Application of 2D, 3D and in-situ techniques in quantitative characterisation and dating of sedimentary rocks

Here we present a practical workflow that can be applied to characterising and dating a variety of sedimentary rocks. The approach integrates multimodal mineralogical, petrological, and in-situ radioisotope characterisation. We utilise the Tescan Integrated Mineral Analyzer (TIMA) for automated, 2D quantitative mineralogical analysis of source and reservoir rocks including shale, sandstone, and carbonate. Subsequently, we integrate X-ray computed tomography (XCT) with TIMA to undertake multimodal, mineralogical and petrological characterisation of samples in order to build a 3D visualisation and volumetric reconstruction of mineralogical phases (and organics) and pore space. The resulting multimodal, 2D-3D XCT-TIMA mineralogy provides quantitative characterisation of sediments (from regional basin scale to local reservoir scale), and identifies appropriate mineral phases for in-situ laser ablation mass spectrometry geochronology (e.g., in-situ U-Pb dating of carbonate minerals, in-situ Rb-Sr dating of potassium-bearing minerals, and U-Pb and (U-Th)/He dating of siliciclastic sediments, etc.). The multi-technique workflow yields quantitative mineralogy and petrology of sediments and provides insights into their provenance, diagenesis, and burial history, with advantages over conventional methods in terms of sample consumption, time, cost, safety, and spatial resolution.