The geochronology and geochemistry of Karoo volcanics in the Lebombo and adjacent areas

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dc.contributor.advisorErlank, A Jen_ZA
dc.contributor.advisorDuncan, A Ren_ZA
dc.contributor.authorBristow, John Williamen_ZA
dc.date.accessioned2015-02-24T04:12:40Z
dc.date.available2015-02-24T04:12:40Z
dc.date.issued1980en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractKaroo volcanics of Jurassic to Cretaceous age crop out in the eastern areas of southern Africa. These volcanics are well preserved in the Lebombo monocline which straddles the borders of South Africa, Swaziland and Mozambique, and in the Nuanetsi and Tuli synclines and Sabi monocline of south-east Zimbabwe. Geochronological and geochemical data have been used to evaluate the geochemistry of the rock types found in the above areas, particularly with respect to the mafic volcanics of the Lebombo. In the eastwardly dipping Lebombo monocline, nephelinites overlain by picrite basalts occur in the northern part of the volcanic succession whereas over the remaining area olivine-poor basalts are dominant. Rhyolitic volcanics in the form of massive flows overlie the basaltic rocks and attain their maximum thickness in Swaziland and the southern Lebombo. The rhyolites are notably thinner to the north of Swaziland and are overlain by an upper sequence of olivine-poor lavas with interdigitated rhyolite flows. Basic dykes are ubiquitous in the Lebombo whereas acid dykes, though present, tend to be localised. In Nuanetsi, picrite basalts, olivine-poor basalts and rhyolite flows with interbedded basic lavas crop out ina major synclinal structure. Dyke rocks are common and late Karoo intrusive complexes cut the lavas. Volcanic rocks in the Tuli syncline consist predominantly of picrite basalts and olivine poor lavas, whereas nephelinites, picrite basalts and olivine-poor lavas crop out in the Sabi Monocline.en_ZA
dc.identifier.apacitationBristow, J. W. (1980). <i>The geochronology and geochemistry of Karoo volcanics in the Lebombo and adjacent areas</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Geological Sciences. Retrieved from http://hdl.handle.net/11427/12534en_ZA
dc.identifier.chicagocitationBristow, John William. <i>"The geochronology and geochemistry of Karoo volcanics in the Lebombo and adjacent areas."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Geological Sciences, 1980. http://hdl.handle.net/11427/12534en_ZA
dc.identifier.citationBristow, J. 1980. The geochronology and geochemistry of Karoo volcanics in the Lebombo and adjacent areas. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Bristow, John William AB - Karoo volcanics of Jurassic to Cretaceous age crop out in the eastern areas of southern Africa. These volcanics are well preserved in the Lebombo monocline which straddles the borders of South Africa, Swaziland and Mozambique, and in the Nuanetsi and Tuli synclines and Sabi monocline of south-east Zimbabwe. Geochronological and geochemical data have been used to evaluate the geochemistry of the rock types found in the above areas, particularly with respect to the mafic volcanics of the Lebombo. In the eastwardly dipping Lebombo monocline, nephelinites overlain by picrite basalts occur in the northern part of the volcanic succession whereas over the remaining area olivine-poor basalts are dominant. Rhyolitic volcanics in the form of massive flows overlie the basaltic rocks and attain their maximum thickness in Swaziland and the southern Lebombo. The rhyolites are notably thinner to the north of Swaziland and are overlain by an upper sequence of olivine-poor lavas with interdigitated rhyolite flows. Basic dykes are ubiquitous in the Lebombo whereas acid dykes, though present, tend to be localised. In Nuanetsi, picrite basalts, olivine-poor basalts and rhyolite flows with interbedded basic lavas crop out ina major synclinal structure. Dyke rocks are common and late Karoo intrusive complexes cut the lavas. Volcanic rocks in the Tuli syncline consist predominantly of picrite basalts and olivine poor lavas, whereas nephelinites, picrite basalts and olivine-poor lavas crop out in the Sabi Monocline. DA - 1980 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1980 T1 - The geochronology and geochemistry of Karoo volcanics in the Lebombo and adjacent areas TI - The geochronology and geochemistry of Karoo volcanics in the Lebombo and adjacent areas UR - http://hdl.handle.net/11427/12534 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/12534
dc.identifier.vancouvercitationBristow JW. The geochronology and geochemistry of Karoo volcanics in the Lebombo and adjacent areas. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Geological Sciences, 1980 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/12534en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Geological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherGeochemistryen_ZA
dc.titleThe geochronology and geochemistry of Karoo volcanics in the Lebombo and adjacent areasen_ZA
dc.typeDoctoral Thesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnamePhDen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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