!04 



NA TURE 



[June 26, i < 



the second suggestion is correct, an:l that erroneous conclusions 

 have been arrived at. There seems, for instance, reason to 

 .-•uggest that these deduction^, even if logically correct for the 

 district delineated, may not apply to the entire northern half of 

 Norway in general before they have been more extensively 

 corroborated. As to this suggestion, I may reply that the 

 district described above compri-es a great area. It includes 

 thus channels of continuous fjords and sounds close upon 120 

 km. in length, and a coast line 90 km. long, and what is most 

 important, that the clnnnel in question is one which, by the 

 orographical structure, has offered one of the most suited 

 channels for the flow of the ice. If the inland ice has not been 

 powerful enough to move forward by this channel, there is, I 

 believe, little probability of finding a single similar channel in 

 Northern Norway in the district between Salten and the North 

 Cape by which the inland ice has moved to the coast. 



If, on the other hand, the southern part of the Scandinavian 

 peninsula is examined, where the inland ice is supposed not only 

 to have filled the fjords but also the entire North Sea and the 

 Baltic, such a circumstance presupposes, in my opinion, condi- 

 tions so gigantic that they may even from the first be doubted. 

 In fact, the area of the snowfall from which these enormous 

 masses of ice must have been originated is not proportionate to 

 the supposed results. Anything corresponding with such a result is 

 not to be found even within the Arctic zone, which at present 

 suffers most from glaciation. The Polar basin itself is, I believe, 

 nowhere filled with ice masse-, which reach the bottom. It is, 

 in my opinion, filled with sea ice in constant drift. 



My deduction i;, therefore, that the theory of the ice-streams 

 from the Scandinavian peninsula having advanced and covered 

 the North Sea, the Baltic, and reached the Central European 

 plain, England, the Orkneys, and the Shetlands, cannot with the 

 facts at our disposal be accepted as a scientific doctrine. 



Travelled Gnuii/e Blocks in the Neighbourhood of Tromso. — Of 

 the loose blocks and boulders which are found in such large 

 numbers about this town, partly embedded in the sand, ar.d 

 partly in old moraine drift, or strewn over the ground, the 

 greatest number had their origin in the s did mountains in the 

 vicinity. The-e may, as we may have reason to assume, be 

 found at the mo.t different elevations, as the agencies which pro- 

 duced them have been in continuous action down to our time. 

 Real travelled blocks, transported to their present place from 

 a distance, appear al-o in quantities in this district, but the latter 

 seem to be confined to certain levels. Of these foreign kinds of 

 travelled bl icks, most are of granite, and I draw particular 

 attention to these, not only on account of their frequent occur- 

 rence, but also from their great dimensions, a great many being 

 thus from a half to one cubic metre, and more. These blocks 

 are mostly rounded, without, however, showing any greater 

 polishing. Stria> are never found on them. 



They appear in greatest number tip to a height of 25 to 

 30 in., and more seld mi between 30 and 38 m. Up to the 

 former height they are everywhere to be found, while in higher 

 elevations they are difficult of discovery. The line of demar- 

 cation upward; is pretty distinctly defined, but the blocks are 

 not always to be found to the above height. There are lines 

 along which the granite blocks are heaped up to this hebht, and 

 beyond they suddenly disappear. The change is so startling that 

 attention is at once arrested. It should, however, be stated that 

 the line mentioned at 38 m. very nearly answers to the level 

 of the shore line graven in the solid rock, which, greatly pro- 

 nounced in this pi ice, may be traced for miles. 



During the summer of 1SS2 I carefully examined these condi- 

 tions, paying the most minute attention to the two sides of 

 Troms Island, 11 "3 km. in length, whence I extended my 

 researches along the sounds on both sides of this island, viz. 

 southwards to trie tracts about the mouth of the Balsfjord, about 

 ti km. in length. But while the travelled blocks will be con- 

 lined upwards to certain levels, no such demarcation will be 

 found downwards. They are to be found down to the lowest 

 level of the littoral belt. Particularly there will within this belt 

 often be found heaps of large blocks ranged in rows along the 

 central tide line, i.e. the line marking half tide. On the Ren 

 Island, too, some eighteen miles north of Tromso, I found once a 

 threat number of granite travelled blocks strewn along the lower 

 levels in a line from south to north. With the exception of 

 ertain parts of Kvals and Kingvats Islands, the mountains along 

 this district will nowhere be found to consist of granite, neither 

 will there be found strata of granite nature to which these travelled 

 rocks might be ascribed. I must, of course, admit that a series 



of continuous researches are certainly required before it is pos- 

 sible with certainty to fix the place of birth of these blocks. 

