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Alkaline igneous rocks of the coastal belt, south of Luderitz, South West Africa : a petrological study
The Luderitz Alkaline Province, as it is at present known, comprises the subvolcanic central complexes of Drachenberg, Pomona, and Granitberg. An attendant dyke swarm strikes NE-SW and crops out between the latitudes of 27°00' and 27°30' S. Stratigraphic indications (now confirmed by a K/Ar age from...
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| Format: | Thesis |
| Language: | English |
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Department of Geological Sciences
2016
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| _version_ | 1867613334641049600 |
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| access_status_str | Open Access |
| author | Marsh, Julian Saville |
| author_browse | Marsh, Julian Saville |
| author_facet | Marsh, Julian Saville |
| author_sort | Marsh, Julian Saville |
| collection | Thesis |
| description | The Luderitz Alkaline Province, as it is at present known, comprises the subvolcanic central complexes of Drachenberg, Pomona, and Granitberg. An attendant dyke swarm strikes NE-SW and crops out between the latitudes of 27°00' and 27°30' S. Stratigraphic indications (now confirmed by a K/Ar age from Granitberg) are that the Luderitz Province is early-Cretaceous in age and therefore older than the Klinghardt phonolites (Eocene) as well as the smaller melilitite and nephelinite intrusions. Granitberg is a circular foyaite complex, in the centre of which is preserved a large fragment of sedimentary rocks that originally formed the roof of the intrusion. The foyaites have been emplaced into the feldspathic sandstones and dolomites of the Bogenfels Formation, and three major intrusive phases can be recognised. The first phase produced chilled nepheline syenites beneath the roof of the intrusion. These chilled rocks grade downwards into coarse-grained foyaites. The second phase was the emplacement of the Inner Foyaite which crystallized as a cylindrically zoned plug, capped by a zone of layered, laminated, and xenolithrich foyaites. The third phase was the emplacement of the Outer Foyaite, into which the Roof Zone and the Inner Foyaite foundered. The Outer Foyaite is zoned with a miaskitic core, and an agpaitic outer zone. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/17697 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:34:28.941Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2016 |
| publishDateRange | 2016 |
| publishDateSort | 2016 |
| publisher | Department of Geological Sciences |
| publisherStr | Department of Geological Sciences |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/17697 Alkaline igneous rocks of the coastal belt, south of Luderitz, South West Africa : a petrological study Marsh, Julian Saville Geology Petrology The Luderitz Alkaline Province, as it is at present known, comprises the subvolcanic central complexes of Drachenberg, Pomona, and Granitberg. An attendant dyke swarm strikes NE-SW and crops out between the latitudes of 27°00' and 27°30' S. Stratigraphic indications (now confirmed by a K/Ar age from Granitberg) are that the Luderitz Province is early-Cretaceous in age and therefore older than the Klinghardt phonolites (Eocene) as well as the smaller melilitite and nephelinite intrusions. Granitberg is a circular foyaite complex, in the centre of which is preserved a large fragment of sedimentary rocks that originally formed the roof of the intrusion. The foyaites have been emplaced into the feldspathic sandstones and dolomites of the Bogenfels Formation, and three major intrusive phases can be recognised. The first phase produced chilled nepheline syenites beneath the roof of the intrusion. These chilled rocks grade downwards into coarse-grained foyaites. The second phase was the emplacement of the Inner Foyaite which crystallized as a cylindrically zoned plug, capped by a zone of layered, laminated, and xenolithrich foyaites. The third phase was the emplacement of the Outer Foyaite, into which the Roof Zone and the Inner Foyaite foundered. The Outer Foyaite is zoned with a miaskitic core, and an agpaitic outer zone. 2016-03-14T07:14:16Z 2016-03-14T07:14:16Z 1973 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/17697 eng application/pdf Department of Geological Sciences Faculty of Science University of Cape Town |
| spellingShingle | Geology Petrology Marsh, Julian Saville Alkaline igneous rocks of the coastal belt, south of Luderitz, South West Africa : a petrological study |
| thesis_degree_str | Doctoral |
| title | Alkaline igneous rocks of the coastal belt, south of Luderitz, South West Africa : a petrological study |
| title_full | Alkaline igneous rocks of the coastal belt, south of Luderitz, South West Africa : a petrological study |
| title_fullStr | Alkaline igneous rocks of the coastal belt, south of Luderitz, South West Africa : a petrological study |
| title_full_unstemmed | Alkaline igneous rocks of the coastal belt, south of Luderitz, South West Africa : a petrological study |
| title_short | Alkaline igneous rocks of the coastal belt, south of Luderitz, South West Africa : a petrological study |
| title_sort | alkaline igneous rocks of the coastal belt south of luderitz south west africa a petrological study |
| topic | Geology Petrology |
| url | http://hdl.handle.net/11427/17697 |
| work_keys_str_mv | AT marshjuliansaville alkalineigneousrocksofthecoastalbeltsouthofluderitzsouthwestafricaapetrologicalstudy |