Alkaline rocks in the Kuboos-Bremen Igneous Province, southern Namibia: the Grootpenseiland and Marinkas Kwela Complexes

The early Cambrian Kuboos-Bremen Igneous Province of northwestern South Africa and southern Namibia comprises a series of intrusive bodies that collectively encompass virtually the entire range of alkaline rock types. Two of these bodies, the Grootpenseiland and Marinkas Kwela Complexes lie immediately north of the Orange River and are amongst the few that show this wide lithological range on a local scale