190 GLACIAL GRAVELS OF MAINE. 



water showed in this ravine at the time of my exploration. The hill slopes 

 outward in all directions, and it does not seem possible there donld be so 

 large an amount of erosion in such a position by either surface waters, 

 boiling springs, or frost damming. The ravine is in places 10 feet deep, 

 and on the lower slopes of the hill no gravel could be found that appeared 

 to have come from this ravine. There is therefore no proof that the shape 

 of the dej)Osit has been materially changed since its original deposition. 



South of this gravel plain in Monmouth is a rather level country show- 

 ing only very low hills. At intervals of about a half mile there are two 

 other slightly round-topped deposits of nearly the same size as that near 

 the lake. Both of them are also divided into nearly equal parts by north- 

 and-south ravines. Seen from the high hills of southern Monmouth, these 

 three ravines appear to be arranged in a nearly straight line. In neither 

 case is there any pointed hill or rock in a line with these ravines, and there 

 is no feature of the ground surface which accounts for them. The gravel 

 and cobbles of all three of these plains are well rounded, and they all 

 contain coarser matter toward the northern and central parts of the plains. 

 They all are imperfect deltas of some sort. The more northern plain is 

 situated at an elevation of about 275 feet, and the gravel plainly does not 

 pass by degrees into the marine clays. It must have been formed where 

 the glacial stream was only partially checked, since it contains fine gravel 

 and coarse sand to the edge, where it ends abi'uptly. This indicates that 

 a glacial river here flowed into a broad pool within the ice. The two more 

 southern of these plains are situated in the midst of the marine clay, yet 

 the transition from the plain of sand to the clay is ver}^ rapid. The current 

 here was more fully stopped than at the northern plain. It is uncertain 

 whether these latter are marine deltas or deltas of glacial lakes. Even if 

 the glacial river here flowed into the sea, it seems to have been confined 

 between ice walls at the sides. The ravines, on this theory, were formed 

 in front of where the glacial torrent shot into the stiller water, the gravel 

 which was carried along by it, so long as it was confined within a narrow 

 ice channel, being thrown out at each side as it entered the broader water- 

 way. The ravines are the channels of the rivers. 



No gravel is found for about one-third of a mile as we continue to go 

 southward, and then we come to a very large mass, on which a cemetery 

 is situated. In addition to sand and gravel, it contains great numbers of 



