ABSTRACT
The appropriate method of extracting a subsurface resource depends on its depth of burial and its physical state-whether it is a fluid, a consolidated rock or anunconsolidated sediment (Fig. 14.1). Fluids such as water, oil and gas are pumped out through wells drilled into the permeable reservoir rocks that contain them. Deeply buried rocks are reached by underground mines and are brought to the surface through interconnected tunnels and shafts. In the British Isles, most coal and some metallic and industrial minerals are won in this way. However, it is often cheaper to extract these commodities by surface mining of shallow deposits. Quarrying refers to surface mining of hard rocks for use as construction materials. Unconsolidated sediments are exploited by other surface extraction methods such as digging of peat and dredging of sand and gravel.
