Cyclopedean tors on Goat Fell

Goat Fell on Arran is granite. Granite is intrusive - magma that wells up but never reaches the surface. It can take a million years to solidify so it grows large crystals. As it cools, it shrinks. This tends to create horizontal and vertical cracks in the rock. The tors created are called Cyclopedean because they look like buildings for giants, made out of huge regular blocks. The Cyclops were giants of Greek mythology. I read up on the granite tors in one of my favourite books, Ronald Turnbull's Granite and Grit. He makes the obvious point that prominent tors on ridges as here and in the Cairngorms should have been wiped out by glaciation. He then explains that the tors actually form underground. Acidic water seeping down from vegetation dissolves the crystals in the cracks in the granite. This leaves blocks underground surrounded by gravel. Eventually, the freezing of the ground in the winter which pushes the gravel up as the water expands into ice causes the gravel to fall back downhill as the ice melts. This clears the gravel over thousands of years from the summit ridges leaving the tors prominent as we see them today.