Standing on this range in Leverett, you have on the west, at about 100 rods distant, a precipitous mountain of sandstone and puddingstone, five or six hundred feet higher than the granite. On the east, a mile or two distant, a mountain of sienite gradually rises to a still greater height than the puddingstone; and on the southwest, at nearly the same distance, you can see an alluvial formation. In general this granite does not rise so high as the adjacent rocks, whether secondary or primitive.
VEINS OF ORE IN THIS GRANITE.
1. Of Galena in Leverett.
This ore forms a narrow vein in the southwest part of the town, on land of Moses Smith, two miles from the Congregational meeting-house. The direction of the vein is nearly north and south, and where I saw it, only a foot wide. The gangue is sulphate of barytes.
2. Of Galena, Copper Pyrites, and Blende.
This vein is a little more than a mile north of the one above described, and it may be a continuation of the same vein. The gangue is nearly an equal admixture of sulphate of barytes and quartz; and galena and sulphuret of copper are disseminated through it in about the same, that is, equal proportions. The blende, which is of a yellowish aspect when the fractured crystal is held in a certain position, appears only occasionally. This vein is several feet wide, has been wrought to a small extent in two places, and its direction is nearly north and south. It is on land of Mr. Field.
Radiated quartz. In the above vein. A considerable tendency to crystallization appears at this place, not only in the quartz, but in the foliated structure of the barytes.
Brown spar. In the same place. But little of this mineral was noticed. It exfoliated before the blowpipe, turned black, and became magnetic.
3. Of Specular Oxide of Iron in Montague.
This is found in a partially detached eminence, 100 feet high, near the north line of Montague, on land of Mr. Taft, a little southwest from the confluence of Miller's river with the Connecticut. The whole hill, not less than 100 rods in circumference at its base, is traversed by numerous veins of this ore; and scarcely a foot of the rock is to be seen that does not contain these, varying in width from a mere line to several inches. The principal vein appears on the top of the hill; and is, as nearly as I could determine, not less than ten feet wide, lying in a north and south direction. The ore seems to be abundant, and generally pure. Masses, that have been separated by blasting, and weighing from 100 to 200 pounds, lie on the surface. A small proportion of sulphuret of iron was observed in some specimens. The gangue is quartz, and the walls and hill granite.