101 



undetermined, and we have to seek for a hypothesis that shall 

 account for the formation of beds of great thickness of finely- 

 comminuted clay, enclosing incalculable quantities of rounded or 

 sub-angular boulders. The clay we might believe to be the product 

 of the grinding action of ice, but we know of no glacial influences 

 that would cause the boulders to be rounded, an effect solely due 

 to marine or fluviatile agency ; but rivers can have had no share 

 in this instance, and we are left to look to the sea alone for an 

 explanation. Is it possible that when this vast accumulation was 

 brought down from the high ground, that the ice came down to 

 the sea, which in this district was, at the beginning of the formation, 

 at a lower level than now? that the mud ground off the rocks was 

 deposited in a zone near the shore, which was constantly sinking?, 

 and that the rocks and stones, brought down as moraine matter 

 were, before their final entombment, subjected to the rounding 

 action of the sea? If this process were continued, and the land 

 sank to the great degree that is assumed by most writers, but little 

 would be left above water, and i^erforce the deposit of glacial 

 matter would nearly cease as the country sank beneath the waves, 

 which would melt its icy covering. Then may have been formed 

 the sand and gravel beds, the result of the sea disintegrating the 

 previously deposited boulder clay, and re-arranging the materials. 

 But the movement of the land changed, the period of subsidence 

 was ended ; and slowly our mountains once more emerged from 

 the sea ; as they did so, they would present more and more surface 

 for the formation of glaciers and land ice, but the cold epoch was 

 on the wane, and though the land rose to a degree nearly equal to 

 the subsidence, the coating of ice never reached its former 

 dimensions; still it could produce prodigious efifects, and the 

 so-called Upper Boulder Clay may be its witness. This theory 

 practically harmonizes with the results mentioned as having been 

 worked out in Ireland, and does away with the necessity of 

 assuming two glacial epochs. 



In studying the Boulder Clay formation, there are perhaps few 

 districts that offer so many advantages as our own north-west coast. 

 I do not know whether the members of the AVhitehaven Scientific 



s 



