Catering for children with special education needs in the provision of early childhood development programme in Zimbabwe : towards a holistic and inclusive framework
- Authors: Chinhara, Henry
- Date: 2016
- Subjects: Children with disabilities -- Education -- Zimbabwe Special education -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/3055 , vital:28244
- Description: The study investigated how primary schools in Chiredzi District in Zimbabwe, cater for ECD “A” and “B” children with special education needs. A mixed method design located in the pragmatism paradigm was used to carry out the study. Post-positivist is an interactive process which produced in-depth, detailed, rich data from personal perspectives and experiences that resulted in realistic understanding of phenomenon, interpreted through the social and cultural context of respondents’ lives. By adopting quantitative and qualitative approaches, the researcher was able to ensure a high level of reliability in the collected data, at the same time obtaining comprehensive information on how primary schools attaching preschool classes in Chiredzi district cater for ECD “A” and “B” children with special education needs. Purposive sampling and cluster sampling procedures were used to solicit information from ECD teachers, school heads, parents, the District Education Team, NGOs and critical government ministries through semi-structured questionnaires, face-t-face interviews, focus group discussions, observations and document analysis. The study established that, while the government carries out its mandate of providing social services to learners with special education needs, they are incapacitated due to lack of resources. The majority of schools are not providing adequate health facilities for learners with special education needs. Furthermore, most schools are not providing nutritional supplementation to vulnerable learners, situations which deprive the learners with the much needed opportunity to grow and develop to the anticipated potential. In addition, the study noted that, ECD “A” and “B” children with special education needs enrolled in classes attached to primary schools do not access Basic Education Assistance Module (BEAM) or Cash Transfers to alleviate the children that are in need. It came out that such a situation impacts on learners’ attendance and subsequently their learning outcomes. Regardless of the stipulations by international treaties on the nature of inclusive education, the study established that, the education system has not yet modified curriculum to accommodate learners with diversified forms of special education needs. The situation is made worse by the fact that, heads of schools, and teachers are not adequately trained to handle learners with special education needs in early childhood development programmes. In addition, schools face the challenge of scarcity of learning resources that support ECD learners with special education needs which seriously impact on the growth and development of young learners at this critical stage of their development. Regardless of the essence of continuous professional development programs, in schools whose purpose is to redress the professional gap in schools, the study found that the CPD are doing very little to transform the mind-set of teachers. The study concluded that learners with special education needs are not benefiting from the current inclusive education programme. The study recommends that following; Stakeholders work together to promote the health and nutritional needs including other social services of ECD learners in classes attached to primary schools. There be a national teacher in-service programme for those teachers deployed in schools, to equip them with the desired skills, and knowledge to handle learners with special education needs, especially at this critical stage of their development. Teachers’ Colleges redesign their curriculum to address inclusive education in schools. Teachers’ Colleges need to empower new graduates with skills and knowledge to handle children with special education needs in schools. Policy makers to advocate for redesigning the curriculum to include children with special education needs to ensure availability of resources in inclusive schools to alleviate the challenges faced by these children. Those policy makers should advocate for a way to ensure that all children with special education be enrolled in mainstream schools. Thus, the study proposed an alternative, holistic, and inclusive education model for schools attaching ECD “A” and “B”
- Full Text:
- Date Issued: 2016
- Authors: Chinhara, Henry
- Date: 2016
- Subjects: Children with disabilities -- Education -- Zimbabwe Special education -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/3055 , vital:28244
- Description: The study investigated how primary schools in Chiredzi District in Zimbabwe, cater for ECD “A” and “B” children with special education needs. A mixed method design located in the pragmatism paradigm was used to carry out the study. Post-positivist is an interactive process which produced in-depth, detailed, rich data from personal perspectives and experiences that resulted in realistic understanding of phenomenon, interpreted through the social and cultural context of respondents’ lives. By adopting quantitative and qualitative approaches, the researcher was able to ensure a high level of reliability in the collected data, at the same time obtaining comprehensive information on how primary schools attaching preschool classes in Chiredzi district cater for ECD “A” and “B” children with special education needs. Purposive sampling and cluster sampling procedures were used to solicit information from ECD teachers, school heads, parents, the District Education Team, NGOs and critical government ministries through semi-structured questionnaires, face-t-face interviews, focus group discussions, observations and document analysis. The study established that, while the government carries out its mandate of providing social services to learners with special education needs, they are incapacitated due to lack of resources. The majority of schools are not providing adequate health facilities for learners with special education needs. Furthermore, most schools are not providing nutritional supplementation to vulnerable learners, situations which deprive the learners with the much needed opportunity to grow and develop to the anticipated potential. In addition, the study noted that, ECD “A” and “B” children with special education needs enrolled in classes attached to primary schools do not access Basic Education Assistance Module (BEAM) or Cash Transfers to alleviate the children that are in need. It came out that such a situation impacts on learners’ attendance and subsequently their learning outcomes. Regardless of the stipulations by international treaties on the nature of inclusive education, the study established that, the education system has not yet modified curriculum to accommodate learners with diversified forms of special education needs. The situation is made worse by the fact that, heads of schools, and teachers are not adequately trained to handle learners with special education needs in early childhood development programmes. In addition, schools face the challenge of scarcity of learning resources that support ECD learners with special education needs which seriously impact on the growth and development of young learners at this critical stage of their development. Regardless of the essence of continuous professional development programs, in schools whose purpose is to redress the professional gap in schools, the study found that the CPD are doing very little to transform the mind-set of teachers. The study concluded that learners with special education needs are not benefiting from the current inclusive education programme. The study recommends that following; Stakeholders work together to promote the health and nutritional needs including other social services of ECD learners in classes attached to primary schools. There be a national teacher in-service programme for those teachers deployed in schools, to equip them with the desired skills, and knowledge to handle learners with special education needs, especially at this critical stage of their development. Teachers’ Colleges redesign their curriculum to address inclusive education in schools. Teachers’ Colleges need to empower new graduates with skills and knowledge to handle children with special education needs in schools. Policy makers to advocate for redesigning the curriculum to include children with special education needs to ensure availability of resources in inclusive schools to alleviate the challenges faced by these children. Those policy makers should advocate for a way to ensure that all children with special education be enrolled in mainstream schools. Thus, the study proposed an alternative, holistic, and inclusive education model for schools attaching ECD “A” and “B”
- Full Text:
- Date Issued: 2016
An analysis of the impact of democratization on debt-led growth : the Nigerian experience, 1970-2000
- Authors: Dinneya, Godson Eze
- Date: 2013-05-22
- Subjects: Debts, External -- Nigeria Nigeria -- Politics and government -- 1960- Nigeria -- Economic policy Nigeria -- Economic conditions -- 1960-
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1074 , http://hdl.handle.net/10962/d1007807
- Description: The debt-for democracy hypothesis is that undemocratic governments were largely responsible for not only the accumulation but also poor management of externally sourced capital resources. External borrowing had therefore failed to lead to growth of the economies of debtor countries under undemocratic political leadership. Despite this explanation of the debt problem conventional empirical analyses of the debt-growth relationship did not include political institutional variables. This study investigates the relationship between democratization and debt-led growth, using Nigeria, a typical debtor country whose politics was dominated by 'undemocratic ' governance, as a case study. Two broad research questions are investigated namely, whether available data support a negative or positive contribution of debt to the growth of the Nigeria economy during the period 1970-2000; and ifso was there any link between the levels of democratization in Nigeria and debt-led growth. Using a census of major political events in Nigeria around four dimensions of democratization, four primary indices of democratization and one composite index were constructed for the period. Using the Taylor (1983) marginal conditions to gauge the contribution of external debt to the growth of the Nigerian economy, the study found that external debt is capable of playing a double edged sword on the performance of the economy. Positive contributions coincided with the periods when Nigeria's oil dominated foreign exchange revenues were robust, and/ or when debt management strategies were better articulated and vice versa. The analyses of the link between democratization and debt-led growth using both correlation and regression techniques, yielded different results in two definitional contexts of debt-led growth. When defined purely in terms of the Taylor marginal conditions for a positive contribution of debt to the economy of a borrowing nation, the results support the pessimist view that democratization impeded growth. On the contrary, when debt-led growth was defined in a broader sense to incorporate variables such as domestic savings and investment, foreign direct investments, public and private consumption and debt burden, there was strong evidence that debt-led growth performed beller at higher levels of democratization than other wise. The result using the narrow definition was found to be a direct consequence of the overriding influence of export performance in the Taylor conditions. With Nigeria's exports almost entirely dominated by extractive industry the result derived using the narrow definition confirmed the theoretical links between natural resource endowment and regime type on the one hand, and external capital and the nature of the host country 's industry on the other. In the first resource dependence allowed the political leadership to be more detached and less accountable to the electorate since they did not need to levy taxes. Secondly foreign investors concerned with security of their sunk investments in the extractive oil induslly in particular favoured continuity of powerfol regimes with less democratic content. In both findings one thing was common: democratization was associated more with those factors whose decreases affect growth positively than with those whose increases improve growth. The conclusion from this is that the impact of democratization is stronger with negative than with positive growth factors. In other words, while democratization may be supportive of growth its greater impact appears to be in limiting the factors that themselves limit growth. To benefit from the favourable impact of democratisation on debt-led growth therefore the study suggests that improvements in the democratisation process in Nigeria is needed It identifies political education as central to this improvement. A model is developed to show how improvements in the political institutional framework may trickle down, through an enabling environment that is capable of engendering growth-enhancing domestic and international responses to lead in the direction of debt-led growth.
