"J^ SURFACE GEOLOGY. 



river, the lowest being interval. West of Hill village an expanse three 

 fourths of a mile long and a half mile wide is divided, by escarpments 15 

 and 20 feet in height, into three distinct terraces, the highest of which is 

 410 feet above the sea. A small terrace, 80 feet higher, is found on its 

 west side. The highest terraces west of the river, well shown much of 

 the way between Hill and Franklin, are from 40 to 60 feet below those 

 on the east. This difference seems to be due to a deficiency in the 

 amount of material supplied, the deposition being influenced by the cur- 

 rent, and attaining its full height only on one side. 



Karnes. A short gravel ridge, projecting five feet above the plain of 

 which it forms the border, and containing pebbles six inches in diameter, 

 was seen in the north part of Franklin, on the west side of the road at 

 one mile south from Hill village. Another gravel ridge, about 20 rods 

 long and 35 feet above the plain on the west edge of which it occurs, was 

 seen in Sanbornton near the river, a mile and a quarter south-east from 

 the last. Both these short ridges are of typical kame gravel; they lie 

 nearly in the middle of the valley, and their heights are about the same, 

 the northern being 385 and the southern 365 feet above the sea. It is 

 not improbable that these are remnants of a formerly continuous kame. 



This coarse gravel was next observed at a railroad cut on Bristol 

 Branch, one mile above Franklin depot ; an excavation of it may be seen 

 in Franklin village, just north of Webster brook, at the west side of the 

 street ; and it is again exposed in the same way a short distance south of 

 the depot. It also forms a ridge, nearly covered by the fine alluvium of 

 the upper terrace, on the east side of the river, one fourth of a mile above 

 the bridge. Southward in this town kames were noted at two places on 

 the west side. 



At Boscawcn village portions of a well marked kame form the escarp- 

 ment of the plain, which has about the same height, near the north end 

 of the street and south from the road to the bridge. One mile farther 

 south we find between the highway and the railroad a ridge several hun- 

 dred feet long, the north part of which is composed of coarse water-worn 

 gravel, while its southern portion seems to be unmodified till. 



The ancient highest flood-plain of the Merrimack from Franklin to 

 Massachusetts line is everywhere well shown by the conspicuous upper 

 terraces. Along much of the way these expand on one or both sides into 



