SOME GLACIAL WASH-PLAINS. 117 



may frequently be found for many yards northward of the 

 frontal lobes. 



The wings or lateral lobes even alone: the ice-contact 

 sometimes aflbrd sand as fine as that found in the southern 

 part of the plain and for the same reason that the stream 

 coursing over the delta was here at its end in deep water. 



Kettle-holes have frequently become the site of small, 

 post-glacial peat deposits, and of fine, loamy sands washed 

 out by rains or borne by the winds from the coarser gravels 

 of kames and plains. These tine sand deposits, since they 

 are usually available without the labor of preparation by 

 sifting, are locally resorted to for masons' supplies. 



CONCLUSIONS. 



From the general studies presented in this paper, the 

 following conclusions have been arrived at by the author : 



1. The wash-plains of southeastern Massachusetts are 

 noticeably arranged in northeast and southwest bands, 

 which correspond to morainal deposits marginal to an ice- 

 lobe retreating across the region immediately west of Cape 

 Cod Bay. 



2. The Providence-Bridgewater line of these deposits 

 presents well-marked submarginal and frontal moraine 

 phases indicating that the marginal portion of the ice-sheet 

 at this stage was in motion. 



3. The alignment of the wash-plains as a whole is 

 indicative of the retreat of the ice as a sheet character- 

 ized by stagnation onl}'^ in isolated blocks and at certain 

 stages of clogging with washed debris in and about its 

 marginal portions. The excessive accumulation of this 

 debris may have given rise to local stagnation in marginal 

 portions of the ice base. 



4. The extraglacial wash deposits assume forms expli- 

 cable as deltas, fans and cones, some of the plains being 



