Geology of Scotland
The bedrock of Scotland is very ancient rock. Archean gneiss, metamorphic beds with granite intrusions were laid down when the Caledonian mountains were built. Coal, oil and iron-bearing carboniferous deposits are there, and so are remains of Palaeogene volcanoes. So the rocks of Scotland north of the Highland Boundary Fault are generally older, and mostly much older, than the rocks of England.