Today, most surface structures and dumps have been removed or reclaimed, and the area is largely forested, though limited remains at Wheal Josiah and Wheal Emma preserve evidence of the original vein assemblages. Devon Great Consols stands as a key example of large-scale sulphide mining in west Devon.

Devon Great Consols, north of Gunnislake on the Devon bank of the Tamar, was the largest and most productive mining complex in Devon and the largest sulphide lode worked in south-west England. Formed from the amalgamation of five mines along a continuous east–west Main Lode nearly 4 km long and up to 10 m wide, it dominated the county’s output of copper, arsenic and pyrite between 1845 and 1906. Over this period it produced more than 0.75 million tons of copper ore, alongside substantial arsenic and pyrite, supported by extensive underground workings, multiple deep shafts, and a transport link to the Tamar at Morwellham. By closure, most copper had been exhausted, though arsenopyrite remained abundant, reflected in arsenic-rich dumps that were later reworked.

The mines exploited hydrothermal sulphide mineralization hosted by metamorphosed Upper Devonian slates and limestones (‘killas’), with quartz and siderite as dominant gangue minerals. The Main Lode and associated veins were later displaced by major NW–SE cross-courses, notably the Great Cross-Course, but show little evidence of classic vertical mineral zonation. Despite repeated deep exploration, expected tin-rich zones were largely absent, a failure attributed to the geometry of a concealed granite body plunging westwards beneath the area and imposing horizontal rather than vertical zoning. Mineralization occurred in several phases, progressing from early tourmalinization and minor cassiterite through arsenopyrite- and chalcopyrite-rich stages, and finally sealed by fluorite and siderite.