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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Petrography, mineral chemistry and Ar-Ar isotope characteristics of the ledig lujavrites, on the SW edge of the Pilanesberg Complex

30 June 2015 (has links)
MSc. (Geology) / The Mesoproterozoic Pilanesberg Alkaline Complex is located in the north central region of the Kaapvaal Craton of South Africa and is one of the largest alkaline intrusive bodies in the world. It is also one of the least studied due to the fact that the dominant exposure of the complex forms part of the Pilanesberg National Park. The Pilanesberg Complex intruded into the western limb of the Paleoproterozoic Bushveld Complex, the complex is a circular structure of 530km2 appearing on the map as a set of concentric rings of different varieties of syenites, capped by extrusive pyroclastic units and lavas. The present study is focused on the petrography and mineral chemistry of the rocks and minerals in an outcrop of mainly lujavrite, which is located in the Ledig nepheline syenite previously referred to as Ledig foyaite, named after an informal settlement by the name of Ledig which is situated approximately a kilometer south of the outcrop. This unit is emplaced in the southern region of the Pilanesberg complex and is believed to be a hybrid of the white nepheline syenite and the green nepheline syenite. A number of different rock types were examined from this outcrop, however, detailed work was only carried out on the lujavrites, in particular the eudialyte bearing lujavrites. The lujavrites consist of porphyroblasts of heterogeneously-sized feldspars, feldspathoids and mafic minerals set within a finer grained material. The bulk rock geochemical data on the Ledig lujavrites indicate considerable variation, but no obvious trends. A selected number of samples collected from the ledig lujavrite outcrop were geochemically analysed, these samples sit within the nepheline syenite field and have a shoshonitic affinity. The samples analysed have a relatively wide range of SiO2 content (20.39% to 52.67%), however the majority of the samples fall between 47.07 and 52.67%, the fluorite rich sample analysed has the lowest SiO2 as well as the lowest alkali content. The lujavrites and tinguaites are silica undersaturated and rich in alkalis. All the samples analysed are alkaline in nature and fall in the ferroan field. There is some variation in the SiO2 content and a large variation in Mg# in the sample population, this appears to be due to different proportions of minerals occurring as phenocrysts. No clear trends emerge, which is in part due to the very large differences in element concentrations within rock types with similar SiO2 content and Mg#. A lack of geochemical variation stemming from Abstract differentiation was expected as the samples were collected from a single outcrop essentially within a single lithology. There are a number of different phases of eudialyte that have been identified and studied from the Pilanesberg, at both the outcrop and in the northern area of the green lujavrites. At the Ledig lujavrite outcrop, there are euhedral magmatic eudialytes, which contain nepheline inclusions as well as post-magmatic eudialytes present in the samples studied. The two textural types have distinctly different chemical compositions. The majority of the feldspars present within the Ledig lujavrites appear, from their texture, to be primary magmatic minerals, however there are also feldspars present within the lujavrites which appear to be a product of secondary unmixing of feldspars as documented by the perthitic textures. Sodalite is present as a magmatic mineral; however, it is most commonly observed in the interstitial spaces and is thought to be an alteration product of nepheline. Analcime occurs in the groundmass, forming in the intergranular reaction rim between mineral phases. The analcime is typically controlled by the shape of the interstices...
2

Bakgatla ba Kgafela : design proposal for the cultural precinct of Saulspoort, Pilanesberg

Burger, L.J. 13 March 2007 (has links)
No abstract available / Dissertation (ML (Prof))--University of Pretoria, 2007. / Architecture / unrestricted
3

Investigating an environmental education curriculum to a developing society's needs: a case study of the programme offered at the Pilanesberg National Park, Bophuthatswana

Johnson, Steven Robert January 1994 (has links)
The Environmental Education programme offered at the Gold Fields Environmental Education Centre (GFEE Centre) in the Pilanesberg National Park, Bophuthatswana, was initiated in response to requests from schools in Bophuthatswana to visit game reserves as 'syllabus related school activities'. Evaluative research into the GFEE Centre programme by an external researcher indicated that the learning experiences largely concentrated on cognitive development, and neglected to influence affective and psychomotor development. After a number of adaptations to the programme, which emphasised a more child-centred approach it was realised that little was known about the background and learning needs of the predominantly BaTswana school children. It was felt by the researcher that the learning activities provided at the GFEE Centre could also possibly be biased by a Western, scientific orientation which possibly lacked relevance to the cultural backgrounds of the pupils. The researcher used an action research approach in a number of workshops with a purposive sample of BaTswana primary school teachers, to gather data. The teachers were encouraged to critically reflect on the background and learning-needs of BaTswana children, with specific regard to environmental issues and worldviews. The information provided by the teachers' reflective deliberations and a seperate research project with school children, indicated that primary school children in Bophuthatswana tend to follow accepted human development patterns in their perceptions of the environment. The influence of either a predominantly rural or urban upbringing during a child's early formative years was considered by the teachers to be significant in determining worldviews, and culture was considered to have an influence on children's learning processes. Their beliefs and experiences were used by them in generating suggestions to correct the GFEE Centre programme. The teachers' also highlighted the fact that there were a number of socio-cultural and institutional issues which influenced the effectiveness of the GFEE Centre programme.
4

A critical analysis of community participation and benefits from conservation : a comparative study of Mthethomusha Game Reserve and the Pilanesberg National Park.

Brayshaw, Carolyn Anne. January 1999 (has links)
This dissertation is an attempt to analyse and address some of the many and complex issues revolving around protected area - community relationships. The success of these relationships are essential if the mission of protected areas are to be achieved. Due to large scale agriculture, high density populations and environmental degradation protected areas are often looked upon as a means to conserve biodiversity. It is for this reason that they play an important role in the natural environmental of South Africa. However, there is a growing realisation that protected areas will not survive unless they become relevant to the communities that surround them. These cOI11nlunities are often characterised by high density populations and low levels of infrastructural and economic development. These developmental requirements need to be considered by protected area management, and a dedicated effort is required by protected areas to assist in meeting these needs. However, the relationship between protected areas and C0111nlunities should not simply focus on meeting the developmental needs of the community, relationships need to allow for communities to participate in decisions and activities that directly impact of their lives. Benefits need to accrue to communities from protected areas for them to support the concepts of conservation. Benefits need to be tangible, intangible and empowering for them to have real meaningful impacts on the communities. Communities need to be actively involve in all aspects of the protected area management and links need to be forged between conservation and development, so that the socio-economic condition of those living closest to protected areas improves. This study uses the relationship between Mthethomusha Game Reserve and the surrounding Mpakeni conmunity, and the Pilanesberg National Park and the neighbouring Bakgatla community to investigate many issues, including the manner in which communities participate and benefit from conservation. The findings of this study reflect that the relationships between communities and protected areas are dependent on a number of factors including~ ownership~ socio-economic condition of the surrounding community~ institutional structures and capacity of the community formal agreements; history of the fonl1ati~n of the protect~d a~ea~ reliance on the protected area for survival and the meaningfulness and appropriateness of the benefits received from the protected area. The experiences of the two case studies has been analysed and compared to develop a theoretical model for community - protected area relationships. This model indicates the primary prerequisites which will contribute to effective and equitable relationships between protected areas and surrounding communities. / Thesis (M.Env.Dev.)-University of Natal, Pietermaritzburg, 1999.

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