1G2 GLACIAL GEAVBLS OF MAINE. 



flows southward. In tlie southeast part of the plain the gravel is deeper 

 and has been eroded considerably by boiling- springs. A ravine 10 feet 

 deep has been eroded back into the plain for one-fourth of a mile or more. 

 In many places this delta-plain is overlain to the depth of 1 to 3 feet with 

 marine clay. From this point southward the system is discontinuous and 

 consists of short ridges, lenticular mounds, and round-topped plains, except 

 a delta-plain at its south end. The gravels are separated by intervals of 

 from one-eighth to one-half of a mile, generally the shorter distance. It is 

 sjDecially noticeable in case of the southern part of this system that the 

 gravels appear on the tops of low hills or at the brow of broad hills, while 

 the lowlands show little or no gravel. The series crosses Medomac Pond, 

 and thence its course is easily followed along the road from North Waldo- 

 boro to Warren. At the western edge of the valley of the Warren ponds 

 the system divides into two series. One crosses to the east side of the 

 valley at once, the other follows the eastern brow of the hills which border 

 this valley on the west. In a mile or two this series also crosses to the east 

 side of the valley, and then takes a course nearly, parallel with the other 

 series. They pass southward, and not far southeast of Warren station they 

 end in sand plains. For the last mile or two they are quite continuous and 

 form plains one-eighth to one-fourth mile wide, and hence resemble the 

 parallel plains of Liberty and Appleton. Their shapes and their situation 

 on the tops of hills prove that they were deposited within ice walls, or the 

 gravel would have spread out into broad fan-shaped plains. The discon- 

 tinuous portion of this system — that part where gaps form a constant 

 feature of the system, not an occasional gap on a steep down slope — is 

 noticeable for the large amount of gravel which it contains, the lenticular 

 plains which cap the hills being larger than the average. In the valley of 

 Georges River and the Medomac above Waldoboro the gravels are in or 

 near the lowest parts of the valley. But in general this system seems to 

 delight in the highest ground that lies in its course, leaving the low valleys 

 for the gaps. 



Two or three short tributaries entered the main glacial river near 

 Sheepscot Great Pond. They drained the large Palermo cirque. Their 

 gravels are but little water polished, and they are evidently only short 

 branches of the main system. 



Length from Palermo to Warren, 23 miles. 



