326 LIFE OF THE PLEISTOCENE 



In Allegheny County, at Angelica, on the Genesee River, parts of trees 

 have been observed beneath tough, firm clay, several yards below the surface. 182 

 This is near the margin of the Wisconsin drift sheet and possibly represents 

 either a Sangamon or a Peorian soil horizon. 



Steller 182a recognizes an interglacial interval in his study of the Saratoga 

 Quadrangle. Of this he says: "In the region within which is included the area 

 of the Saratoga Quadrangle the glacial period, or Ice Age, was broken by at 

 least one interglacial epoch. This deduction is made from the fact that the 

 Hudson River in its course across the southeastern spur of the Adirondack 

 Mountains occupies an indubitably geologically recent valley of trench-like 

 form and yet one that is cut in till. " 



Fairchild 183 also recognizes the possibility of a pre-Wisconsin ice invasion 

 of New York, and says: "The accumulating evidence of more than one glacial 

 epoch in New York adds force to the thought that some of the peculiar 

 relief features of the region have been produced by multiplicity of glaciation and 

 glacial drainage. The lowland of St. Lawrence Valley and east of Lake Ontario 

 exhibits many anomalous features which harmonize with this view. " It would 

 seem, therefore, that the presence of a pre-Wisconsin ice sheet, probably 

 Illinoian separated from the later drift sheet (Wisconsin) by an interglacial 

 interval (probably the Sangamon), is clearly indicated in New York State. 



9. NEW ENGLAND STATES 



One or more interglacial intervals are represented in New England. Near 

 Brandon, Vermont, 50 feet below the surface, lignite was found and was said to 

 be covered by a true drift. 183a In Maine, New Hampshire, and Massachusetts 

 the complexity of the glacial deposits has been recognized and an effort has 

 been made to correlate the New England divisions with those of the Mississippi 

 Valley. All of the till sheets, as well as the interglacial intervals, are recog- 

 nized. 184 These are mostly of marine origin and need not be considered here. 



In the Connecticut Valley there are certain phenomena which represent 

 either interglacial intervals or prolonged oscillations of the Wisconsin ice front. 

 Emerson says: 185 In the long cutting of the canal railroad extension near the 

 camp meeting grounds on the north line of Northampton, the interlocking of 

 the till and sand deposits showed clearly that the ice after receding from this 



182 Tomlinson, Amer. Journ, Sci., (i), XXIII, p. 207. 



I8:a Bull. N. Y. State Museum, No. 183, pp. 1-50. Also Bull. No. 45, pp. 1-194. 



183 Bull. N. Y. State Museum, No. 160, p. 18. 



,83a Thompson, Proc. Bost. Soc. Nat. Hist., 1851, pp. 33-34. 



184 Clapp, Bull. Geol. Soc. Amer., XVIII, pp. 505-556. Correlation table opposite page 

 512. References are given to other works on New England glacial deposits. 



186 Holyoke Folio, p. 7. 



