Liassic

Although in lithological characters almost every variety of rock seems to exist in the central axis of that chain, yet in fact it is composed of Jurassic and liassic deposits, lifted up ten thousand feet […].

Parallel to this, on the north and south, are synclinal axes – the northern one allowing the liassic rocks to appear on the coast […].

The top of a liassic stone wall/foundation, probed to a depth of 1.5 m, was recorded from 50 cm deep.

A totally different liassic stone is Blue Lias, a whitish-grey stone obtainable only in relatively small pieces and difficult to dress.