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• acre-feet per square mile in the region surrounding the lease area (Price and Amow, 1974). The quality of
<br />groundwater in the White River Basin deteriorates with distance downgradient much the same as surface
<br />water but at a greater rate. Dissolved solids concentrations in the groundwater system of the basin range
<br />from about 250 milligrams per liter in the headwaters to possibly 3000 milligrams per liter near the
<br />confluence of the White and Green Rivers. This increase in dissolved solids concentration is the result of
<br />increased contact of water and rock as travel distance increases, with saline shales contributing the major
<br />portion of the dissolved constituents.
<br />II.C.3.b Potential Groundwater Hydrologic Zones As noted in the discussion on the geologic setting of
<br />the lease and adjacent areas, three distinct, mappable lithologic facies or stratigraphic units have been
<br />defined in the lease area, each of which possess potentially different hydrologic properties. To recap, the
<br />upper part of the Iles Formation equivalent consists predominantly of sandstones with few, if any,
<br />significantly thick or continuous coal seams, the top being the B Horizon or Trout Creek Sandstone. This
<br />formation is herein termed the Lower Sandstone Facies. Overlying the Iles Formation, the lower Williams
<br />Fork Formation is predominated by siltstones, coal, mudstones and carbonaceous shales. This hydrologic
<br />zone has been termed the Siltstone and Coal Facies. This zone transists into the Upper Williams Fork
<br />Formation, consisting predominantly of sandstones of terrestrial origin, herein termed the Upper Sandstone
<br />Facies.
<br />Typical cross sections of portions of the lease area are shown in Illustrations 36, 37, and 38. Generally, the
<br />• Lower Sandstone Facies lies below the lowest B coal seam, the Siltstone and Coal Facies comprises the
<br />strata between the lowest B and J coal seams, and the Upper Sandstone Facies consists of all strata above
<br />the J coal seam.
<br />Rocks typical of each facies were taken from surface exposures in the lease area and described. Briefly,
<br />the Lower Sandstone Facies consists of medium-fine to very fine-grained, subangular, light gray to
<br />grayish-white, dirty, arkosic sandstone with poor to very poor sorting, approximately 60 percent quartz, 2 to
<br />5 percent opaques (carbonaceous material); tight, well indurated; cement is somewhat calcareous.
<br />Sandstones of the Siltstone and Coal Facies are fine- to very fine-grained, angular to subangular, light
<br />grayish-yellow, silty, clayey, dirty, very poorly sorted, and somewhat calcareous with limonite fragments and
<br />less than 5 percent opaques (carbonaceous material). The siltstones of the facies are very dense, hard,
<br />and red, with chert nodules and layers (irregular), approximately 75 percent red Siltstone, 20 percent chert,
<br />5 percent carbonaceous fragments, giving a limonite streak; calcareous reaction to weak HCI solution.
<br />The Upper Sandstone Facies consists of medium- to fine-grained, subangular, brownish-yellow (limonite
<br />color), poorly sorted, dirty and somewhat calcareous sandstone with approximately 60 percent quartz, 30
<br />percent silt, clay and rock fragments, and 10 percent opaques.
<br />• Permit Renewal #3 (Rev. 8/99) II.C-50
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