Скачать или смотреть Production of Granite in the Lower Crust: Kinloch Hourn

Mountain buliding causes extreme crustal thickening. For every kilometer of elevation the crust must be thickened by around 8 km. This results in the lower crust heating up to the point where it starts to melt. This is the origin of granites. Here in Kinloch Horn, at the very core of the Glenfinnan Nappe, we see the partial melting process (anatexis) in action. You can find equivalent rocks to this in much younger mountain ranges, such as the Himalaya, where they can be directly related by dating and chemistry to granites which form some of the the highest regions in Nanga Parbat.
This is an example of just how significant Scotland's mountains were when they were growing 400 million years ago.