The Duruchaus Formation in the type area north of Rehoboth comprises a thick sequence of mixed clastic sediments and minor carbonates and meta-evaporites exposed in a large tectonic half-window below allochthonous nappes of the internal, metamorphic zones of the Southern Damara Thrust Belt. The thickness of the sequence is estimated to be at least 6700 m. Arenaceous and coarse, rudaceous rocks within the sequence of mainly ine-grained, argillaceous clastic sediments are more widespread and make up a considerably greater proportion of the Duruchaus Formation than previously reported. The arenaceous beds form prominent, laterally continuous stratigraphic marker units and allow the subdivision of the sequence into formally deined lithostratigraphic units of member rank. In contrast, conglomerates form lenticular lithosomes enclosed by ine-grained facies associations of the thick, dominantly argillaceous members. Meta-evaporitic rocks present in the area are conined to only the highest preserved, argillaceous unit, the Gurumanas Evaporite Member, in the upper part of the sequence. Fine-grained clastic sediments of the thick argillaceous members and associated thin carbonates and meta-evaporites are interpreted as lacustrine and playa-lake sediments deposited in a deep, essentially non-marine, continental rift basin. The regular, cyclic alternation of consistently westward thinning, luvial and luvio-deltaic arenaceous members with the ine-grained lacustrine sediments, is ascribed to repeated, cyclic progradation of coarse sandy, braided luvial systems of the Kamtsas Formation quartzites from east to west, parallel to the long axis of the Duruchaus basin. These probably formed in response to long-term periodic variations in the regional subsidence rate. The lenticular, coarse conglomeratic units interlayered in the thick argillaceous members are believed to have been deposited by gravel-dominated alluvial fans derived from the steep, fault-bounded, southern graben margin of the Duruchaus basin, in response to more local, fault-controlled subsidence.