literature of the subject 507 



Introduction^ 



While in the central United States and in Europe the existence of sev- 

 eral distinct stages of Pleistocene glaciation separated by interglacial 

 stages has long been recognized, there has been until recently a prevailing 

 belief among geologists that New England was unlike the other northern 

 states, and that it was subjected to but one ice advance and retreat, which 

 has commonly been correlated with the Wisconsin glaciation of the Missis- 

 sippi valley. 



The first suggestion of tlie possible complexity of the Glacial period 

 came in 1889,* when Shaler published the probability that southern New 

 England at least has been subjected to two ice-advances, separated by a 

 retreat of considerable duration. His conclusions were liased on the 

 relations of glacial and interglacial beds at Marthas Vineyard and Nan- 

 tucket. In 189G Woodworthf published a description of the clays of 

 southeastern Massachusetts, in which he recognized three glacial stages 

 in southern New England and postulated interglacial stages of consider- 

 able duration at least as far north as Boston. 



In 1905 Fuller continued the correlations previously established on 

 Long island. New York, along the shores of cape Cod, in eastern Massa- 

 chusetts, and nearly as far north as Boston. J 



The present paper is an account of scattering observations in north- 

 eastern Massachusetts, south.eastern New Hampshire, and southern Maine 

 pointing to a similar succession of invasion and drifts in that part of New 

 England. 



Litei!atl'i;e coxcekxing Evidexces of glacial Cojiplexity 



From time to time during the past 50 years, and especially during the 

 past 10 years, papers have appeared by various writers describing appar- 

 ently old till underlying stratified and sometimes fossiliferous deposits in 

 that portion of New England situated northeast of Boston. Most writers 

 believed, however, that the occurrences noted were due merely to brief 

 local retreat^ and advances of the ice-sheet, and not to any definite inter- 

 glacial stage. 



The earliest reference to interglacial beds appears to be that of Stimp- 

 son,. who in 1854§ enumerated 14- species of fossils found in a bed of 



* N. S. Slialer : The geology of Nantucket. BulL no. 53, U. S. Geological Survey. 



t J. B. Woodworth : The glacial brick clays of Rhode Island and southeastern Massa- 

 chusetts. Geology and geography of the clays. Seventeenth Ann. Rept. U. S. Geological 

 Survey, part i, pp. 97.5-988. 



t M. L. Fuller : Bull. no. 285, U. S. Geological Survey, 1906, pp. 4.32-1.33 ; and "Gla- 

 cial stages in southeastern New England and vicinity." Science, new series, vol. ixlv, 

 1906. pp. 467-469. 



§ I'roc. Boston Soc. Nat. Hist., vol. iv, pp. 9-10. 



