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Pan-African imprint on the early mid-proterozoic Richtersveld and Bushmanland sub-provinces near Eksteenfontein, Namaqualand, Republic of South Africa
The present investigation examines the relationship between the Proterozoic Richtersveld and Bushmanland Subprovinces in the westernmost part of the Namaqua Province, near Eksteenfontein, Republic of South Africa. There is a controversy about this relationship because isotopic data contrast with fie...
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Department of Geological Sciences
2017
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| access_status_str | Open Access |
| author | Booth, Peter William King |
| author_browse | Booth, Peter William King |
| author_facet | Booth, Peter William King |
| author_sort | Booth, Peter William King |
| collection | Thesis |
| description | The present investigation examines the relationship between the Proterozoic Richtersveld and Bushmanland Subprovinces in the westernmost part of the Namaqua Province, near Eksteenfontein, Republic of South Africa. There is a controversy about this relationship because isotopic data contrast with field evidence. On a regional scale the Richtersveld Subprovince is separated from the Bushmanland Subprovince by the northward-dipping Groothoek Thrust. North of the thrust the Richtersveld Subprovince is comprised of low grade volcano/ plutonic rocks of the Vioolsdrif Terrane and medium grade volcano sedimentary sequences of the Pella Terrane. Medium grade rocks of the Steinkopf Terrane (Bushmanland Subprovince) lie immediately south of the thrust. Late Proterozoic strata of the Stinkfontein Formation (Gariep Group) overlie the Namaqua Province in the west; Cambrian Nama Group outliers occur east of the Stinkfontein Formation. Isotopic data show that lithologies of the Richtersveld Subprovince formed between 2000 - 1730 Ma, whereas those of the Bushmanland Subprovince are younger. It is not clear whether the Namaqua metamorphic imprint (at 1200 - 1100 Ma), which is manifest in terranes south of the Groothoek Thrust, extended as far as the Vioolsdrif Terrane in the north. Early Proterozoic structural and metamorphic imprints are inferred to have been obliterated during this event. The westernmost part of the Namaqua Province was overprinted for a distance of 100 km from the coast, during the Pan-African event at 700 Ma and 500 Ma. An area measuring nearly 500 km2 , traversing the western extremity of the boundary between the Richtersveld and Bushmanland Subprovinces was mapped on a scale of 1:36,000. Field mapping was carried out with the aid of aerial photographs, whereas laboratory techniques included map compilation, structural analysis, X-ray diffractometry, geochemical (XRF) and electron microprobe analyses. Supracrustal units of the Richtersveld Subprovince are composed of quartzo-feldspathic gneisses, schists, and minor meta-pelites. Supracrustals of the Bushmanland Subprovince are less diverse than those of the Richtersveld Subprovince and have a disconformable relationship with them. Most intrusive rock-types are thick granitic sheets, except the Early Proterozoic Vioolsdrif Granodiorite which forms part of a batholithic pluton in the north. The Sabieboomrante adamellite gneiss, Kouefontein granite gneiss and Dabbieputs granite gneiss could not be correlated with lithologies commonly occurring in the Richtersveld and Bushmanland Subprovinces. They have been given the new rock names. Mafic and ultramafic rocks of the Klipbok complex occur along the strike of the Groothoek Thrust. They form part of the Richtersveld Subprovince. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/26232 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:34:00.978Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2017 |
| publishDateRange | 2017 |
| publishDateSort | 2017 |
