FOUND NEAR BLACKPOOL. 136 



currents of water, and much eroded and washed away. In 

 the hollows caused by such agencies, the littoral deposits 

 of sand and gravel may have been deposited. The land 

 then appears to have subsided and icebergs and glaciers 

 again come into operation, although to a less extent than 

 on the first occasion before alluded to, as the number 

 of rocks, and especially such as are scored and striated, is far 

 less than those met with in No. 4. Subsequently, the whole 

 district has been elevated from the sea into its present 

 position. 



The more that the phenomena of the drift deposits are 

 studied, the more we must be convinced that so far from 

 having been formed in a short period of time, as was once 

 the generally received opinion, when they were erroneously 

 attributed to the Noachian deluge, they have occupied 

 ages in their formation ; during which, they have been 

 more than once raised and depressed, and considerable por- 

 tions of them washed away and replaced by other deposits. 

 These changes of level, there appears to be no reason for 

 believing were of a more speedy nature than the slow and 

 gradual motions of the land we see going forward upon the 

 face of the globe at the present time. The sands and gravels 

 of the deposits are easily recognised as ancient strands and 

 beaches; but the beds of till present us with no such 

 appearances, presenting every indication of having been once 

 the bottoms of ancient seas, in which floated various 

 rocks freighted with numerous icebergs, which, on being 

 dissolved or toppled over, deposited their loads on the soft 

 mud below. 



