaline Complex. The mining lease area covers a roughly triangular segment of Lower, Critical and Main Zone rocks, transgressed to the north and south by magnetite-bearing ferrogabbro of the Upper Zone. The Main Zone at Union Section is the focus of this study. The prime source of sample material for the study is the deep exploration borehole SK2, but additional, supplementary samples were collected on surface and underground, as well as from a second surface exploration borehole, SK4. In line with the recommendations of SACS (1980), the top of the Critical Zone, and therefore the base of the Main Zone, is taken to be the top of the Bastard Cyclic Unit. Sharpe (1985) suggested that the succession from the base of the Main is an isotopically separate entity Zone up to the Pyroxenite Marker from the rest of the Bushveld layered succession. This is not strictly true, as there is evidence that more than one parental magma was involved in the formation of this interval. It is, however, true that there are fundamental differences, particularly in isotopic makeup, between the Main Zone rocks below the pyroxenite Marker and those above (the latter having been assigned by Molyneux (1970) to subzone C of the Main Zone). Kruger et al. (1986, in press) suggested that the Pyroxenite Marker marks the base of the Upper Zone, and this convention is adhered to here. The implication of this is that the rocks which formerly constituted subzone C of the Main Zone are now considered part of the Upper Zone. The Main Zone rocks below the pyroxenite Marker were originally subdivided by Molyneux (1970) into two subzones, A and B. The results of the present study indicate that this subdivision is not justified. Instead, eight units have been distinguished in the Main Zone on geochemical, petrological and mineralogical bases. Each of these units is characterized by a coherent set, or progression, of chemical and petrological characteristics. The specific assignment of genetic connotations to these units has been deliberately avoided , at least until further studies of the Main Zone prove this to be justified. The demarcation of the eight units is illustrated in the composite diagram (Fig. 34) in the back pocket of this work, and the reasons for the subdivisions are listed in Table 6 (at the end of chapter 7 of this thesis). Until the late 1970's, it was thought that most layered cumulates formed by crystal settling (Wager and Brown, 1968). More recently, there has been a fundamental conceptual change, and many workers now believe that most cumulate rocks formed by in situ crystallization at the floor and walls of the magma chamber (McBirney and Noyes, 1979, Irvine, 1980a; Campbell, 1987). There is, however, some evidence for the physical separation of phases undergoing cotectic crystallization, particularly in the Upper Critical Zone and lower part of the Main Zone (Eales et al., 1986). This process, which has been alluded to in the past by various authors (Ferguson and Botha, 1963; Vermaak, 1976) involves the flotation of early-formed plagioclase crystals due to their positive bouyancy in tholeiitic liquids. The result is an apparent decoupling of the chemistry of pyroxene and plagioclase, as in unit IV of the Main Zone, where plagioclase becomes more anorthitic upwards, whilst pyroxene becomes more iron-rich. There is some substantial evidence, particularly in reversals in the strontium isotope initial ratio and the orthopyroxene Mg/(Mg+Fe) ratio , for multiple intrusion in the Main Zone. Although the largest and most important magma influx in the Main Zone was a high-R₀ aluminous tholeiite, as suggested by Sharpe (1985), the intrusive history of the Main Zone is believed to be far more complex than Sharpe (op. cit.) suggested. Significantly, there is strong evidence for small influxes of Upper Zone-type (Fe-rich tholeiite) magma in the upper reaches of the Main Zone. These are believed to be precursors to the major influx of Upper Zone-type magma at the pyroxenite Marker (Kruger et al, 1986, in press). The fate of intercumulus liquids in cumulate rocks has recently recieved substantial attention (Sparks et al., 1985; Morse, 1986; Barnes, 1986: Campbell, 1987). It is believed that the migration, or at least redistribution, of intercumulus liquids has played a vital role in modifying fractionation trends in the Main Zone. More importantly, the accumulation of late-stage intercumulus liquids is believed to be responsible for the formation of the Fe-rich ultramafic pegmatite bodies that interrupt the layered cumulates in borehole SK2 / Adobe Acrobat 9.53 Paper Capture Plug-in

