Bodmin Moor

Abstract

Bodmin Moor is a 208 km2 granite upland massif and forms one of the many high altitude moorland areas of southwest England controlled by the injection of the Cornubian batholith. Prominent bedrock benches around the upland at altitudes of 305, 259–289, 228–244 and 206 m have been interpreted as planation surfaces, with the lowest surface proposed as an early Pleistocene or late Pliocene marine erosion feature. Little is known about the development of the largely rectilinear drainage network, but this is likely to have been structurally controlled. The broad, flat-topped interfluves between the major fluvial incisions have been related to the former base of the zone of weathering, which was exposed after long term stripping of regolith by periglacial processes. Indeed the massif is dominated by a periglacial landform legacy, with an assemblage of landforms that includes castellated summit tors with cantilevered or delicately balanced in situ corestones, multiple generations of large permafrost creep-related, boulder-fronted gelifluction lobes and sheets, and periglacial slope deposits or head with a characteristic two-tiered stratigraphy. This assemblage is likely a product of periglacial landscape maturity created by the operation of periglacial and permafrost processes through multiple cold climate stages and therefore the Bodmin Moor granite massif is a more suitable exemplar than Dartmoor of a mature upland periglacial landsystem unaffected by glacierization.