Arsenic anomalies of an arid region determined from sediment geochemistry


Sediment geochemical data for four 1° × 2° quadrangles in northern Mexico were merged. Exploratory data analysis (EDA) was applied to the resulting dataset (N = 2,046) in order to identify areas with arsenic (As) anomalies and their possible source. Two types of anomalies were identified. Mild As anomalies had a threshold value of 9.40 mg/kg and clustered around outcrops of volcanic rock and non-producing sulfide mineral deposits. Extreme As anomalies had a threshold value of 14.41 mg/kg and clustered near sulfide mineral deposits and towards the center of drainage basins. Spatial distribution suggests that the source of mild anomalies is enriched natural concentrations while mine tailings and/or man-made contaminants are the source of extreme anomalies.


Geography, Geology, and Planning

Document Type

Conference Proceeding

Publication Date


Journal Title

Water-Rock Interaction - Proceedings of the 13th International Conference on Water-Rock Interaction, WRI-13