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(a) DEM of the western coastal Kaoko region and (b) morphostratigraphic transect. In the Purros canyon are remnants of glaciogenic sediments, and therefore the canyon is tentatively interpreted here as a relict glacial landform. See Fig. 2 for location.
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The modern relief of Southern Africa is characterised by stepped plateaus bordered by escarpments. This morphology is thought to result from stepwise uplift and ensuing continental-scale erosion of the region as it rode over Africa’s mantle ‘superplume’ following the break-up of Gondwana, i.e. since the mid-Mesozoic. We demonstrate in this contribu...
Contexts in source publication
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... demonstrated that the Purros escarpment separating the high standing plateau to the coastal plain already existed by the LPIA as indicated by glacial striae found on the scarp (Fig. 2) within these canyons (Fig. 4). We therefore suggest that these canyons forming the downstream continuation of exhumed glacial valleys may correspond to gorges similar to those characterizing the base of Quaternary glacial valleys found in almost all terrains that experienced repeated Quaternary glaciations (e.g., Lajeunesse, 2014;Livingstone et al., 2017). Such an ...
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... and radiate outward from the Windhoek highland. Most of these valleys have been interpreted or inferred as exhumed glacial valley by Martin (1975, 1981, see also Miller, 2011). However, the only irrefutable evidence for a glacial origin is the N-S-oriented Black Nossob (1975,1981). Although these valleys have conspicuous U-shaped cross-profile ( Fig. 4c), no glaciogenic sediments or morphologies have been mapped or described in the literature or observed during our own fieldwork within the thalweg of these valleys. A Dwyka outcrop has been described in the vicinity of the Nausgamab valley (Fig. 4, Faupel, 1974), which would witness at least local glacial processes; we however did not ...
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... dome and the cities of Johannesburg and Pretoria also probably sit on a glacial surface, although further work need to be done to confirm such a hypothesis. (b) View of the Vredefort dome area where the Vaal river valley shows a U-shaped profile reminiscent of glacial erosion. A small portion of the Vaal River floodplain is seen at centre-right ( Fig. 4.5 in Gibson & Reimold, 2015) https://doi.org/10.5194/egusphere-2024-467 Preprint. Here, however, no direct evidence for glacial action (striated pavements, glaciogenic sediments) was ...
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... stratigraphy of the margin at the mouth of the Orange River demonstrates the presence of a protoOrange delta from the uppermost Lower Cretaceous draining a large portion of the subcontinent (see Figure 4 in Baby et al., 2018b). This agrees with the thermochronological data from the southern ...
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... Africa. https://doi.org/10.5194/egusphere-2024-467 Preprint. Discussion started: 14 March 2024 c Author(s) 2024. CC BY 4.0 License. Fig. 4.5 in Gibson & Reimold, 2015) https://doi.org/10.5194/egusphere-2024-467 Preprint. Discussion started: 14 March 2024 c Author(s) 2024. CC BY 4.0 License. Escarpments delineating the highlands from the basins and glacial valleys carved into it are represented as bold solid lines where attested or as dashed lines where suspected (see ...
