90 



especially that which has been ice-borne. The basaltfor- 

 mations north of Scoresby Sund are only found at the 

 outmost parts of the country, and consequently the icebergs 

 of the present day cannot contain basaltic material; the coast- 

 ice may perhaps convey some, but this will only be a small 

 quantity. The ice from the ice-age , which filled up the bays 

 right to the mouths, must on the contrary have eroded a 

 large amount of the basalt territory, and this accounts for 

 the fact that, although the basalt occupied all the outer- 

 most tracts except in the case of Liverpool Kyst, com- 

 paratively little of it is found in the samples nearest 

 the coast but much more in deposits farther out. When 

 we come very close to the shore larger quantities of basalt 

 will again be found, which have their origin direct from 

 the coast. 



4) The 4**^ factor whereby material is conveyed to the 

 deposits is the solid rock of the sea-floor. Where we have 

 to do with such, the mechanical constitution of the samples 

 is most varied, according as they have been obtained in close 

 proximity to some rock or at some distance from it. The 

 existence of submarine rocks is often shown by just such 

 a seemingly unreasonable variation between adjacent deposits. 

 Something the same is the case with regard to the miner- 

 alogical nature of the samples. As each mountain consists 

 as a rule of only one kind of rock, a deposit which gets 

 its material from such will be of a very homogeneous con- 

 sistency. We have a still more certain sign of the presence 

 of submarine rocks, when the fragments vary suddenly from 

 one sample to another, if, for example, we have two adjacent 

 samples, one of which consists of basalt, and the other of 

 granite, we may conclude with certainty that Ihey must pro- 

 cure their material from rocks at the bottom of the sea, 

 unless they have been obtained so close to the shore that tiie 



