Geology. &e. of the Connecticut. 6i 
er a sandstone of the es ws gee this poner must 
be ereenee 3 as a be ween them 
14. Coli ORMATION. 
Variety of Psammite. Brongniart. 
Grey Wacke Slate. Eaton. 
Colored brown by Umber. 
as long been known to mineralogists that coal was 
fond wong the Connecticut; and I denominate the rocks 
— it the coal formation, simply because its beds 
occur in them, and in no other rock; the old red sandstone 
ceataipitip none at all, but lying belérw it. The coal forma- 
tion embraces numerous varieties and sub-varieties of rocks, 
st of which alternate with one another and the principal 
tS are the following. 1. Sessions: This strictly 
this class: it alternates with the other va- 
rietiSe ani in Berlin contains coal. But spt yy reine 
cient reasons for giving it a separate color — description 
which it is unnecessary here to mention. 2. Trap, Tuff’. s 
ae Breceia, Cleaveland.) This occurs on oe east side of 
Mou om on the west bank of Connecticut river, and a 
oils = lie. between other rocks of the coal formation and 
the greenstone, and perhaps alternates with the greenstone ; 
tee { cannot say much as to its geological nenines. as 1 
a reddish brown abundant cement of comminuted and de- 
composed sandstone, greenstone or wacke. Scales of mica 
appear scattered in the rock which seem to have belonged to 
the sandstone. It exhales an argillaceous odour, is difficult to 
break, and is about of the hardness of old redsandstone. ‘he 
imbedded masses of greenstone are larger than the quartz 
or sandstone. I noticed some, six, eight, and even twelve inch- 
es across. Perhaps this rock is not the real trap tuff of Eu- 
rope. If not, it certainly deserves the name of greenstone 
conglomerate: although many of the imbedded masses and 
* Some other corrections or rs to be made in the bg? de accompanying 
that aedllekity an map. But asl intend to comprehend all tha is importan 
in that paper in this Sketch, a particular specification of Serbetions re 
unnecessary, 
