The Blue Lead showing lies within the Cariboo Terrane of the Omineca Belt. The area is underlain by the Hadrynian Cunningham Formation, Cariboo Group. The Pleasant Valley Thrust, a major thrust fault which marks the division between the Cariboo Terrane to the east and the Barkerville Terrane to the west, lies immediately to the west of the showing.

The Cunningham Formation is characterized by limestone, dolo- stone and fine grained marble. These rocks are in gradational contact with the underlying, dominantly clastic, rocks of the Issac Formation and the overlying clastic Yankee Belle Formation. These three formations are all considered to be of Hadrynian age.

Mineralization consists of galena in quartz stringers cutting Cunningham Formation limestone.