Mendip Hills In some areas the limestone and the dolomitic conglomerate have been mineralised with lead and zinc ores. From the time of Roman Britain until 1908, the hills were an important source of lead. These areas were the centre of a major mining industry in the past and this is reflected in areas of contaminated rough ground known locally as "gruffy". The word "gruffy" is thought to derive from the grooves that were formed where the lead ore was extracted from veins near the surface. Other commodities obtained included calamine (zinc ore), manganese, iron, copper and baryte. The eastern area reaches
Kambalda type komatiitic nickel ore deposits folded podiform adcumulate to mesocumulate bodies which lack typical spinfex flow-top facies and exhibit an orthocumulate margin. This may represent a sill or lopolith form of intrusion, not a channelised flow, but structural modification of the contacts precludes a definitive conclusion. Definitive Kambalda-type Intrusive equivalents Probable Kambalda-type Kambalda type komatiitic nickel ore deposits Kambalda type komatiitic nickel ore deposits are a class of magmatic iron-nickel-copper-platinum-group element ore deposit in which the physical processes of komatiite volcanology serve to deposit, concentrate and enrich a Fe-Ni-Cu-(PGE) sulfide melt within the lava flow environment of an erupting komatiite volcano. The classification of the