Alderley Edge, Cheshire, England

Minor copper, lead and zinc sulphides cement Triassic sandstones close to faulting. Copper, lead and zinc secondary carbonates, and cobalt-rich wad ('asbolite'), were mined during the seventeenth to nineteenth centuries.

Major Minerals:

Chalcocite, djurleite, galena, sphalerite, covelline

Minor Minerals:

Chalcopyrite, pyrite, marcasite, nickeliferous pyrite, TiO2 minerals

Trace Minerals:

Include tetrahedrite, bravoite, haematite, gersdorffite, nickel-cobalt sulpharsenides, detrital ilmenite, magnetite, chromite, zircon


Authigenic anatase overgrowths occur on detrital TiO2 minerals. Framboidal pyrite, compositionally zoned bravoite, nickeliferous pyrite and rare nickel-cobalt sulpharsenides are inclusions within the primary chalcopyrite-galena-sphalerite pore space cement. Alteration of the primary sulphides is intensive and rhythmically precipitated chalcocite, djurleite and cerussite form a major cement around clastic silicate grains. The alteration of chalcopyrite and sphalerite to secondary copper sulphides is widespread and the copper sulphides are argentian


Ixer and Vaughan, 1982