2 24 PREHISTORIC E UROPE. 



In the maritime districts of Southern England and Northern 

 France loose superficial accumulations attain a considerable 

 development. They occur as more or less wide-spread cover- 

 ings that vary in thickness from a few feet up to many yards, 

 and extend from the sea-coast inland to a less or greater dis- 

 tance. They were long ago noticed by Dr. Borlase, who 

 described their essential features, and since his time they have 

 given rise to some interesting discussions as to their origin. 

 In the south of England they are known under the general 

 name of " head." They consist of a more or less coarse agglom- 

 eration of angular dSris, and large blocks set in a matrix of 

 earthy matter. Sometimes the " head " has an appearance 

 of rude bedding, but not such as could be attributed to sub- 

 aqueous arrangement. ~No included water -worn stones or 

 pebbles, according to Mr. Godwin-Austen and others, are ever 

 to be found. As a rule, the deposit is quite unfossiliferous, but 

 Mr. Prestwich has detected in the sections of it which are 

 exposed in the neighbourhood of Weymouth several land- and 

 freshwater-shells. The stones and blocks are all of local origin, 

 and have generally not travelled far. Some, however, have 

 evidently been carried farther than others, but not a single frag- 

 ment belongs to other drainage-areas than that in which any 

 given mass of the "head" occurs. Mr. Godwin -Austen, to 

 whom we are indebted for a very interesting and suggestive 

 description of this peculiar formation, 1 reflecting upon the fact 

 that no such accumulation is now taking place in the districts 

 where it occurs, comes to the conclusion that the " head " has 

 resulted from long - continued subaerial waste under severer 

 conditions of climate than now obtain in regions bordering on 

 the English Channel. To obtain such conditions he supposes 

 the land to have been formerly elevated to such an extent as to 

 bring the whole of the higher portions of this country into 

 regions of excessive cold. 



675 ; J. Martins : Ibid., 3 e Ser. t. iv. p. 653 ; Collenot : Ibid., 3 e Ser. t. iv. p. 656 ; 

 Delafoud : Ibid., 3 e Ser. t. iv. p. 665 ; De Lapparent : Ibid., 3 e Ser. t. iv. p. 671. 

 1 Quart. Joum. Geol. Soc, vols. vi. p. 97 ; vii. p. 121 ; xii. p. 40. 



