Assessment of mineralogical variations in sedimentary basins using core sample analysis

Thesis Abstract

Sedimentary basins serve as critical repositories of Earth's mineral and hydrocarbon resources, yet the mineralogical composition and its spatial variations within these basins remain incompletely understood, often impeding optimal resource exploration and sustainable extraction strategies. This research aims to comprehensively assess mineralogical variations in sedimentary basins through detailed core sample analysis, thereby providing insights into dominance patterns, diagenetic processes, and depositional environments. The specific objectives include quantifying mineralogical compositions within a representative sedimentary basin, analyzing spatial distribution patterns, investigating the relationships between mineral content and lithofacies, and developing predictive models for mineralogical variability based on core data. Employing a quantitative research design aligned with a positivist paradigm, the study analyzes a stratified sample of 150 core sections acquired from four boreholes across a well-characterized sedimentary basin in the Great Plains region. Core samples, representative of the basin’s depositional sequences, were subjected to mineralogical analysis through X-ray diffraction (XRD), complemented by petrographic examination via thin section analysis under polarized light microscopy for validation and contextual interpretation. To ensure data reliability and validity, calibration standards and duplicate analyses were incorporated, with inter-laboratory cross-checks performed periodically. The data were analyzed using a combination of descriptive statistics, spatial correlation analysis, and multivariate techniques such as principal component analysis (PCA) and multiple regression to elucidate the mineralogical variability and its controlling factors. Geostatistical methods, including variogram analysis and kriging, were employed to develop spatial distribution maps of key mineral phases. The study draws upon theories of sedimentary diagenesis and depositional environment modeling, notably the concepts of facies assemblages and mineral stability fields, to interpret the observed mineralogical patterns comprehensively. The anticipated findings include significant spatial heterogeneity in mineral compositions, with dominant phases such as quartz, feldspar, clay minerals, and carbonate minerals exhibiting distinct distribution patterns correlated with depositional environments and diagenetic alterations. The analysis is expected to reveal statistically significant relationships between mineral abundances and lithological facies, as well as insights into the paleoclimatic influences on mineral assemblages. Furthermore, the predictive models developed will facilitate anticipating mineralogical variations in unexamined sections based on stratigraphic and environmental parameters. This study contributes substantially to the existing body of knowledge by providing a systematic, data-driven framework for understanding mineralogical heterogeneity in sedimentary basins through core analysis. It advances the application of integrative analytical methods combining mineralogical, petrographic, and geostatistical techniques within a cohesive interpretative paradigm grounded in sedimentology and diagenetic theories. Additionally, the research offers practical implications for geological modeling, resource estimation, and mining or hydrocarbon exploration initiatives, particularly in basin settings with limited mineralogical datasets. The main conclusion underscores the critical role of mineralogical heterogeneity in influencing basin-scale resource distribution and geotechnical properties. The study recommends the adoption of integrated core analysis protocols in sedimentary basin assessments and advocates for further research incorporating geochemical and isotopic analyses to complement mineralogical data. Future studies should explore temporal mineralogical evolution through diagenetic modeling to refine predictive capabilities further and enhance resource exploitation strategies in similar basin environments.