- Full Text:
An analysis of the impact of democratization on debt-led growth : the Nigerian experience, 1970-2000
- Authors: Dinneya, Godson Eze
- Date: 2013-05-22
- Subjects: Debts, External -- Nigeria Nigeria -- Politics and government -- 1960- Nigeria -- Economic policy Nigeria -- Economic conditions -- 1960-
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1074 , http://hdl.handle.net/10962/d1007807
- Description: The debt-for democracy hypothesis is that undemocratic governments were largely responsible for not only the accumulation but also poor management of externally sourced capital resources. External borrowing had therefore failed to lead to growth of the economies of debtor countries under undemocratic political leadership. Despite this explanation of the debt problem conventional empirical analyses of the debt-growth relationship did not include political institutional variables. This study investigates the relationship between democratization and debt-led growth, using Nigeria, a typical debtor country whose politics was dominated by 'undemocratic ' governance, as a case study. Two broad research questions are investigated namely, whether available data support a negative or positive contribution of debt to the growth of the Nigeria economy during the period 1970-2000; and ifso was there any link between the levels of democratization in Nigeria and debt-led growth. Using a census of major political events in Nigeria around four dimensions of democratization, four primary indices of democratization and one composite index were constructed for the period. Using the Taylor (1983) marginal conditions to gauge the contribution of external debt to the growth of the Nigerian economy, the study found that external debt is capable of playing a double edged sword on the performance of the economy. Positive contributions coincided with the periods when Nigeria's oil dominated foreign exchange revenues were robust, and/ or when debt management strategies were better articulated and vice versa. The analyses of the link between democratization and debt-led growth using both correlation and regression techniques, yielded different results in two definitional contexts of debt-led growth. When defined purely in terms of the Taylor marginal conditions for a positive contribution of debt to the economy of a borrowing nation, the results support the pessimist view that democratization impeded growth. On the contrary, when debt-led growth was defined in a broader sense to incorporate variables such as domestic savings and investment, foreign direct investments, public and private consumption and debt burden, there was strong evidence that debt-led growth performed beller at higher levels of democratization than other wise. The result using the narrow definition was found to be a direct consequence of the overriding influence of export performance in the Taylor conditions. With Nigeria's exports almost entirely dominated by extractive industry the result derived using the narrow definition confirmed the theoretical links between natural resource endowment and regime type on the one hand, and external capital and the nature of the host country 's industry on the other. In the first resource dependence allowed the political leadership to be more detached and less accountable to the electorate since they did not need to levy taxes. Secondly foreign investors concerned with security of their sunk investments in the extractive oil induslly in particular favoured continuity of powerfol regimes with less democratic content. In both findings one thing was common: democratization was associated more with those factors whose decreases affect growth positively than with those whose increases improve growth. The conclusion from this is that the impact of democratization is stronger with negative than with positive growth factors. In other words, while democratization may be supportive of growth its greater impact appears to be in limiting the factors that themselves limit growth. To benefit from the favourable impact of democratisation on debt-led growth therefore the study suggests that improvements in the democratisation process in Nigeria is needed It identifies political education as central to this improvement. A model is developed to show how improvements in the political institutional framework may trickle down, through an enabling environment that is capable of engendering growth-enhancing domestic and international responses to lead in the direction of debt-led growth.
