406 J. D. Dana—Taconie Rocks and Stratigraphy. 
nearly east-and-west, and the dip southward; but this is true 
also of the schist, so that the conformability continues. This is 
true also to the north, as the T-shaped symbols on the map 
point out. 
Abreast of North Adams, the dip of the limestone and schist 
is as given in section 48, the dip being eastward ; and between 
this point and the locality of section 7“ the dip varies to verti- 
cal and thence to westward as in that section. The facts make 
Greylock a broad tray-like synclinal at the south. 
The synclinal character of the Greylock mass is manifest 
also from its high limestone basement which it has on both 
sides (except for half a mile, in the line of the range, between 
N. Adams and Williamstown), that is all the way from south 
of the Hopper, northward to within a short distance of the 
Notch road, nearly south of Braytonyille ; and then abreast of 
Adams for about three miles, the limestone has this great height 
above the valley, like a high substructure of 400 to 500 feet ; 
southeast of Blackinton, by aneroid nearly 500 feet. The 
lower 400 to 500 feet of the Hoosac valley consequently were 
cut down through limestone. The upper hmitof the limestone 
is, consequently, about 1150 feet above the sea-level; and this 
is nearly one-third of the whole altitude of Greylock—2, 505 
feet. The high limestone basement of Greylock in N. W. 
Massachusetts has its counterpart in the similar high basement 
of Mt. Washington in 8. W. Massachusetts, and that of Mt. 
Anthony in Bennington, Vt. 
Section 49 crosses the road on Stone Hill, Wilhamstown, 
where the limestone and quartzyte outcrop together. The lime- 
stone, quartzyte (the chief rock of the hill) and the black 
siliceous slate conform in angle of dip along the surface with 
only short intervals between the outcrops. Whether there is a 
fault or not between the limestone and quartzyte I found no 
49. Across part of Stone Hil, S. of Williamstown. 
section for determining. Deer Hill, south of Stone Hill, con- 
sists of arenaceous or quartzytic mica schist. Bald Mountain, 
between Williamstown and Clarkesburgh, is of quartzyte with 
some schist, as described by Emmons; and a prolongation of it 
appears to ‘extend south of Braytonville into the north end of 
the Greylock mass, along the ascending road (but chiefly on its 
eastern side) for a ‘mile. 
Section 50. At the northwest base of Mt. Anthony, in Ben- 
nington, Vermont. At the eastern base I found the lime- 
stone and schist to dip westward corresponding in position 
* The letter Q, which should be here on the map, is by oversight omitted. 