| 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:11427/26232 Pan-African imprint on the early mid-proterozoic Richtersveld and Bushmanland sub-provinces near Eksteenfontein, Namaqualand, Republic of South Africa Booth, Peter William King Geology, Stratigraphic - Precambrian. Geology - South Africa - Richtersveld Geology - South Africa - Bushmanland Geology - South Africa - Namaqualand The present investigation examines the relationship between the Proterozoic Richtersveld and Bushmanland Subprovinces in the westernmost part of the Namaqua Province, near Eksteenfontein, Republic of South Africa. There is a controversy about this relationship because isotopic data contrast with field evidence. On a regional scale the Richtersveld Subprovince is separated from the Bushmanland Subprovince by the northward-dipping Groothoek Thrust. North of the thrust the Richtersveld Subprovince is comprised of low grade volcano/ plutonic rocks of the Vioolsdrif Terrane and medium grade volcano sedimentary sequences of the Pella Terrane. Medium grade rocks of the Steinkopf Terrane (Bushmanland Subprovince) lie immediately south of the thrust. Late Proterozoic strata of the Stinkfontein Formation (Gariep Group) overlie the Namaqua Province in the west; Cambrian Nama Group outliers occur east of the Stinkfontein Formation. Isotopic data show that lithologies of the Richtersveld Subprovince formed between 2000 - 1730 Ma, whereas those of the Bushmanland Subprovince are younger. It is not clear whether the Namaqua metamorphic imprint (at 1200 - 1100 Ma), which is manifest in terranes south of the Groothoek Thrust, extended as far as the Vioolsdrif Terrane in the north. Early Proterozoic structural and metamorphic imprints are inferred to have been obliterated during this event. The westernmost part of the Namaqua Province was overprinted for a distance of 100 km from the coast, during the Pan-African event at 700 Ma and 500 Ma. An area measuring nearly 500 km2 , traversing the western extremity of the boundary between the Richtersveld and Bushmanland Subprovinces was mapped on a scale of 1:36,000. Field mapping was carried out with the aid of aerial photographs, whereas laboratory techniques included map compilation, structural analysis, X-ray diffractometry, geochemical (XRF) and electron microprobe analyses. Supracrustal units of the Richtersveld Subprovince are composed of quartzo-feldspathic gneisses, schists, and minor meta-pelites. Supracrustals of the Bushmanland Subprovince are less diverse than those of the Richtersveld Subprovince and have a disconformable relationship with them. Most intrusive rock-types are thick granitic sheets, except the Early Proterozoic Vioolsdrif Granodiorite which forms part of a batholithic pluton in the north. The Sabieboomrante adamellite gneiss, Kouefontein granite gneiss and Dabbieputs granite gneiss could not be correlated with lithologies commonly occurring in the Richtersveld and Bushmanland Subprovinces. They have been given the new rock names. Mafic and ultramafic rocks of the Klipbok complex occur along the strike of the Groothoek Thrust. They form part of the Richtersveld Subprovince. 2017-11-14T13:52:46Z 2017-11-14T13:52:46Z 1990 2017-03-27T13:39:13Z Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/26232 eng application/pdf Department of Geological Sciences Faculty of Science University of Cape Town |
| spellingShingle | Geology, Stratigraphic - Precambrian. Geology - South Africa - Richtersveld Geology - South Africa - Bushmanland Geology - South Africa - Namaqualand Booth, Peter William King Pan-African imprint on the early mid-proterozoic Richtersveld and Bushmanland sub-provinces near Eksteenfontein, Namaqualand, Republic of South Africa |
| thesis_degree_str | Doctoral |
| title | Pan-African imprint on the early mid-proterozoic Richtersveld and Bushmanland sub-provinces near Eksteenfontein, Namaqualand, Republic of South Africa |
| title_full | Pan-African imprint on the early mid-proterozoic Richtersveld and Bushmanland sub-provinces near Eksteenfontein, Namaqualand, Republic of South Africa |
| title_fullStr | Pan-African imprint on the early mid-proterozoic Richtersveld and Bushmanland sub-provinces near Eksteenfontein, Namaqualand, Republic of South Africa |
| title_full_unstemmed | Pan-African imprint on the early mid-proterozoic Richtersveld and Bushmanland sub-provinces near Eksteenfontein, Namaqualand, Republic of South Africa |
| title_short | Pan-African imprint on the early mid-proterozoic Richtersveld and Bushmanland sub-provinces near Eksteenfontein, Namaqualand, Republic of South Africa |
| title_sort | pan african imprint on the early mid proterozoic richtersveld and bushmanland sub provinces near eksteenfontein namaqualand republic of south africa |
| topic | Geology, Stratigraphic - Precambrian. Geology - South Africa - Richtersveld Geology - South Africa - Bushmanland Geology - South Africa - Namaqualand |
| url | http://hdl.handle.net/11427/26232 |
| work_keys_str_mv | AT boothpeterwilliamking panafricanimprintontheearlymidproterozoicrichtersveldandbushmanlandsubprovincesneareksteenfonteinnamaqualandrepublicofsouthafrica |