caa a22 4500 477064426 CHVBK 20180405111408.0 cr unu---uuuuu 170330e19961201xx s 000 0 eng 10.1007/BF02440101 doi (NATIONALLICENCE)springer-10.1007/BF02440101 Subduction, mega-shear systems and Late Palaeozoic basin development in the African segment of Gondwana [Elektronische Daten] [Johan Visser, Hermann Praekelt] Basins within the African sector of Gondwana contain a Late Palaeozoic to Early Mesozoic Gondwana sequence unconformably overlying Precambrian basement in the interior and mid-Palaeozoic strata along the palaeo-Pacific margin. Small sea-board Pacific basins form an exception in having a Carboniferous to Early Permian fill overlying Devonian metasediments and intrusives. The Late Palaeozoic geographic and tectonic changes in the region followed four well-defined consecutive events which can also be traced outside the study area. During the Late Devonian to Early Carboniferous period (up to 330 Ma) accretion of microplates along the Patagonian margin of Gondwana resulted in the evolution of the Pacific basins. Thermal uplift of the Gondwana crust and extensive erosion causing a break in the stratigraphic record characterised the period between 300 and 330 Ma. At the end of this period the Gondwana Ice Sheet was well established over the uplands. The period 260-300 Ma evidenced the release of the Gondwana heat and thermal subsidence caused widespread basin formation. Late Carboniferous transpressive strike-slip basins (e.g. Sierra Australes/Colorado, Karoo-Falklands, Ellsworth-Central Transantarctic Mountains) in which thick glacial deposits accumulated, formed inboard of the palaeo-Pacific margin. In the continental interior the formation of Zambesi-type rift and extensional strike-slip basins were controlled by large mega-shear systems, whereas rare intracratonic thermal subsidence basins formed locally. In the Late Permian the tectonic regime changed to compressional largely due to northwest-directed subduction along the palaeo-Pacific margin. The orogenic cycle between 240 and 260 Ma resulted in the formation of the Gondwana fold belt and overall north-south crustal shortening with strike-slip motions and regional uplift within the interior. The Gondwana fold belt developed along a probable weak crustal zone wedged in between the cratons and an overthickened marginal crustal belt subject to dextral transpressive motions. Associated with the orogenic cycle was the formation of mega-shear systems one of which (Falklands-East Africa-Tethys shear) split the supercontinent in the Permo-Triassic into a West and an East Gondwana. By a slight clockwise rotation of East Gondwana a supradetachment basin formed along the Tethyan margin and northward displacement of Madagascar, West Falkland and the Gondwana fold belt occurred relative to a southward motion of Africa. Springer-Verlag, 1996 African basins nationallicence Madagascar nationallicence Falkland Islands nationallicence Gondwana tectonics nationallicence Late Palaeozoic geography nationallicence Palaeo-Pacific margin nationallicence Visser Johan Department of Geology, University of the Orange Free State, P.O. Box 339, Bloemfontein, ZA-9300, South Africa aut Praekelt Hermann Department of Geology, University of the Orange Free State, P.O. Box 339, Bloemfontein, ZA-9300, South Africa aut Geologische Rundschau Springer-Verlag 85/4(1996-12-01), 632-646 0016-7835 85:4<632 1996 85 531 https://doi.org/10.1007/BF02440101 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02440101 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Visser Johan Department of Geology, University of the Orange Free State, P.O. Box 339, Bloemfontein, ZA-9300, South Africa aut NATIONALLICENCE 700 1- Praekelt Hermann Department of Geology, University of the Orange Free State, P.O. Box 339, Bloemfontein, ZA-9300, South Africa aut NATIONALLICENCE 773 0- Geologische Rundschau Springer-Verlag 85/4(1996-12-01), 632-646 0016-7835 85:4<632 1996 85 531 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer