English: Basalt columns, west coast of Kerrera Paddling up the west of Kerrera, the rock is almost entirely basalt, dipping roughly northwest into the sea (this makes for low-angled slabs which take the swell and produce the sort of sloshing that can upset an unwary sea kayaker who ventures too close - not a problem on this calm day). This layer displays the characteristic columnar form of basalt which cooled quickly after solidification, quite common in lava flows and volcanic vent plugs. Large areas of the west of Scotland including Mull and Kerrera form part of the Tertiary Volcanic District, formed by volcanic activity when the mid-Atlantic first formed and the continents of Europe and North America started to move apart.