62 SURFACE GEOLOGY. 
appear to have been formed at the disappearance of the ice-sheet, princi- 
pally consisting of material contained in its mass and set free at its melt- 
ing. Their origin was like that of the finer alluvium of the lowland 
valleys; and their date was at the end of the long period in which nearly 
all our deposits of this kind were formed. 
Modified drift of similar character occurs upon the South Branch. At 
the Crawford house, where several mountain torrents fall into the valley 
and form this stream, a great depth of very coarse stratified detritus has 
been brought down. This superficial deposit forms the water-shed be- 
tween the Connecticut and the Saco, carrying it a third of a mile north- 
west from the rocky summit of the pass, which is at the gate of the 
Notch. 
A well marked series of kames, or ridges of very coarse gravel, extends 
along the South Branch from about a mile north of the Crawford house 
nearly to its mouth. It appears again on the north-east side of the Am- 
monoosuc, between the mouth of this branch and the Fabyan house. 
Here it forms a single steep, narrow ridge, from 30 to 4o feet high, 
around which the river passes in a long southward bend. This ridge is 
conspicuously seen from the railroads on the opposite side. The mound 
known as the “Giant’s grave,” which was levelled down for the site of the 
Fabyan house, was a similar ridge about 300 feet long. This was noticed 
by Sir Charles Lyell, in his journey through the White mountains, who 
says it presented “the same appearance as those mounds which are 
termed ‘osar’ in Sweden.”* Other deposits of the same kind lie between 
this place and the White Mountain house, at the north edge of the allu- 
vial area. This series of kames appears to have been formed by a glacial 
river, which was fed from the melting ice-fields of the Mt. Washington 
and Mt. Willey ranges. Similar kames, which were also formed by 
glacial streams tributary to the Ammonoosuc valley, are seen along the 
Cherry Mountain road south from its summit. 
That the ice of this area, near the end of the glacial period, moved west- 
erly down this valley, is shown by abundant morainic boulders, which 
have been transported from Mt. Deception to the Twin Mountain house, 
where the glacier seems to have paused after its retreat from the lowlands 
and the valley below. The kames which we have described mark its 
* Lyell’s Second Visit to the United States. 
