Geoscience Reference
In-Depth Information
FIG
46.
Tin mine workings near Cape Cornwall, west Cornwall. (Copyright Dae Sasitorn
& Adrian Warren/www.lastrefuge.co.uk)
In some of the granites, hot fluids from below altered the mineral feldspar (one of
the dominant granite minerals) and turned it into the soft clay mineral kaolinite. The
china clay industry has developed round the presence of this mineral, which has usu-
ally been extracted from the altered granite by washing it out with powerful water jets.
This process has changed the scenery dramatically, particularly around the St Austell
granite. For every tonne of useable kaolin, 5 tonnes of waste granite material are pro-
duced, and heaps of this waste are obvious scenic features in these areas (Fig. 47). The
famous Eden Project at Bodelva, near St Austell, has been constructed inside a large
former china clay quarry.
