By glaciers, Scotland
The Scottish Highlands are made up of metamorphic and igneous rocks. Their features show that they formed during a great mountain-building episode, as plates carrying northern and southern Britain collided. Evidence from radio-active minerals in the rocks tells us that this happened between 470 and 400 million years ago.
Much more recently, the area was covered by ice during global climatic cold periods (Ice Ages). Glaciers that formed then, like glaciers in Norway or New Zealand today, had enormous erosive power because the ice contains rocks gouged from the valley floor or fallen from the mountains to either side. This ice-with-rocks scrapes along like a giant strip of very coarse sandpaper, carving out deep, U-shaped valleys like Glen Coe. Fossil evidence shows that the last glaciers in Britain melted around 10,000 years ago.
Much more recently, the area was covered by ice during global climatic cold periods (Ice Ages). Glaciers that formed then, like glaciers in Norway or New Zealand today, had enormous erosive power because the ice contains rocks gouged from the valley floor or fallen from the mountains to either side. This ice-with-rocks scrapes along like a giant strip of very coarse sandpaper, carving out deep, U-shaped valleys like Glen Coe. Fossil evidence shows that the last glaciers in Britain melted around 10,000 years ago.
Glen Coe, Scotland
Copyright M Hambrey from www.glaciers-online.net
