290 GLACIAL GRAVELS OF MAINE. 



where there were large numbers of them they could hardly fail to betray 

 the fact that they were once rounded by water movements and were not 

 fragments of fracture and cleavage. In Maine there are places near the 

 White Mountains where I found till containing numerous water-rolled 

 stones, but in general such matter is veiy small in amount as compared 

 with what was once angular gravel or talus matter. I find in the till no 

 adequate representation of the water-rounded stones of a more ancient 

 glacier. In the terminal moraine near Waldoboro there are few it any 

 such; none were observed. 



11. The Waldoboro terminal moraine is 6 miles long, and is much 

 larger than anything of the kind at Portland. So far as I have yet- discov- 

 ered, it does not prove a readvance of the ice, but can equally well be 

 assumed to have been formed at the ice front during a pause in the retreat. 

 There is still stronger reason for this conclusion in the case of the Portland 

 deposits; yet if it shall be hereafter proved that there was an advance of 

 the ice immediately preceding the time of the formation of this moraine, 

 we still have the small size of these deposits to account for before corre- 

 lating them with the great kettle moraine, or with a retreat and readvance 

 of the ice for hundreds of miles, such as took place in the Northwest. 



Summary. — Two liuBs of reasoulug point toward two possible glaciations 

 of Maine. The first is based upon the finding of two different layers of 

 the till, possibly the till of two different ice periods. No sedimentary or 

 fossiliferous beds have been found between them, and a better interpreta- 

 tion is that they are derived from two different kinds of rock — one local, the 

 other from a distance. The second refers to the finding of till or glacial 

 gravel overlying fossiliferous marine beds. It is certain that the marine 

 beds in Maine overlie a stratum of till most or all of which was subglacial. 

 They therefore were deposited late in the Ice period of that coast, when the 

 ice had receded far back from its extreme limit. Waiving all doubts as to 

 the Portland beds having been caused by landslips, and assuming the most 

 favorable construction, i. e., that there are terminal moraines and other 

 glacial deposits overlying marine sediments, we must consider the signifi- 

 cance of this assumed fact. My interpretation of the facts is that there is 

 no proof that these supposed advances of the ice were for any but very 

 limited times and distances, as is proved by the small size of the deposits 

 and the fact that the glaciation and development of the marine beds vary 



