Geological and geophysical investigation of the South Eastern Karoo Basin, South Africa
- Authors: Baiyegunhi, Christopher
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11532 , http://hdl.handle.net/10353/d1021280
- Description: Geological and geophysical methods were used to investigate the southeastern Karoo Basin of South Africa in an area extending from longitudes 24 o E to 29o E and latitudes 32o S to 35o S. This was undertaken in order to reveal geologic structures, isochore thicknesses of the geologic sequence and their variations across the study area, proffer the possible provenance of the sediments and assess the potential of oil and gas accumulation. The methodology used includes field investigation, rock sampling, preparation of thin sections, petrographic studies, X-ray diffraction analysis, density measurements, porosity calculations, extraction of elevation data from Google Earth, 2½ D gravity profile modelling, generating of isochore (true vertical) thicknesses and depositional surfaces maps from the models, PetroMod 1D modelling and qualitative interpretation of magnetic, gravity and radiometric maps.Petrographic study was carried out on twenty six thin sections of rocks from the eleven geologic formations that cover the study area. Petrographic studies on the diamictite of the Dwyka Group shows abundance of monocrystalline quartz, granite and quartzite components in the breccias which possibly indicate the existence of granitic and metamorphic rocks in the source areas. The sandstones of the Ecca and Beaufort Groups are immature, greywacke and the heavy mineral assemblages signify that the minerals are of granitic, volcanic and metamorphic origin. The magnetic maps show two main magnetic anomalies, a major one trending in a northeast to southwest direction which is part of the Beattie magnetic anomaly and another that is a “bean-shaped” anomaly. The radially averaged power spectrum shows two depths to magnetic sources. The first depth is about 0.6 km which is the average depth to the top of the shallow sources, while the average depth to the top of the deep sources is about 15 km. The shallow sources are connected to magnetic minerals within the Beaufort Group while deep magnetic sources were inferred to be in the basement. The gamma ray spectrometric map shows areas with relatively high gamma radiation count. The high radiation count is possibly due to the uranium and thorium in the detrital materials, as well as the enrichment of radioelements in the feldspars (k-feldspar), calcite, quartz, zircon and clay minerals in the fluvial channel sandstones of the Beaufort Group. A total of two hundred and fifty-eight (258) rock samples were collected in the field and densities (dry, wet and grain densities) and porosities were determined in the laboratory. The Karoo Supergroup density values range from 2.526 – 2.828 g/cm3. The average porosities range from 0. 49 – 3.31 %. The dry densities and porosities of all the formations are inversely correlated with correlation coefficient values (R) that range from 0.9491 - 0.9982. The density of the dolerite intrusions (mostly sill) ranges from 2.700 – 2.837 g/cm3 whilst the porosity range from 0.1118 – 0.3868 %. The Bouguer anomaly map shows an increase in gravity values from -140.7 mGal in inland to about 60.1 mGal in coastal areas. This dominant gravity variation is inferred to be due to a deeper basement and/or Moho that get shallower from inland towards the coast. The Moho is at about 45 km depth inland and shallows to about 42 km at the coast. The 2½ D gravity modelling was done for fourteen (14) profiles with each profile having three (3) models corresponding to minimum, average and maximum densities to obtain the thicknesses of the geologic sequence. The current isochore thicknesses extracted from the gravity models show that the Beaufort Group is the thickest of all the groups that make up the Karoo Supergroup with maximum vertical thickness of up to 634 m, followed by the Ecca and Dwyka Groups with maximum vertical thicknesses of about 3207 m and 727 m, respectively. The maximum elevation for the Dwyka, Ecca and Beaufort sediments are about 500 m, 400 m and 285 m, respectively, whilst the maximum depth below sea level are around 8500 m, 7000 m and 5500 m, respectively. The PetroMod1D model result yield average vitrinite reflectance and temperature values of about 6 % and 500 ℃ respectively for the lower Ecca Group which belong to the dry gas window based on classification by several authors. Thus the rocks of the lower Ecca Group are thermally matured for hydrocarbon (shale gas) generation that can merit gas exploration in the Karoo Basin.
