The area described in the following pages is that portion of the Warmbad District of South West Africa bounded on the north by the railway line and stretching southwards to the Orange River. It was geologically surveyed in 1926 and 1927 by the writers who, for guidance and consultation, had the work of Dr. P. Range, "Geologie des deutschen Namalandes", and two papers by Dr. W. Versfeld in the "South African Journal of Science".