Area: 48.0 hectares.
A new site listed as being of national importance in the Geological Conservation Review. The site is owned by the Dartmoor National Park Authority.
Description and Reasons for Notification:
The site provides exposures of two principal variants (the ‘Giant’ and ‘Blue’ varieties) of the coarse, megacrystic biotite-granite of Dartmoor. These rocks (of Permo-Carboniferous age), and the relationships between them, have been of critical significance in the evolution of geological thought concerning the genesis of the Cornubian granites. Initially considered to be two distinct intrusions, it is now realised that much of the variation between the two types is gradational. A third granite, of finer grain size, forms a later cross-cutting sheet which displays pronounced vertical columnar jointing.