Text in Afrikaans / Prospektering is een van die eerste en belangrikste stappe in die mineraalontginningsproses en dit word ondersoek teen die agtergrond van die Mineraalwet 50 van 1991, wat die belangrikste "mynwette" herroep en die Suid-Afrikaanse mineraal- en mynreg in vele opsigte op 'n heel nuwe grondslag geplaas het. Die hoofdoel met hierdie proefskrif is om prospekteerregte te sistematiseer en te bepaal of dit beperkte saaklike regte daarstel. Ten aanvang word bepaal welke aktiwiteite prospektering daarstel en welke stowwe regtens as minerale kwalifiseer. Daar word gekyk na die regte waarvan prospekteerregte dee! vorm of waaruit dit afgelei word, naamlik eiendomsreg en mineraalregte. Die afskeiding van minerale van grond, die afskeiding van mineraalregte van grondeiendomsreg en die afskeiding van prospekteerregte van mineraalregte en grondeiendomsreg, asook die inhoud van en beperkings op die uitoefening van prospekteer- en mineraalregte, word ook ondersoek. Daar word veral aangetoon dat mineraalregte nie so wyd is as wat algemeen aanvaar word nie en dat dit 6f by die af skeiding van die roerende minerale tot niet gaan of uitgeput raak 6f in eiendomsreg daarop oorgaan. Prospekteerregte word meestal verleen by wyse van prospekteerkontrakte, waarvan daar verskillende verskyningsvorme bestaan en waarvan die een wat in die Registrasie van Aktes Wet 47 van 1937 omskryf word, as uitgangspunt geneem word. Aangesien die reg om te myn ook die reg om te prospekteer insluit, word die verlening van mynregte en antler verkrygings van prospekteerregte ook behandel. Alvorens gemeneregtelike prospekteerregte egter uitgeoefen mag word, meet magtiging daarvoor by die staat verkry word. Die verlening van statutere prospekteer- en mynmagtigings het by die inwerkingtreding van die Mineraalwet 50 van 1991 grondige veranderings ondergaan wat tesame met die relevante oorgangsbepalings ondersoek word ten einde die uitwerking van die wet op prospekteerregte te bepaal. Die vereistes vir en die regsaard van die verskillende regte word ondersoek ten einde 'n oorsig van prospekteerregte daar te stel en dit vlugtig met veral Australiese reg te vergelyk. Daar word tot die gevolgtrekking geraak dat blote prospekteerregte nie beperkte saaklike regte daarstel nie. / Prospecting is one of the first and most important steps in the minerals exploitation process and is examined against the background of the Minerals Act so of 1991, which repealed the most important "mining" legislation and in many ways placed the South African mining and minerals law on a completely new basis. The main purpose of this thesis is to systematise prospecting rights and to establish whether they constitute limited real rights. It is at the outset determined which activities constitute prospecting and which materials qualify in law as minerals. The rights from which prospecting rights are derived or of which they form part, namely ownership and mineral rights, are considered. The severing of minerals from land, the severing of mineral rights from landownership and the severing of prospecting rights from mineral rights and landownership, as well as the contents of and limitations on the exercising of prospecting and mineral rights, are also examined. It is in particular shown that mineral rights are not as comprehensive as is generally accepted and that they either terminate or are exhausted upon severance of the movable minerals from the land or are converted into ownership thereof. Prospecting rights are mostly granted by way of prospecting contracts, of which different varieties exist and of which the one defined in the Deeds Registries Act 47 of 1937 is taken as the starting point. Since the right to mine includes the right to prospect, mining rights and other acquisitions of prospecting rights are also considered. Before common law prospecting rights may be exercised, however, authority to do so must be obtained from the state. Upon the commencement of the Minerals Act 50 of 1991, the granting of statutory prospecting and mining authorisations underwent fundamental changes, which are examined with the relevant transitional provisions to determine the effect of the act. The requirements for and the juridical nature of the various rights are considered in order to establish an overview of prospecting rights and briefly to compare them mainly with Australian law. The conclusion is reached that mere prospecting rights do not constitute limited real rights. / Jurisprudence / LL. D.

