RECESSIONAL ICE BORDERS IN BERKSHIRE, MASS. 325 



as a pocket map with Leverett's second monograph/ With 

 these exceptions, the recessional moraines of Pennsylvania and 

 New York have been recognized in only a few places and in 

 short and scattered fragments. Salisbur}- has mapped a few 

 fragments of recessional moraines which cross northern New 

 Jersey.^ 



Essentiall)' the same statement applies to New England. 

 Emerson has identified a number of positions of the ice-front in 

 central Massachusetts in places where it served as the retaining 

 barrier for temporary glacial lakes or for the building of terraces 

 of sand and gravel. 3 Woodworth has mapped two recessional 

 halts on the western end of Long Island back of the great 

 terminal moraine, and has made out the position of several con- 

 secutive ice-fronts by sand plains in the vicinity of Narragansett 

 Bay."* Grabau has done the same in southeastern Massachusetts 

 in the study of Lake Bouve.^ Crosby has found one or two 

 morainic fragments and the positions of several ice barriers for 

 lakes in northeastern Massachusetts.'' 



While these observations have added much to our knowledge, 

 no considerable consecutive series of halts has been made out 

 through them, nor has the course of the ice-front at any particu- 

 lar halt been traced continuously across the country for scores 



'Frank Leverett, "Glacial Formations and Drainage Features of the Erie 

 and Ohio Basins," Monograph XLI, U. S. Geol. Surv., 1902. 



*R. D. Salisbury, "Glacial Geology," Geol. Stirv. of New Jersey, Vol. V (1902); 

 also, " Pleistocene Formations," New York City Folio, U. S. Geol. Surv., Folio No. S3, 

 1902. 



3B. K. Emerson, "Pleistocene," Holyoke Folio, U. S. Geol. Surv., Folio No. 50, 

 1898; also, "Geology of Old Hampshire County, Massachusetts," Monograph XXTX, 

 U.S. Geol. Surv., 1900; also, " Geology of Eastern Berkshire County, Massachusetts," 

 U. S. Geol. Surv., Bull. No. 159, 1899. 



■»J. B. Woodworth, "The Retreat of the Ice Sheet in the Narragansett Bay 

 Region," Am. Geol., Vol. XVIII (1896), pp. 150-68; also, " Pleistocene Geology of 

 Portions of Nassau of Queens County and Borough," N. Y. State Mus. Bull. No. 48, 

 1901. 



5A. W. Grabau, " Lake Bouve, an Extinct Glacial Lake in the Southern Part of 

 the Boston Basin," Boston Soc. N'at. Hist., Occ. Papers, Vol. IV, Part 3 (1900), pp. 

 601-94. 



^ \V. O. Crosby, "Geological History of the Nashua Valley during the Tertiary 

 and Quaternary Periods," Tech. Quart., Vol. XII (1899), pp. 288-324. 



