THE 



JOURNAL OF GEOLOGY 



MAY- JUNE, igoj 



THE CORRELATION AND RECONSTRUCTION OF 

 RECESSIONAL ICE BORDERS IN BERKSHIRE 

 COUNTY, MASSACHUSETTS.' 



PRELIMINARY STATEMENT. 



The studies which form the basis of this paper were made 

 chiefly in connection with the mapping of the surficial geology of 

 the Housatonic quadrangle, which comprises the southern two- 

 thirds of Berkshire county and lies mainly in western Massa- 

 chusetts, but partly also in New York and Connecticut. The 

 southern half of the Taconic quadrangle, comprising the north- 

 ern third of Berkshire county and an equal area in New York, is 

 also included. This presentation of some of the results is offered 

 by permission of Professor T. C. Chamberlin, under whose 

 direction the studies were made. 



One of the most important things brought out by the study 

 of this area relates to the retreat of the ice-sheet, or, rather, to 

 the retreat of its frontal edge or margin, across Berkshire county. 

 As is well known from the extensive studies of Chamberlin,^ 

 Leverett,3 and others in the states west of New York, the retreat 



' An abstract of this paper was presented before Section E of the A. A. A. S. at 

 Washington, January 2, 1903. 



^T. C. Chamberlin, "Preliminary Paper on the Terminal Moraine of the 

 Second Glacial Epoch," Third Ann. Rep. U. S. Geol. Sttrv., 1883. 



3 Frank Leverett, "The Illinois Glacial Lobe," Monograph XXXVIII, U. S. 

 Geol. Surv., 1899. 

 Vol. XI, No. 4. 323 



