228 The American Geologist. ApHi. loos 
at the greater depths, owing to glacial or other deposits 
filling the original channels. 
The submarine fjords crossing the continental shelf 
characteristically reach to a depth of 400-500 metres, and in 
the north, the land-bounded fjords inside have a similar but 
only slightly greater depth, while in the south, the inner 
ones are much deeper. Between the inner and outer fjords, 
the channels are often shallowed to within 300 metres of 
the surface of the sea. This 400-500 metre base level is re- 
peated on the ridge between Scotland and Norway and in 
Baffin bay. 
In central Norway, there is a tendency of the fjords to 
follow a combination of longitudinal and transverse val- 
leys. This is regarded as proof that the surface features of 
the country are due to water erosion and not to glacial, 
according to Prof. J. H. L. Vogt. The conclusion that the 
longitudinal ones are due to the erosion of rivers is also 
supported by Dr. H. Reush and Prof. W. C. Brogger. While 
the denuding agents may have obliterated the last traces of 
the folds, Nansen thinks that such tectonic causes brought 
to the surface the layers of the more yielding rocks upon 
which the agents have acted. With this additional expres- 
sion, the author agrees with Vogt that the broad longitu- 
dinal and the narrow transverse valleys owe their origin to 
running water and not to glaciers for "a great ice sheet has 
necessarily a much greater tendency than running water 
to carve valleys along directions radiating from the central 
region or axis of the land," etc. (p. 57). Even the Norwe- 
gian channel, though perhaps primarily determined by 
structure was fashioned by running water and not by 
glaciers, which were "hardly sufificiently dependent on the 
tectonic structure of the underlying ground to form parallel 
valleys" to those of the plateau (p. 62). Along with pre- 
vious writers Nansen considers the Norwegian channel as 
the continuation of the Baltic river draining that basin, 
which originated by tectonic dislocations, in some remote 
period, but whose present outline is due to atmospheric 
erosion (first river, then glacial) and subsequent partial 
filling with drift (p. 63). The breadth of the channel does 
not interfere with the theory endorsed. 
