140 MAN AND THE GLACIAL PERIOD. 



beach. Mr. Lamplugh, whose description of the ' Drifts 

 of Flamborough Head,' * constitutes one of the gems of 

 glacial literature, considers that there is clear evidence 

 that the land stood at this level for a long period. The 

 beach is covered by a rain- wash of small extent, and that 

 in turn by an ancient deposit of blown sand, while the 

 lowest member of the drift series of Yorkshire covers the 

 whole. Mr. Lamplugh thinks that the blown sand may 

 indicate a slight elevation of the land ; but the beach ap- 

 pears to me to be the storm beach, and the reduction in 

 the force of the waves such as would result from the ap- 

 proach of an ice-front a few miles to the seaward would 

 probably produce the necessary conditions. 



" Six miles to the northward of Flamborough, at Spee- 

 ton, a bed of estuarine silt containing the remains of mol- 

 lusca in the position of life occurs at an altitude of ninety 

 feet above high -water mark. Mr. Lamplugh inclines to 

 the opinion that this bed is of earlier date than the ' buried 

 cliff ' ; he also admits the possibility that its superior alti- 

 tude may be due to a purely local upward bulging of the 

 soft Lower Cretaceous clays upon which the estuarine bed 

 rests by the weight of the adjacent lofty chalk escarp- 

 ment. 



" The evidence obtained from inland sections and bor- 

 ings in different parts of England has been taken to in- 

 dicate a greater altitude in preglacial times. Thus, in 

 Essex, deep borings have revealed the existence of deep 

 drift- filled valleys, having their floors below sea-level. 

 The valley of the Mersey is a still better example. Nu- 

 merous borings have been made in the neighbourhood of 

 Widnes and at other places in the lower reaches of the 

 river, making it clear that there is a channel filled with 

 drift and extending to 146 feet below mean sea-level. 

 This, with several other instances, has been taken to in- 



* Quarterly Journal of the Geological Society, vol. xlvii. 



