The Homestake mine, discovered in 1876, is one of the oldest and largest continuously operating gold mines in North America. Production of almost 36 million ounces of gold has come from 128 million metric tons of ore. Economic gold mineralization is confined primarily to the chemically precipitated iron formation of the Proterozoic Homestake Formation.
The Precambrian sequence, in the Lead area, was subjected to two deformation periods during a single metamorpbic episode of Proterozoic age (Reid, 1989). This tectonism resulted in fold and ore trends ranging from N25°W to N19°E and metamorphic grades increasing from middle greenschist in the southwest to lower amphibolite facies in the northeast within the Lead area. Later deformation periods in the region had negligible impact on the ore trend configuration within the Homestake mine.