216 GLACIAL GRAVELS OF MAINE. 



deposited by g-lacial streams in the sea over the marine clays. Tliis can be 

 established only by excavations reaching' below the beach g-ravels. 



In Portland and Cape Elizabeth the gravels of this system are suspi- 

 ciously near those of the great Androscoggin Lakes-Portland system. No 

 connection is yet proven between them, and they are therefore classified as 

 distinct systems, l^he stones of this series are in general well rounded, 

 though not so much worn as in many of the longer systems. 



The length of the system is 18 miles. 



ANDROSCOGGIN LAKES-PORTLAND SYSTEM. 



This is a large and important discontinuous system of peculiar type 

 and affording many interesting problems for investigation. For convenience 

 it will be referred to as the Portland system. 



The course of the Androscoggin River is circuitous. Its head waters 

 flow west into New Hampshire, and this part of its valley is a gently roll- 

 ing plain from 5 to 20 miles wide. In this plain is situated a series of large 

 lakes, which may be termed the Androscoggin Lakes. From Gorham, New 

 Hampshire, the river turns eastward into Maine again, and this part of its 

 valley is bordered on each side by high hills, which thus separate it from 

 the vallej^ of the upper Androscoggin as well as from the valleys of Crooked 

 River, the Little Androscoggin, and other streams flowing southward. From 

 the region of the Androscoggin Lakes several low passes lead through the 

 high hills, one southeastward from Umbagog Lake along the valley of the 

 west branch of the Ellis River, and another from Lake Molechunkemunk 

 southward down the Swift River. I have not explored these passes. The 

 valleys of both the streams just mentioned contain much alluvium, which 

 may wholly or in part be an osar-plain or frontal plain. A third pass leads 

 from Rangely Lake southeastward down the valley of Sandy River. The 

 highest part of the pass is 205 feet by aneroid above Rangely Lake. I 

 could find no g'lacial gravel along this pass. The lowest of all the passes 

 leads from Lake Welokennebacook southward along Black Brook to 

 Andover. This I will name the Black Brook Pass. 



An interrupted gravel ridge begins on the west shore of Lake Moose- 

 lookmeguntic and follows that shore to the outlet of the lake (here running 

 east and west), when it crosses to the south shore and thence follows the 

 east shore of Lake Welokennebacook for some miles, when it appears to 