 With the materials at present at our disposal, however, we may 

 arrive at some safe conclusions. 



The granite field nearest from the sea inland is found far up 

 in the Divi Valley. Of other granite strata inland there cannot 

 here be a question. 



This granite field is 124 km. from the Troms Island. Nearer 

 than the above-described district is, however, the coast with 

 extensive strata of gneiss-granite, which appears particularly 

 prominent over the Kval Island situated just west of the Troms 

 Island. From either of these the travelled blocks must have 

 their origin. 



If, now, the Divi Valley is accepted as their place of origin, 

 the transport Ins been effected from the inland coastwards. If, 

 on the other hand, the Kval Island is designated as their place 

 of production, the transport must have taken place in opposite 

 directions, viz. from the coast landwards. 



If we now examine the petrographical composition of the 

 travelled blocks, a great many will be found to be formed of 

 varieties whic 1 belong to the gneiss-granite of the coast. But 

 there may, on the other hand, be found many blocks among 

 them which se;mpetrographically to be less related to the gneiss- 

 granite, but to resemble typical inland granite far more. 



At first sight, therefore, one would conclude that the travelled 

 blocks might have been brought by both named roads. In thi-, 

 respect I must, however, point out that the gneiss-granite of the 

 coast may petrographically vary considerably, and that it may 

 be interspersed by or ru 1 into granite of purer character. In 

 spite even of the greatly varying petrographical forms under 

 which the travelled granite blocks may appear in the neighbour 

 hood of Tromso, I do not therein see any reason for denying 

 that the travelled blocks may in general have their origin from 

 the gneiss-granite. There are, however, several circumstances 

 which tend to refute the theory of the blocks having been moved 

 thither ft 011 the granite fields in the Divi Valley. If the blocks 

 were thus carried down to to the Troms Island and adjacent 

 sounds, it mu-t have been effected in either of the following 

 ways : — 



1. Either from the upper part of the Maals River across the 

 mountain ridges down to the bottom of the Balsfjord, and thence 

 outwards to the Troms Island. 



2. Or along the bed of the Maals River tn the bottom ot 

 Malangen, and thence further through the sounds which here run 

 in an easterly direction towards the Troms Island, between the 

 mainland and the southern side of the Kval Island. 



And here I must point out that the granite stratum in the 

 Divi Valley appears with its western edge at a height of about 

 188 m. above the sea. The Divi River runs, however, intc 

 the Maals River a* an elevation of about 7S in. above the 

 sea, while the bottom of the Balsfjord is separated from the 

 Maals Valley and thus also from the Divi Valley by a higher 

 mountain ridge in which the deepest bisections, reading towards 

 the Balsfjord, lie at an elevation of about 160 m., i.e. about 

 -S m. higher than the conflux between the Divi and the Maals 

 Rivers. If, therefore, the blocks from the Divi Valley travelled 

 down 1 the bottom of the Balsfjord, they must have done so 

 over passes which lay 7S m. higher than the conflux between 

 the two rivers I Although it might be most natural to assume- 

 that the ice-streams of the Divi Valley followed the bed of the 

 Maals River, the suggestion that an arm from the same might 

 have moved over the higher ridges down to the bottom of the 

 Balsfjord is certainly one which cannot be ignored. Bui, if this 

 was the case, the granite blocks which had been carried from 

 the Divi Valley in this way ought to be found at the bottom 

 of the Balsfjord at a higher elevation than 30 m. above the 

 sea. Whether travelled granite blocks will be found at the 

 bottom of this fjord is a question which cannot be answered, as 

 but little attention has yet been paid to the same. I am, how- 

 ever, of the opinion, from my own investigations, that they arc- 

 totally absent in this place. 



If granite blocks were, on the other hand, carried down into 

 the Balsfjord by this road, they must, judging by the height to 

 which they are found near Tromso, have been carried from thi-. 

 place further by drift ice. The beginning of the transport 

 belongs thus to a period when the real Glacial age was closed, 

 and the continuous ice-layer broken up. In this case it might 

 be assumed that the travelled blocks should be found in large t 

 numbers along the sides of the Balsfjord, and decreasing 

 in numbers from the bottom of the fjord outwards to 



