The Rocks of Lewis

While walking on the Isle of Lewis it is hard to ignore the rocks that line the shores of the beaches around the island. The layers of colours are amazing and they are some of the oldest rock formations in the world, some are over 3 billion years old, and are known as Lewisian Gneiss. The rocks are beautifully marbled with layers of browns, greys, purples and pinks. The patterns and colours were hard to ignore as we walked along the sand and the sizes varied from chips to boulders to whole cliff faces, it was an amazing sight. The Lewisian Gneiss page on the Virtual Hebrides website gives a more detailed background: Lewisian Gneiss is metamorphic, in that volcanic heat and pressure has altered its structure somewhat, originally the rocks were like granite which changed as the Earth's crust became molten and they solidified, which is the reason you can see great variations in the way the layers are displayed, ranging from the white, to pale grey and even ...