Summit of Goat Fell, Isle of Arran, Buteshire. Typical upland granite topography.

Characteristic jointing in the coarser granite, causing it to break up into slabs and weather into 'tors' (isolated upright crags with deep weathering along joints, giving a somewhat rounded appearance).

Arran is one of the series of Tertiary volcanic centres grouped along the west coast of Scotland and relates to a period of crustal extension between 55 and 61 million years ago. Similar aged lavas and intrusions in the Faeroes and East Greenland were all once part of the same Tertiary igneous province, before being separated by the opening of the Atlantic Ocean.

SCRAN:00-000-146-608-C; British Geological Survey