REPORT OF THE DIRECTOR, 1922 161 
It is doubtful if there is an unequivocal frontal-recessional 
moraine which is at the same time an ice-built dump marking a 
halt in the retreat of a still moving ice sheet, through the whole 
length of the Hudson and Champlain valleys. he short sections 
west of the Palisades which have been identified as such by com- 
petent observers are the most difficult to explain. They are com- 
monly weak belts from one to three miles in length, incapable 
of correlation with each other, with a proglacial topography 
assumed to have been recently uncovered by the ice, and with 
the demands of the drainage. Where not open to a different 
interpretation, they appear to represent either localized stream- 
ing through the otherwise stagnant glacier, or the results of that 
type of motion in a large, isolated body of ice mentioned by 
Salisbury in the Glacial Geology of New Jersey (page 86). More- 
over there are several ways in which transverse belts of drift 
may be formed on the surface of glacial ice and such superglacial 
accumulations may have been let down upon the land from a 
stagnated mass without wholly destroying their character and 
continuity. Every transverse belt of till 1s not necessarily a 
frontal moraine. | 
The term moraine as originally used indicated nothing more 
definite than the glacial origin of the drift as opposed to theories 
of “ waves of translation” and so forth; it was used to define any 
recognizable accumulation of drift and should be so used today. 
However, the preconception of an ice wall retreating reluctantly 
under the influence of a warming climate was strong, and when 
the water-built forms were separated and given special designa- 
tions, whatever was left to fill out the concept “ moraine” 
appears to have been tacitly accepted as something built by ice 
and water at the margin of the glacier, “ the glacier”? meaning 
the still moving body of ice thrusting southward under pressure 
from an indefinite distance behind it. And evidence of the pres- 
ence of ice during deposition appears to have been taken as proof 
of the edge of a still active glacier, even where the stagnant con- 
dition of the ice masses is quite clear. All the buried blocks 
which had given rise to kettle depressions were regarded as frag- 
ments broken from the face wall of the receding glacier and con- 
veniently inhumed, the drainage being diverted in time to prevent 
the obliteration of the pits by further sedimentation as the blocks 
melted. 
