Heavily jointed limestone wave-cut platform, Lilstock, Somerset, UK. This Langport blue lias formation was laid down in shallow seas 183 to 204 million years ago in the Jurassic and Triassic periods. After the deposits were formed stresses created the joints (cracks) which have been widened by wave action. As the strata are horizontal the sea has scoured away all the rock above this bed leaving a flattish wave cut platform.