BRA VATS ON LINES OF FORMER SEA-LEVEL IN FINMARK. 543 



where, indeed, the escarpment is singularly characteristic, and 

 identical with that now presented by the rocks below, while the 

 interval between this line and the actual sea level is covered with 

 large pebbles. 



Similar appearances may also be noted in the Komagfjord and 

 in the Kypfjord, where the indentation produced in the coast by 

 the sea is very distinct, and the appearance of a projecting bank is 

 manifest to the eye ; and a marked tendency to the formation of 

 new banks of this kind may be observed in those spots where the 

 sea still washes at the foot of terraces formed at an earlier period. 

 This latter phenomenon is clearly seen at Sandfald and Hammer- 

 fest, and at the mouth of the little stream which empties itself at 

 the bottom of Rypf jord. A like coincidence between the appear- 

 ance of new and ancient lines of this kind has been observed by 

 Mr. Keilhau in the province of Drontheim *, and it thus appears 

 that we must look chiefly on the flanks of the terraces for those 

 marks, by which to determine the existence of elevations posterior 

 to the first. 



The other causes referred to by Mr. Darwin must not be for- 

 gotten. The conservative influence of vegetation on banks thus 

 formed must certainly be taken into account in explaining the 

 perfect condition of the slope of the great terrace of Sandfald, be- 

 tween the Kongshavensfjeld and Elvebakken, and the steepness of 

 the slope, although a secondary consideration, certainly ought to 

 exclude from this category the cases in which this inclination is 

 very inconsiderable and does not amount to more than 8° or 10°. 



A far more influential cause than the latter is the nature of the 

 rock itself, its tendency to decomposition, and the manner in which 

 its beds or lamina? are presented to the erosive action of the waves. 

 It must, indeed, be clear that the position in which stratified rocks 

 are placed with respect to the waves will have great influence on 

 the effect produced, and that a rock little affected by atmospheric 

 exposure, but readily worn away by the action of the waves, will 

 long retain the marks of erosion, while if the conditions are dif- 

 ferent the result will be greatly different. 



The mountains of Alten-f jord and of all this part of the coast be- 

 long to the group of metamorphic rocks, but the nature of the rock 

 differs widely, since calcareous beds are found at Storvignses and 

 at Talvig, between Korsnses and Skillif jord ; amphibolic rocks on 

 the island of Seiland and near Hammerfest ; while diallage, quartz - 

 ose sandstones, and argillaceous schists are not rare. I have not 

 myself been able to judge of the relative influence of these rocks 

 on the different phenomena of the neighbourhood. 



The last cause noticed by Mr. Darwin is the situation of the line 

 relatively to the surrounding coast lines ; and that geologist has 

 concluded, from the examination of these lines at Lochaber, that 

 an inland situation is favourable to the formation of the banks. 

 According to this view, we ought rather to find indications of them 



* Nyt Magazin for Naturvidenskaberne, vol. xi. p. 54. 

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