4 6 



THE DEPOSITS OF THE SEA-BOTTOM. 



Station 98. A hundred small stones, up to 5 cm , some angular, some half-rounded. 80 of them 

 were black basalt, 10 gray basalt, 7 brown, disintegrated basalt, two vesicular lava, and one obsidian. 



Station 105.' One red quartz-porphyry, with small grains of quartz, of a diameter of 2 cm , rounded. 



Station 115. One gray basalt with grains of olivine, rounded and rolled, of a diameter of io cm . 



Station 125. One gray, hornstone-like rock with small grains of pyrite; the size 5 cm , the form 

 quite irregular, almost angular. 



Station 127. From this locality, close to the north coast of Iceland, an immense mass of stones 

 was brought home, which were all rolled to an uncommonly high degree. All those examined by 

 me, consist of basalt 



Station 143. One piece of vesicular black basalt, of a diameter of i-5 cm . 



As a common rule it can be said that the results which we get from the stony ingredients of 

 the specimens, essentially correspond with those got from the other parts; the few exceptions have 

 already been noted under the different stations, and they commonly tend to show that the Greenland 

 material is more predominant in proportion to that from Iceland, than is the case in the finer ingre- 

 dients. This again is accounted for by the fact that while the stones cannot well be supposed to 

 have been transported in any other way than by ice, the direct transport by water, on the other hand, 

 plays a very great part with regard to the sandy and clayey ingredients of the specimens. Most of 

 the material from Greenland is now carried into the sea frozen up in the ice, while this is only to a 

 smaller degree the case with that from Iceland. The conseqiience of this upon the whole will be 

 that the material from Greenland will not be sorted to so high a degree with regard to the size of 

 the grains, as that from Iceland; thus of the former as well the stones as the finer ingredients may 

 be carried to a large distance, while this, with regard to the Icelandic' material, is only the case with 

 the comparatively small part that is transported by the ice, while all the rest is sorted in such a way, 

 that the stones are deposited immediately at the land, while the sand and the clay is carried out the 

 farther, the finer it is. 



A rather curious phenomenon has still to be mentioned here, that is to say, the ferruginous and 

 manganic crust with which the stones of the sea-bottom are covered. With the basaltic stones this 

 circumstance is not very conspicuous; but by all the light-coloured rocks we see that the side rising 

 above the clay, is more or less dark-coloured, often quite black, while the side turned downward has 

 the natural colour of the rock, or is only of a slightly darker shade. The colour of the coating is 

 otherwise somewhat changing; the upper side may be brown, red-brown, dark brown, dark violet, or 

 black; the lower side light brown, or light yellow -brown , if upon the whole it be coloured. From 

 one and the same station all the stones are coloured in the same way, thus for inst at station no. 18 

 where the phenomenon is most prominent, all the upper surfaces are black, and all the lower ones 

 absolutely colourless, while brown shades are found in the transition between both. The coating is 

 easily disolved in diluted hydrochloric acid to a yellow solution containing iron and manganese, which 

 substances are often on deeper water disengaged to a large amount by the sea-water. The few pieces 

 of limestone found in the specimens, have no such coating, from which fact, however, cannot be drawn 

 the conclusion that such a disengagement cannot take place on limestone. 



