Deep within the hyper-arid Namib Desert at Narabeb, which is today isolated by 100-m high linear dunes, is a 36-m section of lacustrine mudstones and interbedded sands. The slightly calcareous and laminated sands of this sequence are composed mainly of rounded to subrounded, lightly stained quartz that is similar to the sands of the underlying Tertiary Tsondab Sandstone Formation and the surrounding dunes of the Namib Sand Sea. The six calcareous mudstone units in this sequence are variably laminated and sandy, contain halite-filled fractures, and have been radiocarbon dated at 20,000-26,000 yr B.P. The interrelationship of sediments at this site with Middle to Early Stone Age implements suggests an age of more than 20,000 years, whereas 234U/230Th dating of the basal mudstone gave an age of 210,000-260,000 yr B.P.