Geology, &c. of the Connecticut. 29 
Gneiss. 
The more I examine the rocks in New-England, the bet- 
ter convinced I am that the extent of this rock in this re- 
gion, has been overrated by geologists. The truth is, that 
almost in every place which I have examined, mica slate al- 
ternates with gneiss, or overlies it, so as to oceupy nearly, 
sometimes more than half the surface. Hornblende. slate 
and granite, also occur in the same series. In passing fre 
Northampton to Boston, I have never found any gneiss 
of Worcester ; although in going from Providence to Hart- 
ford, this stratum occurs only twelve miles from the former 
place and continues with alternations of mica slate, 4 
in the vicinity ; and vice versa, , 
slate appeared, 7 have he been able to ‘discover veins 
or beds of granite. And wherever granite veins exist, gra- 
nite beds are not usually far off. 1 might say more on this 
subject: But it has only recently attracted my particular 
attention, therefore I desist. Iam satisfied, however, that 
—— of the phenomena of Glen Tilt are patente in New- 
unglan 
Sa a ane er age secondary. 
TL j > 20. © » err eh pay id and 
secondary greenstone of the aceasta is very imper- 
fectly stated page 32 vol. 6. The mere fact that the 
tive greenstone forms beds in other rocks does not distin- 
same situation. But the former, at the sides of the a 
passes by imperceptible gradations into other rocks, suc 
as ponies chlorite slate, &c. thus excluding the 
idea that it could have been forced in between _* strata of 
other rocks after their consolidation: whereas the latter 
rock is distinctly characterized to the very line of junction 
with the sandstones and puddi unless there be a 
pg os Sea changea few inches on either side of this line, 
as if by hea 
