48 ECONOMIC GEOLOGY. 
They have cut into pyritiferous schists, sinking upon a vein six feet 
’ wide, richer than the usual mass of 40 feet thickness. Many bunches of 
copper were taken out, and I understand from F. L. Bartlett, of Portland, 
that nickel is present in the ore. 
On Cate’s hill, in Berlin, is a vein showing the minerals pyrite, chalco- 
pyrite, bornite, magnetite, hornblende, and tremolite. The ores are 
sparsely disseminated. 
This region promises well to the explorer, and it will doubtless be 
heard from in the future. Our map shows that the rocks continue here 
from the Ammonoosuc district, though interrupted by intrusive por- 
phyries. 
Tur Warren MINE. 
In the gneiss of Warren there is a bed of tremolite more than fifty 
feet wide, in connection with which is a vein of copper and zinc. Mica 
schist, dipping 45° N. 50° E., encloses the bed. Veins of pure copper ore 
with reticulations of quartz abound in the hanging wall, and a bed of the 
same material occurs along the line of the junction of the tremolite and 
schist. Veins of the copper, bunches of iron pyrites, and a resplendent 
black blende occur also in the midst of the tremolite, as well as a little 
rutile. Most of the tremolite carries copper pyrites, and the rock must be 
stamped and washed to allow of separation. The annexed plan shows 
Fig. 7.—PLAN OF THE WARREN MINE. 
a, Quartz; b, Ore vein; c, Trap. 
the mutual relations of the three trap dykes, veins of quartz, and the ore 
vein. It was prepared by Mr. Huntington, and is not drawn to a scale. 