- Full Text:
- Date Issued: 2015
- Authors: Baiyegunhi, Christopher
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11532 , http://hdl.handle.net/10353/d1021280
- Description: Geological and geophysical methods were used to investigate the southeastern Karoo Basin of South Africa in an area extending from longitudes 24 o E to 29o E and latitudes 32o S to 35o S. This was undertaken in order to reveal geologic structures, isochore thicknesses of the geologic sequence and their variations across the study area, proffer the possible provenance of the sediments and assess the potential of oil and gas accumulation. The methodology used includes field investigation, rock sampling, preparation of thin sections, petrographic studies, X-ray diffraction analysis, density measurements, porosity calculations, extraction of elevation data from Google Earth, 2½ D gravity profile modelling, generating of isochore (true vertical) thicknesses and depositional surfaces maps from the models, PetroMod 1D modelling and qualitative interpretation of magnetic, gravity and radiometric maps.Petrographic study was carried out on twenty six thin sections of rocks from the eleven geologic formations that cover the study area. Petrographic studies on the diamictite of the Dwyka Group shows abundance of monocrystalline quartz, granite and quartzite components in the breccias which possibly indicate the existence of granitic and metamorphic rocks in the source areas. The sandstones of the Ecca and Beaufort Groups are immature, greywacke and the heavy mineral assemblages signify that the minerals are of granitic, volcanic and metamorphic origin. The magnetic maps show two main magnetic anomalies, a major one trending in a northeast to southwest direction which is part of the Beattie magnetic anomaly and another that is a “bean-shaped” anomaly. The radially averaged power spectrum shows two depths to magnetic sources. The first depth is about 0.6 km which is the average depth to the top of the shallow sources, while the average depth to the top of the deep sources is about 15 km. The shallow sources are connected to magnetic minerals within the Beaufort Group while deep magnetic sources were inferred to be in the basement. The gamma ray spectrometric map shows areas with relatively high gamma radiation count. The high radiation count is possibly due to the uranium and thorium in the detrital materials, as well as the enrichment of radioelements in the feldspars (k-feldspar), calcite, quartz, zircon and clay minerals in the fluvial channel sandstones of the Beaufort Group. A total of two hundred and fifty-eight (258) rock samples were collected in the field and densities (dry, wet and grain densities) and porosities were determined in the laboratory. The Karoo Supergroup density values range from 2.526 – 2.828 g/cm3. The average porosities range from 0. 49 – 3.31 %. The dry densities and porosities of all the formations are inversely correlated with correlation coefficient values (R) that range from 0.9491 - 0.9982. The density of the dolerite intrusions (mostly sill) ranges from 2.700 – 2.837 g/cm3 whilst the porosity range from 0.1118 – 0.3868 %. The Bouguer anomaly map shows an increase in gravity values from -140.7 mGal in inland to about 60.1 mGal in coastal areas. This dominant gravity variation is inferred to be due to a deeper basement and/or Moho that get shallower from inland towards the coast. The Moho is at about 45 km depth inland and shallows to about 42 km at the coast. The 2½ D gravity modelling was done for fourteen (14) profiles with each profile having three (3) models corresponding to minimum, average and maximum densities to obtain the thicknesses of the geologic sequence. The current isochore thicknesses extracted from the gravity models show that the Beaufort Group is the thickest of all the groups that make up the Karoo Supergroup with maximum vertical thickness of up to 634 m, followed by the Ecca and Dwyka Groups with maximum vertical thicknesses of about 3207 m and 727 m, respectively. The maximum elevation for the Dwyka, Ecca and Beaufort sediments are about 500 m, 400 m and 285 m, respectively, whilst the maximum depth below sea level are around 8500 m, 7000 m and 5500 m, respectively. The PetroMod1D model result yield average vitrinite reflectance and temperature values of about 6 % and 500 ℃ respectively for the lower Ecca Group which belong to the dry gas window based on classification by several authors. Thus the rocks of the lower Ecca Group are thermally matured for hydrocarbon (shale gas) generation that can merit gas exploration in the Karoo Basin.
