Drift of the North German Lowland.— Salisbury. 311 
topography of the latter, and while it is locally a very conspicu- 
ous feature because of its sharp definition and wall-like character, 
it is quantitatively rather insignificant compared with the great 
ridge characterized by the ‘‘ground moraine landscape.” The 
‘‘oround moraine landscape” topography is generally best de- 
veloped immediately within this terminal moraine (Hudmordne). 
Outside the same, there are extensive areas of sand and gravel 
(overwash plains), whose surfaces show little relief. 
This diminutive ridge, to which, and to which only, the name 
terminal moraine is applied by the north German geologists, has 
no exact counterpart, so far as I know, in the United States. It 
is explained by supposing that the ice, in its retreat northward 
remained stationary for a somewhat protracted period in the posi- 
tion which the little ridge now occupies. It is believed to have 
been constructed out of ground moraine material, from which the 
finer parts were removed by the waters arising from the melting 
of the ice. The interlardings of till and stratified sand are ex- 
plained by supposing oscillations of the ice margin. When the 
ice overrode the incipient ridge. it is supposed to have left a 
record of its transgression in a bed of till. When the ice re- 
treated, discovering the growing bowlder wall, this retreat is sup- 
posed to be recorded in the beds of stratified sand and gravel 
which sometimes occur between the coarser materials of the 
moraine. ‘This terminal moraine (Ludmordne) has not been traced 
throughout its whole extent. It has been traced for considerable 
distances in the region north of Berlin, and is known at various 
points east and west of that region. By Dr. Wahnschatfe it is 
not regardedas marking the limit of ice advance in the last glacial 
epoch. So far as I am aware, it is not known except in connec- 
tion with the ‘‘ground moraine landscape” topography, though 
the universality of this relationship is not indicated by our author. 
Bowlder Belts. The bowlder belts into which the German term- 
inal moraine sometimes passes are identical in character with the 
bowlder belts of the United States. The American bowlder belts 
are believed to be accumulations of bowlders which were carried 
forward within the body of the ice (considerably above its base), 
and to have arrived at the surface of the ice before they reached 
its terminus, because of surface ablation. ‘Transferred thus from 
an englacial to a superglacial position, they were carried forward 
upon the surface of the ice to its edge, andthere ‘‘dumped” upon 
