Gold Chapter (855 KB) - Ministry of Mines and Energy

Mineral Resources of Namibia Precious Metals - Gold
Figure 2: Locality map of the Rehoboth gold fields
nuggets occurs within this zone (Borton, 1976)
(Fig. 3).
Gold production from the oxidised zone,
mined between 1936 and 1938 to a depth of 60
m, totalled 31.47 kg, while concentrates
contained 68.5 g/t gold (De Kock, 1930 and
1932; Kovaloff, 1933; Anon, 1964 and 1967;
Whitfield, 1990).
More recent surface investigations have
shown that gold is associated with lenses of
smoky quartz containing pyrite, chalcopyrite
and magnetite over a strike length of 300 m.
However, grades and widths vary considerably.
Several drillholes intersecting the shear zone
indicated that the highest gold grades are always
associated with magnetite rather than pyrite
(Borton, 1975).
Maximum grades obtained in the oxidised
zone, which extends vertically to some 70 m
below surface, were 7.1 g/t gold over 2 m; the
sulphide zone maximum grade was 3.7 g/t over
62 cm. Reserves total 76 640 t at a grade of 7.06
g/t (Borton, 1975).
4.1 - 8
Further exploration resulted in a maximum
grade of 9.1 g/t being obtained from a similar
geological setting approximately one kilometre
to the northeast of the old mine (Borton, 1976
and 1978; Whitfield, 1990).
2.6.2 Elim Formation
2.6.2.1 Kobos Copper and Gold Mines, Kobos
321
The dormant Kobos copper mine, 55 km
southwest of Rehoboth, produced only minor
gold during its life (see copper chapter for more
detail). However the Kobos gold mine, located
some 4 km southeast of the copper deposit,
produced a total of 35.454 kg of gold between
1935 and 1941 (Anon, 1964).
Gold-bearing quartz veins containing
hematite, limonite and malachite occur in
chlorite schist and sericitic quartzites that are
interpreted as a metamorphosed felsic to
intermediate volcanic rocks. The veins vary in
thickness from a few centimetres to 60 cm,
strike approximately east–west for a distance of
about 3 km and dip from 70 o to 85 o to the north.