je" 
Geology and Mineralogy of a part of Massachusetts, &c. 19 
hills. It occurs also in New Ashford, Richmond, West 
Stockbridge, Egremont and Sheffield. It is more exten- 
sive along the boundary line between the states of New- 
ork and Vermont, associated with the limestone and mi- 
ca-slate, as in ee county of Berkshire. The same stratum 
may be traced in a direct line from Williamstown over 
North West Hill, through Pownal and Bennington in Vt. 
On the west side of the Taconick range in the state of 
New York, this argillite is alsoabundant. See the * Geo- 
logical and Agricul Survey of Rensselaer County,” pa- 
ges 9 and 18,and Mr. Barnes’ Section of the Canaan Moun- 
tain,” Vol.V. p. 11, of the American Journal of Science and 
is rock appears therefore to alternate with the 
weste rn range of mica-slate, and talco-micaceous slate as- 
sociated with it. On the east side it can scarcely be con- 
sidered a continuous rock ; at least it cannot be traced 
through the whole section. But on the west side, it ap- 
pears to be abundant and continuous, and to form a regular 
stratum. It extends farther south in this section than the 
county of Reagan though f am not able to state its ex- 
tent at the sout 
This argillite is found also in small gam in a0 mica- 
slate i in the eastern range of mountai hav n it in 
larlborough, and it is found in Plainfield, still ae 
his stratum of argillite has a shining aspect, and is ined 
different from that along the Hudson river.* It is sometim 
tortuous. In other parts its strata are easily divisible into 
large tables, forming roof slate. It is wrought extensively 
in Hoosack, Lebanon, aad Hillsdale. 
the New J da. 
Encyc. seems desi 
gus of placing argillite as one rock by 
fo 
itself; acknowledges that. ie remains und 
in the older varieties of it, meaning’ the argillite found in the rocks, gen- 
, erally te primitive With the same acknow nt respect- 
ing mestone, he appears to aren: it all as one formation. Surely 
this ¥ orn alk rocks to one formatio 
Be deere Prof. Eaton is Sr. 00h to consider the aoe. along the 
border o separated 
from that of the ee “ through out the whole extent, ip a coutinniie 
north and south range of well Dr reeteraed metalliferous limestone; and 
it gta in ng ae with the European granary of shining argillite.” 
1. and ie Survey of I Reamaleer County, page 