D.Phil. / Please refer to full text to view abstract

M.Sc. / The study site for this project is New Clydesdale Colliery situated in the Witbank Coalfield, South Africa. The Witbank Coalfield is located within the northern part of the Karoo Basin where the major coal deposits in South Africa are located. Optimum ash fusion temperatures derived from coal in this region are approximately 1400°C, and higher, although temperatures above 1300°C are also acceptable. In certain coal seams the ash fusion temperatures drop well below this optimum temperature, leading at times to problems in the user industry. Ash fusion temperature which is the temperature at which the mineral matter in coal begins to soften, flow and fuse, is an important aspect relating to coal utilization but is little understood and under-studied in South Africa. The objective of this thesis is to attempt to determine what factors, mineralogical or inorganic chemical, influence variations in the ash fusion temperatures in certain coal samples. An understanding of this problem will have a bearing on the ultimate assessment of a coal for utilization purposes, in general, and ash deposition prediction in future boiler plants in particular. This study is somewhat pioneering as no detailed studies have been undertaken or published previously. Samples were collected at four sites from New Clydesdale Colliery. The sample sites were selected based on pre-existing knowledge of the ash fusion temperatures obtained from company analytical sheets. The sites were therefore representative of low and high ash fusion temperature coal. The first two sites were located in the opencast area where the No. 2 seam is actively being mined. The other two sites were located underground where mining has ceased. Conventional analyses conducted on the samples include proximate analyses, calorific values, percentage sulphur, and ash fusion temperatures. Further analyses performed included ash analyses (composition of ash), X-ray diffraction, scanning electron microscopy and petrographic studies. It was found that although complex relationships exist between ash fusion temperature and the various geological and coal parameters, positive results were obtained. These indicate a possible relationship between low ash fusion temperatures and i) finer size fractions, ii) an increase in iron content present in the form of pyrite and iii) the form in which pyrite is present, namely cleats. High ash fusion temperatures tend to correlate with i) the absence of pyrite or ii) pyrite present as framboids.

The mineralogy and petrology of two kimberlites, a peripheral monticellite kimberlite, and its core of phlogopite kimberlite, from the West Auxiliary Pipe at Dutoitspan Mine are described. The mineralogy of the two kimberlites differs mainly in the presence of phlogopite macrocrysts, greater abundance of angular crustal inclusions, more heavy minerals and higher diamond grade in the phlogopite type. Microprobe analyses of olivine, phlogopite, monticellite, oxide minerals and garnet are presented. Silicate compositions are comparable in both kimberlites and zoning of olivine grains is typically towards a rim of Fo₈₉₋₉₀ʻ irrespective of whether cores are more Fe-rich or more Mg-rich. This is caused by re-equilibration after fluidised emplacement in the earth's crust of macrocryst-bearing kimberlite magma. Olivine aggregates were derived from sheared mantle lherzolite and single-crystal macrocrysts were formed at higher mantle levels from a kimberlitic crystal-mush magma. This was emplaced in the crust by rapid gas streaming. The post-fluidisation phenocrysts of olivine and phlogopite which formed then are in general more Fe-rich than macrocrysts. Re-equilibration of ilmenite results in the formation of complex perovskite and titanomagnetite mantles. Phlogopite macrocrysts are preserved in the monticellite contact rock where rapid quenching prevented their resorption and allowed separation of an immiscible carbonate melt, giving the abundant groundmass calcite. Atoll-textured spinels are found in the contact rock. Major and minor trace-element analyses of whole rock samples are presented and discussed, bringing into account the problem of contamination by crustal inclusions. Whole rock chemistry supports derivation of the kimberlites as partial melts of mantle material in the presence of a lithophile-element-enriched fluid. The monticellite contact rock is highly enriched in REE, Nb, and Sr due to rapid freezing of this perovskite-enriched phase. The monticellite type is more enriched in lithophile elements than the phlogopite type, which supports derivation of the monticellite type by a small degree of partial melting, further melting reducing the relative concentrations of lithophile elements to give the phlogopite kimberlite chemistry.

M.Sc. (Geology)

The Grahamstown clay deposits extend in a broad belt from 26°23 to 26°50 East longitude and from 33°15 to 33°22 South latitude along two distinct geomorphological features, the Grahamstown Peneplane (650 m) and the Coastal Plain (520m). The clay deposits traverse four different lithologies including the Bokkeveld Shale, Witteberg Shale, Dwyka Tillite and Ecca Shale. The two planes invariably have a covering of silcrete which is also present over most of the clay deposits except where erosion has taken place. X-ray fluorescence analysis shows that chemically there is a fairly wide variation between and witnin the deposits. The greatest variation is in the Si0₂/Al₂0₃ ratio which appears to be controlled by the parent lithology and to some extent by the amount of leaching. K²0 shows an increase in concentration with depth and therefore indicates the limits of hydrolysis and leaching and of the clay. X-ray diffraction study shows the Peneplane and Coastal Plain deposits to be quite distinct. The Peneplane deposits consist of kaolinite, illite and quartz and the Coastal Plain deposits of kaolinite, illite, quartz and pyrophyllite. The presence of pyrophyllite is not fully understood as there is no indication of major faulting, metamorphism or pyrophyllite in the parent rock. The pyrophyllite most probably represents a transformation product of kaolinite. The kaolinite from the various deposits shows a considerable variation in crystallinity in both the X-ray diffraction traces and electron photomicrographs. The most poorly crystalline kaolinites are from the Coastal Plain deposits and the difference in crystallinity is most probably due to differences in the degree of hydrolysis and the parent rock material in the case of the tillite. Genetically all of the deposits are residual types generated by hydrolysis and subsequent leaching of micas and feldspars. The principal elements leached are silicon, iron and potassium. The hydrolysis and leaching took place over a long period of time in the flat lying areas of the Peneplane and Coastal Plain. The deposits are exploited economically and the clay is used principally in the tile, pottery and whiteware industries with some usage in the paper, refractory and brickmaking industries. The price commanded by raw kaolin is not very high and as a result the clay industry in Grahamstown is not as viable economically as it could be.

