Late-Precambrian correlation and the relationship between the Damara and Nama Systems of South West Africa

Abstract:

Recent findings about the late-Precambrian stratigraphic succession in the areas between the Orange River and the Klinghardt Mountains and south of Windhoek throw new light on the relationship between the Damara and Nama Systems. In the Orange River area the formations of the Gariep Group are unconformably or pseudo-conformably overlain by the Nama System. In central and northern South West Africa a similar relationship is exhibited by the Nosib Group and overlying Damara System. Pronounced similarities between the sedimentation and deformational history of both Nosib and Gariep indicate a probable correlation of the two groups and this result is also supported by radiometric ages. It follows that Damara and Nama are most likely either completely or partly coeval. The latter may represent a shelf facies of the former geosynclinal succession. The Gariep and Nosib deformation apparently started with the subsidence of their respective troughs and may have lasted from approximately 850 m. y. to 600 m. y. This tectonic event is older than the Damara Orogeny (550 to 450 m. y.) and may be time-equivalent to the Katanga Episode. Two late-Precambrian glaciations were widespread in South West Africa and their sedimentary deposits are important for the correlation of Gariep/Nama with Nosib/Damara. © 1971 Ferdinand Enke Verlag Stuttgart.

Año de publicación:

1971

Keywords:

Fuente:

scopus