28 Geology and Mineralogy of a part of Massachusetts, &c. 
In the bed of limestone near Williams College, 
there passes a rock of mica-slate, containing considerable 
quartz and some talc. This rock appears to have heaved 
the limestone in opposite directions. The limestone on 
the west of this rock and actually in contact with it, in- 
clines to the west at an angle of 41° with the horizon; but 
at a few feet below the surface, the limestone bends more 
ing state, had been bent upwards by the mica-slate, and 
then solidified. As the rock has been uncovered for sever- 
al feet in depth, it is evident that the inclination of the 
mica-slate is to the east; and the limestone is so covered 
that the distance it extends to the west cannot be ascer- 
tained. A few rods distant is another similar appear- 
ance, caused by the same rock in a parallel stratum. 
mica-slate, as well as the argillite, often presents 
tortuous strata. In New Marlborough, a mile e ' 
meetinghouse, is a singular instance. It may be traced 
for severa S. rge mass beside the road, resembles 
how much is to be done, before a correct knowledge of the 
causes, which have given to the crust of our globe its pre- 
sent appearances, will be attained. 
The general course of the strata may be seen, pretty 
nearly, upon a map of New-England, and of the state of 
New-York, east of the Hudson, from the direction of the lar- 
ger rivers. The course of the stratum of mica-slate, is nearly 
oan with the western boundary of Mass., quite to Long 
sland Sound. This is the range, there containing more 
gneiss, which was crossed by Prof. Silliman, and noticed 
in this Journal, Vol. II. p. 201. 
The granular limestone of this .section, about eighty 
miles in length, preserves a very direct course, in a line 
parallel to that of the mica-slate. The eastern range of it 
seems to be continued from New-Marlborough, through 
