150 
GEOLOGY OF THE SECOND DISTRICT. 
CHAPTER IX. 
'Individual rocks composing the Taconic system; their characters; absence of fossils .—- 
Mineral products. — Conclusion. 
The order in which the Taconic rocks 'lie being unsettled, or at least not fbeing so clearly- 
established as is desirable, I am not particularly anxious to follow the usual order in the 
'description-of the individual masses composing this system. 'I shall therefore'commence with 
the most western mass of slate, which I have denominated Taconic slate. 
This rock is extremely fine grained, with delicate inelastic laminae, and only slightly cohe¬ 
rent ; or in other words, the laminae are separated ^ easily from each other, especially where 
'the rock/is near /the surface. The 'Color is dark, passing into light blue, and often stained 
brown by decomposed sulphuret ofdron. Smalbmasses of quartz are often enclosed between 
the laminae of slate. A waved or slightly wrinkled state of the laminae is commonly/exhibited, 
attended with a pearly lustre, tand /often with a reddish brown 'color. 'No 'organic remains 
have, however, been found in the rock/; fit-is even destitute of those-obscure markings which 
are mWedfucoids. Although then it has fa general resemblance to the magnesian slate, which 
forms the greatest part if/not the whole'of the Taeonic mountain, itfis not so/coarse, contains 
less quartz, and rarely if any chlorite. It is not, however, possible to describe this mass 
with sufficient precision to identify it without regard to its position. It may be said to lie 
between the Hudson river rocks on the west, and the sparry limestone on the east: it is un¬ 
doubtedly overlapped by the former rocks, and it passes beneath the latter under a dip of 30° 
or 35°. The line of junction with the slates upon the west is exceedingly obscure, and I am 
not aware that it has been observed. On the east, however, the junction of the slate with 
the limestone is clear and distinct. It may be observed two or three miles east of Hoosic 
corners, on the Bennington road, near the hematitic ore bed. The layers of the slate and 
limestone alternate several times with each other, before the limestone finally prevails. I 
have not been able to make even an approximate estimate of the thickness of this slate: 
towards the western edge, the rock is concealed beneath debris of stones and soil. 
This rock holds a definite position in the series, and may be traced very clearly for one 
hundred and fifty to two hundred miles, without any variation of character,. Its strike varies 
but little from a north and south course, and may be traced by drawing lines near to, and 
parallel with the New-York State line upon the east. The r.ock, immediately upon its 
