WATER CHEMISTRY AND IRON OXIDE MINERALOGY AT AN ABANDONED PYRITE MINE NEAR CONTRARY CREEK, LOUISA COUNTY, VIRGINIA

Contrary Creek, located in Louisa County, Virginia, is the recipient of mine drainage from abandoned 18th and 19th century gossen and pyrite mines. Our assessment concentrates on surface water, stream bed coatings, and seeps adjacent to one of the former mines, known as the Sulfur Mine. At this site, mine spoils piles, and abandoned shafts and tunnels are sources of acidic drainage. Preliminary ICP-AES stream water data indicates elevated concentrations of dissolved zinc, aluminum, and iron, confirming and updating findings of previous studies. Redox potential and pH were determined in the field. Redox potential measured in Contrary Creek waters ranged from 320 mV to 500 mV, and were as high as 550 mV in an onsite pond. Stream water pH ranges from 2.2 to 6.0, while pH values at seeps range from 2.2 to 3.1. XRD results indicate the presence of schwertmannite, ferrihydrite, and jarosite coatings in seeps and pools between the former mine and the stream. Contrary Creek sediments are coated primarily with goethite, with smaller amounts of schwertmannite and ferrihydrite. This suggests transformation of the latter minerals to goethite with increasing distance from the mine seeps. An examination of the metals content of soils at seeps and other discharge points near the mine is in progress.