USGS research documents acid-rock drainage and metal contamination from a 270-meter roadcut through the Ordovician Bald Eagle Formation at Skytop, Pennsylvania. The study analyzes mineral composition, including up to 34 wt. % Fe and 28 wt. % S, and measures contamination in seep waters, such as >100 mg/L dissolved Zn. Data was collected following construction halts in 2004 to understand environmental impacts from sulfide mineral weathering.
Use Cases
- Model metal transport (Fe, Zn, As) from sulfide weathering using measured mineral wt. % and seep water concentrations.
- Predict acid generation potential from rock samples using acid-base accounting data like net neutralization potential.
- Analyze the formation of efflorescent sulfate salts (copiapite, melanterite) based on wet/dry cycle and mineral inclusion data.
- Assess groundwater contamination risk from episodic salt dissolution using field pH measurements and dissolved metal levels.
Strengths
- Provides detailed quantitative geochemistry for rock samples, including specific wt. % measurements for Fe, S, Zn, Pb, As, and Cd.
- Links field observations of seep water contamination (>100 mg/L Zn, >1 mg/L As, Co, Cu, Ni) directly to identified mineral sources.
Limitations
- Sample size and spatial extent are limited to a single 270-meter roadcut section, reducing generalizability.
- Temporal data is from a specific 2004 event, lacking long-term monitoring of contamination trends.
Provenance
- Source
- United States Geological Survey (USGS) via NASA Earthdata/CEOS_EXTRA.
- Collection Method
- Field sampling and laboratory analysis of rock and water from the Skytop roadcut.
- Time Range
- 2004
- Freshness
- null
- Geography
- Skytop, Centre County, Pennsylvania, USA.