December 2, 2013 by Joseph Skulan (Note: Recently a correspondent in Spain asked me to explain GTac’s plans to mine iron in the Penokee hills of northern Wisconsin, and the issues surrounding these plans. Believing that my reply to his request could serve as a useful introduction to the Penokee mine issue for people unfamiliar […]
Tag Archives: pyrite

The Tyler Shale: Waste Overburden or Phosphate Ore?
March 1, 2012 by Hematite Proponents of the proposed iron mine in the Penokees claim that there are two kinds of rock: overburden waste rock (the Tyler shale) and iron ore. To date, the main concern with the Tyler is the presence of sulfide in the form of pyrite, or iron sulfide. When disturbed by […]