 Granite tors form important elements in the landscape in these areas.Metamorphism of the country rocks and hydrothermal circulation of metal-rich fluids in the cooling rock provided the source of the extensive metalliferous deposits of the region (primarily copper and tin).Later weathering of the granite led to deposits of kaolin which has been excavated as it is an important source of china clay and ball clay used in the production of such products as porcelain and shiny printing paper.