biotite series

Botha (1960) noted the presence of biotite as a component of Mulden Group arenites in the Tsumeb area; Hedberg (1979) considered that this biotite was exclusively rounded and detrital (in contrast to muscovite, which he believed to be of metamorphic origin, supported by its parallel alignment to a weakly developed cleavage (see also Hughes 1987).

Various authors confirm the presence of biotite in the feldspathic sandstone bodies (Söhnge 1964; Hughes 1987); curiously, however, biotite is omitted from the description of feldspathic sandstone by Lombaard et al. (1986).

Biotite also occurs as a component of the kersantite dykes that intersect the ore-body between surface and 20 Level (Söhnge 1964; Lombaard et al. 1986; Hughes 1987).

Please also refer to the notes on phlogopite.