10 Geology^ &,'c. of the Connecticut. 



near the mouth of Miller's river, it appears in one or two 

 detached eminences of considerable hei,2;ht ; directly west 

 of which, only a few rods, is another hill of puddingstone 

 similar to that of Toby. The c ranite can be traced nearly 

 all the way through Northfield at a low level, and in 

 the north of this town it seems to pass under the geest and 

 higher rocks, and to appear again in Winciiester and Ches- 

 terfield, of greater width, and here it is beautifully porphy- 

 ritic. As we go north, the rock exists in distinct beds in mi- 

 ca slate and gneiss, and also it appears at the tops of moun- 

 tains sometimes forming conical hills almost naked. Wit- 

 ness the west part of Surrey and Alstead. 



The texture of this granite is coarse, in some instances 

 very coarse, the plates of mica beis.g several inches across. 

 Its usual colour is white. A beautiful variety, however, 

 occurs in Leverett, in which the felspar, which is abundant, 

 is of a light blue; the quartz of a dark blue, approaching to 

 black; and the mica the usual light gray. This a rare va- 

 riety, and a fragment of a crystal of this blue felspar meas- 

 ured in its longest direction 8 inches. 



This range of granite contains several veins of metals, 

 such as galena, copper pyrites, blende and iron ; which will 

 be more particularly described hereafter. 



Much of this range exists in the form of beds and ruins: 

 yet so far as I have examined it, it will not be easy to prove 

 that the whole of it can be referred to this form. I am yet 

 of opinion that along the central parts of the range may be 

 seen emerging an original fundamental deposit of granite. 



These are all the depositories of granite of considerable 

 extent, which I have discovered in the region embraced by 

 the map. Granite exists in many other places along this 

 river in beds and veins ; but not of sufficient extent to claim 

 to be represented on the map. It is possible, however, that 

 what I call beds and veins, may not in all cases be such : 

 For it is generally allowed, I believe, that the basis rock in 

 all New-England is granite, and this nucleus, if I may so 

 call it, is doubtless very uneven, having many prominences 

 and corresponding hollows. In some places, perhaps, these 

 projections have never been covered by other rocks, such 

 for instance, as black Mountain. In other cases there is 

 every appearance to indicate that the higher rocks have 

 been worn away, and thus the granite has been disclosed : 



