Mineralogy and Ore Textures of the Shepard MTN Iron Deposit, Iron Co., Missouri. (Geology/Geophysics Section).
Dudley, M.A. and J.L. Nold. Department of Earth Science, Central Missouri State University. MINERALOGY AND ORE TEXTURES OF THE SHEPARD MTN IRON DEPOSIT, IRON CO., MISSOURI The St. Francois Terrane of southeastern Missouri hosts 6 major iron occurrences and over 30 minor occurrences. The Shepard Mountain Deposit represents one of the largest minor iron deposits and occurs about a mile SW of the Pilot Knob underground magnetite deposit. The ores are exposed as two northeast-trending, near vertically dipping veins, hosted by Middle Proterozoic rhyolites. Ore mineralization is characterized by abundant magnetite and lesser amounts of hematite with minor quartz, pyrite, chalcopyrite, maghemite?, chlorite, goethite, and sericite. Textures indicate a complex history of oxidation and reduction. Magnetite commonly forms euhedral aggregates and is present less commonly with colloform habit. Hematite is present as specular laths and as martitic replacement textures in magnetite. One of the unusual features of the deposit is the partial reduction of specular hematite to magnetite. Although the primary mineralization suggests similarities to the Pilot Knob under-ground and Iron Mountain deposits, the gangue mineralization in the Shepard Mountain deposit shows none of the diversity observed in these nearby larger deposits. Mineralogical and textural evidence indicates probable deposition of Fe-oxides from Si-poor hydrothermal solutions.
|Printer friendly Cite/link Email Feedback|
|Publication:||Transactions of the Missouri Academy of Science|
|Article Type:||Brief Article|
|Date:||Jan 1, 2001|
|Previous Article:||Stratigraphy and Fluid Evolution of the Bushy Park Deposit, South Africa. (Geology/Geophysics Section).|
|Next Article:||Feasibility of Applying Horizontal Well Technology to the Heavy Oil Sands of Western Missouri. (Geology/Geophysics Section).|