The geology of the southern part of the Otavi Mountainland, S. W. A

Abstract

Abstract provided by author:

The area mapped to the south of the Otavi Mountain Land covers a part of the "Otavi-Damara" transitional zone with its characteristic tectonic and depositional features. Lateral variation in facies, from argillaceous to calcareous sediments, plays an important part and is complicated by gradually transgressive metamorphic aureoles and intricate local structures

The object of the present survey was primarily to serve the economic interest of the Tsumeb Corporation Ltd. under whose mineral rights' the area is being held

Evaluation of the economic aspects of the area could naturally be made only after obtaining a detailed picture of the structural relationships. The investigation furthermore necessitated correlation of local formations with known horizons of the previously established classification in the adjoining Otavi Mountain Land. This endeavour has inevitably been confronted by key-problems which in the past loomed up as the main obstacles in identifying the local formations with their stratigraphic equivalents in the type-areas, viz., (a) an overall lack of exposures over extensive parts of the area (b) the deciphering of the structure and the age of the phyllite of the Otavi Valley (c) assessing the misleading factor of variation in facies

Economically, the results of the survey appear to warrant further detailed work in some localities, as inferred from favourable structures. From the investigation it furthermore became evident that the "Otavi" and "Damara" Formations comprise a single system, while correlation of the individual stratigraphic units within them could be carried out to fairly close approximation, including the determination of the relative ages of all the formations