DILUVIUM. 281 



appears. Along the face of the chalk, slight traces of it are here and 

 there perceptible, and in these situations, the vertical flint veins that 

 traverse the cUff, invariably pass behind, and are concealed from view, by 

 the insular patches of shingle. 



The face of the chalk is remarkably even ; it is not, however, vertical, 

 but forms a precipitous slope. In the upper part, the chalk is much 

 broken, and contains two horizontal veins of tabular flint ; the inferior 

 strata are more regular. It is particularly necessary for the reader to bear 

 in mind, that although the chalk with its horizontal flint veins, (vide Tab. 

 V. fig. 1), is higher than the insular portions of the shingle bed, it is not 

 situated perpendicularly above them ; the cliff", as before mentioned, forms 

 an incHned plane, its summit receding considerably from the shore : con- 

 sequently a vertical section would cut off'aU traces of the shingle*. 



On the eastern extremity of the recess, the chalk is traversed by 

 numerous veins of marl, but in other respects presents nothing worthy of 

 observation. At the termination of the chalk, a bold projection of the 

 cliff" occurs, in which the shingle and calcareous bed appear in their 

 usual position and proportions. 



Towards Eottingdean the cliff"s increase in altitude, but the calcareous 

 bed diminishes considerably in thickness, and wherever a vertical section 

 is exposed, is seen lying upon the shingle, in contact with a sloping 

 bank of broken chalk ; the latter being evidently the ruin of the ancient 

 chalk cliff's, the flints it contains presenting no appearance of having 

 suflPered either from attrition, or exposure. 



To the west of Rottingdean, the cliff's are chiefly composed of the 

 regular chalk strata, containing, as usual, horizontal beds of siliceous 

 nodules, and veins of tabular flint. Veins of marl are also very numerous, 

 and there is one of remarkable extent, which appears beneath the shingle, 

 and extending in a horizontal direction to within a short distance of 



* It was probably from want of attention to this circumstance, that the I'espectable 

 writer previously alluded to, was led to adopt the opinion, that the shingle bed was situated 

 between two distinct beds of flinty chalk. 



