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The absence of organic remains, as well as vegetable mould, 

 except in the npper and more recent deposits, points to a period 

 of extreme cold, when the hills were bare and desolate, and the 

 waste occasioned by sub-aerial influences was continuous and 

 excessive. No surface soil is found beneath the gravel beds, 

 the commencement of their formation, therefore, was before 

 any depth of soil had accumulated on the slopes of the hiUs. 

 The accumulation of Gravel appears to have been spread over a 

 very long period, and having regard to the presence of land 

 shells in the finer deposits of the River Gravel, it is probable 

 that the formation of the Angular Gravel beds commenced 

 before the Eiver Gravel was re-arranged by the streams, and 

 re-stratified. Perhaps the period to be assigned to its com- 

 mencement is that of the re-current period of cold, during the 

 latter part of the Glacial epoch. And it continued to form 

 while the slopes remained exposed, and ceased only as vegetable 

 matter began to cover up the surface. 



