The Old Man of Storr and other pinnacles on the Isle of Skye -- a bizarre landscape made up of the shattered debris of lavas which have slid downslope on a base of sedimentary rocks.
The Trotternish peninsula in the north east of Skye is dominated by a spectacular ridge of hills that runs for over 30km along its backbone. There are 13 named summits, from Beinn Dearg in the south to Meal na Suiramach in the north. The ridge rises to its highest point at the 719m summit of the Storr, above the tortured landslip topography that includes the iconic pinnacle - The Old Man of Storr. The ridge is home also to the Quiraing, another landslip area of pinnacles and gullies, this time below the summit of Meal na Suiramach. The hills here are composed of horizontal flows of basaltic lavas, which built up on top of each other to a depth of around 800m. On the east side of the peninsula the underlying sedimentary rocks have collapsed under the weight of the basalt, tipping everything sideways to form the distinctive landslips. The result is a wonderful combination of unique scenery, outstanding views and first-rate walking terrain along the crest of this undulating escarpment.
When we stayed in Portree recently, we could see the Old Man of Storr in the distance, but sadly we had no time to visit it. The landslides are generally assumed to be post-glacial -- and indeed some sections of the slides are still moving. I assume that the trigger mechanism was pressure release following the removal of glacier ice; this is what triggered off scores of landslides in Iceland, and my best guess is that the big landslides on the North Pembrokeshire coast west of the Witches Cauldron were also set off when Devensian ice that had been pressed against the coast finally melted away.
2 comments:
Why the focus(and?) On Stonehenge,and what has it got to do with Storr? Why not mention the stone rings at Calanais and Brodgar(both older than Stonehenge and both probably equally influenced by the Ice Age if not more so)?
Hi -- I'd appreciate it if you could use your name in any future comment! This blog is about Stonehenge, the Ice Age and the relations between the two. Many posts are about Ice Age features that have nothing to do with Stonehenge -- no apologies about that. As for Calanais and Brodgar, I do indeed have posts about both sites. Just use the search box and you will find them! And yes, the influence of glacial processes at both sites was considerable, if somewhat under reported in the media!
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