Last year, 2017, we visited Sanna Bay, in Ardnamurchan, Scotland, to get there, you drive through a ring of hills which form a world famous geological structure, a classic example of a ring complex. From space the ring of hills looks rather like a crater on the moon, but it was formed in a very different way. They are quite amazing to drive through when you realise they are ancient volcanoes. I have added a few details about them. We then arrived at, Senna Bay, truly beautiful, we were blessed with stunning weather, the first we had for over a week. This is a photo tour of the rings and the wonderful walk we had along the beach.
The rocks of the ring of hills were called the Great Eucrite, by JE Ritchie of the British Geological Survey, when he made the first geological map of Ardnamurchan in the 1920’s. The rocks of the Great Eucrite form a ring of hills because they were resistant to the glaciers that carved this only 20,000 years ago. Eucrite, is a variety of gobbro, the coarsely crystallise quiver of basalt. Large crystals form when igneous rocks crystallise slowly beneath the surface of the Earth in magma chambers.
Four ancient volcanoes on the west coast of Scotland…….When the American and Eurasian tectonic plates began to drift apart 55 – 60 million years ago, and the North Atlantic began to open, what are now north islands of, Mull, Rum and Skye, together with the peninsula of Ardnamurchan, formed a chain of volcanoes.