BEACHES, ETC., OF THE SOUTH OF ENGLA:N-D. 295 



§3. ORIGrN" OF THE FoRElGN BoTTLDEES IN THE E,AISED BeACHES. 



Ifc was at first supposed that the eastward set of the tide and 

 wind had, in former times as now, carried the shingle from the 

 older rocks of Devon and Cornwall towards the Sussex coast, and 

 that the boulders of crystalline and Palaeozoic rocks found on this 

 coast had come from that source. 



God win- Austen, however, pointed out that there were objections 

 to this conclusion, and considered that the presence of chalk-flints 

 in the Eaised Beaches of Devon indicated that the marginal move- 

 ment of the materials was from east to west, or the reverse of what 

 takes place at present.^ At the same time he held that the large 

 old-rock boulders must have been carried by ice independently of 

 the coast-line, and could not be referred to any rocks on the English 

 coast. He believed that many of them might be compared with a 

 series from the rocks composing the Cotentin, the Channel Islands, 

 or Britanny, the agreement in many cases being close and striking. 

 There were, however, instances in which the boulders could not be 

 referred to any of the JFrench rocks, and this led him to suggest 

 that an old coast-line, composed partly of Palaeozoic and crystalline 

 rocks, extended across the area of the English Channel between 

 jS"ormandy and Sussex before the opening of the Straits of Dover,'^ 

 and that it was from rocks on that ancient coast-line, brought upbj 

 the east-and-west anticlinal axis passing south of the Isle of Wight, 

 that the Sussex boulders were derived. He instanced as evidence of 

 their existence in the Channel the fact that in depths of 45 to 50 

 fathoms he had there found pebbles of granite and of Silurian 

 rocks, and he inferred these pebbles to have belonged to rock-masses 

 composing the ancient coast.^ 



Mr. Codrington thought that the foreign-rock boulders of the 

 Hampshire and Sussex coasts were derived from rocks on the French 

 side of the Channel.^ Sir Charles Lyell, speaking of the Pagham 

 boulders, observed that they are not of northern origin, but must 

 have been drifted by coast-ice from the coast of Normandy or 

 Britanny, or from land which may once have existed to the south- 

 west, in what is now the English Channel, at a period when the 

 cold must have been at its height.^ 



There is, however, no reason to believe that the Straits of 

 Dover were closed at the time of the Eaised Beaches, as, besides 

 the old Beach at Sangatte, the marine bed at the base of the 

 valley-deposits in the old estuary of the Somme is, no doubt, 

 synchronous with the Beaches in the open, thus establishing an 

 almost continuous coast-line on that side of the Straits. On our 



^ Quart. Journ. Geol. Soc. vol. vi. (1850) p. 88. 



2 Ibid. vol. xiii. (1857) p 59. 



3 iJicZ. pp. 61 &71. 



* Ibid. Tol. xxvi. (1870) p. 535. 



5 ' The Antiquity of Man,' 4th ed. p. 330. 



Q. J. G. S. No. 190. X 



