LASER ABLATION ICP-MS TRACE ELEMENT MAPPING OF HEAVY METAL DISTRIBUTION IN MINING-IMPACTED SEDIMENTARY ROCKS

Abstract

Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) has emerged as a transformative analytical technique for investigating the spatial distribution of heavy metals in mining-impacted sedimentary rocks. Unlike conventional bulk chemical analyses, which provide only average elemental concentrations, LA-ICP-MS enables high-resolution in-situ mapping of trace elements, preserving the mineralogical and textural context of contamination. This review examines recent advancements in laser ablation technology, aerosol transport systems, mass spectrometric architectures, and quantitative calibration strategies that have significantly improved analytical accuracy and spatial resolution. Special emphasis is placed on the advantages of 193 nm excimer lasers, low-dispersion ablation cells, and time-of-flight ICP-MS systems for rapid multi-element imaging. The study further explores the geochemical mechanisms controlling heavy metal sequestration, including adsorption, mineral substitution, and redox-driven remobilization processes in sedimentary environments affected by mining activities. Emerging computational approaches such as machine learning, dimensionality reduction, and automated mineral classification are also discussed as powerful tools for interpreting high-dimensional elemental datasets. Several case studies from major mining regions, including the Athabasca Basin, Sullivan Mine, and Qaidam Basin, demonstrate the practical applications of LA-ICP-MS in environmental forensics, critical metal recovery, and contamination source apportionment. In addition, developments in three-dimensional voxel mapping and correlative microscopy highlight the growing capability of the technique to investigate subsurface transport pathways and mineral-scale weathering processes. Overall, LA-ICP-MS mapping represents a major advancement in environmental geochemistry, offering unparalleled insight into heavy metal behavior, environmental risk assessment, and sustainable resource management in mining-impacted geological systems.