The petrology and geochemistry of the layered Molopo Farms Complex, South Africa
- Authors: Hlungwani, Ripfalo Peace
- Date: 2018
- Subjects: Molopo Farms Complex (Botswana and South Africa) , Geochemistry - South Africa , Petrology - Souh Africa , Geology - South Africa
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/295342 , uj:32159
- Description: M.Sc. (Geology) , Abstract: Please refer to full text to view abstract.
- Full Text:
- Authors: Hlungwani, Ripfalo Peace
- Date: 2018
- Subjects: Molopo Farms Complex (Botswana and South Africa) , Geochemistry - South Africa , Petrology - Souh Africa , Geology - South Africa
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/295342 , uj:32159
- Description: M.Sc. (Geology) , Abstract: Please refer to full text to view abstract.
- Full Text:
Isotopic resetting of zircon : influence of age, temperature and chemical environment
- Authors: Magwaza, Boniswa Nolwazi
- Date: 2019
- Subjects: Sedimentation and deposition - South Africa , Geology - South Africa
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/417502 , uj:35360
- Description: Abstract: To assess the causes and extent of isotopic resetting of zircon, U-Pb and Lu-Hf analyses have been performed on zircons from Archean and Bushveld granites as well as Transvaal sediments which have been intruded by magmas of the Bushveld Complex, Pilanesberg Complex, Spitskop Complex, Goudini Complex, and Karoo dolerites in the vicinity of Bushveld Complex using laser ablation multi-collector inductively coupled plasma source mass spectrometry (LA-MC-ICPMS). U-Pb results for zircon analyses from both Archean granites and Transvaal sedimentary rocks indicate that they have undergone partial Pb loss and age resetting. Pb loss was influenced by radiation damage in zircons and metamorphism. Contributions from the Bushveld Complex thermal overprint cannot be excluded, based on evidence from concordia diagrams and 207Pb/206Pb ages; two samples of Magaliesberg sandstones (MEMG 3, 4), closest to the contact with the Marginal Zone, are affected the most. The presence of common Pb and its correction also contributed in shifting the data towards younger 207Pb/206Pb ages. Younger alkaline intrusions as well as Karoo dolerites did not have much influence on zircon signatures. There are only small differences in initial Hf ratios of analyses within the same sample, indicating that the Lu-Hf isotope system remained undisturbed. There are no appreciable effects on trace element concentrations to support that disturbance in U-Pb signatures of zircons is accompanied by their modifications. .. , M.Sc. (Geology)
- Full Text:
- Authors: Magwaza, Boniswa Nolwazi
- Date: 2019
- Subjects: Sedimentation and deposition - South Africa , Geology - South Africa
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/417502 , uj:35360
- Description: Abstract: To assess the causes and extent of isotopic resetting of zircon, U-Pb and Lu-Hf analyses have been performed on zircons from Archean and Bushveld granites as well as Transvaal sediments which have been intruded by magmas of the Bushveld Complex, Pilanesberg Complex, Spitskop Complex, Goudini Complex, and Karoo dolerites in the vicinity of Bushveld Complex using laser ablation multi-collector inductively coupled plasma source mass spectrometry (LA-MC-ICPMS). U-Pb results for zircon analyses from both Archean granites and Transvaal sedimentary rocks indicate that they have undergone partial Pb loss and age resetting. Pb loss was influenced by radiation damage in zircons and metamorphism. Contributions from the Bushveld Complex thermal overprint cannot be excluded, based on evidence from concordia diagrams and 207Pb/206Pb ages; two samples of Magaliesberg sandstones (MEMG 3, 4), closest to the contact with the Marginal Zone, are affected the most. The presence of common Pb and its correction also contributed in shifting the data towards younger 207Pb/206Pb ages. Younger alkaline intrusions as well as Karoo dolerites did not have much influence on zircon signatures. There are only small differences in initial Hf ratios of analyses within the same sample, indicating that the Lu-Hf isotope system remained undisturbed. There are no appreciable effects on trace element concentrations to support that disturbance in U-Pb signatures of zircons is accompanied by their modifications. .. , M.Sc. (Geology)
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Petrography and Geochemistry of Early-Middle Jurassic Mafic Dykes from the H.U. Sverdrupfjella, Antarctica
- Authors: Morake, Mabuela Andries
- Date: 2018
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/446270 , uj:39073
- Description: M.Sc. (Geology) , Abstract: The Early to Middle Jurassic break-up of Gondwana produced large-volume magmatic events, resulting in large igneous provinces (LIPs) such as the Karoo LIP in southern Africa and Ferrar LIP in East Antarctica. The Jurassic magmatism in western Dronning Maud Land (WDML), Antarctica is regarded as part of the Karoo LIP. The mafic dykes from H.U. Sverdrupfjella in WDML,intrude the off-craton Mesoproterozoic Maud Belt, and little to no data has been published (Harris et al., 1995; Curtis et al., 2008) on their geochemical compositions and age. The new geochemical and geochronological data for H.U. Sverdrupfjella mafic dykes display similarities to, and differences from Jurassic lavas and dykes from elsewhere in WDML and the Karoo LIP...
- Full Text:
- Authors: Morake, Mabuela Andries
- Date: 2018
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/446270 , uj:39073
- Description: M.Sc. (Geology) , Abstract: The Early to Middle Jurassic break-up of Gondwana produced large-volume magmatic events, resulting in large igneous provinces (LIPs) such as the Karoo LIP in southern Africa and Ferrar LIP in East Antarctica. The Jurassic magmatism in western Dronning Maud Land (WDML), Antarctica is regarded as part of the Karoo LIP. The mafic dykes from H.U. Sverdrupfjella in WDML,intrude the off-craton Mesoproterozoic Maud Belt, and little to no data has been published (Harris et al., 1995; Curtis et al., 2008) on their geochemical compositions and age. The new geochemical and geochronological data for H.U. Sverdrupfjella mafic dykes display similarities to, and differences from Jurassic lavas and dykes from elsewhere in WDML and the Karoo LIP...
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