ee 
nae 
Geology of a part of Massachusetts, &c. 241 
eccurrence of these rocks nine times* in the distance of 
three miles, making four alternations of the two, and 
leaving the mica-slate on the west of the limestone. 
The county of Dutchess lies directly south of Columbia 
county, and extends to the state of Connecticut. Th e 
small county of Putnam, which contains the principal part 
of the highlands east of the Hudson, is on the south of 
Dutchess county. s 
The mica-slate of the Taconick mountain is continued 
penrarte ee the western rt of a ee and Sha- 
ing s 
ng 2008 east af it. t crossed it in two: 4 olaves » and fous d 
the mica-slate associated with primitive argillaceous slate 
upon both sides of it, as described in the above. geo 
Vol. VIII. p. 19, of this Journal. The e granular limestone 
is continued parallel with the range of mica-slate along 
the east side of Dutchess county, and, according to infor- 
mation, of Putnam county also. If is associated, as in 
rkshire county, with great quantities of dolomite, SO “ 
friable as to be continually falling me and and of com- 
Mon magnesian limestone. There can be no doubt of the 
continuation of the range or beds of onan limestone in 
ee direction from Berkshire county towards Long Island 
The rocks between this range of Pr ened and the 
highlands I was not able to examine. Although it is pag 
desirable to have the result of an examination of this se 
tion; the continuity of this range of mica-slate cannot ‘a 
affected by it. For, if this range of mica-slate should be 
distinctly connected with the gneiss of the highlands, it 
would only show the repetition of some of the older 
rocks on the west of the mica-slate, _ nearer to the 
transition rocks. If transition rocks are interposed be- 
tween the two, the highlands would fecby be more. sq 
horses separated from the _nacgpete woken of New-I 
* With respect to Salisbury this fact is mentioned, p. 211, Vol. Il. of this 
Jourtial, on the authority of the Editor. 
Voi. VI. No. 2 risk 
