Madison limestone, Montana

The hnal example in this set is from the Madison regional aquifer study by Plummer et al. (1990). The Madison Limestone aquifer occurs in Wyoming, Montana, and South Dakota. Plummer et al. (1990) utilized a combination of saturation index constraints, inverse modeling, and carbon... 

Colorado, is hosted in folded and brecciated Mississippian dolomite, shale, sandstone and coal, which is in fault contact with Precambrian gneiss. The Precambrian gneiss is anomalously enriched in uranium, and a Mesozoic or Caenozoic age of mineralization in the Mississippian host rocks, formed by downward percolation of uraniferous groundwater from the adjacent Precambrian terrain, is inferred. Mineralization in the Pryor Mountains region, Montana, is hosted in karsts developed with the Mississippian Madison limestone and consists of uraninite-tyuyamunite grading up to 7% UsOg associated with clay minerals and silicified collapse breccias. A Caenozoic age of mineralization, under conditions similar to those of Pitch mine, is favoured. 

Pitrat, C. W. Thermoluminescence of limestone of Mississipian Madison group in Montana and Utah. Amer. Assoc. Petroleum Geol. Bull. 40, 942 (1956). 

Figure 1.A Concentric bands of hematite in a chert nodule in the Madison Group Limestone of Montana. The bands are 1 mm thick. The nodule ( 40 cm across and ovoid in shape) con-...

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