It consists of a series of plateaus formed of sedimentary rocks which mainly belong to three formations of widely separated ages, and which rest on a platform of granitic and metamorphic rocks.
On the northern side granitic masses occur in the zone of Ariege amongst the Jurassic and Lower Cretaceous beds.
The Tamar flows from north to south on the Devonian plain, which lies between Dartmoor on the east and the similar granitic boss of Bodmin Moor (where Brown Willy rises to 1345 ft.) on the west.
The left or northern bank of the Danube from Regensburg downwards presents a series of granitic rocks called the Bavarian Forest (Bayrischer Wald), which must be regarded as a branch of the Bohemian Forest (Bohmer Wald).
These are penetrated by intrusions of granitic and felsitic character; one of these masses in Papa Stour is a handsome pink felsite.
The streams flowing from the central area have cut deep gorges and canons, and among the ridges the granitic rocks have assumed many strange forms. Though rising from a semi-arid plateau, these mountains have sufficient rainfall to support an abundant plant growth, and have derived their name from the fact that their slopes are dark with heavy forests.
The Devonian period, as in Victoria, was marked by a series of granitic intrusions, which altered the older beds on the contact, while the quartz-porphyry dikes, which are intrusive in the Silurian rocks at the Mount Bischoff tin mine, doubtless belong to this period.
Coutances is beautifully situated on the right bank of the Soulle on a granitic eminence crowned by the celebrated cathedral of Notre-Dame.
The volcanoes of Bolivia lie almost entirely in the Western Cordillera - the great summits of the eastern range, such as Illimani and Sorata, being formed of Palaeozoic rocks with granitic and other intrusions.
The Eastern Andes is a magnificent range in the southern part of Peru, of Silurian formation, with talcose and clay slates, many quartz veins and eruptions of granitic rocks.