Lucky Friday | geology
There have been two ore-bearing structures mined at the Lucky Friday unit. The first, mined through 2001, was the Lucky Friday vein, a fissure vein typical of many in the Coeur d’Alene Mining District. The orebody is located in the Revett Formation, which is known to provide excellent host rocks for a number of orebodies in the Coeur d’Alene Mining District. The Lucky Friday vein strikes northeasterly and dips steeply to the south with an average width of six to seven feet. Its principal ore minerals are galena and tetrahedrite with minor amounts of sphalerite and chalcopyrite. The ore occurs as a single continuous orebody in and along the Lucky Friday vein. The major part of the orebody has extended from the 1,200-foot level to and below the 6,020-foot level.
The second ore-bearing structure, known as the Lucky Friday Expansion Area, is located in the Wallace Formation. It has been mined since 1997 pursuant to an operating agreement with Silver Hunter Mining Company ("Silver Hunter"), our wholly owned subsidiary. During 1991, we discovered several mineralized structures containing some high-grade silver ores in an area known as the Gold Hunter property, approximately 5,000 feet northwest of the then existing Lucky Friday workings. This discovery led to the development of the Gold Hunter property on the 4900 level. On November 6, 2008, we, through Silver Hunter, completed the acquisition of substantially all of the assets of Independence Lead Mines Company ("Independence"), including all future interest or royalty obligations to Independence and the mining claims pertaining to the operating agreement with Hecla Limited that was assigned to Silver Hunter.
