WCR: Linkages Between the Chemical Weathering of Black Shales and Metal Contamination in Aquatic Systems

Arkansas State University Main Campus, Jonesboro AR

Investigators

Abstract

HANNIGAN 0233661 ABSTRACT Despite large-scale explorations of connections between water quality and bedrock weathering, large gaps in our understanding of these relationships remain. Contaminants, such as metals extracted from soft sedimentary rocks such as black shales, are released to rivers and groundwaters and subsequently are transported to water supplies. While it is clear that black shales contribute to the metal budgets we lack the basic information necessary to gauge the impact of black shale weathering on water and sediment quality. This study will explore the geochemical behavior of metals during black shale weathering in several catchments (three underlain by black shales, one underlain by limestone and the fifth impacted by agricultural activity). Data collection will integrate several disciplines including geochemistry, mineralogy, hydrology and ecotoxicology. Physical and chemical hydrologic data, metal chemistry of environmental media (precipitation, surface water, groundwater, soil, stream sediments etc.) and bioassay and sediment-water quality testing will be integrated over an 18 month collection period. These data, when considered in concert, are critical to assessing metal loading in black shale regions and the impact of metal release on aquatic ecosystems.