- Full Text:
- Date Issued: 2015
A participatory communication approach of rural cattle project: a case study of Nguni cattle project in the Eastern Cape, South Africa
- Authors: Usadolo, Sam Erevbenagie
- Date: 2011
- Subjects: Communication in community development -- South Africa , Nguni cattle -- South Africa , Participatory rural appraisal
- Language: English
- Type: Thesis , Doctoral , PhD (Com)
- Identifier: vital:11370 , http://hdl.handle.net/10353/d1015407 , Communication in community development -- South Africa , Nguni cattle -- South Africa , Participatory rural appraisal
- Description: project. It did this by reviewing relevant literature in development communication. The review done showed that literature is replete with arguments critical of the dominant paradigm due to its top-down nature of communication. Scholars critical of dominant paradigm argue that participatory communication should be given a prominent role to ensure that stakeholders work in concert to realise the stated objectives of their development project. The study highlighted many contentious issues surrounding the nature and practices of participatory communication. It pointed out that the issues have played themselves out in literature in the form of different typologies of participatory practices, which were dealt with extensively in this study. The discussion of participatory communication in literature is also mindful of different models of communication and the space they occupy in participatory communication practices. In this study, there was a discussion of transactional communication models as depicted by Nair and White (1993:52) and Steinberg (1997:19). Both scholars emphasise that participatory communication will not achieve its stated purpose without mutual agreement of the parties in communication. They equally stress the recognition of the possible effects of some contextual factors which may have bearing on the prevailing nature of communication. A review of different communication tools used by participatory development communicator was given in the study. These different communication tools were discussed in view of how these tools can be used to advance participatory practice in a development project, especially with reference to the project examined in this study. Using qualitative research method, different and appropriate interview methods such as semi-structured, focus group and post-survey interviews were used to collect data from the respondents in this study. The analysis and discussion of the data revealed that different challenges on the ground could affect participatory communication practices in a development project. With regard to the project examined in this study, the analysis showed that there is a weak stakeholder relationship, especially stakeholders identified in this study as field officers. The study highlighted that stakeholders such as the agricultural extension officers and animal health technicians are not very active in the implementation process of the project. Some of the reasons pointed out is the fact that the secondary stakeholder such as the Provincial Department of Agricultural (PDoA) to which these field officers belong is not playing active role in ensuring that they complement the efforts of other field officers such as the IDC representatives. The second reason is the fact that the participatory focus of the project was not properly communicated to the beneficiaries. This also transpired in their inability to reflect participatory practice in their relationship with the beneficiaries and other stakeholders of the project. Other challenges, among others, as pointed out in the analysis showed that participatory communication practice requires expert personnel to be successful. In the case of the project examined, apart from the fact that there is shortage of manpower to handle the challenges mentioned in the study, there is no communication expert among the few active personnel in the field. The findings of this study showed that there was no clear role and identification of responsibilities let alone coordination of all actors involved in the project. Through the selected case study, this study has not only provided avenue to explore both theoretically and practically participatory communication, but has added to participatory communication discourse that there is no easy answer to challenges field officers encounter in practice. This is the reason the different participatory practices characterising nature of the project this study has investigated was given.
- Full Text:
- Date Issued: 2011
- Authors: Usadolo, Sam Erevbenagie
- Date: 2011
- Subjects: Communication in community development -- South Africa , Nguni cattle -- South Africa , Participatory rural appraisal
- Language: English
- Type: Thesis , Doctoral , PhD (Com)
- Identifier: vital:11370 , http://hdl.handle.net/10353/d1015407 , Communication in community development -- South Africa , Nguni cattle -- South Africa , Participatory rural appraisal
- Description: project. It did this by reviewing relevant literature in development communication. The review done showed that literature is replete with arguments critical of the dominant paradigm due to its top-down nature of communication. Scholars critical of dominant paradigm argue that participatory communication should be given a prominent role to ensure that stakeholders work in concert to realise the stated objectives of their development project. The study highlighted many contentious issues surrounding the nature and practices of participatory communication. It pointed out that the issues have played themselves out in literature in the form of different typologies of participatory practices, which were dealt with extensively in this study. The discussion of participatory communication in literature is also mindful of different models of communication and the space they occupy in participatory communication practices. In this study, there was a discussion of transactional communication models as depicted by Nair and White (1993:52) and Steinberg (1997:19). Both scholars emphasise that participatory communication will not achieve its stated purpose without mutual agreement of the parties in communication. They equally stress the recognition of the possible effects of some contextual factors which may have bearing on the prevailing nature of communication. A review of different communication