1993-03-30_HYDROLOGY - M1977378 - Laserfiche WebLink

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by mining activities, yet it contains relatively high concentrations of lead and manganese. The Sunnyside Cross Cut did not intersect any significant mineralization. Water from the Sunnyside Cross Cut therefore should not be significantly impacted by oxidation of sulfides exposed by mining; yet it also contains relatively high concentrations of lead and manganese. Waters from the West Drift and Footwall Drift may contain a relatively small volume of water which cascades down from open stopes after reacting with exposed sulfides and oxygen. Waters from the West Drift and Footwall Drift should not be considered to represent ground-water chemistry. Fault #1 and Fault #2 intersect the American Tunnel a little over one half mile from the portal (between track repair footages 3000 and 3250). Ground water entering the tunnel at these locations contains much greater concentrations of dissolved metals and has a lower pH than ground water in the vicinity of the Washington Inclined Shaft. Water from Fault #1 and Fault #2 contains high concentrations of zinc, lead, manganese, cadmium and iron. The increased concentrations of metals and lower pH may be due to a longer flow path or greater residence time within the deep fracture-flow system. Seeps associated with considerable iron staining of soil are locally known as iron bogs. Such iron bogs are common along both the north and south forks of Cement Creek. The iron staining is due to iron oxides and hydroxides precipitating out of metal laden ground water. There are iron bogs associated with most of the abandoned mine portails, but iron bogs also exist where there are no mines located uph 11 (such as near the head of the South Fork of Cement Creek). The iron bogs located rear A ndoned portals may be accentuated by water which has picked sanjuan\sunny\110361\oct91 Rpt 24 Rev.2/11/92 effl simon womu=uE[H"IMrL H