J. D. Dana—Geology of Vermont and Berkshire. 47 
slate may be seen in numerous places in all parts of the county. 
He adds that he had not “ met with a spot where the limestone is 
in direct contact with quartz rock; but as this rock frequently 
alternates with gneiss and mica slate, and the latter with the 
limestone, they must all be regarded as interstratified with one 
another.” 
Before Professor Hitchcock’s observations were made, Professor 
Dewey announced in this Journal, in 1819, that the Berkshire 
limestone at the Cave or Falls in Adams, east of Williamstown, 
and also west of the Hoosac, rests on mica slate. Further, Pro- 
fessor Silliman, in the second volume, 1821, gives an account of 
the interstratification of the limestone and mica slate in Salisbury, 
Ct., west of the Housatonic, saying that “in the course of five or 
Six miles there are as many alternations and successions of these 
two rocks,” and “their junction in some places is exactly defined.” 
ifting force, or that of conformability in the formations, because 
of the abrupt local changes, which sometimes amounted to 50 
or in di i 
; <ception absent and the conformability to the schist is placed 
yond doubt. 
An unconformable limestone ledge is alluded to above as 
ne in the valley near the Devany bluff. The conformable 
'mestone-outcrops extend along the side of the valley for a 
