Volcanic rocks of the Gaub Valley Formation (GVF) and intrusive rocks of the Weener Igneous Complex (WIC) have been studied in an area south of the Gamsberg within the Southern Margin Zone of the Pan-African Damara Orogen. The emphasis of this study is placed on the facies and contact relationships of these rock types. The Gaub Valley volcanic rocks can be distinguished in domains distal and proximal to a volcanic centre. Distal domains are characterized by fine-grained, finely-banded sericitic schists of regional extent, here interpreted as meta-ash tuffites and intercalations of different types of meta-lapilli tuff. They are interpreted as outflow facies of a caldera. Proximal domains comprise a variety of rock types including meta-crystal tuffs, meta-pyroclastic breccia, accumulations of scoria and pumice, lava and feeder channels. They form chaotic deposits and are interpreted as caldera fill. The boundary between distal and proximal domains often coincides with a zone of granitic lensoid bodies inferred to be a ring structure related to the intrusion of the WIC. Both the concentric distribution of a caldera fill facies around the WIC and the development of a granitic ring structure, indicate that the WIC represents the subvolcanic source area from which magma has intruded the volcanic rocks of the GVF in a sheet-like fashion. A comagmatic evolution of the volcanic rocks of the GVF and the WIC is proposed. The tectonic history comprises two main deformation phases, both of Damaran age. No pre-Damaran deformation has been recognized in the rocks of the GVF and WIC. D1 is the dominant deformation and produced NW-trending and NE-facing folds and stretching lineations parallel to the fold axes. The main effect of the D2 deformation was the rotation of D1 structures into NW-dipping attitudes. The deformation acted heterogeneously on both the rocks of the WIC and GVF. Therefore, in domains of low deformation, primary pyroclastic structures have survived the tectonic overprint.