Heavy mineral sands ore deposits

It is equally likely that some concentrations of heavy minerals (aside from the usual gold placers) exist within streambeds, but most are of a low grade and are relatively small.

The Tormin mine, on the Western Cape of South Africa's coastline, provides a unique ocean beach feature, which exposes the resource to wave and tidal conditions that result in a natural jigging effect.

Rocks are occasionally eroded directly by wave action shed detritus, which is caught up in longshore drift and washed up onto beaches where the lighter minerals are winnowed.

The heavy minerals within the source sediments attain an economic concentration by accumulation within low-energy environments in streams and most usually on beaches.

The resultant 'clinker' sands left behind were mined during low tide following major storm events, suggesting that most beach placer deposits are formed during such cycles.

Tectonic activity, which results in coastlines rising from the ocean, may also cause a beach system to become stranded above the high-water mark and lock in the heavy mineral sands.

Similarly, a beach system that is drowned by the subsidence of a coastline may be preserved, often for millions of years, until it either is covered by sedimentation or rises from the ocean.

The coast of Namibia is host to economic diamantiferous beach sands, which are exploited by building sea walls and isolating stretches of coastline.

[4] Similar mineral sand mining operations were carried out for 35 years in and adjacent to National Parks at Hawks Nest, New South Wales, and continue on Stradbroke Island, Queensland.