The Bien Venue massive sulphide deposit is associated with a felsic volcanic succession developed in the north-eastern part of the Barberton Greenstone Belt, Eastern Transvaal. The deposit is situated 8km east-north-east of Louw's Creek between the Lily Syncline to the south and the Stentor Pluton to the north. The stratigraphy of the Onverwacht, Fig Tree and Moodies Groups in the vicinity of the deposit is poorly documented, and the exact stratigraphic position of the host felsic volcanics is not known. They are tentatively correlated with the felsic volcanics from the Theespruit Formation, Onverwacht Group. The felsic volcanics have undergone low-grade greenschist facies metamorphism and occur as quartz-sericite schists. Detailed petrography enables sub-division of the volcanic succession into distinct units. A lapilli metatuff unit hosts the base metal and precious metal mineralisation. The sulphides are best developed in the upper part of this unit, together with intercalated barite-rich horizons and cherts. A series of structural events have modified the attitude of the lithological units and disrupted the continuity of the orebody. The orebody comprises stratabound lenses of massive to semi-massive and often banded sulphides, as well as disseminated sulphide mineralisation. The dominant base metal mineralogy consists of pyrite, sphalerite, chalcopyrite, galena and tennantite. Native silver and various copper-silver sulphides are also associated with the base metal sulphides. A vertical zonation of the mineralisation exists, from pyrite-chalcopyrite-rich ore in the footwall, to pyrite - chalcopyrite-sphalerite-galena-barite-rich ore towards the hanging wall. Geochemical studies indicate that the Bien Venue lithologies are rhyolitic to rhyodacitic in composition and show a calc-alkaline affinity. The mobility of some elements at Bien Venue has been clearly demonstrated. This is believed to be associated with hydrothermal alteration that has led to SiO2 and MgO enrichment, as well as K2O depletion, in the wall rocks of the deposit. The geological setting and nature of the mineralisation at Bien Venue suggest that it is an example of a volcanogenic exhalative sulphide deposit. In terms of the classification scheme suggested by Hutchinson (1973, 1980), Bien Venue would best be described as a Primitive type deposit that contains barite. / Thesis (M.Sc.)-University of Natal, 1990

The targets of the research were the gravel and sand deposits of different genetic type, as well as promising areas in the area of Lithuania. The present work defines the principle applied for construction of dynamical models of non-metal mineral deposits. The possibilities of automated analysis and evaluation of mineral deposit prospecting data have explored; the methodology for automation of mineral deposit use design solutions has created and introduced into a computer software; the possibilities of automation for calculation of production (mining) volumes according to the surveyor measurements have explored; the possibilities of automation for recording and controlling the production (mining) have explored in the dissertation. The modelling is done in 3D space enabling to see 3D perspective images of a pit from any point selected and prognosticate the course of excavation works. / Tyrimų objektais buvo pasirinkti įvairių genetinių tipų žvyro ir smėlio telkiniai bei prognoziniai plotai išsidėstę Lietuvos teritorijoje. Disertacijoje yra apibrėžtas nerūdinių naudingųjų iškasenų telkinių dinaminių modelių sudarymo principas; išnagrinėtos naudingųjų iškasenų telkinių žvalgybos duomenų automatizuotos analizės ir vertinimo galimybės; sukurta naudingųjų iškasenų telkinių naudojimo projektinių sprendinių automatizavimo metodika ir įdiegta į programinę įrangą; išnagrinėtos kasybos apimčių pagal markšeiderinius apmatavimus apskaičiavimo automatizavimo galimybės; išnagrinėtos kasybos proceso apskaitos ir kontrolės automatizavimo galimybės. Modeliavimas atliekamas trimatėje erdvėje, kas sudaro galimybę matyti trimačius perspektyvinius karjero vaizdus iš bet kokio pasirinkto taško ir numatyti naudingųjų iškasenų telkinių kasybos darbų eigą.

