Geology and Mineralogy of a part of Massachusetts, fc. 5 
rocks on the surface of the earth. The fact is that the 
granite is here surrounded by gneiss or mica-slate. To 
suppose the incumbent rocks to have been worn away so as 
to show the granite, involves the fundamental point of the 
Wernerians, viz. universal Seon, and a very wonder- 
ful elevation of often very smal] and thin portions of gran- 
ite above the common ied to form the veins in the mica- 
slate, as well as the action of causes more powerful than 
any peter to be operating at the present time. 
of granite in Middlefield is far greater than any 
othiir i in this section. It lies in oe and is the only 
granite put down upon 
osition of Granite—In Chester is a mass 
Granite ite | in mica-slate, of which Dr. Emmons gives 
the following representation. (See Plate 2. 
A, is the granite, of a cuneiform shape, lying on the sur- 
face of nearly vertical strata of mica-slate. The granite is 
connected with nearly perpendicular veins of granite, Band 
C passing up through the strata of mica-slate, BD. 
2. GNEISs. 
Colored Purple. 
This rock to be of a very limited extent in this 
section of our country, though it is more abundant than 
granite. "It occurs indeed in various places wots the east- 
ern partof Berkshire Co. in small quantities. In Windsor, 
Peru, and Middlefield, it is found as a continuous rock, 
several miles in length, ‘and sometimes more than half a mile 
in breadth. It is a coarse light ht whitish rock, con- 
sisting chiefly of feldspar. ve not noticed this rock 
a mile pe of the meeting house, i is another appearance of 
gneiss, the extentof which is not well ascertained. I have 
put upon the map, the gneiss of the south east part of this 
section, on the authority of Mr. Hitchcock in his papers ale 
