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the subsurface during dry periods that may comprise a reservoir of zinc-bearing material <br />(Lindgren and Ransome, 1906; Denny et al., 1930). As the precipitation induced infiltration <br />flows into these large fractures, it readily rinses out the soluble salts, which in tum increases the <br />zinc concentration in the Carlton Tunnel flow. Thus, the relatively rapid flow of the <br />anomalously high infiltration into the diatreme through the large fractures explains not only the <br />increased flow from the Carlton Tunnel but also the increased zinc concentrations. <br />The increasing metal concentrations resulting from this process would be more significant in the <br />early stages of increased flow when the rapid dissolution of salts would have the most significant <br />impact on water chemistry; at later stages of the high-flow event the metal concentrations would <br />gradually decline. This observation is consistent with CC&V's monitoring data that showed <br />higher zinc concentrations during the initial rinsing (in mid-May and early-June, 1999) and <br />decreasing concentrations since that time (Figures 5 and 6). <br />The combination of a series of dry precipitation months during the winter of 1998/1999 followed <br />by record snowmelt and rainfall in April 1999 combined to generate elevated zinc concentrations <br />during the first flush of water through the diatreme. <br />• <br />Cripple Crcek & Victor Gald hlining Compnny Shepherd 11i!lcr. !nr <br />npJAMONDIP~OF/YlllOpfbTRganL4mrAnmJ.Jar 10 NorcmGer L. 1999 <br />