Abstract:
The Damara orogeny in Namibia is part of the Neoproterozoic to early Paleozoic Pan–African orogeny in Southwest Africa. This paper systematically combs the characteristics of geological units, magmatism, metamorphism, tectonic dynamics mechanism and uranium mineralization in the Damara orogenic belt. The orogenic belt is mainly composed of seven geological units: the northern terrane, the northern margin, the northern zone, the central zone, the southern zone, the southern margin, and the southern foreland. Based on the characteristics of plate movement, the tectonic evolution of this orogenic belt has been divided into five stages, mainly including intraplate rift (750 Ma), continuous expansion (730~600 Ma), ocean–continent subduction (580~560 Ma), subduction collision (550~540 Ma) and late collision (530~460 Ma). This orogenic belt is endowed with plenty of uranium resources, mainly formed at 510~490 Ma, closely related to tectonic and magmatic activities in origin, with a peculiar metallogenic specialization. According to the analysis and summary of existing data, this article believes that the pre–Damara basement, which is rich in uranium, is the main source of ore–forming materials of the alaskaite type uranium deposit. The parent magma related to mineralization is the result of combined action of assimilation, contamination and fractional crystallization. The tectonic activity provides a favorable site for the emplacement, enrichment and precipitation of the uranium–rich magma.