52 J. D. Dana on the Quartzite, Limestone, ete. 
of the slope (from which the steeper part of the mountain rises) 
is 80 or 90 feet above the Smith farm plain. 
The range of steeply dipping schist, V' (fig. 5), which near 
Glendale has about the same width as V?, is not 50 feet wide 
(between the steeply inclined limestones A', A®*), at its ter- 
mination just north of Smith’s farm (Sm on map) ; which shows 
that the fold V* is pinched out as it nears the mountain. 
rom the above facts we have good grounds for the follow- 
ing additional conclusions. 
III. The limestone of Eastern Alford, of the north end of 
Williamsville valley about Freedley’s quarry, of the Housatonic 
valley, and that of Glendale and Stockbridge all belong to one 
strat Moreover, this same stratum of limestone extends 
from the Freedley quarry region (F Q on the map), at the north 
end of Tom Ball ridge, without break, I believe, north to West 
Stockbridge, three miles distant in the same Williams river 
valley ;* and thence farther north, as I know from observation, 
through Richmond to Pittsfield ; and also south from Alford ito 
Egremont and Canaan. It is evidently one continuous mass. 
IV. While in Monument Mountain there is a single broad 
uplift of the rocks, there are, directly north of it within a mile 
(section in fig. 5), two steep synclinals of mica slate; and this 
mica slate is part of the Monument Mountain formation. = 
V. In the synclinal V? (figure 5) the folded stratum of mica 
‘slate is a little less than 300 feet thick, since the whole breadth 
is 200 yards and the dip nearly vertical; and this directly over- 
lies the limestone. Now near the Old Furnace on the Housa- 
tonic river the thickness of the mica slate over the limestone 18 
only 50 or 60 feet; and this is overlaid in Monument Mount- 
-ain by 200 or 250 feet of quartzite ; and, above this, 300 feet at 
least of mica schist and gneiss; and then higher up another 
thick stratum of quartzite. Therefore, in the short distance of 
a mile and a half, the lower quartzite of Monument Mountain, 
-¢, 200 to 250 feet thick, has wholly disappeared, and inst 
of it there is mica slate. This quartzite, to the northward, even 
before reaching the line of the Old Fnrnace, is mostly well 
bedded, and although mainly concealed by soil; shows evidence 
of thinning in that direction. 
VI. In the section in fig. 5, at its west end, the quartzite of 
Monument Mountain, g', overlying the schist and limestone 
mear the Old Furnace, would naturally be looked for in the 
rocks of the Tom Ball ridge above the limestone. But it does 
not exist in any part of the slopes, nor does it outcrop to the 
south, except at the southern end of the ridge. Hence again 
= » map the roads terminating at W S lead to the village of West Stock- 
bridge, and that at C to the village of West Stockbridge Center, west of the West 
Stockbridge ridge. 
