Geochemical, Mineralogical, and Environmental Characteristics of Metamorphosed Black Shales of the Central Appalachians, with Comparisons to Metalliferous Shales of the Northern Appalachians
Foley N, Southworth S, Schultz AP, Ayuso RA, Robinson GR, Seal RR. 2011. Geochemical, Mineralogical, and Environmental Characteristics of Metamorphosed Black Shales of the Central Appalachians, with Comparisons to Metalliferous Shales of the Northern Appalachians. Pages 111-114. In U.S. Geological Survey Appalachian Region Integrated Science Workshop Proceedings. Gatlinburg, Tennessee. October 22-26, 2001
ABSTRACT: Primary geochemical features of metamorphosed black shales that occur throughout the Central and Northern Appalachian regions reflect their original depositional environments, despite mineralogical reactions as a result of regional metamorphism and weathering. Near-surface reactions of sulfide minerals and water in these black shales causes acid drainage and the release of potentially toxic trace elements such as arsenic, copper, manganese, and mercury. High and anomalous contents of these elements represent pervasive and challenging problems associated with many rivers and streams in the Eastern United States. Acid rock drainage occurs naturally and is not associated with human activities. Simple weathering of rocks that host low-grade occurrences of iron sulfide minerals, for example, sedimentary pyrite layers in black shales is enough to pose potentially significant acid drainage problems. Release of potentially toxic trace elements such as arsenic, copper, manganese, and mercury that are either present as minute sulfide or sulfosalt mineral inclusions or structurally bound as trace elements in the lattice of the host sulfide minerals can also result in significant environmental impacts on surface and ground waters.
- Type
- Conference Proceeding Paper
- Authors
- Foley, Nora; Southworth, Scott; Schultz, Arthur; Ayuso, Robert; Robinson, Gilpin; Seal, Robert
- Units
- GRSM
- Keywords
- Anakeesta, APHN, Appalachian Highlands Network, geochemical, geology, Great Smoky Mountains National Park, GRSM, GRSM-00729, GRSM-00748, minerology, SER, shale, Southeast Region