- Full Text:
Exploring opportunities for action competence development through learners' participation in waste management activities in selected primary schools in Botswana
- Authors: Silo, Nthalivi
- Date: 2011
- Subjects: Environmental education -- Botswana -- Case studies Environmental education -- Study and teaching (Primary) -- Botswana -- Case studies Environmental education -- Activity programs -- Botswana -- Case studies Student-centered learning -- Botswana -- Case studies Refuse and refuse disposal -- Environmental aspects -- Botswana -- Case studies Active learning -- Botswana -- Case studies Competency-based education -- Botswana -- Case studies Teacher-student relationships -- Botswana -- Case studies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1541 , http://hdl.handle.net/10962/d1003423
- Description: The broader aim of this study is to probe participation of learners in waste management activities in selected primary schools in Botswana and through these activities, explore opportunities for action competence development. The study starts by tracing and outlining the socio-ecological challenges that confront children and the historical background of learner-centred education which gave rise to an emphasis on learner participation in Botswana education policy. It then maps out the development of children's participation in the global, regional and Botswana contexts by tracing the development of environmental education from early ecological and issue resolution goals of environmental education to sustainable development discourses. The focus is on policy issues and how learner participation has been represented and implemented in environmental education. The study then probes the rhetorical and normalised emphases on participation, and seeks further insight into how learners can be engaged in participatory learning processes that are meaningful, purposeful and that broaden their action competence and civic agency. The study uses the Cultural Historical Activity Theory (CHAT) methodology to build a picture of waste management activity systems in primary schools and to bring to the surface contradictions and tensions in learner participation in these activity systems. These contradictions are used to open up expansive learning participatory processes with learners using the Danish action competence framework. The expansive learning process uses action competence models that provide potential for transformative participation with learners, and new and different opportunities for learner participation. Case study research was used and conducted in the south eastern region of Botswana in three primary schools in three contexts, namely urban, peri-urban and rural. The data was largely generated through focus group interviews during workshops with children and observations of waste management activities. These two methods formed the main data generation methods. They were complemented by semi-structured interviews with teachers, and other actors in the waste management activities, learners' activities and work, learners' notes, photographs and children's drawings as well as show-and-tell explanations by learners. Content analysis and the abductive mode of inference were used to analyse data in all three case studies. Findings from the first phase of the study reveal that participation of learners in waste management activities was largely teacher-directed. This resulted in a mis-match between teachers views of what practices are necessary and important, and children's views of what practices are necessary and important in and for environmental education. Due to culturally and historically formed views of environmental education, the study reveals that teachers wanted children to pick up litter, and this was their primary environmental education concern. Learners on the other hand, identified sanitation management in the school toilets as their primary waste management concern. Teachers had not considered this an environmental education concern. Using the action competence expansive learning approach, the second phase of the study addressed this tension by opening up dialogue between teachers and learners and amongst the learners themselves through an expansive learning process supporting children's participation and action competence development. Through this teacher-learner dialogical engagement, a broader range of possibilities became available and ideas around participation were radically changed. The study further reveals that the achievement of this open dialogue provided for a better relationship within the school community. And with improved communication came better ideas to solve waste management issues that the community still face on a daily basis, such as too much litter. Newly devised solutions were practical and had a broader impact than the initial ones that teachers had always focussed on. They included mobilising the maintenance of toilets, landscaping the school premises and even re-contextualising the litter management that had always caused tensions between learners and teachers. Children seemed to be developing not only a better understanding of the environment, but also developing the ability to resolve conflict amongst themselves and with their elders. By engaging in dialogue with children, they became co-catalysts for change in the school community. This study shows that if children's participation is taken seriously, and if opportunities for dialogue exist between teachers and children, positive changes for a healthier environment can be created in schools. It reveals that children also appeared to be feeling more confident and more equipped to consider changes in their environment outside of the school community. The study further shows that participation in environmental education involves more than cognitive changes as proposed in earlier constructivist literature; it includes in-depth engagement with socio-cultural dynamics and histories in the school context, such as the cultural histories of teachers, schooling and authority structures in the cultural community of the school. The study recommends that there is need to strengthen Teacher Education programmes to develop teaching practices and support for teachers to identify ways of engaging learners' views on issues in the school in open, dialogical ways. Such Teacher Education programmes should deepen teachers' understandings of learners' zone of proximal development (ZPD), demonstrating how dialogue and scaffolding are part of a teacher's role in supporting learning. This is shown in the three case studies that form part of this study. Finally, the study also deepens insights of using the Cultural Historical Activity theory (CHAT) to shed light on issues surrounding learner participation within the socio-cultural and historical environmental education contexts of the schools. The action competence models used in the study provide a tool for revealing forms of learner participation. This tool can be used for critical reflections and monitoring of teaching practices in schools.