Tyrimų objektais buvo pasirinkti įvairių genetinių tipų žvyro ir smėlio telkiniai bei prognoziniai plotai išsidėstę Lietuvos teritorijoje. Disertacijoje yra apibrėžtas nerūdinių naudingųjų iškasenų telkinių dinaminių modelių sudarymo principas; išnagrinėtos naudingųjų iškasenų telkinių žvalgybos duomenų automatizuotos analizės ir vertinimo galimybės; sukurta naudingųjų iškasenų telkinių naudojimo projektinių sprendinių automatizavimo metodika ir įdiegta į programinę įrangą; išnagrinėtos kasybos apimčių pagal markšeiderinius apmatavimus apskaičiavimo automatizavimo galimybės; išnagrinėtos kasybos proceso apskaitos ir kontrolės automatizavimo galimybės. Modeliavimas atliekamas trimatėje erdvėje, kas sudaro galimybę matyti trimačius perspektyvinius karjero vaizdus iš bet kokio pasirinkto taško ir numatyti naudingųjų iškasenų telkinių kasybos darbų eigą. / The targets of the research were the gravel and sand deposits of different genetic type, as well as promising areas in the area of Lithuania. The present work defines the principle applied for construction of dynamical models of non-metal mineral deposits. The possibilities of automated analysis and evaluation of mineral deposit prospecting data have explored; the methodology for automation of mineral deposit use design solutions has created and introduced into a computer software; the possibilities of automation for calculation of production (mining) volumes according to the surveyor measurements have explored; the possibilities of automation for recording and controlling the production (mining) have explored in the dissertation. The modelling is done in 3D space enabling to see 3D perspective images of a pit from any point selected and prognosticate the course of excavation works.

The purpose of this study was to determine the effect of oral contraceptives (OC) on bone health in active women during early adulthood. Thirty-eight women between the ages of 18 and 35 years participated in this study. Participants were placed into two groups: 1) those who had taken OCs (Ortho Tri-Cyclen for a minimum of two years (n=22) and 2) those who had never taken OCs (n=16). The two groups were matched based on age, nutritional habits, percent body fat, and activity level. Participants completed a health history questionnaire, food frequency questionnaire, and received a full body scan via dual energy x-ray absorptiometry (DEXA). An independent t-test revealed no significant difference (p < 0.05) between the bone mineral density of the women taking OCs (1.188 g/cm2 ± 0.09) and those women who never consumed OCs (1.207 g/cm2 ± 0.09). The effect of taking OCs in a young healthy population of women appears to have no osteogenic influence on bone health. / School of Physical Education

The effects of phosphorus fertilization on the growth and survival of Liatris pycnostachya, Physostegia virginiana, and Sporobolus heterolepis seedlings were examined in a prairie restoration project. Treatment included fertilizing once at the time of planting. Plant responses were measured on two soil types, Bono (very high phosphorus levels, lower and flatter) and Morley (very low phosphorus levels, on a slight hill with some slope). P fertilization did not increase the growth of any species on either soil type, although results may have been limited by the effects of surrounding plant competition. Only one significant difference in plant growth was observed between fertilized and unfertilized plots; control Liatris pycnostachya and Physostegia virginiana in the Bono soils produced more shoots than fertilized plants of the same species. P- fertilized Liatris pycnostachya in Morley soil had significantly higher survivorship than unfertilized plants. In contrast, P-fertilized Physostegia virginiana in the Bono soil had the significantly lower survivorship than unfertilized plants. For the other species on either soil type, the survivorship was not significantly different. Because P-fertilization produced very limited benefit, and even adverse plant responses in some cases, the recommendation of this study is that P-fertilization should not be applied at the time of planting of prairie restoration projects. / Department of Biology

Twenty-five animals that were randomly selected on the basis of sex and age from among the animals feeding exclusively on communal grazing in Mogosane village and were used to investigate the mineral (P, Ca and Mg) status, especially P, based on blood and faecal P and to estimate the quantity of P they consumed from the pasture they were grazing. The project was conducted in the same area each month for one year, and no supplement was given. Months were blocks and seasonal changes were factors and the animals were experimental units within a block. Faecal, blood and grass samples were used as indicators of P, Ca and Mg minerals within experimental units, and Analysis of Variance was done to determine whether the P status of native pastures had a significant effect on the total P, Ca and Mg utilization and movement in and out of the blood and throughout the faeces during different periods the year. Body mass, condition scores and rainfall were also recorded during this trial. When the mineral status was investigated in this trial, it was found that mineral content in blood and faeces was directly related to the minerals in the pasture since these indicators were curvilinear increasing from winter months to spring months peaking in summer months with highly (P< 0.05) significant values when grazing was best and declining as the grazing became worse during autumn and winter months. The values of the body condition of the animals increased and declined with the values of body mass. Blood P concentration was very inconsistent and varied greatly and did not follow the same increasing and decreasing pattern followed by faeces and the grass. This emphasizes the fact that the P content of blood is not always good indicator of the P status in the animal. The mean faecal P concentration during winter was lower with the value of 1.23 ± 0.13 mg/g, during spring was low with the value of 1.8 ± 0.06 mg/g, during summer was higher with the value of 3.22 ± 0.12 mg/g and during autumn was high with the value of 1.98 ± 1.04 mg/g. The mean concentration of P in the grass during winter was lower with the value of 0.92 ± 0.04 mg/g, during spring was low with the value of 1.16 ± 0.08 mg/g, during summer was higher with the value of 1.68 ± 0.06 mg/g and during autumn was high with the value of 1.22 ± 0.09 mg/g. The seasonal rainfall correlated with the faecal and grass P values vary much with the value of 0 mm in the winter season, with the value of 26.33 mm in the spring, the value of 90.4 mm during summer and the value of 44.83 mm during autumn. Condition scores and body masses had the values of 2.08 units/201.4 Kg during winter season, had the values of 3.07 units/272.29 Kg in spring season, had the values of 3.88 units/371 Kg during summer season and the values of2.75 units/286.65 during autumn season, respectively. / Thesis (M.Sc. (Agric.)) --North-West University (Mafikeng Campus), 2005.

