Spatial distribution, potential sources and geochemical baseline of Fe and potentially toxic elements in stream sediments in Quadrilátero Ferrífero, Brazil

• Published in: Applied geochemistry Vol. 190; p. 106483
• Main Authors: Medeiros Filho, Lucio Cardoso de, Salomão, Gabriel Negreiros, Dall’Agnol, Roberto, Almeida, Gabriel Soares de, Amarante, Rafael Tarantino, Sahoo, Prafulla Kumar, Guimarães, José Tasso Felix, Silva Filho, Emmanoel Vieira da, Marques, Eduardo Duarte, Leão, Lucas Pereira, Mendonça, Raquel Fernandes, Soares Junior, Abraão Gomes
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2025
• Subjects: Geochemical baseline; Geochemical Mapping; Lithogeochemical Controls; Multivariate Geochemical Analysis; Quadrilátero Ferrífero (QF); Stream Sediments; Stream Sediments; Lithogeochemical Controls; Quadrilátero Ferrífero (QF); Geochemical baseline; Geochemical Mapping; Multivariate Geochemical Analysis
• ISSN: 0883-2927
• DOI: 10.1016/j.apgeochem.2025.106483

This study investigates geochemical baselines and the spatial distribution of potentially toxic elements (PTE) in stream sediments of the Quadrilátero Ferrífero (QF), Brazil—an iron-rich province with complex geology and extensive mining activity. A total of 804 microcatchments were sampled and analyzed for 15 environmentally relevant elements (including Fe, As, Cd, Hg, Ni, and Zn), selected based on their ecological significance, toxicity, and geogenic occurrence in mineralized terrains. Geochemical baselines were calculated using median ±2 × median absolute deviation (mMAD) and Tukey's Inner Fence (TIF), with mMAD providing more conservative and robust thresholds. A compositional data analysis (CoDA) framework was applied using isometric log-ratio (ilr) transformation and robust principal component analysis (RPCA) to explore geochemical-lithological affinities. Results showed that metavolcano-sedimentary sequences, especially from the Rio das Velhas and Minas Supergroups, exhibit elevated concentrations of multiple PTEs, while metabasic and ultrabasic units are enriched in Cr, Ni, and Co. The TTGM unit also showed distinctive enrichment in Ba and Pb. Spatial patterns suggest that lithology is one of the main controls on PTE distribution and represents a valuable tool for interpreting geochemical variation in mineralized regions. These findings offer a solid basis for environmental monitoring and future integration with land use data to support contamination risk assessments and sustainable watershed management in areas such as the QF. •Mapping for 15 potentially toxic elements (PTE) determined across 804 microcatchments in the Quadrilátero Ferrífero, Brazil.•Robust baselines using mMAD and TIF highlight spatial variability linked to distinct lithologies.•Compositional data analysis (CoDA) with ilr transformation and RPCA revealed clear geochemical-lithological affinities.•Lithology was identified as a key factor influencing natural PTE distribution in a mineral-rich setting.•Findings support tailored environmental assessments and integration with land use for contamination risk analysis.