The psammitic, pelitic, calcareous and partly evaporitic metasediments of the Duruchaus Formation (Nosib Group) at the southern margin of the intracontinental Pan-African Damara Belt were studied with regard to sedimentology and facies. They were deposited during the Nosib rift stage in the early development of the Damara Orogen. Two different facies have been recognized in the quartzitic marker beds in the upper part of the Duruchaus Formation in the Gurumanas area. The pebbly, partly coarse-grained quartzites of the Arovley Member in the centre of the Gurumanas Dome represent a fluvial sequence. This is clearly indicated by the sedimentological inventory, particularly by the regular cyclic development of fining upward sequences in sections of 1 to 10 m thickness. The often distinctly finer-grained, and vertically aggregated flood plain sediments in the upper portions of the cycles can be attributed to a meandering stream type with otherwise predominantly sandy sediments. These fluvial deposits were formed in the lower course of the 'Kamtsas rivers'. The almost entire absence of planar and longitudinal cross-bedding in upper point bar sediments of respective sequences and the occasionally poorly sorted, coarse sand and gravel fractions in the basal quartzite of a se-quence are indicative of a temporally and locally lower sinuosity and thus of increase in transport energy in the river bed. The development of an overall fining upward through the sequences of the upper Arovley member documents a lateral transition from flood plain sediments of the 'Kamtsas rivers' to finer-grained, marginal deposits of a 'Duruchaus lake basin'. Lateral sediment supply to this elaborate river regime from alluvial fans, probably originating from the escarpment of the "southern half graben", is suggested by thin intercalations of fanglomerates which were incorporated into the cycles of the river sediments. The second, more distal facies type in the linearly transported Duruchaus clastics is exemplified by the Narais Member. Many of the finergrained quartzites of the Narais Member which are intercalated in metapelitic-calcareous basin sediments exhibit a rudimentary coarsening upward sequence in the upper portions of the section. This is supportive of rudimentary deltaic sediment fans at the mouth of the 'Kamtsas rivers', which may have projected progressively into a perennial 'Duruchaus lake' at the depocentre. Finally, the above mentioned facies types in the upper Duruchaus Formation will be incorporated into the facies scheme presented here. Facies relationships in the investigated portion of the Duruchaus Formation indicate general fluvial transport to the south-west, into a perennial lake situated in the depocentre. Synsedimentary gravitative and early tectonic deformation structures in the unconsolidated sediments (faulting, slumping, dewatering, etc.) provide evidence of tectonic unrest during the Duruchaus sedimentation. The quartzite members in the Duruchaus profile may be understood as distal equivalents of the coarse clastic Kamtsas facies sequence which is mainly exposed Further to the east. In the Geelkop Dome area 'Kamtsas rivers' discharged into the lacustrine realm of the Duruchaus facies. Under this aspect the conventional lithostratigraphic definition of the Kamtsas and Duruchaus Formation (SACS, 1980) deviates from the true facies differentiation between alluvial-fluvial (Kamtsas) and lacustrine-evaporitic (Duruchaus).