The paper intends to show the genetic relation between the ore deposits and the granite intrusive of southeastern Maine. The deposits are ores of copper, zinc, lead, and a little silver, occurring mostly in the so-called Ellsworth schist, and some in the diorite and Silurian rocks. Nearly all of them occur from ¼ to 2 miles from the contact with the granite. A rude zonal arrangement of the deposits around the granite is noticed. Their genetic relation is further confirmed by the paragenesis of ore minerals. The sequence is apparently as follows: magnetite, arsenopyrite, pyrite, pyrrhotite, sphalerite, chalcopyrite, and galena. This sequence holds true in general in spite of the fact that the mines are scattered over more than 100 miles. The influence of the granite intrusion upon the surrounding rocks is studied in some detail. Particular emphasis is put on the petrographic description of the thermal metamorphism imposed on the schist. A short description is given for each mine and prospect.