- Full Text:
- Date Issued: 2011
- Authors: Silo, Nthalivi
- Date: 2011
- Subjects: Environmental education -- Botswana -- Case studies Environmental education -- Study and teaching (Primary) -- Botswana -- Case studies Environmental education -- Activity programs -- Botswana -- Case studies Student-centered learning -- Botswana -- Case studies Refuse and refuse disposal -- Environmental aspects -- Botswana -- Case studies Active learning -- Botswana -- Case studies Competency-based education -- Botswana -- Case studies Teacher-student relationships -- Botswana -- Case studies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1541 , http://hdl.handle.net/10962/d1003423
- Description: The broader aim of this study is to probe participation of learners in waste management activities in selected primary schools in Botswana and through these activities, explore opportunities for action competence development. The study starts by tracing and outlining the socio-ecological challenges that confront children and the historical background of learner-centred education which gave rise to an emphasis on learner participation in Botswana education policy. It then maps out the development of children's participation in the global, regional and Botswana contexts by tracing the development of environmental education from early ecological and issue resolution goals of environmental education to sustainable development discourses. The focus is on policy issues and how learner participation has been represented and implemented in environmental education. The study then probes the rhetorical and normalised emphases on participation, and seeks further insight into how learners can be engaged in participatory learning processes that are meaningful, purposeful and that broaden their action competence and civic agency. The study uses the Cultural Historical Activity Theory (CHAT) methodology to build a picture of waste management activity systems in primary schools and to bring to the surface contradictions and tensions in learner participation in these activity systems. These contradictions are used to open up expansive learning participatory processes with learners using the Danish action competence framework. The expansive learning process uses action competence models that provide potential for transformative participation with learners, and new and different opportunities for learner participation. Case study research was used and conducted in the south eastern region of Botswana in three primary schools in three contexts, namely urban, peri-urban and rural. The data was largely generated through focus group interviews during workshops with children and observations of waste management activities. These two methods formed the main data generation methods. They were complemented by semi-structured interviews with teachers, and other actors in the waste management activities, learners' activities and work, learners' notes, photographs and children's drawings as well as show-and-tell explanations by learners. Content analysis and the abductive mode of inference were used to analyse data in all three case studies. Findings from the first phase of the study reveal that participation of learners in waste management activities was largely teacher-directed. This resulted in a mis-match between teachers views of what practices are necessary and important, and children's views of what practices are necessary and important in and for environmental education. Due to culturally and historically formed views of environmental education, the study reveals that teachers wanted children to pick up litter, and this was their primary environmental education concern. Learners on the other hand, identified sanitation management in the school toilets as their primary waste management concern. Teachers had not considered this an environmental education concern. Using the action competence expansive learning approach, the second phase of the study addressed this tension by opening up dialogue between teachers and learners and amongst the learners themselves through an expansive learning process supporting children's participation and action competence development. Through this teacher-learner dialogical engagement, a broader range of possibilities became available and ideas around participation were radically changed. The study further reveals that the achievement of this open dialogue provided for a better relationship within the school community. And with improved communication came better ideas to solve waste management issues that the community still face on a daily basis, such as too much litter. Newly devised solutions were practical and had a broader impact than the initial ones that teachers had always focussed on. They included mobilising the maintenance of toilets, landscaping the school premises and even re-contextualising the litter management that had always caused tensions between learners and teachers. Children seemed to be developing not only a better understanding of the environment, but also developing the ability to resolve conflict amongst themselves and with their elders. By engaging in dialogue with children, they became co-catalysts for change in the school community. This study shows that if children's participation is taken seriously, and if opportunities for dialogue exist between teachers and children, positive changes for a healthier environment can be created in schools. It reveals that children also appeared to be feeling more confident and more equipped to consider changes in their environment outside of the school community. The study further shows that participation in environmental education involves more than cognitive changes as proposed in earlier constructivist literature; it includes in-depth engagement with socio-cultural dynamics and histories in the school context, such as the cultural histories of teachers, schooling and authority structures in the cultural community of the school. The study recommends that there is need to strengthen Teacher Education programmes to develop teaching practices and support for teachers to identify ways of engaging learners' views on issues in the school in open, dialogical ways. Such Teacher Education programmes should deepen teachers' understandings of learners' zone of proximal development (ZPD), demonstrating how dialogue and scaffolding are part of a teacher's role in supporting learning. This is shown in the three case studies that form part of this study. Finally, the study also deepens insights of using the Cultural Historical Activity theory (CHAT) to shed light on issues surrounding learner participation within the socio-cultural and historical environmental education contexts of the schools. The action competence models used in the study provide a tool for revealing forms of learner participation. This tool can be used for critical reflections and monitoring of teaching practices in schools.
