BEACHES, ETC., OF THE SOUTH OE ENGLAND. 



285 



matrix of sand with a large proportion of comminuted shells, Avhich 

 is often concreted. Balani {B. crenatiis, Darw. ?) are attached 

 thickly to the raised rock up to a height of from 10 to 12 feet 

 above high-water mark. Entire shells are not common ; the most 

 abundant species are Purpura lapillus^ Littorina littorea, Patella 

 vuJc/ata, Cardivm edule^ Myt'dus edulis, Mya truncata, and Ostrea 

 edulis. Foraminifera are numerous. The complete list of the shells 



Fig. 9. — Section at Baagy Pointy North Devon. 



J>evonian siaces 



will be found on p. 300. Amongst them is Cardium papillosura^ not 

 now known to range farther north than Falmouth. The block of 

 red granite in the beach at Baggy Point measured 7x5x2 feet. 

 I found also a smaller block of a fine-grained white granite, and 

 one of hornblendic granite in another part of the cliff. 



A special feature to notice in connexion with the liaised Beaches 

 from the Land's End to North Devon is the frequent occurrence of 

 Blown Sands or Dunes, 6, over the Beach and under the Head. 

 These sands show bedding and false- bedding, and are very com- 

 monly concreted, owing to the presence of shell-sand which has 

 furnished the cementing carbonate of lime. They attain in places a 

 thickness of from 20 to 30 feet or more, though they have frequently 

 been denuded and deeply indented by the superimposed Head. 

 These prove that, after the formation of the Beach, the coast must 

 have undergone sufficient elevation to raise the Beach above wave- 

 action, and also, if we are to judge by the depth of the old river- 

 channels on the Cornish coast, many feet above the level that the 

 Beaches now have. From the size of the pebbles in the Beaches 

 and the extent of the old Dunes, we may conclude that this coast was 

 exposed to even v^^ilder gales from the westward than at the present 

 day. Large portions of the dunes now forming on these coasts are 

 derived from these old Blown Sands, for which they may often be 

 easily mistaken. 



