J. D. Dana— Geology of Vermont and Berkshire. 43 
Further, in the most eastern of the limestone areas, in 
Tyringham, twelve miles east of the Taconic range, a hill, 
just west of the village, having a height of 450 feet above the 
ridge near its base, consists of well stratified limestone to 
within sixty-five feet of the top, (fig. 9); and above this of 
mica schist (the contact distinct), and very hard whitish thick- 
ded gneiss; the whole dipping southeast 20° to 28°, with 
the strike N. 40°-45° W. Within the limestone stratum, fifty 
feet below its upper limit, there is a thin layer of mica schist. 
These examples are sufficient to illustrate the point in view. 
Two others are given beyond. 
(2.) Interstratified quartzyte and schists. 
At the east front of Monument Mountain, half way from 
Stockbridge to Great Barrington, quartzyte overlies mica schist 
and gneiss (fig. 10), the dip 15° to 25°, to the southeast. The 
West end of Monument Mountain. East front of Monument Mountain. 
x Woda is a hard kind without bedding, but vertically jointed. 
front and rises to its greatest height a little back from the front, 
ern hal 
no bedding whatever; but in most parts of the mountain it is 
tather mica schist than gneiss. * 
t Mountain, rising from the Great Barrington Valley half 
my Patri ‘o the concealment of the rocks by the soil. The stratum of schist in 
state ep published section was inferred to exist there below the quartzyte, as I 
mountains south of the old furnace, and from some ve 
ma: Masses of limestone on the east bank of the river, above the furnace, which 
¥ Possibly be transported blocks. 