- Full Text:
- Date Issued: 2011
Petrogenesis of the upper critical zone in the Western Bushveld Complex with emphasis on the UG1 Footwall and Bastard units
- Authors: De Klerk, William Johan
- Date: 1992
- Subjects: Petrogenesis -- South Africa Formations (Geology) -- South Africa Mineralogy -- South Africa Geochemistry -- South Africa Petrology -- Africa, Southern Rustenburg Platinum Mines
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4986 , http://hdl.handle.net/10962/d1005598
- Description: This study is an account of the stratigraphic sequence, the petrography, mineralogy (microprobe investigations of orthopyroxene, clinopyroxene, olivine and plagioclase feldspar), and whole-rock major- and traceelement geochemistry of the silicate cumulates of the Upper Critical Zone in the western Bushveld Complex. Two parts of the study - an investigation of a 350m column incorporating the MG3 and UGI Footwall Units, and a comparison of two additional Upper Critical Zone profiles with a previously compiled profile between the UGI and Bastard Units - are focused on RPM Union Section in the northwestern sector of the Complex. The third part is a detailed vertical and lateral investigation of the Bastard Unit at the top of the Critical Zone, which draws on sampling and data compilation from seventeen profiles in the western limb of the Complex. The MG3 Unit (45m) is made up of a lower chromitite layer overlain by a norite-pyroxenite-anorthosite sequence while the UGlFW Unit (295m) is composed of a related series of lower chromitite layers (MG4) overlain by a pyroxenite-norite-anorthosite sequence capped by the UGI chromitite layer. These mafic cumulates display a distinctive pattern of oscillating cryptic variation in whole-rock Mg/(Mg+Fe), FeO/Ti0₂, Cr/Co and Ni/V ratios through the sequence. Sympathetic oscillations are recorded for compositions of orthopyroxene and plagioclase feldspar and eight subcycles are recognised through the UGlFW Unit. The entire sequence is characterised by the presence of small, spheroidal, embayed and irregularly shaped plagioclase grains which are poikilitically enclosed in cumulus orthopyroxene grains of both pyroxenites and norites. This texture is indicative of partial resorption of pre-existing feldspar primocrysts within the melt prior to their being incorporated into the host orthopyroxene grains. Textural, geochemical and isotopic data suggest that this sequence was built up by periodic additions of fresh, relatively primitive liquid into fractionated resident liquid, and subsequent mixing within the magma chamber. The Bastard Unit sequence, described in Chapter 4, is the last and most complete cyclic unit (c. 60m) of the Critical Zone, and its upper contact defines the boundary between the Critical and Main Zones of the Complex. This Unit can conveniently be sub-divided into a lower part, where orthopyroxene occurs as a cumulus phase, and the upper part which is composed entirely of anorthosite (Giant Mottled Anorthosite). The basal part of the Unit (≤ 18m) comprises a thin chromitite layer < O.5cm) overlain by a pyroxenite-melanorite-norite-leuconorite sequence. The basal pyroxenite is orthocumulate in character and rapidly gives way to norites and leuconorites. A distinct threefold subdivision emerges within the Giant Mottled Anorthosite which is predominantly an adcumulate which becomes orthocumulate in character at its top. Apart from minor deviations in thicknesses these lithologies are recorded over the entire strike-length covered in this study. Profiles of cryptic variation are compiled for orthopyroxene, plagioclase and whole-rock data and show that the Bastard Unit displays a characteristic pattern which is maintained throughout the western Bushveld Complex. A minor yet distinctive reversal in cryptic variation is revealed at a level which is stratigraphically variable within the lower Giant Mottled Anorthosite, and results in a double cuspate pattern. A remarkable feature of the basal Bastard pyroxenites is that although the modal proportion of mafic to felsic constituents varies systematically away from the northwestern sector, the Mg/(Mg+Fe) ratio of orthopyroxenes remains constant at 0.804 over a lateral strike distance of 171km. Within the upper part of the Unit the orthopyroxene is markedly Fe-rich and it is here that inverted primary pigeonite appears for the first time as a cumulus phase. In addition, K-feldspar, oscillatory zoned plagioclase grains and high levels of incompatible trace elements are noted at this level. On the basis of the data presented it is concluded that the Bastard Unit represents the crystallisation of a final, relatively large influx of hotter primitive liquid, with upper Critical Zone affinities, and subsequent mixing with a column of cooler (less dense) supernatant liquid which had in part hybridized with the overlying Main Zone magma. It is hypothesised that this new liquid was emplaced as a basal flow beneath supernatant liquid and that it initiated the deposition of mafic cumulates at its base. The supernatant liquid is interpreted as representing the fractionated residuum produced by crystallisation of earlier cyclic units, with plagioclase on the liquidus, and that it contained an abundance of small plagioclase primocrysts in suspension. Development of the Unit can be viewed as a two-stage process. In the lower half of the unit, chemical and physical parameters typical of the new magma dominated the crystallisation process, and resulted in cumulates very similar to other relatively complete Upper Critical Zone units. In the upper, leucocratic sequence, above a minor reversal, crystallisation was from a liquid which was the product of mixing of a minor pulse of primitive liquid with the reservoir of hybridized supernatant liquid. Although the Bastard Unit is not continuous around the entire Western limb of the Complex, it is concluded that it developed in a single, or connected, magma chamber and that its irruptive feeder zone was located in the proximal northwestern facies of the Complex.
