4 Geology and Mineralogy of a part of Massachusetts, &« 
1. GRANITE. 
Colored purple, and marked with parallel lines. 
Granite is found in Adams, Hinsdale, New-Marlborough, 
Worthington, Middlefield, Chester, and in most of the towns 
on the eastern part of this section. It occurs in small 
quantity and at a less elevation than most of the mica-slate. 
Though it is found in several places in nearly the same 
direction, it is interrupted or covered with other rocks. In 
Adams and Hinsdale it is in small quantity, and several 
hundred feet lower than the mica-slate on the east of it. 
In the eastern part of Middlefield, granite is a continuous 
yock, two or three miles in length, and more than half a 
mile in breadth. It is on the east side of the highest part of 
the range of mountains, and many hundred feet below the 
summit of the mica-slate on the west of it. This, like most 
ef the granite, is coarse grained, with a small quantity of 
mica, and contains no minerals imbedded in it. Like that 
of Europe, it is not a stratified rock. In Chester, Sandis- 
field, Granville, &c., granite is found in veins or alternating 
layers in mica-slate, from a few feet to a few inches or part | 
of an inchin breadth. Dr. E. Emmons has observed that 
the veins of granite in Chester, sometimes diminish in 
breadth until they can no longer be traced. In these cases 
they cannot be considered as alternating layers. 
Porphyritic Granite is found in large masses in Middle- 
field and Chester. 
After an examination of the granite in several places, I 
am inclined to the opinion that it must be considered as 
beds or veins, rather than as a continuous rock like the mica- 
slate. ‘Fhe beds as well as the veins of granite, lie in the 
direction of the strata of gneiss or mica-slate : for it is not 
essential to the notion of a vein, according to Cleaveland 
and the European Geologists, that it should run across the 
strata. 
The appearance of the granite in this section seems more 
easily accounted for upon the Huttonian than the Werne- 
rian hypothesis. If granite were formed from materials in 
a state of fusion, it would more probably be found at a 
lower level than the rocks which here contain it, than if it 
were merely a crystalline deposite made before all other 
