TUB BENNETTS BROOK PLAIN. 617 



Tlie U])per straluni extended over the whole smftiee of tlie phiin and 

 seems to have l)een de])osited when the river reached this level only in its 

 floods. Following down this plain (1 b t) for more than a mile one is con- 

 fronted by a great escarpment which stretches obliquely across the road 

 from the rock}^ hillside to the river bluff, and rises 80 feet above the lower 

 plain, or 380 feet above the sea, and reaches 400 feet when it rests against 

 the rocks. Seen from the hills across the river, its upper edge is sharply 

 preserved and its horizontally fluted slope is clearly a portion, preserved 

 intact, of the ri\'erward face of a great submerged bank and not a stream- 

 cut scarp. The road rises to the surface of this high plain next to be 

 described. 



THE BENNETTS BROOK PLAIN, OR MORAINE TERRACE. 



The plain stretches far southward into Bernardston and Gill, expanding 

 rapidl}- to more than a mile in width. It is the true high ten-ace or bench 

 (1 s h) of the ]\Iontague Lake. The surface is as level as any river teiTace 

 for more than a half mile back from the edge overhanging the river, and for 

 a long way south A small reef of rock projects above the general surface 

 near its northern end, and the gravel is scooped out in front and along the 

 sides, the grooves running out southward into the common level of the 

 plain exactly as the sands are hollowed out around the pier of a bridge. 

 Shallow, empty watercourses run over its surface and toward the river. 



With these exceptions the plain shows a true level as one rides along 

 the road or crosses it at an}" point going east toward the river, a distance in 

 many places more than a half mile. If, however, one goes westward to the 

 mountain, taking, for instance, the field road to A. Whitehead's, north of the 

 Lily Pond, in about 100 rods flat hollows begin to appear, at first only 

 5 to 6 feet deep and 20 to 30 feet in radius, but growing deeper and closer 

 together until the whole surface is covered by regular kettle-holes about 20 

 feet deep and separated only by narrow ridges which rise everywhere just 

 to tlie level of the plain, and' the road goes up and down as if it were 

 built along the edge of a saw. Farther on the cols between these 

 hollows grow lower, and by degrees the kettle-holes merge into broad, 

 irregular depressions, several of which are occupied by ponds 50 to 75 rods 

 long and about 40 to 50 feet Ijelow the general sm-face. These ponds were 

 almost wholly dried up in the dry time when I examined them, and showed 



