OVERVIEW OF THE IMPACT OF MINING ON THE ... - IIED pubs

Several thermal springs are located in the area around the Waterberg Mountains; most of these are used as
medicinal spas.
4.14.1.2 Geology
In the upper reaches of the Crocodile River, the geological features are characterized by the presence of
extensive dolomite and limestone formations surrounding a central core of acidic and intermediate intrusive
rocks. The Elands River rises in an area characterized by unconsolidated sedimentary strata and mafic and
ultramafic intrusive rocks. In contrast, the headwaters of the Pienaars River are located in an area underlain by
formations of acid and intermediate lavas, arenaceous and argillaceous strata, and basic and acidic rocks of the
Bushveld Complex and the granites of the Waterberg Formation.
Extensive areas of unconsolidated and semi-consolidated sedimentary rocks of the Transvaal Supergroup
underlie the northern areas of the catchment. These are intruded by wide belts of basic or mafic lavas in the
south, with intrusions of basic, mafic and ultramafic rocks in the north. Virtually the entire northern portion of the
sub-catchment is underlain by wide expanses of acid and intermediate intrusive rocks, with intercalated
assemblages of compact sedimentary and intrusive rocks.
4.14.1.3 Pedology, agriculture and land use
Soils in the sub-catchment can be divided into four main groups:
• Moderate to deep sandy loam soils on flat and undulating terrain overlying dolomite, limestone and
sandstones in the upper reaches of the catchment;
• Moderate to deep sandy loam soils lining long stretches of the Crocodile River valley in its middle reaches;
• Moderate to deep clay loam soils over much of the middle portions of the sub-catchment (located away from
the river channels), overlying the more porous unconsolidated sedimentary material; and
• Moderately shallow to moderately deep, clayey loam to clay-rich, fine-grained soils over most of the lower
reaches of the sub-catchment.
Most of the clayey loam soils are highly suitable for commercial agriculture when sufficient water is provided.
Virtually all of the suitable soils are contained within the jurisdiction of formal irrigation boards or Government
Water Control Areas. Further away from the main river channels, most of the land use is given over to smallscale
irrigation from farm dams as well as the raising of small and large livestock and game animals. A very
wide variety of crops are produced, ranging from intensive vegetable production to Tobacco, Maize, Cotton,
Citrus and Sub-tropical Fruits, Sorghum, Sunflowers and Soya bean. Minor areas of plantation forestry (mostly
Eucalyptus, with some Pine) are also located in the wetter portions of the sub-catchment. The timber is used
primarily for fencing poles and house construction.
Several large cities and numerous smaller towns are present in the upper reaches of the sub-catchment. The
number and density of population declines with increasing distance from the upper reaches. A wide variation of
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