374 THE DEPOSITS. 



rocks from the face of the cliffs and for the deposit of such 

 on the lower levels. One is visible at Moulin Huet Bay. 



We also account for the erratics found on the 25 feet 

 beaches in England as well as in the lower Head, for 

 the bergs evidently travelled up Channel, as already stated, 

 and were pressed by the jam in the narrow part of the Channel 

 to the South coasts of England. 



It has always been a puzzle how rocks occurring only in 

 the Channel Islands and on the French coasts found their 

 way to the English 25 feet beaches, and still more how these 

 blocks became striated. 



Given the presence of ice in the Channel and allowing 

 for its circulation then it is a puzzle no longer. 



This is the explanation adopted by Mr. Clement Reid. 

 Of the English survey (see Geo. Soc, Transactions i YehY\iSLry 9 

 1892) to account for the erratics on the beach at Selsey. In 

 his paper he figures one which is extensively striated and 

 leaves no room for doubt as to ice being the cause of its 

 presence where found. 



Professor Bonney (see same paper) considered one of the 

 erratics to be Scotch, and I see no reason why it should not 

 have been carried down the Irish sea and then forced into the 

 Channel. 



The submergence continued until the island was again 

 completely under water. The proofs of this I shall give after 

 I have described the deposits of clay, for it is on this that I 

 have to depend for the evidence of the next stage. 



I now have to give the evidence showing that a local 

 ice-cap was present on the island at the time of the maximum, 

 and probably during the rise and decline of the glaciation. 



The evidence ranges itself under four heads, as follows : — 

 1 st. — The smoothing of hard rocks. 

 2nd. — The straight lines of erosion. 

 3rd. — The distributed boulders. 

 4th. — The altered form of the valleys. 



I have stated that the rocks consisted of hard and soft. 

 The hard resisted the influences of the soaking in the sea and 

 must have consisted of sharp pointed outcrops, having much 

 the type and appearance of the present sea-level form. The 

 rocks on the top of the island were of the same nature as 

 those now visible rising out of the sea, and the conditions when 

 the top of the island was awash must have been the same; 

 hence the upper surfaces of the island consisted of pointed 

 hills with sharp rocks lifting their heads above any debris, 

 which rested on their slopes and covered their bases 



