Conformable copper deposits in sandstones laid down under terrestrial conditions, usually red in colour. The sands are usually porous and copper minerals, normally chalcocite, develop in the pores. Such deposits are found in many parts of the world, e.g. in the Permian of the Urals, and in the Triassic of central England, Nova Scotia, and the south-western USA.
Subjects: Earth Sciences and Geography.