『Abstract
　The chemical compositions of natural waters is affected by the weathering of geologic materials at or near the surface of the Earth. Laboratory weathering experiments of whole-rock sulfide rocks from the Shoe-Basin Mine (SBM) and the Pennsylvania Mine (PM) from the Peru Creek Basin, Summit County, Colorado, indicate that the mineral composition of the sulfide rocks, changes in pH, the duration of the experiment, and the formation of sorbents such as Fe and Al oxyhydroxides affect the chemical composition of the resulting solution. Carbonate minerals in the rock from SBM provide buffering capacity to the solution, contribute to increases in the pH and enhance the formation of Fe and Al oxyhydroxides, which sorb cations from solution. The final solution pH obtained in the experiments was similar to those measured in the field (i.e., 2.8 for PM and 5.0 for SBM). At PM, acidic, metal-rich mine effluents is discharged into Peru Creek where it mixes with stream water. As a result, the pH of the effluent increases causing Fe and Al oxyhydroxide and schwertmannite to precipitate. The resulting solids sorb metal cations from the water thereby improving the quality of the water in Peru Creek.』

1. Introduction
　1.1. Geology and mineralogy of the mines studied
2. Methods
3. Results and discussion
　3.1. Mineralogy of mine sulfide samples
　3.2. Experimental weathering of sulfide rock from the shoe basin mine
　3.3. Experimental weathering of sulfide rock from the Pennsylvania mine
　3.4. Evolution of the experimental-weathering solutions
　3.5. Mixing of effluent from the Pennsylvania mine with Peru Creek
4. Conclusions
Acknowledgements
References