Historically, irresponsible mining companies have escaped their duty to rehabilitate. The Mineral Petroleum Resources Development Act does not oblige mining companies to rehabilitate if their operations ceased before the Minerals Act came into force. In the court case De Beers Consolidated Mines v Ataqua Mining (Pty) Ltd and others 2006 1 SA 432 (T), the court held that the Mineral Petroleum Resources Development Act is not applicable to tailings dumps that were created through mining that had been conducted under the Minerals Act. This ruling leaves unanswered the question about who would be liable to rehabilitate old order tailings dumps once such tailings dumps are re-mined or not mined at all. The aim of this dissertation is to determine whether companies that ceased mining operations before the Mineral Petroleum Resources Development Act came into effect could be held liable for rehabilitation by introducing the scenario that applied in the De Beers court case. / Thesis (LL.M. (Environmental Law))--North-West University, Potchefstroom Campus, 2010

Downhole sampling of unboiled liquid at 1350 and 1500 m depth in the seawater-dominated Reykjanes high-temperature geothermal system in Iceland shows that metal concentrations measured at surface are minimum values due to mineral precipitation in the wells; by analogy of similar tectonic setting, host rocks and fluid composition, the metal concentrations measured in many black smoker vents at the seafloor are also minima. Fluids in the Reykjanes geothermal system react with mid-ocean ridge basalt at temperatures as high as 346°C and contain Fe 9-140 ppm, Cu 14-17 ppm, Zn 5-27 ppm, Pb 120-290 ppb, 1-6 ppb Au, and 28-107 ppb Ag. Fluids discharged at surface from the same wells have orders of magnitude lower metal concentrations due to precipitation caused by boiling and vapor loss during depressurization. Upstream of the orifice plate at high pressure (40 bar, 252°C) the precipitates consist mainly of sphalerite and chalcopyrite with a trace of galena and bornite. At the orifice plate of old wells, the pressure decreased sharply to 11 bar (188°C), resulting in abundant deposition of amorphous silica together with minor sphalerite and traces of chalcopyrite. In new wells the pressure at the orifice plate decreases to 22 bar (220°C); this pressure decrease and concomitant boiling causes deposition of fine-grained bornite-digenite solid solution together with sphalerite and galena on the fluid flow control valve. In high-pressure wells (average wellhead pressure 45-35 bar) most metals (mainly as sphalerite) are deposited downstream of the orifice plate, with up to 950 ppm Au and 2.5 wt.% Ag. Bulk concentrations in the scales vary between 15-60 wt.% upstream and downstream of the orifice plate and diminish from there. Iron increases up well from 8 to ~20 wt.% and decreases downstream of the orifice plate from 6 to 2 wt.% at the separation station; Cu downhole is ~3 wt.% but increases to 25 wt.% on the fluid flow control valve and then decreases; Pb downhole 100s ppm but at the wellhead is ~3 wt.%, increasing to 15 wt.% at the fluid flow control valve, then decreasing sharply from there.

Historically, irresponsible mining companies have escaped their duty to rehabilitate. The Mineral Petroleum Resources Development Act does not oblige mining companies to rehabilitate if their operations ceased before the Minerals Act came into force. In the court case De Beers Consolidated Mines v Ataqua Mining (Pty) Ltd and others 2006 1 SA 432 (T), the court held that the Mineral Petroleum Resources Development Act is not applicable to tailings dumps that were created through mining that had been conducted under the Minerals Act. This ruling leaves unanswered the question about who would be liable to rehabilitate old order tailings dumps once such tailings dumps are re-mined or not mined at all. The aim of this dissertation is to determine whether companies that ceased mining operations before the Mineral Petroleum Resources Development Act came into effect could be held liable for rehabilitation by introducing the scenario that applied in the De Beers court case. / Thesis (LL.M. (Environmental Law))--North-West University, Potchefstroom Campus, 2010

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