Geology, Yc. of the Connecticut. 65 
substance of the rock, which I have sometimes suspected 
might be petrifactions; and perhaps they are so. When 
this rock is disintegrated it forms an admirable material for 
the construction of roads; a good example of which may be 
seen in the road between Hartford and Weathersfield. 
ere the profile crosses this rock, it has a dip of 45° ; 
and as already observed under the article greenstone, it 
forming to the a Sea 2, the greenstone, thus forming 
saddle shaped strata. In some instances we notice a sudden 
curve from this cause, of 90°. At the first copper mine we find 
on passing down the river, a narrow spur of the greenstone ex- 
tends a short distance into the slate, and the vein of ore here 
passes from the greenstone into slate. Halfa mile south of 
this point we find the slate crossed obliquely to the direction 
of the strata by parallel seams dividing it into strips from one 
to six inches wide and often five feet long. Sometimes we find 
in these divisions six sided prisms of quartz, lying partially 
imbedded and exhibiting both terminations in great perfec- 
tion. I have seen seams very narrow containing green car- 
bonate of copper, the sides of the vein being beautifully gla- 
zed, having a highily specular aspect, and orming the saal- 
bande of the Germans. The width of the rock on the sec- 
tion is about fifteen rods, extending across the mouth of Fall 
Ege 
0. Greenstone—(No, 1.) This has been already 
Pie when treating of that rock. Thickness of the for- 
mation, 20 ro 
No. 11. Sime as No. 9, (No. 3.) Thickness of the stra- 
tum, 6 —_ m6 § 45° 
No. d Slate—resembles the last, but is more mi- 
wow’ is 5 divisible i into thinner lamine, the surface of which 
is even, and the color is less red. Abeautiful rock. Thick- 
ness 6 fect, dip 45°. 
No. 13. Reddish micac dstone-S hat 
erated, the imbedded pebbles of quartz and flesh een fel- 
spar, small and rounded, less fissile pos the last, layers 
thicker. Thickness ers feet, di 
. No, 14. Same as No. ®. Thicknose 15 feet, dip 49° 
No. 15. Same " No. - Ps 15 rods, dip 40°, 
Vol. VI....No. 
