Abstract:
The Waterberg Group consists chiefly of a succession of coarse elastic
sedimentary rocks which shows two upward-fining sequences. The sedimentary
rocks belong to the Mokolian erathem and they are 1700-1900 Ma old.
The depository evolved as a continental, fault-bounded basin in
the northern part of the Kaapvaal craton. The basin is bounded in the south
by the Murchison lineament and in the north by the southern part of the
Pal al a shear zone. The Murchison lineament is interpreted to be a
long-lived, fundamental strike-slip fault system. Deformation lamellae in
quartz in the Alma Formation near Thabazimbi, are thought to have resulted
from transpressive strain along this fault zone.
The Swaershoek and lower Sterkrivier Formations are interpreted to
have been deposited as fan deltas and were possibly reworked in a littoral
palaeo-environment. The Alma and upper Sterkrivier Formations are
interpreted as a series of alluvial fans forming a bajada along the scarp
caused by the uplifted block on the southern side of the Murchison
strike-slip fault zone. The Skilpadkop and Setlaole Formations are
considered to have been deposited on narrow braidplains. The Makgabeng
Formation was deposited during the more stable period that followed and it
is interpreted to be the result of a large dune field, which may have been
coastal in nature towards the south. Problematic trace-like structures occur
in the southeastern part of the basin in a littoral intercalation in the
Makgabeng Formation. The upward-coarsening Aasvo~lkop Formation is thought
to have been deposited in a shallow through-flow lake, although fluvial
deposition was probably more important towards the top of the formation.
The Mogalakwena and Sandriviersberg Formations are interpreted as
having been deposited by large braided rivers, forming an extensive
braidplain which probably continued to the southwest, through Botswana into
the northern Cape Province, where it may be represented by the Fuller Member
