Читать книгу Walking on Rum and the Small Isles. Rum, Eigg, Muck, Canna, Coll and Tiree онлайн

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The last major glaciation of the Quartenary Ice Age began about 30,000 years ago, when glaciers covered the island and the tops of the highest mountains protruded through the ice as ‘nunataks'. Frost-shattering created scree slopes on these summits, and freeze-thaw processes have sorted rock particles into remarkable regular patterns such as the stone stripes and polygons near the summit of Orval.

The ice sheets retreated around 10,000BC. During glacial periods sea levels dropped, rising again when the glaciers melted. The landmass sank under the weight of the ice cap, then rose again as the ice retreated. The land continued to rise beyond the maximum increase in sea level, forming the raised beaches found around the coastline 12–30m above the present sea level, especially between Harris and A'Bhrideanach.

Tundra vegetation gave way to forest. The climate warmed 6000 years ago, encouraging forestation to a higher altitude than at present, before becoming cooler and damper around 1000BC, and peat expanded at the expense of woodland. A dearth of cultivable land also led to woodland clearance by early farming communities.