76 



It has been seen that quartz has a special tendency to 

 appear in great quantities in the samples, even where one would 

 expect it to be almost absent. In samples Nos. 37, 40, and 41 

 from the south of Кар Brewster, though the sample seems 

 to consist almost exclusively of basaltic material we see that 

 there is from 10 to 16perCt. of quartz present. This is con- 

 nected with the wellknown tendency which quartz has to appear 

 in grains of sand, so that the percentage of it in a sand 

 deposit is always many times greater than its percentage in 

 the rocks from which it was derived. Sand which originates 

 from granitic material will thus contain 60 — 70 per Ct. of 

 quartz, while much less than half of the granite consisted of 

 this mineral. If we determine the ratio between the different 

 rocks which have contributed to the formation of the sand in 

 a sample, we must always reduce the amount of quartz very 

 considerably, and must also make smaller changes with regard 

 to the ratio between the other minerals. In the three samples 

 above-mentioned we should probably come very near to the 

 real ratio if we fixed the quartz at 3 — 5 per Ct., then the 

 total amount of quartz, felspar and hornblende would become 

 about 10 in these samples, which number would about represent 

 the amount of granitic material contained in them. 



For the rest, the amount of quartz is fairly equal through 

 out the samples; it culminates at 70 per Ct. in No. 2; and 

 thus corresponds pretty closely with the amount in some of 

 the samples obtained during the ingolfexpedition to the 

 West-coast of Greenland. There the collective mass of quartz 

 and felspar reaches 80 per Ct., while it here, in No. 2, amounts 

 to 82 per Ct., which is perhaps the highest percentage generally 

 reached in granitic sand. It must, however, be remarked that 

 the ratio for the East-Greenland samples is somewhat difficult 

 to determine, for on the one hand the proximity of basalt, 

 slate etc. will diminish the amount of quartz, on the other 

 hand the presence of sandstone will augment it, as sand 



