158 NEW YORK STATE MUSEUM 
aus, DMS eAINCla, Ole) evs, LAS IT GILAVCILAIL, ICI: 
SHEED ROM DAS Ay RIN INGA ins ORAS 
IBC JONSUN el, COON 
Some years ago, a survey of the surface geology of the Albany 
and Berne quadrangles was made by the writer for the State 
Museum. As the field work progressed it became evident that 
the region could not be interpreted in accordance with the gener- 
ally accepted theory of the “retreat” of the last continental ice 
sheet, namely: the gradual melting back of a fairly definite face 
of live ice. Small glacial channels across the southern slopes of 
drumlins first attracted attention; later on, the clean, unmodified sur- 
face of the fluted and drumlinized area of the Helderberg plateau 
north of the Catskills? negatived the assumption that glacial lakes had 
ever existed on its northern slopes, held in by an ice barrier at 
the north, or that ponded waters from the Schoharie valley had 
ever found outlet across these slopes as such an ice front with- 
drew. In an early report of progress (unpublished) the sugges- 
tion was made that: following the late advance of the glacier 
during which the drumlins had been made, a mass of exception- 
ally clean ice (judging from the meager amount of recessional 
drift) had lain stagnant over the plateau and had melted off in 
place. 
As the history of the retreat of the Wisconsin ice sheet from 
eastern New York had never been worked out in detail the 
desirability of a wider knowledge of neighboring fields was 
strongly felt. Both Peet? and Woodworth? in their parallel sur- 
veys of the Hudson and Champlain valleys had, properly, sub- 
ordinated the problems of the recession of the ice to the main 
problem in hand and, though many important observations had 
been made concerning the relations of deposits to the remains 
of the glacier, the preconception of a withdrawing ice front was 
apparently never seriously questioned by either. Therefore, the 
necessity of establishing wider relations which might be expected 
to throw light on the supposedly stagnant ice field over the Hel- 
derberg was the original point of departure for the investigation, 
the results of which are given herewith. 
C7, IRIN, Jo ly Bob Geol Soe, Avil, 28970, TOM, 
* Peet, C. E. Jour. Geol., 12:415-69 and 617-60, 1904. 
> Woodworth, J. B. Ancient Water Levels. N. Y. State Mus. Bul. 84 
