Coast-parallel palaeochannels off southern Namibia

Abstract Boomer and airgun seismic data revealed ancient river channels incised into the middle shelf between Kerbehuk and Chameis Bay, Namibia. This palaeochannel complex, some 15 to 20 metres deep and often several hundred metres wide, cuts into Upper Cretaceous strata and is frequently deeply buried by sediment of Late Quaternary age. The channels were obviously formed during a sea-level regression to below — 100 metres as the channels' banks lie at — 90 metres off Kerbehuk and at — 105 metres west of Chameis Bay. An acoustic blanketing layer south of Kerbehuk and inadequate data prevent knowledge of their true extent, but it is surmised that these channels parallel the present-day coast, perhaps for more than 50 kilometres. The reason for their strange course is not known.