294 PROF. J. PRESTWICH ON THE RAISED 



At the northern end of the Bay, a remnant of Boulder Clay with 

 some large blocks rests on a striated surface of the Cambrian rocks. 

 This is in places immediately overlain by a local Head of angular 

 rock-fragments and Boulder Clay debris. A little to the south of 

 this an irregular Head rests on 15 to 20 feet of Blown Sands. At 

 the southern end of the Bay there are several imperfect sections, 

 one of which shows traces of a Beach consisting of large rounded 

 blocks and a few pebbles, resting on a ledge of nearly vertical strata 

 8 feet above the present beach. Again, at a short distance from this, 

 a Head, 15 feet thick, extends over and beyond some Blown Sands. 

 In another small section traces of a Beach also appear at the base 

 of these sands. Putting these sections together, I imagine that the 

 following diagram would represent the original order of succes- 

 sion : — ■ 



Fig. 13. — Diar/ram representing a restored section of the cliff 

 at the southern end of Whitesand Bay. 





I., I 



/"/• 



a. Head of angular fragments of the local rocks, including 



some large blocks of granite derived from the Eoulder 



Clay 15 ft. 



b. Light-coloured sands, with small angular and subangular 



fragments of slate to 20 ft. 



c. Beach, mainly represented bj^ large worn and rounded blocks 



of various rocks, probably in part derived from the adja- 

 cent Boulder Clay beds. 

 1. Lower Cambrian rocks. 



There seemed to me to be a close connexion between the incline 

 of the Head and the curvature of the edges of the fissile rocks over 

 which it passed, but on this point 1 could not feel quite sure. The 

 recent blown sands or dunes which occupy the shore in the centre 

 of the Bay are, no doubt, like those at Croyde in Barnstaple Bay, 

 largely reconstructed from the old dunes. 



At the northern end of Abereidy Bay a Head forms a terrace 15 

 to 20 feet high, and at Dinas Bay there seems to have been an old 

 strait of the Eaised Beach period. Beyond this, my visit to the 

 Welsh coast had not the present special object in view, but I am 

 not aware that any liaised Beaches exist along that part of the 

 cjast. 



