s: 



But, as lias been slio\vn above, in tbe samples of this expedi- 

 tion a number of i-ases have been found in which adjacent 

 deposits differ very widely with regard to their mechanical con- 

 stitution, which differences must certainly be due to purely local 

 relations of the bottom of the sea. 



If we consider the mineralogical nature of the samples, 

 we shall be able to draw from it certain conclusions with re- 

 gard to the depositing power of ice. As icebergs have their 

 origin in so many different localities, the material they convey 

 must also be very mixed; if therefore the samples show pro- 

 nounced mineralogicai differences directly connected with the 

 geological nature of the nearest tracts of land then in such 

 cases the influence of the ice must have been rather slight. 

 These considerations prove plainly that in the samples nearest 

 land the deposition of ice has played no great part. In the 

 deposits lying farther from land the case is somewhat different, 

 for these will generally contain a very mixed material conveyed 

 in other ways, and which cannot be easily distinguished from 

 that which has been conveyed by ice; there is, however, as 

 has often been mentioned above, sufficient reason to suppose 

 that in these also the influence of the ice is comparatively 

 slight. 



On the other hand, merely from the mineralogicai nature 

 of the samples we can conclude that the drift-ice must be of 

 some importance with regard to deposition, and that, in these 

 parts, at least some transport of pebbles must take place. 

 For, it will often be seen that beside the chief ingredients of 

 the sample, which plainly show by their homogeneousness that 

 they have originated in rocks of the neighbouring land or of 

 the bottom of the sea, there will be found a few others, whicli 

 <annot have been derived from any neighbouring place, and 

 must thus have been conveyed hither by icebergs. For instance, 

 if. out of 100 grains, we have 90 granite, and the rest sedi- 



