Читать книгу The Isle of Mull. Mull, Ulva, Gometra, Iona and Erraid онлайн

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Even the untrained eye can see that most of Mull is made of lava; the tell-tale flows ripple across the landscape virtually everywhere. The lava poured from volcanoes at a time when the north Atlantic was forming, and Mull was torn apart from its then neighbour Greenland as the vast super-continent which once joined North America and Europe divided. The molten lava that erupted 50–60 million years ago, at intervals of thousands of years, forms Mull’s stepped tablelands. Into these, intrusions of other rocks, all formed by fire, later took place, creating the mountains of Mull’s central igneous complex, of which the Geological Survey of Scotland in 1924, said: ‘Mull includes the most complicated igneous centre as yet accorded detailed examination anywhere in the world.’ Volcanic explosions and intense earthquakes shook Mull throughout its formative years, and one of the old fault lines, the Great Glen Fault, which touches upon the southern part of Mull, is still occasionally active.

As with the rest of Britain, Mull’s final shape was carved by glaciers that melted only 10,000 years ago, leaving behind deep U-shaped valleys between the mountains and long glaciated lochs. Of these, Glen Clachaig is a supreme example. It is a wild and fascinating landscape, made all the more intriguing by even a superficial understanding of what you are looking at. That glaciers were a part of Mull’s geological profile is evidenced by the presence of isolated boulders, or erratics, that litter the landscape. Elsewhere, as at the head of Loch Scridain and Loch na Keal, you find the rocks have been heavily scored by the passage of ice-borne rocks. Once the glaciers were gone, the landscape that remained was little different from what you see today; in a sense it remains quite primeval, boasting a geological antiquity that is quite tangible and endlessly absorbing.