246 DHE JOURNAL OF GEOLOG Yz 
much beyond the reach of the greatest river-floods of today. 
Similar evidence of interglacial erosion is met with in many 
other mountain-regions of middle EKEurope—in the Carpathians, 
the Riesengebirge, the Black Forest, the Vosges and central 
France. In the last-named region the evidence shows that dur- 
ing the time that separated two glacial epochs the rivers dug 
out valleys some goo feet in depth. 
Such are some of the facts which have led many observers 
to believe in the periodicity of glacial action. There are several 
other lines of evidence that lead to the same conclusion, but it 
is needless to discuss these here as I have treated them more or 
less fully elsewhere. All that I shall attempt at present is to 
sketch in outline the general succession of glacial and inter- 
glacial horizons which can be more or less clearly made out in 
Europe. To avoid confusion I shall give to each of these hori- 
zons a separate name. 
I. SCANIAN. 
The earliest glacial deposits of northern Europe occur in 
Skane—the old division of southern Sweden—hence the provi- 
sional name I suggest. These indicate the former existence of 
a great Baltic glacier which overflowed the southern part of the 
Scandinavian peninsula from southeast to northwest. No glacial 
deposits have been recognized on this horizon elsewhere in 
northern Europe. It is most probable, however, that the Arctic- 
shell beds of Norfolk known as the Chillesford Clay and Wey- 
bourn Cras belong to this: stage. Wo! the same ihorizonma 
assign the first glacial epoch of which we have evidence in the 
Alpine Lands. At this stage the glaciers of that region filled 
all the mountain-valleys and in many cases deployed upon the 
‘‘Vorlander,’ where their terminal moraines and associated 
fluvio-glacial gravels are still conspicuous. To the same epoch — 
ought probably to be referred the ancient Diluvium of the pla- 
teaux of central France. According to Penck the snow-line in 
the Alpine Lands must have been depressed some 4000 feet 
below its present level. 
