The Auborus formation of the Bethanie district South West Africa

Abstract

Abstract provided by author:

Felspars and biotite show various stages of alteration. A little recrystallization of quartz has taken place. The main heavy minerals are ore (largely specularite), garnet, epidote, zoisite, clinozoisite, mica, monazite, zircon and tourmaline. Zircon has been classified on colour, roundness, inclusions and zoning; tourmaline on colour, roundness and inclusions

Bedding in the sandstone is from thin to laminated. The commonest sedimentary structures are cross-beds, mud cracks and clay-pellet impressions. Other features are ripple marks, parting lineations, flute casts and rain prints

The red colour was probably produced in the source area. Diagenetic processes have produced spots of decoloration; and some joints show decoloration. Chemical analyses have been made of the red beds and a decolored spot

Pebble, cobble and boulder conglomerates contain a great variety of rock types, which have mostly been identified as coming from nearby southerly sources. A matrix is always present. The sandstone is a uniform red colour, very fine-grained, well sorted, very well compacted and is felspathic and arkosic in character. Rock fragments are ubiquitous. The colouring matter is intergranular, crystalline hematite