THE 
AME RICAN GEOLOGIST. 
Vol, XV. MAY, 1895. No. 5. 
CLIMATIC CONDITIONS SHOWN BY NORTH AMER- 
ICAN INTERGLACIAL DEPOSITS.* 
By Warren Upham, Cleveland, Ohio. 
(Plate X.) 
CONTENTS. 
Fluctuations of the borders of the Ice-sheet during both its growth and decline 273 
Early interglacial lignite on the Missinaibi and Kenogami rivers 275 
Records of the Drift chiefly limited to the culmination and departure of the Ice- 
sheet 276 
Boreal and Arctic species probably characteristic of interglacial deposits during 
the epoch of general ice accumulation 276 
Temperate species of interglacial deposits during the epoch of ice departure 277 
Minnesota and Iowa 279 
Northwestern Illinois 283 
Southern Illinois, Indiana, and Ohio 284 
Toronto and Scarboro, Ontario 285 
New England and New Brunswick 291 
Division of the Glacial period in the Glacial and Chaniplain epochs 293 
Periods and Epochs of Quaternary time 294 
Epochs and Stages of the Glacial period 29s 
Fluctuations of the Bordeus of the Ice-sheet duking 
BOTH ITS Growth and Decline, 
Within moderate limits the snow accumulation producing 
and maintaining the Pleistocene ice-sheet in North America 
is known to have fluctuated, now relinquishing and again re- 
claiming certain marginal tracts, as shown by fossiliferous 
beds intercalated between deposits of till. Both the time of 
general growth and the time of general decline of the ice- 
sheet were undoubtedly diversified by these oscillations. 
Stages of the recession, as indicated by the series of great 
glacial lakes on the northern borders of the United States, are 
shown in Plate X, Interglacial beds, enclosing fossils and 
*Rt'ail before tlie (ifologiciil Societv nf Americii at tin- Jiailimore 
meeliiig, Dec. 28, 1804. 
