Laserfiche WebLink
Mayo and Associates, LC <br />• 4,2.2 Bowie Sandstone <br />Unlike the relatively thin overlying channel sandstones, the 150 to 200 foot thick Bowie <br />Sandstone underlies the entire E Seam. The Bowie Sandstone is a major beach/offshore <br />bar deposited sand that occurs 10 to 15 feet below the E Seam. For comparison clean <br />sand of the Rollins Sandstone was sepazated from the B Seam by about 50 feet of <br />generally low hydraulic conductivity laminated sandstone and carbonaceous mudstone <br />(Mayo and Associates, 1998). Because the depositional history, mineralogical <br />composition, geometry, and structural azchitecture of the Bowie Sandstone are similar to <br />--. <br />the Rollins Sandstone there is the potential for appreciable groundwater inflows into E <br />Seam workings. ,7 <br />• Issues related to potential goundwater inflow from the Bowie Sandstone into E Seam <br />_ workings are two fold: <br />1. what aze the likely consequences if the Bowie Sandstone is fully saturated?, and <br />2. what is the likely hood that the $owie Sandstone is fully saturated? <br />4.2.2.1 Potential consequences of fully saturated conditions <br />Potential sources, locations and mechanism of groundwater rechazge, and groundwater <br />flow path locations and mechanisms in the Bowie Sandstone should be similaz to those in <br />the underlying Rollins Sandstone. The most likely recharge location is along the <br />cliff/slope face on the east side of Minnesota Creek, although, some rechazge may occur <br />neaz the contact with the Mt Gunnison intrusive. The extent of bedrock fracturing <br />Evaluation of Potential Groundwater Inflows 62 February 24, 2004 <br />Associated with E Seam Mining, <br />~ West Elk Mine, Somerset, Colorado <br />