- Full Text:
- Date Issued: 1992
- Authors: De Klerk, William Johan
- Date: 1992
- Subjects: Petrogenesis -- South Africa Formations (Geology) -- South Africa Mineralogy -- South Africa Geochemistry -- South Africa Petrology -- Africa, Southern Rustenburg Platinum Mines
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4986 , http://hdl.handle.net/10962/d1005598
- Description: This study is an account of the stratigraphic sequence, the petrography, mineralogy (microprobe investigations of orthopyroxene, clinopyroxene, olivine and plagioclase feldspar), and whole-rock major- and traceelement geochemistry of the silicate cumulates of the Upper Critical Zone in the western Bushveld Complex. Two parts of the study - an investigation of a 350m column incorporating the MG3 and UGI Footwall Units, and a comparison of two additional Upper Critical Zone profiles with a previously compiled profile between the UGI and Bastard Units - are focused on RPM Union Section in the northwestern sector of the Complex. The third part is a detailed vertical and lateral investigation of the Bastard Unit at the top of the Critical Zone, which draws on sampling and data compilation from seventeen profiles in the western limb of the Complex. The MG3 Unit (45m) is made up of a lower chromitite layer overlain by a norite-pyroxenite-anorthosite sequence while the UGlFW Unit (295m) is composed of a related series of lower chromitite layers (MG4) overlain by a pyroxenite-norite-anorthosite sequence capped by the UGI chromitite layer. These mafic cumulates display a distinctive pattern of oscillating cryptic variation in whole-rock Mg/(Mg+Fe), FeO/Ti0₂, Cr/Co and Ni/V ratios through the sequence. Sympathetic oscillations are recorded for compositions of orthopyroxene and plagioclase feldspar and eight subcycles are recognised through the UGlFW Unit. The entire sequence is characterised by the presence of small, spheroidal, embayed and irregularly shaped plagioclase grains which are poikilitically enclosed in cumulus orthopyroxene grains of both pyroxenites and norites. This texture is indicative of partial resorption of pre-existing feldspar primocrysts within the melt prior to their being incorporated into the host orthopyroxene grains. Textural, geochemical and isotopic data suggest that this sequence was built up by periodic additions of fresh, relatively primitive liquid into fractionated resident liquid, and subsequent mixing within the magma chamber. The Bastard Unit sequence, described in Chapter 4, is the last and most complete cyclic unit (c. 60m) of the Critical Zone, and its upper contact defines the boundary between the Critical and Main Zones of the Complex. This Unit can conveniently be sub-divided into a lower part, where orthopyroxene occurs as a cumulus phase, and the upper part which is composed entirely of anorthosite (Giant Mottled Anorthosite). The basal part of the Unit (≤ 18m) comprises a thin chromitite layer < O.5cm) overlain by a pyroxenite-melanorite-norite-leuconorite sequence. The basal pyroxenite is orthocumulate in character and rapidly gives way to norites and leuconorites. A distinct threefold subdivision emerges within the Giant Mottled Anorthosite which is predominantly an adcumulate which becomes orthocumulate in character at its top. Apart from minor deviations in thicknesses these lithologies are recorded over the entire strike-length covered in this study. Profiles of cryptic variation are compiled for orthopyroxene, plagioclase and whole-rock data and show that the Bastard Unit displays a characteristic pattern which is maintained throughout the western Bushveld Complex. A minor yet distinctive reversal in cryptic variation is revealed at a level which is stratigraphically variable within the lower Giant Mottled Anorthosite, and results in a double cuspate pattern. A remarkable feature of the basal Bastard pyroxenites is that although the modal proportion of mafic to felsic constituents varies systematically away from the northwestern sector, the Mg/(Mg+Fe) ratio of orthopyroxenes remains constant at 0.804 over a lateral strike distance of 171km. Within the upper part of the Unit the orthopyroxene is markedly Fe-rich and it is here that inverted primary pigeonite appears for the first time as a cumulus phase. In addition, K-feldspar, oscillatory zoned plagioclase grains and high levels of incompatible trace elements are noted at this level. On the basis of the data presented it is concluded that the Bastard Unit represents the crystallisation of a final, relatively large influx of hotter primitive liquid, with upper Critical Zone affinities, and subsequent mixing with a column of cooler (less dense) supernatant liquid which had in part hybridized with the overlying Main Zone magma. It is hypothesised that this new liquid was emplaced as a basal flow beneath supernatant liquid and that it initiated the deposition of mafic cumulates at its base. The supernatant liquid is interpreted as representing the fractionated residuum produced by crystallisation of earlier cyclic units, with plagioclase on the liquidus, and that it contained an abundance of small plagioclase primocrysts in suspension. Development of the Unit can be viewed as a two-stage process. In the lower half of the unit, chemical and physical parameters typical of the new magma dominated the crystallisation process, and resulted in cumulates very similar to other relatively complete Upper Critical Zone units. In the upper, leucocratic sequence, above a minor reversal, crystallisation was from a liquid which was the product of mixing of a minor pulse of primitive liquid with the reservoir of hybridized supernatant liquid. Although the Bastard Unit is not continuous around the entire Western limb of the Complex, it is concluded that it developed in a single, or connected, magma chamber and that its irruptive feeder zone was located in the proximal northwestern facies of the Complex.
