298 K. Pettersen — The Rise and Fall of Continents. 



the actual contact would probably undeceive the careful student, as 

 the merely seeming fault would bear little resemblance, on close 

 examination, to a bona fide fracture ; but it is necessary to remember 

 that our knowledge of the existence of faults usually rests upon more 

 or less probable inference rather than direct observation. 



Many coralline limestone formations are regarded by geologists as 

 ancient reefs, and other limestones more compact may very well 

 have had this origin, for it is well known that on modern reef's much 

 of the rock formed only yesterday, as it were, is exceedingly compact 

 and almost destitute of recognizable organic remains. My knowledge 

 of the stratigraphy of our old reef limestones is too imperfect to 

 enable me to determine whether their relation to the bordering 

 formations is often such as I have sketched above, but it seems very 

 improbable that this relation should not exist in some cases. 



III. — The Slow Secular Eise ok Fall op Continental Masses. 

 By Karl Pettersen, Tromso. 



JOINING a foreign geologist, who was staying here a while last 

 summer on his journey to the North, I followed the old shore- 

 line or sea-level of Bredviken, cut in the solid rock, and extending 

 along the north part of the island of Tromso, near the sound bearing 

 the same name. When, at the end of that line, about Oerendalen, we 

 threw a glance at the low ground beneath, named Skatoeren, this 

 appeared furrowed with a series of natural ditches, stretched hori- 

 zontally and parallel to the present coast. Seen from above, they 

 were marked very sharply and distinctly. This attracted my attention, 

 the more so as I had often been there, and as frequently traversed the 

 plain, without having discovered the fact. "We accordingly went 

 down on the low ground to examine the matter more closely, but 

 it did not appear there so distinctly, as might be supposed when 

 seen from above. But after a more searching examination, we 

 succeeded in detecting a series of more or less distinct and parallel 

 furrows. Our time being limited, however, we could make no closer 

 inquiry for the moment ; but as I considered the matter worth more 

 minute studying, I returned to the place a few days afterwards. 



I did not see furrows this time from above as distinctly as last, 

 owing to a less favourable light, and on the plain itself I now found 

 it very difficult to trace every single furrow. The only way to do 

 so was to fix your eye from above upon a single furrow, then walk 

 down to it, and follow its course across the plain. 



The flat low ground at Skatoeren is, it seems, composed altogether 

 of remains of shells, mixed with sand. It ascends gradually from 

 the present shore for nearly 120 metres up to a height of about 

 10 metres, thus forming the base of a row of hills that rise 

 from its upper side. The plain has, it is evident, extended a great 

 deal farther north. In course of time great washings and slips 

 have taken place in that direction, and thus the plain in our day 

 ends in a steep bank, consisting completely of shell-sand. The 

 subsoil of the lowland, which consists of shells and sand, is over- 



