Scottish Highlands in the Torridon Hills such as Liathach and Beinn Eighe in Wester Ross. These foundations are interspersed with many igneous intrusions of a more recent age, the remnants of which have formed mountain massifs such as the Cairngorms and the Cuillin of Skye. A significant exception to the above are the fossil-bearing beds of Old Red Sandstone found principally along the Moray Firth coast and partially down the Highland Boundary Fault. The Jurassic beds found in isolated locations on Skye and Applecross reflect the complex underlying geology. They are the original source of much North Sea oil. The Great Glen
Cuillin the summits had no recorded name prior to this period, although names for corries and other features were in existence. Many of the summits are thus named after early climbers such as John MacKenzie (Sgùrr MhicChoinnich), Alexander Nicolson (Sgùrr Alasdair), and Norman Collie (Sgúrr Thormaid). The Cuillin now consists of two estates divided by Glen Sligachan. The hills on the west side of Glen Sligachan (the Black Cuillin) remained the property of Clan MacLeod despite the long history of conflict between them and Clan MacDonald. The earliest formal record of MacLeod ownership was in a land grant from the Crown