Banded iron-formations (BIFs) are chemically precipitated sedimentary rocks in which Fe-rich bands or laminae alternate with Fe-poor ones. They formed within a specific time-span of the geological record. Their occurrence is restricted between 2.3 and 1.9 Ga, and characterises virtually all the major Precambrian-aged sedimentary basins of the world. The Precambrian Transvaal Basin in Griqualand West, South Africa, is noted for its well-developed BIF units. The Kuruman and Griquatown BIFs comprising the Asbesheuwels Subgroup (up to 1000m thick) are the best known and thickest of these. As far as metallogenesis is concerned, the Kuruman BIF is of major importance, for it carries the world's largest crocidolite (blue asbestos) deposits. The uppermost, youngest member of iron-formation deposition in the Griqualand West Sequence is represented by the Voëlwater BIF. The direct association between the latter and the giant Mn-deposits of the Kalahari Field, renders the Voëlwater association unusual, if not unique, in the geological record. The Voëlwater BIF represents a typical example of the so-called "Superior-type", and in the area of study it has undergone late-diagennetic to low-grade metamorphic processes. This is evident from the mineralogical composition and textural signature of the various BIF lithologies. Specifically, the minerals that make up the Voëlwater BIF are mainly chert(quartz), Fe-oxides (magnetite and hematite), Fe-silicates (greenalite, stilpnomelane, minnesotaite, riebeckite, Fe-mica), Fe-carbonates (members of the dolomite-ankerite series and siderite), calcite and pyrite. Soft-sediment deformation structures and shear-stress indicators are abundant in carbonate-rich and granular, silicate-rich BIF lithologies respectively. The bulk chemical composition of the study rocks is relatively simple and is characterised by the abundance of essentially three elements, namely Si, Fe, and Ca, which make up more than 90% of the total chemical composition of the Voëlwater BIFs. The detrital component of the study rocks is negligible. Mn-enrichments characterise all the transitional lithologies towards the interbedded Mn-orebodies, as well as the well-developed, hematitic BIF-unit between the Ongeluk lavas and the lower Mn-horizon. In terms of trace element composition, no significant enrichments or depletions, were encountered, except for some unusually high values of Sr and Ba and Co in carbonate-rich and Mn-rich lithologies respectively. Geochemical comparisons on the basis of major, trace and light rare-earth element composition verified the similarity between the Voëlwater BIF and other major Superior-type BIFs of the world (e.g. Kuruman, Griquatown, Sokoman, Biwabik, Gunflint, Mara-Mamba, Brockman, etc.). The processes that led to the formation of the Voëlwater BIFs may have been very similar to the ones described in various genetic models proposed in recent years. They would have involved a combination of: i. hydrothermal processes related to mid-ocean ridge (MOR) or hot-spot activity that acted as major iron suppliers; ii. storm-mixing in stratified oceans (bottom, anoxic, Fe⁺² reservoir-thermo- pycnocline zone-upper, mixed, SiO₂-saturated layer), largely dictated by seasonal changes and contemporaneous volcanism; iii. periodic, convection-driven upwelling mechanisms acting as major Fe-precipitators; and, iv. organic carbon productivity that was responsible for the anoxic diagenesis of the initial sediment. However, the origin of Fe and Mn for the genesis of the Voëlwater sediments was difficult to explain with typical convection-cell models in active mid-ocean ridges, in contrast to previous hypotheses. Instead, large-scale endogenous processes in the form of magma convection, underplating, differentiation and associated degassing, may have played a critical role in the supply of metals for the formation of large amounts of BIFs in the Precambrian. The present study of the Voëlwater BIF also bears strong implications regarding the metallogenesis of Mn in the Precambrian. The common association of Mn with carbonate-bearing sediments, the transitional character of the Voëlwater BIF towards carbonate lithologies (Mooidraai dolomites) and the critical timing of the deposition of the former in terms of the Precambrian atmospheric-lithospheric- hydrospheric evolution, may be important indicators for the exploration of large Mn-deposits in Precambrian sedimentary basins of the world.

