Szczegóły publikacji
Opis bibliograficzny
Genetic aspects of the Katangan megabreccias: Neoprotezoic of Central Africa / Marek Wendorff // Journal of African Earth Sciences ; ISSN 1464-343X. — Błędny ISSN 0899-5362. — 2000 — vol. 30 iss. 3, s. 703–715. — Bibliogr. s. 713–715, Abstr., Rés. — Afiliacja autora: University of Botswana. — Conference for the 50th Anniversary of the Geological Survey of Botswana
Autor
- Wendorff Marek
Dane bibliometryczne
| ID BaDAP | 53092 |
|---|---|
| Data dodania do BaDAP | 2010-09-03 |
| Tekst źródłowy | URL |
| DOI | 10.1016/S0899-5362(00)00047-6 |
| Rok publikacji | 2000 |
| Typ publikacji | referat w czasopiśmie |
| Otwarty dostęp |  |
| Czasopismo/seria | Journal of African Earth Sciences |
Abstract
The structure of the external, fold-and-thrust region of the Neoproterozoic Katangan orogenic belt of Central Africa is characterised by thrust sheets, gravitationally transported towards the foreland region in the north, and associated with prominent megabreccias. The thrust sheets contain a more or less complete succession of the Katangan sedimentary rocks. The megabreccias form tabular and wedge-shaped, mostly chaotic bodies, underlying the allochthonous sheets and composed of subangular to rounded fragments of Katangan provenance. Fragments range from millimetres to many kilometres in size and are set in an abundant clay matrix with dolomitic cement. It is commonly accepted in the literature that the Katangan megabreccias are of entirely tectonic origin; friction acting beneath the advancing thrust sheets is thought to be the main process responsible for fragmentation and abrasion of clasts. However, the analysis of stratigraphical, textural and structural features presented in this paper implies a sedimentary genesis of the Katangan megabreccias. It is shown that they resulted from subaqueous re-sedimentation by mass gravity flows of clastic materials eroded from the emergent tops and fronts of the advancing thrust sheets, in front of which olistostrome wedges were deposited. The deposition of each individual olistostrome body stopped when the approaching thrust block overrode it due to the acceleration of gravity gliding. These processes, and their products, define the Katangan foreland region. The olistostrome sedimentary model has significant implications for our understanding of the structural and tectonostratigraphic evolution of this sector of the Katangan belt.
