Acid Generation Potential in Sevier Shale Roadcuts: Weathering Stages and Acidity Evolution
Abstract
This study investigates the relationship between field-observable characteristics and geochemical properties of the Ordovician-aged Sevier Shale to develop practical guidelines for roadside reclamation. When left non-vegetated after excavation, Sevier Shale frequently causes erosion, acid drainage, and water quality degradation. Samples collected from various weathering stages across Northeast Tennessee were analyzed for visual indicators (color, texture), field reactions (HCl, H₂O₂), and laboratory parameters (pH, electrical conductivity). Previous research suggested that the results should reveal significant correlations between weathering intensity, indicated by color changes from dark gray/blue to yellowish-brown, and geochemical properties, including acidity and salinity. The transformation from pyrite-rich fresh shale to oxidized material generates sulfuric acid while producing gypsum, creating complex mineral transformations that influence vegetation establishment or lack thereof. This research results should provide reclamation needs with field-applicable methods to identify problematic shale material, allowing for targeted treatment strategies during roadcut stabilization and reclamation projects which can also be confirmed with laboratory results. The findings should establish a practical assessment framework to improve the long-term management of disturbed Sevier Shale sites throughout the Appalachian region.
Start Time
16-4-2025 9:00 AM
End Time
16-4-2025 10:00 AM
Room Number
272
Presentation Type
Oral Presentation
Presentation Subtype
Research-in-Progress
Presentation Category
Science, Technology and Engineering
Faculty Mentor
Daniel Johnson
Acid Generation Potential in Sevier Shale Roadcuts: Weathering Stages and Acidity Evolution
272
This study investigates the relationship between field-observable characteristics and geochemical properties of the Ordovician-aged Sevier Shale to develop practical guidelines for roadside reclamation. When left non-vegetated after excavation, Sevier Shale frequently causes erosion, acid drainage, and water quality degradation. Samples collected from various weathering stages across Northeast Tennessee were analyzed for visual indicators (color, texture), field reactions (HCl, H₂O₂), and laboratory parameters (pH, electrical conductivity). Previous research suggested that the results should reveal significant correlations between weathering intensity, indicated by color changes from dark gray/blue to yellowish-brown, and geochemical properties, including acidity and salinity. The transformation from pyrite-rich fresh shale to oxidized material generates sulfuric acid while producing gypsum, creating complex mineral transformations that influence vegetation establishment or lack thereof. This research results should provide reclamation needs with field-applicable methods to identify problematic shale material, allowing for targeted treatment strategies during roadcut stabilization and reclamation projects which can also be confirmed with laboratory results. The findings should establish a practical assessment framework to improve the long-term management of disturbed Sevier Shale sites throughout the Appalachian region.