64 Geology, Sc. of the Connecticut. 
dip. The distances were all estimated by the eye, but it is 
persunedt they will in general be found not far from the truth. 
rom No. | to 56, inclusive, the stratified rocks all dip to 
the east, as is eviduns from the section. he Nos. included 
in parenthesis, refer to the general descriptions of the rocks 
of the coal formation in the beginning of the article. 
No. 1, Horblende Slate—Strata highly inclined, often be- 
coming an aggregate of hornblende, quartz and mica, having 
a porphyritic aspec 
No, 2. Mica Slate—Dip 20° to 30°, undulating and tor- 
tuous, pseine on the east into argillite. 
No. 3. Limestone—In beds in mica ‘slate, already deseri- 
bed in the. preceding pages. Unstratified. 
No. 4. Argillite—Dip 60° to 90°. ‘The southern limit of 
this rock hardly reaches the line of the section: but a mile or 
ap its relative position is as represented on the profile. 
ld Red Sandstone—With red conglomerate. Dip 
usualy asmuch as 20° eines sb than is usual for this rock. 
No. . Alluvion——A. sw 
No. r Gld Red Sandstones-Di between 20° and 30°. 
No. 8. Secondary Greenstone—It is probable this forms 
a bed between the old red sandstone and the coal formation : 
but the former rock is never seen passing under it in this vi- 
cinity ; ay therefore, it must not be thus represented on 
the Width about half a mile. On the eastern side it 
has, for a Saw feet in width, somewhat of astratified structure. 
0. 9. Red, Fissile, Friable, Argillaceous, Sandstone, 
Slate_-(No. 3.) It is fine grained and often micaceous, of 
the color of brick, is easily cut by a knife, yields an argilla- 
ceous odour, has an undulating surface generally, and is liable 
to disintegration, This is probably the most abundant o' 
the rocks of the coal formation; and it usually lies next to 
the greenstone and alternates with it. It is found over a - 
large extent of country on the east side of the greenstone 
ridge, stretching from Amberst to Berlin; although in Con- 
necticut it more frequently is wanting in the mica and its 
surface ig more uneven. It forms much of the flagging 
stone in Hartford and exists in place a foot or two below the 
surface in that city; though it seems here in some instances 
to approach to the nature of shale. The surface of the lay- 
ers often appears a little glazed and is sometimes traversed 
by numerous little ridges a mere line in thicknes and of the 
