142 GLACIAL GEAVELS OF MAINE. 



the clays of the valley of Martin Stream in Pljanouth and Dixmont must 

 be considered as probably having- been deposited above the highest level of 

 the sea, and therefore in a lake contained between the ice which was still 

 unmelted toward the north and the high east-and-west hills of Troy and 

 Dixmont on the south. If so, where did the supposed lake ovei'flow? 

 There are two low passes by which the water of such a lake could have 

 escaped southwestward into the Sandy Stream Valley in Thorndike, after 

 the waters had accumulated to a depth of about 100 feet, provided no 

 barrier of ice then existed in that direction. But no clays analogous in any 

 way to those of the Martin Stream in Dixmont are found along these val- 

 leys, and hence there is no proof of an overflow this way; neither do I 

 find proof of such overflow westward into Troy. The order of events 

 here is probably about as follows: The Corinna-Dixmont glacial river 

 emptied for a time into an enlarging- glacial lake, inclosed between the ice 

 and the high hills on the east and south. The outlet of this lake was 

 toward the Penobscot Bay or in some unknown direction. During the 

 retreat of the ice the glacial water may have escaped into the open valley 

 of Martin Stream at or near Plymouth Village, but if so it could have been 

 for only a short time. The gravel plain at the north base of the hill 

 situated just north of Plymouth Village may point to another glacial lake, 

 formed north of that hill, and the clay bordering the osar northward to 

 East Newport may have been- deposited by a broad channel which jjracti- 

 cally formed an enlargement of this lake. There are plains of sedimentary 

 clay in Plymouth extending an unknown distance northeastward toward 

 Etna Bog, and these may mai"k an overflow to the Penobscot Bay. How 

 far this is marine remains to be determined by future investigation. 

 The length is about 20 miles.-' 



EAST TROY KAMES. 



About 3 miles southwest from the delta-plain in which the Corinna- 

 Dixmont system ends, a discontinuous series of short ridges and cones of 

 glacial gravel begins on the hills north of Martin Stream, crosses the valley 

 of that stream near East Troy, and then ascends the hills lying to the south 

 to a height of about 100 feet. It appears to end in a thin gravel plain a 

 little north of a low pass leading into Jackson. Not far north of where the 



' The clays estendiug from Dixmont eastward are now (1893) considered by me to be marine. 



