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 
to the west and has an inclination of only 9°. The 
appearance, when this rock was laid bare, was such 
as must have taken place if the limestone, when in a yield- 
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. 
The mica-slate, as well as the argillite, often presents 
tortuous strata. In New Marlborough, a mile east of the 
meetinghouse, is a singular instance. It may be traced 
for several rods. A large mass beside the road, resembles 
a pile of huge saddletrees, placed closely upon each other, 
the lower ones indeed having a greater proportional hori- 
zontal distance between the parts than the upper. Had 
the rock been bent upwards by a force acting from below, 
and then hardened in that position, it must have taken the 
form this mass presents. Many similar irregularities in the 
rocks might be mentioned. ‘They serve to convince us 
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 
parallel with the western boundary of Mass., quite to Long 
Island Sound. This is the range, there containing more 
gneiss, which was crossed by Prof. Silliman, and notice 
in this Journal, Vol. II. p. 201. ) 
be 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 
