342 J. D. Dana—Helderberg rocks in the Connecticut Valley. 
Directly west of the village (B) rises the ridge called West 
Mountain (W); the locality is on the eastern slope of a lo 
part of this ridge, north of the higher portion.* 
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The rock of West Mountain and of its continuation to the 
orth is clay-slate, it being part of the great slate formation 
of Eastern Vermont, quarried in several places for roofing slate. 
The Helderberg beds overlie the slate. 
itchcock’s section in the Vermont Report gives the order 
of succession. Another is here annexed. ‘There is, first, %& 
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the upper member (though near the foot of the slope), @ greys 
black mica slate (1); below this (higher up the slope), te bed 
slate. The strike of the beds, along a line from the foot o ri 
slope up to the limestone, is about N. 45°-50° E.,f with et 
30° to 35°; the dip of the limestone at the quarry 18 wit a 15°, 
and, higher on the hill, that of the lower quartzite is 10° to 10» 
re ite) 
* The locality is on the land of Mr. Williams. After passing his house (whit) 
take the path leading up the hill back of the northern end of the a: : 
Tock encountered is the slate of the Helderberg series; then quartz re found 
after ascending about 150 feet, the limestone. The Crinoidal remains a nings- 
on the weathered surfaces of blocks quarried out from the more woe ts 
OUP er ag course, as elsewhere. The variation of the compass !* 
estward, 
