84 DESCRIPTION OF THE COAST. 



and further on reach an elevation of two hundred and seventy feet ; 

 but part of the castle garth is, perhaps, fifteen feet higher. The first 

 rock which is seen above the pier is a ferruginous sandstone with fossil 

 shells, which is ascertained to be identical with the rock of Kelloways in 

 Wiltshire. Above lies the gray argillaceous earth which occupies the 

 place of the Oxford clay ; this gradually passes into the calcareous grit. 

 and some beds of the coralline oolite surmount the whole. These strata 

 decline in the eastern face of the hill, so that the Kelloways rock sinks 

 below the level of high- water, and at a projecting point the Oxford 

 clay keeps the foot of the cliff; but soon rising again, where the hill 

 fronts the north, they ascend towards the drawbridge. The fort on the 

 northern face of the hill, is levelled on nearly the lower beds of coralline 

 oolite ; of this rock thirty feet appear on the hill above ; its whole thick- 

 ness here is nearly forty feet : below are about eighteen feet of solid 

 calcareous grit beds : these rest on three layers of hard calcareo-siliceous 

 balls, lying in soft yellow sand, twenty-eight feet thick : then succeed 

 fifty feet of calcareous grit, hard above but graduating below to the 

 next stratum, the Oxford clay ; which, being one hundred and thirty-five 

 feet thick, occupies the remainder of the hill to high-water mark. 



These strata, rising towards the drawbridge, have been subjected to 

 a very uncommon dislocation, the effect of which is the uplifting of the 

 Kelloways rock to the level of the lower part of the calcareous grit Kel- 

 loways fossils are found in this uplifted portion on the north side of the 

 drawbridge, * two hundred feet above the sea. This uplifted portion 

 is very narrow, as will be seen by consulting the general section. 

 Bushel's fort is upon the lowest soft part of the calcareous grit, which can 

 hardly be distinguished from the Oxford clay. The stratum so named 

 is found in the upper part of the cliffs beyond ; whilst below it occurs 

 the Kelloways rock, rich in ammonites, grypheeae, aviculas, &c. The 

 cornbrash is found beneath, full of terebratulae, unioniform shells, 



* Mr. Smith discovered this singular fault, and communicated it to me : his eagerness on the 

 occasion led him to overstrained exertion ; and the consequence was a very alarming privation of 

 muscular power in his legs ; from which his friends have since rejoiced in his perfect recovery. 