The Kalagadi Manganese mine in the Kuruman area of the Northern Cape Province of South Africa contains reserves of Mn ore in excess of 100Mt. Mineralization in the mine lease area is restricted within the Hotazel Formation of the Voȅlwater Subgroup, belonging to the Postmasburg Group, the upper subdivision of the Transvaal Supergroup. Surface topography is characterized by flat lying, undulation with minimal faulting and the ore are slightly metarmophosed. This study investigates the general geology of the mine, lithostratigraphic subdivision and correlation of the economic Lower Manganese Orebody (LMO) of the Kalagadi Manganese Mine in order to guide mining plan and operations once the mine is fully commissioned. At the commencement of this study, Kalagadi Manganese mine was a project under exploration with no specific geology of the mine lease area and no lithostratigraphic subdivision. The study also aimed determining the extent of lithostratigraphic correlation between the LMO economic orebodies of the Kalagadi Manganese mine with that of underground Gloria and open-pit Mamatwan mines. Four methods including petrographic microscope, Scanning electron Microscope (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses were applied mainly for the mineral identification, chemical composition and ore characterization of the Lower Manganese Orebody (LMO) at Kalagadi Manganese mine. The results of this study indicates the following: (1) Eleven textural distinct zones with economic zones restricted to the middle while the lower grade zones are confined to the top and bottom of the LMO; (2) The economic zones, comprising of Y, M, C and N subzones attain an average thickness of 10 m and are graded at an average of 40% Mn while the Mn/Fe ratio varies from 6 to 9; (3) The most economic zones are M and N subzones which are mostly characterized by oxidized ovoids and laminae, a characteristic applicable even to other zones of economic interest; (4) Braunite is the main mineral of the manganese ore and is often integrown with kutnahorite and other minerals (hematite, hausmannite, Mg-calcite, calcite, jacobsite, serpentine and garnet) which are present in variable amounts; (5) The Mg-rich calcite (Ca, Mg)CO3 is the second dominant manganese carbonate mineral and it corresponds to elevated MgO concentration and is often associated with marine environment. The occurrence of the Mgcalcite is not common in the manganese ore of this area except for the Mn-calcite, which was not determined by XRD analyses in this study; (6) MnO is the most abundant major oxide in the manganese ore while other major oxides present in decreasing order of abundance are CaO, SiO2, Fe2O3, and MgO. The oxides TiO2, Na2O, K2O, Al2O3, and Cr2O3 are depleted and are mostly  0.01wt% and  0.001wt% respectively while P2O5 concentrations are low ranging from 0.02wt% to 0.3wt%. The trace element concentrations of Ba, Zn and Sr in most borehole samples are slightly elevated ranging from 100ppm to 3.9% (36000pm) while Co, Cu, Ni, Y, As, Zr, V and La rarely exceed 50ppm. The enrichments of Cu, Zn, Ni, Co and V that are commonly associated with volcanogenic hydrothermal input in chemicals may reach up to 70ppm; (7) The mineralogical and geochemical characteristics of the manganese ore in the Kalagadi Manganese mine lease area are similar to that of Low-Grade Mamatwan-Type ore. The cyclicity (Banded Iron Formation ↔ Hematite lutite ↔ braunite lutite) and alternation of manganese and iron formation have been confirmed; and (8) The oxygen δ18O isotope values (18‰ to 22‰) indicate a slight influence of metamorphism of the manganese ore. No positive correlation exists between δ13C vs δ18O values and Mn vs δ13C values. Such observations indicate minimal action of organic carbon during manganese precipitation where the organic matter was oxidized and manganese content reduced. On the other hand, the manganese carbonates (CaO) are positively correlated with carbon isotope, this indicates diagenetic alteration and the involvement of biogenic carbonate during the formation of manganese carbonates. It is concluded that the lithostratigraphic subdivision at Kalagadi Manganese mine is best correlated physically, mineralogically and geochemically with that of Gloria mine operating in the Low Grade Mamatwan - Type ore while correlation with an open-pit Mamatwan mine is also valid.

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.