50 J. D. Dana on the Quartaite, Limestone, ete., 
uninterruptedly through the eastern valley of Alford and be- 
yond, nearly encircling the mountain. Tom Ball ridge is thus 
cut off completely from the West Stockbridge ridge, half a mile 
of nearly level land, with outcropping limestone, intervening 
between their bases 
The limestone in he northern Perk of the Alford valley has 
generally a strike of N. 10 to 20° EH: (but at one place N. 8° W.), 
and an saat dip of 45° to 50°; ; at the Churchill marble 
quarry (CQ, map), a north and south strike, with a dip of 90°, 
but a hundred yards north the dip diminishes to 40° to the east- 
ward, and 300 south, to 30° and 35°; near Alford village, at one 
place the strike is N. 25° E. ; at the south end of the valley N. 2° 
to 5° EK. (but at one place N. 20° E.), the dip mostly 50 to 70°, 
0° 
Heaths varying to 90°. The variations are such as occur in all 
the limestone regions, but less than usual, owing to the high 
inclination of the beds. a Churchill’s marble quarry there is 
no division of the rock into layers through a thickness of 50 
feet, while at the quarries north and south of it above referred 
to, where the dip is 80° to 40°, the layers are 1 to 6 or 8 a 
thick. The great thickness at Churchill’s quarry is owing to 
the soldering of many layers together, which took place at the 
time of metamorphism under the pressure producing the uplift 
and accompanying the crystallization. Such an obliteration of 
the layers when the dip is high is common throughout the 
limestone region of the Green Mountains. 
wo important conclusions may be here stated. 
I. The limestone of the Housatonic fold, A’ in the sections, 
is the same stratum with that of the northern part of the 
Williamsville valley and that of Eastern Alford. 
II. This limestone passes beneath the Tom Ball ridge, and 
the rock of this ridge is, therefore, an overlying stratum, and has 
a synclinal position. 
c. The section in figure 5 extends eastward to Glendale. 
The mica slate V?, already referred to (and which extends 
— along by 0’ and ’ to the western side of Monument Moun- 
has a width in this section of about 200 yards. The strike 
. 2° E. to N. 5° W., and dip 60° to 80° to the eastward. 
Next to the eastward comes limestone, A?; first, with a steep 
* The latter ridge Me ee yee ee map), and its line is a more western one. 
The mica slate of ridge is the same with that of Tom Ball, and is similarly 
seamed with quartz bg tp oaths 20°-25° E., and the dip 40°-45° E. 
