The rocks of the area date from the period of the Triassic, when
much of Britain was desert, to the Jurassic, when much of the
region was covered in tropical seas. At Kilve, two types of :edimentary
rocks are dominant: blue lias, a type of blue-grey limestone
of moderate resistance to erosion, and softer beds of shales
that vary in colour from black to grey and brown. The limestone is
welljointed and has a distinctively blocky structure. The shales ~e
flaky in appearance and are friable to the touch. They are also nch
in mineral oil, and on the top of the cliffs on the trackway between
the village and the beach are the ruins of a 19th century in?ustrial
plant in which the rocks were heated in order to extr~ct O