- Full Text:
- Date Issued: 1992
The ballads of Carl Loewe : examined within their cultural, human and aesthetic context
- Authors: Mierowska, Jean Elaine Nora
- Date: 1989
- Subjects: Loewe, Carl, 1796-1869. Songs. Selections Loewe, Carl, 1796-1869. Songs
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2649 , http://hdl.handle.net/10962/d1002314
- Description: This thesis has been written in order to provide, especially for the non-German-reading musician, a fuller picture of Loewe and his ballads than has been available up to now. This picture is developed within the literary background history of the ballad poems, and the literary, mental, and musical climate at the beginning of the Romantic era; further, Loewe's life, as revealed in his many letters, his diaries, and his autobiography, provides the human context from which the ballads emerge as a logical extension of his personality. These earlier parts of the thesis have considerable bearing on the appreciation of Loewe's timely position in musical history, treating as they do with the popularity of the ballad poems, the rapid expansion of the means of musical/emotional expression, and the complete acceptance of that most romantic and versatile of soloinstruments, the piano. Loewe's temperamental affinity with the poetry of the ballads is shown to have affected his choice of subject, and in many cases the ultimate quality of the music is obviously dependent upon the strength or otherwise of his attraction. After observations on Loewe's vocal and piano writing, the thesis treats the ballads primarily with regard to their feeling and emotional content, and investigates the musical means by which this is conveyed. Categories are suggested, and ballads of similar dramatic, pictorial, or emotional type are discussed and compared. Certain formal characteristics are examined, in particular Loewe's use of highly organised motivic work in certain ballads, which foreshadows its later use by Liszt, Wagner and others. Over one hundred of Loewe's 120 ballads are dealt with, some in extensive detail~ and copious musical examples are given. The few comparatively well-known ballads receive due attention, but it was regarded as important to bring to light some of the more neglected or unknown ballads, many of which possess great beauty and originality, amply repaying study and, still more, performance. As a corollary, the approach of the performer is considered, and the Conclusion argues for an informed :esthetic appreciation of Loewe's ballads and their place in teday's vocal repertoire.
- Full Text:
- Date Issued: 1989
- Authors: Mierowska, Jean Elaine Nora
- Date: 1989
- Subjects: Loewe, Carl, 1796-1869. Songs. Selections Loewe, Carl, 1796-1869. Songs
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2649 , http://hdl.handle.net/10962/d1002314
- Description: This thesis has been written in order to provide, especially for the non-German-reading musician, a fuller picture of Loewe and his ballads than has been available up to now. This picture is developed within the literary background history of the ballad poems, and the literary, mental, and musical climate at the beginning of the Romantic era; further, Loewe's life, as revealed in his many letters, his diaries, and his autobiography, provides the human context from which the ballads emerge as a logical extension of his personality. These earlier parts of the thesis have considerable bearing on the appreciation of Loewe's timely position in musical history, treating as they do with the popularity of the ballad poems, the rapid expansion of the means of musical/emotional expression, and the complete acceptance of that most romantic and versatile of soloinstruments, the piano. Loewe's temperamental affinity with the poetry of the ballads is shown to have affected his choice of subject, and in many cases the ultimate quality of the music is obviously dependent upon the strength or otherwise of his attraction. After observations on Loewe's vocal and piano writing, the thesis treats the ballads primarily with regard to their feeling and emotional content, and investigates the musical means by which this is conveyed. Categories are suggested, and ballads of similar dramatic, pictorial, or emotional type are discussed and compared. Certain formal characteristics are examined, in particular Loewe's use of highly organised motivic work in certain ballads, which foreshadows its later use by Liszt, Wagner and others. Over one hundred of Loewe's 120 ballads are dealt with, some in extensive detail~ and copious musical examples are given. The few comparatively well-known ballads receive due attention, but it was regarded as important to bring to light some of the more neglected or unknown ballads, many of which possess great beauty and originality, amply repaying study and, still more, performance. As a corollary, the approach of the performer is considered, and the Conclusion argues for an informed :esthetic appreciation of Loewe's ballads and their place in teday's vocal repertoire.
- Full Text:
- Date Issued: 1989
Pauline Smith : between worlds
- Authors: Driver, Dorothy
- Date: 1987
- Subjects: Smith, Pauline, 1883-1959
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2266 , http://hdl.handle.net/10962/d1004792
- Full Text:
- Date Issued: 1987
- Authors: Driver, Dorothy
- Date: 1987
- Subjects: Smith, Pauline, 1883-1959
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2266 , http://hdl.handle.net/10962/d1004792
- Full Text:
- Date Issued: 1987
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