K1MMERIDGE.

187

After passing Worth barrow bay (PI. XXXVII. No. 2.) alineof cliffs appeared, similar to, and continuing in the same directionwith, South cliff, above mentioned, but higher. This is calledGad cliff. On the top is the series of thin Purbeck limestonestrata, which in the west end are level with the sea; but theysuddenly rise to the east, exposing more and more of the oolitebelow; and at the east end they are cut off entirely by the slopeof the hill, and are not seen again along this shore. The oolitealso rises to the east, and is cut off in the same manner, otherstrata from below it, and entirely different, making their appear-ance ; and forming a low, but vertical, cliff, of which the strataare horizontal.

This is the place called Kimmeridge, well known as produc-ing a singular species of coal. This coal is slaty clay stronglyimpregnated with bitumen, and does not exhibit any signs ofvegetable origin. It burns very readily, with a brisk flame,affording a good heat, but gives out a very disagreeable smell.It is used only by the people in the village; and is found in theface of the cliff, where it forms a bed two or three feet thick.Compressed shells of the cornua ammonis, converted into pyrites,are not unfrequent in it.

The whole of the Kimmeridge strata, consisting of a series ofargillaceous and calcareous layers, are situated below the Portlandoolite ; by which I mean, that their geognostic place is lower,for the oolite is no longer seen here.

These dark coloured strata alone now formed the cliffs as faras a small bay called Chapman’s pool, which is very near to St.Adhelm’s head. In this extent are the bays of Kimmeridge andEncombe.