Braewick Beach

Braewick beach is divided into two halves by the Melby Fault, with sedimentary and volcanic rocks at one end and granite at the other.

At the west end of Braewick beach are lavas that erupted from the Eshaness volcano about 395 million years ago, covering sandstones that formed on the bed of a river. At low tide you see a layer of dark basalt containing small holes called vesicles which were gas bubbles in the molten lava. Below this is a bed of grey sandstone containing lapilli - fragments of volcanic rock which blasted from the volcano and rained down into the river. In places the cliffs are made up of jumbled rocks from a mudflow, probably triggered by the collapse of an unstable volcano cone. Sometimes flash floods swept down the volcano to collect in ponds and lakes. You can find red and grey banded sandstones that formed at the bottom of such a lake. At the other end of the beach is granite, formed from molten rock which cooled in a magma chamber deep below the ground. Movements along the Melby Fault, which runs through the middle of the beach, have brought it into contact with the volcanic rocks and sandstones. Above the granite is a thick layer of glacial till – debris deposited by a glacier during the last ice age.