in the vicinity of Great Barrington, Mass. 261 
In this bluff, and in the fields adjoining the road (R in figure) 
just south and southeast of it, there occur the alternations of 
limestone, quartzite and mica schist or gneiss, already alluded 
11. 
sanvetnennnen etn estecneet+9 wate ee cece, 
watecrenan enter Boe SMe 
Biren 
place—about four miles east of Great 
—was made known to the writer by Mr. 
P. Stevens, of New York, who, many years since, studied the 
alternations of the rocks and made a section of the region. 
The succession is as follows, commencing below, or in the 
field to the south of the road (R). 
hite granular limestone—that of the valley. 
1 
2. Mica schist, a thin bed. 
3. Hard jointed QUARTZITE, 30 feet. 
4, Same, limestone, 60 feet. 
5. QuaRTzITE, like the lower, 20 feet. 
6. Gneiss, 80 feet. é ye 
7. (North of the road, R) bluish granular limestone, crumbling. 
8. Mica schist, 6 to 8 fe 
9. QUARTZITE, 100 feet (Devany’s quarry). 
0° to 85° to 
But At the 
quarry, which is two hundred yards to the eastward, the dip 1s 
20° 80° to the phate ab 5 The change of strike - 
other facts, including the northwestward dip in geile <§ e 
Ridge, show that the low anticlinal opens widely to the south: 
—the axis being inclined to the northwa 
rd. 
_ ist evince the little genetic 
. e alternations of quartzite and schi be gi EY 
y) 
10. Gneiss (overlying the quartzite at the eri ) 
is 
artzl 
(No. 8 in the section above) has but little lateral extent ; for 
oa a hundred yards off in the direction of the strike there 1s 
no 
Modern ones in the irregularities of the bottom an 
lining of sand-banks, 
* 
