DAVIS: GLACIAL EROSION. 
291 
at accordant grade, and hence the main valleys could not then have 
been cut much deeper than the side valleys are now cut; not so 
deep, indeed, for the side valleys have been somewhat deepened by 
glacial action, if one may judge by their trough-like form as well as 
by the evidence of intense glacial action all over the uplands, even 
over most of the surmounting hills and mountains. Hence, to 
develop the existing discordant valley system from a mature pre¬ 
glacial valley system of normal river erosion, requires a great deep¬ 
ening of the fiords by ice action, again to be measured in thousands 
of feet. Thus there seems to be no escape from the conclusion that 
glacial erosion has profoundly modified Norwegian topography. 
As far as I could judge from my brief excursion over the highlands, 
either one of the two suppositions above considered is permissible, 
provided only that strong glacial erosion comes after the river work 
of the current cycle. 
If the Hardanger fiord may be taken as the type of its many 
fellows, one may say that hanging lateral vallej^s are the rule, not 
the exception, in Norway. Furthermore, the smoothed, spurless 
walls of the larger fiords, composed of firm bare rock from the 
upland to water edge, do not resemble the ravined and buttressed 
sides of normal valleys. The marks of downward water erosion 
are replaced by what seem to be marks of nearly horizontal pluck¬ 
ing and scouring. Blunt-lieaded valleys and corries (botner) both 
seem beyond production by normal weathering and washing. Yet, 
striking as these features are, they do not seem to me so compul¬ 
sory of a belief in strong glacial erosion as the hanging valleys 
that have so little relation to the fiords beneath them, and the 
flaunting waterfalls that descend so visibly from the hanging 
valleys, instead of retiring, as is the habit of falls all over the 
unglaciated parts of the world, into ravines where they are hid to 
sight from most points of view. 
The rocky islands that rise from the shallower parts of the fiords 
should not be taken as signs of feeble glacial erosion, but rather as 
remnants surviving from the destruction of larger masses in virtue 
of some slight excess of resistance. A well-known example of this 
kind is near Odde at the head of the large southern arm (Sorfjord) 
of the upper Hardanger fiord ; but in the same neighborhood are 
several fine hanging valleys, one of which is shown in Plate 3, 
Figure A , its open floor is high above the fiord level; its cascading 
stream, the Strandfos, descends into Sandven Lake, just south of 
the side valley occupied by the well-known Buer glacier. 