tools used by participatory development communicator was given in the study. These different communication tools were discussed in view of how these tools can be used to advance participatory practice in a development project, especially with reference to the project examined in this study. Using qualitative research method, different and appropriate interview methods such as semi-structured, focus group and post-survey interviews were used to collect data from the respondents in this study. The analysis and discussion of the data revealed that different challenges on the ground could affect participatory communication practices in a development project. With regard to the project examined in this study, the analysis showed that there is a weak stakeholder relationship, especially stakeholders identified in this study as field officers. The study highlighted that stakeholders such as the agricultural extension officers and animal health technicians are not very active in the implementation process of the project. Some of the reasons pointed out is the fact that the secondary stakeholder such as the Provincial Department of Agricultural (PDoA) to which these field officers belong is not playing active role in ensuring that they complement the efforts of other field officers such as the IDC representatives. The second reason is the fact that the participatory focus of the project was not properly communicated to the beneficiaries. This also transpired in their inability to reflect participatory practice in their relationship with the beneficiaries and other stakeholders of the project. Other challenges, among others, as pointed out in the analysis showed that participatory communication practice requires expert personnel to be successful. In the case of the project examined, apart from the fact that there is shortage of manpower to handle the challenges mentioned in the study, there is no communication expert among the few active personnel in the field. The findings of this study showed that there was no clear role and identification of responsibilities let alone coordination of all actors involved in the project. Through the selected case study, this study has not only provided avenue to explore both theoretically and practically participatory communication, but has added to participatory communication discourse that there is no easy answer to challenges field officers encounter in practice. This is the reason the different participatory practices characterising nature of the project this study has investigated was given.
- Full Text:
- Date Issued: 2011
A comparative analysis of the rights of the child with particular reference to child soldiers
- Authors: Anwo, Joel Olasunkanmi
- Date: 2008
- Subjects: Children's rights -- Child welfare -- Demobilization of children , Disarmament -- Reintegration
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: vital:11108 , http://hdl.handle.net/10353/102 , Children's rights -- Child welfare -- Demobilization of children , Disarmament -- Reintegration
- Description: The recruitment, enlistment and forceful conscription of children as soldiers is a cause for grave concern all over the world and most especially in Africa, where years of factional fighting, civil wars and cross border conflicts have raged, children and youth have been pulled into violence not only as victims, but also as perpetrators. The involvement of children in war posses a severe challenge to prevailing moral and legal norms of the conduct of modern warfare. A major problem and most controversial issue, among others, is on the age at which children should be eligible to become combatants. Children, who may be viewed as a valuable resource due to their often inherent malleability, wish to avenge family member(s) killed in war, sense of immunity to danger, and or feeling of power in participating in the violence. Can the use of children as soldiers be effectively regulated in Africa? All efforts to assist child soldiers in recovering from the devastating effects of wars often unwillingly helped promote the growing number of child soldiers. This is in part because wars are now more fought internally among rebel armies and factions vying for power with the government and thus enlist children into their various armies. The study comes to a conclusion that drastic steps need to be taken to ameliorate this unfortunate situation. This formed the basis of the recommendations offered in the thesis to assist the African continent.
- Full Text:
- Date Issued: 2008
- Authors: Anwo, Joel Olasunkanmi
- Date: 2008
- Subjects: Children's rights -- Child welfare -- Demobilization of children , Disarmament -- Reintegration
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: vital:11108 , http://hdl.handle.net/10353/102 , Children's rights -- Child welfare -- Demobilization of children , Disarmament -- Reintegration
- Description: The recruitment, enlistment and forceful conscription of children as soldiers is a cause for grave concern all over the world and most especially in Africa, where years of factional fighting, civil wars and cross border conflicts have raged, children and youth have been pulled into violence not only as victims, but also as perpetrators. The involvement of children in war posses a severe challenge to prevailing moral and legal norms of the conduct of modern warfare. A major problem and most controversial issue, among others, is on the age at which children should be eligible to become combatants. Children, who may be viewed as a valuable resource due to their often inherent malleability, wish to avenge family member(s) killed in war, sense of immunity to danger, and or feeling of power in participating in the violence. Can the use of children as soldiers be effectively regulated in Africa? All efforts to assist child soldiers in recovering from the devastating effects of wars often unwillingly helped promote the growing number of child soldiers. This is in part because wars are now more fought internally among rebel armies and factions vying for power with the government and thus enlist children into their various armies. The study comes to a conclusion that drastic steps need to be taken to ameliorate this unfortunate situation. This formed the basis of the recommendations offered in the thesis to assist the African continent.
- Full Text:
- Date Issued: 2008
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