RELATIONS OF GRAVEL DEPOSITS IN THE NORTH- 

 ERN PART OF GLACIAL LAKE CHARLES, MASSA- 

 CHUSETTS. 



INTRODUCTION. 



Among the most impressive features of the glacial deposits in 

 eastern Massachusetts is the great abundance of sandplains, which 

 occur by scores in all the large valleys. The characteristic flat sur- 

 faces, lobate fronts, steep or kettled ice- contact slopes, and tributary 

 eskers testify to the formation of the plains as deltas in glacial lakes, 

 through transportation of the sand and gravel from the ice in which 

 it was incorporated by powerful glacial streams flowing either upon 

 or beneath the ice, and deposition in standing water along the glacier 

 front. In association with the true sandplains are areas of kames, 

 eskers, and other irregular deposits varying from mere patches of 

 gravel to tracts several square miles in extent. At intervals during 

 a period of two or three years the writer has had opportunity to study 

 in detail the sands and gravels within a certain limited area, and 

 takes this opportunity to give a few of his results, hoping they may 

 throw some additional light upon the glacial-lacustrine history of the 

 region. . 



LAKE CHARLES. 



Lake Charles is the name given to the lake, or series of lakelets, 

 which occupied the valley of the Charles River during the decay of 

 the latest or Wisconsin ice-sheet.^ The region drained by the river 

 embraces portions of the counties of Suffolk, Norfolk, Worcester, and 

 Middlesex, and is covered by the Boston, Framingham, Dedham, 

 Franklin, and Blackstone topographic sheets. All portions of the 

 valley are crowded by thick deposits of sand and gravel, among which 

 fiat sandplains are conspicuous, wave-cut shore lines have been occa- 

 sionally noted, and on the east and south sides of the basin a num- 



^W. O. Crosby and A. W. Grabau, American Geologist, Vol. XVII (1896), 

 No. 2, pp. 128-30; F. G. Clapp, "Geological History of the Charles River," Techno- 

 logical Quarterly, Vol. XIV (1901), No. 3, pp. 171-201; No. 4, pp. 255-69; and Ameri- 

 can Geologist, Vol. XXIX (1902), pp. 218-33. 



