Abstract
The NE-trending Damara Belt formed during the collision of the Congo and Kalahari cratons between 590 and 470 Ma. The Rooikuiseb Anticlinorium (RK) is a northeast-trending regional structure in the southern Central Zone (sCZ) of the Damara Belt. The Central Zone (CZ) exhumed orogenic root zone forms the central part of the Damara Belt. The northeast-trending CZ has been affected by high-grade metamorphism (lower- to upper amphibolite facies and granulite facies), accompanied by pervasive partial melting and voluminous magmatism. The metamorphic grade documented varies along the trend of the sCZ, from anatectic granulite facies metamorphic conditions in the southwest to sub-solidus lower amphibolite metamorphic conditions in the northeast. Therefore, it has been suggested that the southwest part of the sCZ, which has experienced higher-grade metamorphism, perhaps represents a lower structural level (lower to middle crust). In contrast, the northeast part of sCZ, which has undergone lower-grade metamorphism, may represent a higher structural level (the upper crust). Therefore, the sCZ is modelled as having a ductile, partially molten, lower structural level and a brittle-ductile, higher structural level. The RK is in the proposed southwest part of the sCZ that may represent a lower structural level. The deformation record of the regional-scale structural domes in the sCZ has been reconciled as either a single phase of progressive deformation or multiple phases, depending on the structural inventory of the domes and interpretations of the deformation structures. Several tectonic models have also been proposed for the dome structures in the sCZ. Regional-scale interference folding has been proposed for some structural domes in the southwest part of the sCZ (i.e., NV domes, Palmenhorst, and Ida domes). The multiple phases of deformation are temporally constrained by age dating, structurally-controlled intrusive rocks, and leucosomes at these domes. Additionally, no regional-scale shear zones capable of facilitating rotation and overprinting existing deformation structures (i.e., fold interference patterns) during progressive deformation at the dome-scale were observed at these domes. Therefore, the deformation history of these domes is better explained by multiple phases of deformation (multiphase deformation) based on interpretations of the deformation...