High-Resolution Chemical Fingerprinting in Carbonate Sedimentology: LA-ICP-TOF-MS Methodologies, Advantages, and Emerging Applications

Carbonate sediments are key archives of Earth-surface system evolution, recording climate-ocean-biosphere coupling, diagenetic fluid-rock interaction, and ore-forming and reservoir processes. However, they are inherently heterogeneous across multiple spatial scales, not only in depositional and diagenetic fabrics but also among primary constituents (grains, cements, and matrix), which commonly display distinct elemental inventories. This compositional variability means that bulk analyses inevitably integrate chemically and genetically distinct domains, thereby obscuring primary geochemical signals and potentially biasing interpretation. High-spatial-resolution analysis is therefore essential for resolving component-specific geochemical signatures while enabling reliable, quasi-simultaneous determination of both major and trace element abundances at the micrometer scale, preserving compositional contrasts among carbonate components and diagenetic phases that are otherwise lost in bulk measurements. Laser ablation-inductively coupled plasma-time-of-flight mass spectrometry (LA-ICP-TOF-MS) provides rapid, multi-element imaging at micrometer-scale resolution, enabling direct characterization of elemental variability across carbonate components and diagenetic phases. This review summarizes recent advances in analytical workflows, with emphasis on carbonate-matched calibration, carbonate-specific standardization strategies, and robust data reduction approaches. Case studies highlight applications in compositional mapping of carbonates, phase-resolved semi-quantitative mapping in mixed siliciclastic-carbonate systems, and integrated petrographic-geochemical interpretation of diagenetic alteration, supported by elemental imaging combined with cathodoluminescence and other petrographic datasets. Under appropriate analytical conditions, LA-ICP-TOF-MS resolves growth-related chemical variability, authigenic phases, and spatial patterns of diagenetic modification in complex carbonate systems, providing a robust framework for component-resolved geochemical interpretation and more reliable reconstruction of Earth-surface processes.