Title:

Alkaline rocks in the Kuboos-Bremen igneous province, southern Namibia: The Kanabeam multiple ring complex

Publication Year:
1991
Abstract:

The Kanabeam Complex forms one of many igneous centres that make up the early Cambrian (-520 Ma) Kuboos-Bremen igneous province. Situated about 12 km NE of the Orange River in southern Namibia, the complex measures only 3 km by 2 km, but contains within its modest dimensions practically every rock type encountered throughout the entire igneous province. The oldest intrusive phase recognised in the complex produced a series of concentric rings of nepheline syenite, which was subsequently intruded by a plug of quartz syenite. Later phases involved saturated microsyenites and a variety of granitic rock types differing in texture and quartz content. The intrusive axis shifted progressively from SW to NE, following the regional trend of the Kuboos-Bremen line, and was accompanied by a change from undersaturated to oversaturated rock types. Late phonolitic breccia pipes pierce the plutonic rocks along major contacts and contain, amongst other lithologies, several alkali gabbroic types which may have been derived from deeper unexposed parts of the complex.

Publication Title:

Communications of the Geological Survey of Namibia

Publisher:
Geological Survey of Namibia
Volume:
7
Pages:
3-13
Item Type:
Journal Article
Language:
en
Keywords: