Warren C. Day Gary B. Sidder Cheryl M. Seeger George A. Desborough Joseph R. Hatch Joel S. Leventhal Warren C. Day Diane E. Lane L. M. Nuelle 1992 <p>No abstract available.</p> application/pdf 10.3133/b1989AC en U.S. Geological Survey Geology and mineral paragenesis of the Pea Ridge iron ore mine, Washington County, Missouri: Origin of the rare-earth-element- and gold-bearing breccia pipes. Some mineralogical and geochemical aspects of middle and upper Pennsylvanian marine black shales in part of the midcontinent region. Mineralogical and geochemical analysis of the metal- and organic-rich Grassy Creek Shale of the New Albany group (Upper Devonian and Lower Mississippian) in Hardin County, southern Illinois reports