280 Prof. Sedgwick and Mr, Murchison 



and as, in colour and aspect, it differed entirely from any rocks by which we 

 were surrounded, we first imagined it to be an outlying mass of oolite or 

 green sand ; nor were we undeceived, until we actually descended to the 

 shore, so precisely did it resemble the sea-worn cliffs of many of our younger 

 secondary formations. We then found that the top of this undercliff was 

 occupied, to a depth of eight or ten feet, by a mixed detritus of angular frag- 

 ments of the adjacent rocks, contained in a matrix of sandy loam. Beneath 

 this drift, the yellow cliffs, which had attracted our attention, consisted, at 

 their upper part, of finely laminated sand, with here and there an imbedded 

 sea-shell, such as a common cardium or oyster, but generally in too fragile a 

 condition to bear extraction. These beds of sand are about 25 feet thick ; 

 and, as they pass downwards, they become harder, and are occasionally inter- 

 rupted by a course of small water-worn pebbles, perfectly identical with com- 

 mon beach shingles. Though usually arranged in horizontal laminas, these 

 sands presented, at intervals, those appearances of false bedding so common 

 in our tertiary and secondary strata (see vignette), putting on the form of 

 wedges, the laminas of which run diagonally across the principal layers of the 

 deposit. In descending to the shore, we found the lower part of the cliff 

 passing into solid sandstone, and, finally, into a hard bed of shingle, or con- 

 glomerate, resting upon the highly inclined and broken edges of rocks, which 

 we refer to the " Silurian System." 



This portion of the cliff, consisting of hard sandstone and associated shingle 

 beds, contains several marine shells, of existing species, among which are 

 Cardium edule, Patella vulgaris, Mi/tilus edulis, Solen, Donax trunculus?.* 



On examining this portion (the lowest part being generally about three 

 feet above high-water mark, at spring tides), we were forcibly struck with 

 the analogy which the strata presented to many rocks formed before the pre- 

 sent aera. The grains of sands are agglutinated into a compact mass, which, 

 on fracture, exhibits a shining, chatoyant lustre, common to calcareous grits 

 of the secondary rocks, with an occasional tendency to run into concretionary 

 forms; and these regularly bedded, stony masses, pass into grit and shingle 

 on the one hand, and into soft, incoherent sand, on the other. The maximum 

 thickness of these lower consolidated strata, at the point where we first met 

 with them, is about 11 feet, of which the upper seven feet are sandstone, and 



* We believe that all the shells in this raised beach belong to existing species. We should 

 not, however, have been surprised had it contained some organic spoils resembling those of a 

 warmer climate : for seed vessels of Mimosae, inhabitants of the Mexican Gulf and the West 

 Indies, are annually washed on these shores, by currents probably connected with the great Gulf 

 stream. We met with several examples of this kind. 



