228 GLACIAL GRAVELS OF MAINE. 



lliver past Gray Village to North Gray. At the same time a bay 10 to 

 20 miles wide covered the lower valley of Royal River and extended as 

 far north as Danville Junction. It joined the first-named arm of the sea at 

 North Gray. Thus a large part of Cumberland and Gray at that time 

 formed an island, separated from the mainland by a sheet of water 1 to 5 

 miles wide in northern Gray and in New Gloucester. The southeastern por- 

 tion of the great delta-plain of New Gloucester and Gray passes graduallj' 

 into clay about 1^ miles north of North Gray. The western portion, which 

 partly presents the external features of an osar-plaiu, partl}^ those of reticxi- 

 lated kames, extends southward to within three-fourths of a mile of Gray 

 Village. The southern portion is a plain of gravel, with cobbles and some 

 bowlderets, from one-fourth to three-fourths of a mile wide. It ends in a 

 ■steep bank and is covered at its base by the sedimentary clay. The coarse- 

 ness of the matter composing this plain proves that it was not deposited in 

 the open sea far beyond the ice front. 



The late glacial history of this region must be about as follows: First, 

 a broad plain of coarse gravel, etc., was deposited within an ice channel or 

 series of channels along the western side of the great plains. Near Dry 

 Mills, in the northern part of Gray, this plain of coarse matter does not 

 extend back to the hills, but ends on the west in a rather steep bank. It also 

 forms the barrier which has dammed back the waters of Dry i\:Iills Pond. 



Subsequently the ice melted, and the sea advanced so that the glacial 

 river formed a marine delta east of the original osar-plain. 1 his is the 

 delta not far north of North Gray. Still later the sea advanced up the 

 valley of the west branch of Royal River, and the glacial river flowed 

 into the sea in this valley not far east of Sabbathda}' Pond in New 

 Gloucester. 



South of the great plains of New Gloucester and Gray there are two 

 •discontinuous series. They are provisionall}' classified as delta branches 

 of one system, though it is difficult to determine whether they were 

 contemporaneous. 



The first of the western series is the level plain on which Gray Village 

 is situated. It is separated from the more western plain above described 

 by an interval of more than a mile of marine clay. On the north bowlderets 

 and cobbles abound, but the material grows finer toward the south, and 

 the sand plain ends in marine clay within about three-fourths of a mile. 



