550 Kakl a. Grönwall. 



to a place about 100 metres eastwards of that section about 90 — 

 115 metres above the sea (found both as free-lying boulders and in 

 situ). N:o 10 and 11, again, are from the westernmost spot in Hekla 

 Sound where plant-fossils were discovered. 



It is impossible to ascertain with perfect certainty the thickness 

 of this group, but in Koch's section no limestones have been found 

 lower than 200 metres above the sea, and, in the Conglomerate 

 section they do not make their appearance before a height of 130 

 metres over sea-level, alternating with the conglomerate. We ven- 

 ture to assume that the conglomerate which alternates with the lime- 

 stone is the basal conglomerate of the Lower marine group, and 

 occupies the same level as that of the sub-stratum of the lowest 

 limestones in Koch's section. We should presume, then, that 200 

 metres is the probable minimum thickness of these terrestrial beds, 

 even if there exists a great possibility that, in consequence of the 

 further extension of the deposit westwards, the actual thickness is 

 two or three times as great. 



B. The Lower Marine Group has been formed during the 

 transgression of the Carboniferous sea over the terrestrial formations. 

 As we have already pointed out, this transgression has occurred 

 gradually, and accompanied by slight oscillations which become 

 very evident by the alternating of formations with different develop- 

 ment of faciès: limestones with marl-shales and sandstones. That 

 the limestones, too, point to the vicinity of land and shallow water 

 is clearly shown by their character, as they are seldom entirely 

 pure limestones but, as a rule, clayey; the terrigenous material, the 

 original mud, which was carried out to sea, is, too, found collected 

 in beds of marl-shale which alternate with the limestone. The large 

 amount of bituminous substances contained both in the marl-shale 

 and in the dark limestone, need by no means point to a great depth 

 of sea for the formation of these rocks, as the remaining character- 

 istics of the rocks give such decided indications of a fairly shal- 

 low sea. 



The profiles from Holm's Land and Amdrup's Land present 

 certain differences which, it is true, for the most part are, probably, 

 the result of some fortuitous circumstances in making the collections 

 but which, nevertheless, make it necessary to undertake somewhat 

 detailed comparisons between the rock-specimens collected at the 

 two places in question. The differences existing between Koch's 

 section and the Conglomerate section are not very important, and 

 are in part the result of the dip of the strata, so that the comparison 

 of these sections does not present very great difficulties. The mutual 

 connection, loo, between the sections from Amdrup's Land, the two 



