The western coastal plain of South Africa contains a significant resource of detrital heavy minerals by world standards.
The heavy mineral sand deposits occur in a current active beach environment (eg Tormin mine) as well as in older palaeo-beach raised strandlines found inland (inland strandlines) eg Tronox Namakwa Sands.
Apart from the mid-Jurassic, Cretaceous and Tertiary (Paleogene) sediments along the coast, numerous small fossiliferous, marine and terrestrial deposits of Neogene age outcrop along the coastal zone.
The onshore mineral sands are marine palaeo-terraces “Inland Strands”, aeolian sands and fluvial sediments. These targets were formed during Miocene, Pliocene and Quaternary/Pleistocene coastal transgression (sea move inland) and regression cycles.
The lithological units of the Western Strandline can be described as below:
Aeolian sand – non mineralised
Red Aeolin sand – mineralised
Silcrete Duricrust/ dorbank
Orange Feldspathic Sand – non mineralised
Orange Feldspathic Sand – mineralised
Dorbank – mineralised
Strandline – mineralised
Base pebble beds – mineralised
Schist basement
For purposes of estimation, the lithology has been grouped into the following:
Red Aeolian sand
Silcrete Duricrust/dorbank
Orange Feldspathic Sand
Main Strandline Mineralisation (including the thin mineralised dorbank)
Secondary perched str ........
