265 soil sample sites along two continental-scale transects in North America provide major- and trace-element concentration data. One transect spans from northern Manitoba to the US-Mexico border, and the other follows the 38th parallel from the Pacific to Atlantic coasts. The data was collected and analyzed by the USGS, with samples analyzed using methods including ICP-MS, ICPAES, and atomic absorption spectrometry.
Use Cases
- Model spatial distribution of trace elements like arsenic, lead, and cadmium across continental gradients using site location data.
- Analyze relationships between soil horizons (O, A, C) and concentrations of major elements such as aluminum, iron, and calcium.
- Assess local spatial variability in element concentrations by comparing duplicate samples collected 10 meters apart.
- Investigate correlations between soil depth (0-5 cm samples) and concentrations of nutrients like phosphorus and potassium.
- Map continental-scale geochemical baselines for elements including uranium, thorium, and mercury from the transect samples.
Strengths
- Data from 265 distinct sampling sites across two major transects.
- Analysis includes over 40 specific major and trace elements per sample.
- Includes duplicate samples at one in four sites to estimate local variability.
- Samples collected from up to four separate soil horizons per site.
Limitations
- Exact row count and sample size per element are not specified.
- Temporal coverage and last update date are unknown, potentially limiting time-series analysis.
- Geographic coverage is limited to two specific transects, not a complete national survey.
Provenance
- Source
- USGS (United States Geological Survey) via NASA Earthdata.
- Collection Method
- Systematic sampling along defined transects with random selection within 1-km strips, followed by laboratory analysis using ICP-MS, ICPAES, and atomic absorption spectrometry.
- Time Range
- null
- Freshness
- null
- Geography
- North America: one transect from northern Manitoba, Canada to the US-Mexico border near El Paso, Texas; another transect along the 38th parallel from San Francisco, California to the Maryland Atlantic coast.