Saturday, 15 June 2013

Fingal's Cave, Staffa

Fingal's Cave, Staffa. Columnar basalt. From the British Association for the Advancement of Science photograph collection
BGS image ID: P246033
Fingal's Cave, Staffa. Columnar basalt. From the British Association for the Advancement of Science photograph collection. Date: 1906.


Oblique aerial view of The Great Face, the south end of the island of Staffa. Argyll and Bute. The Boat Cave is on the left and Fingal's Cave on the right. Massive, straight, well-formed columnar jointing in the Tertiary volcanic lava flow. The classic type of columnar jointing consists of a close-packed series of hexagonal 'prisms' lying perpendicular, in this case, to the base of the lava flow. Columnar jointing is formed by contraction during the cooling of the lava when a pattern of tensional forces acting towards a number of centres is set up. These forces tend to pull open a series of joints which ideally assume a hexagonal pattern.
BGS image ID: P000773
Oblique aerial view of The Great Face, the south end of the island of Staffa. Argyll and Bute. The Boat Cave is on the left and Fingal's Cave on the right. Massive, straight, well-formed columnar jointing in the Tertiary volcanic lava flow. The classic type of columnar jointing consists of a close-packed series of hexagonal 'prisms' lying perpendicular, in this case, to the base of the lava flow. Columnar jointing is formed by contraction during the cooling of the lava when a pattern of tensional forces acting towards a number of centres is set up. These forces tend to pull open a series of joints which ideally assume a hexagonal pattern. Date of image: 1977.

Bob McIntosh

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