Diamond-Bearing Gravels Along the Lower Kwango River DRC - Geology and Resource Potential of the Congo Basin - page 338

Geomorphological zones - KwangoRiver (modified aer J D Ward)

Bedrock Zone 1 st Splay Broad Valley Valley Narrows 2 nd Splay

Trap sites

Hard Bedrock Soft Bedrock Soft Bedrock Soft Bedrock Soft Bedrock

Deposit
type

Sloots, scours, push
bars, bedrock gravel
dominates

Bar (head)
gravels

Wide terraces,
wide flats with
excessive sand

Narrow terraces,
narrow flats,
gr

River Valley
widens again,
opportunities
for gravel
deposition

s polymorph
increases gravel
content

è

River
model
plan view

Push
Bar

Scour

2 nd SPLAY

Targets 1 st SPLAY Flat 3-11 K48,K52,K56

K24,K33

SAND

Bedrock SAND Gr s Polymorph

è

Moderate Volume,
Low to
Moderate Grade

Volume
and Grade

High Volume,
Moderate Grade

Low Volume,
Low Grade

Low Volume, High Grade

Prospectivity GOOD GOOD POOR MODERATE

MODERATE

Fig. 16.8 Targets in the form of splays, flats and terraces, along the Kwango River over BRC joint venture ground

Fig. 16.9 Geomorphological zones in the lower Kwango River with predicted trapsite and gravel development (after Ward)