Comparative Analysis of Hydrothermal Mineralization in Intrusive and Extrusive Rock Settings

Thesis Abstract

Hydrothermal mineralization significantly influences economic mineral deposits, yet comparative studies examining the mineralogical and geochemical characteristics of mineralization in intrusive versus extrusive rock settings remain limited. This research addresses the persistent knowledge gap concerning the variation in mineralization processes, mineral assemblages, and associated geochemical signatures between these geological environments. The primary aim is to elucidate the distinctive and overlapping features of hydrothermal deposits associated with intrusive and extrusive rocks to enhance predictive models for mineral exploration and deepen the understanding of hydrothermal processes. The study sets out to achieve three specific objectives (1) to characterize the mineral assemblages and textures in mineralized zones associated with intrusive and extrusive settings; (2) to analyze and compare the geochemical signatures, including trace element and isotope compositions, of mineralizing fluids and deposits in both environments; and (3) to develop a conceptual model delineating the key controls on mineralization processes within each geological context. Employing a comparative cross-sectional research design, the study focuses on two representative mineralized zones, one within an intrusive igneous complex and the other within an extrusive volcanic edifice, located in a mineral-rich geological belt. The population comprises all mineralized zones identified through prior geological mapping and geophysical surveys within these regions. A stratified random sampling technique was used to select 30 drill core samples—15 from each setting—ensuring representative mineralization styles and alteration zones. Data collection entailed detailed petrographic analysis, mineral chemistry using electron microprobe analysis (EPMA), and geochemical assays, including inductively coupled plasma mass spectrometry (ICP-MS) for trace elements, and isotope analyses (Sr-Nd-Pb isotopic ratios) to trace fluid sources. To assess the mineralogical variability, mineral phases were identified and quantified through petrographic microscopy and quantitative X-ray diffraction (XRD). Geochemical data were statistically analyzed using multivariate techniques—including principal component analysis (PCA) and hierarchical clustering analysis—to discern patterns and differences between the two settings. Additionally, regression models and ANOVA tests evaluated the significance of variations in trace element concentrations and isotopic ratios, testing hypotheses related to fluid sources, temperature regimes, and mineralization sequences. It is anticipated that the study will reveal notable differences in mineral assemblages; for instance, intrusive settings are expected to host larger, late-stage mineral veins with abundant sulfide mineralization, whereas extrusive contexts may present more pervasive alteration zones with economically relevant oxide mineral deposits. Geochemical analyses are expected to demonstrate distinct fluid signatures, with intrusive mineralization exhibiting higher temperature indicators and more evolved magmatic signatures, while extrusive deposits may show signatures indicative of crustal or meteoric fluid contributions. The research is also expected to identify key controlling factors, such as host rock composition, geothermal gradient, and structural features, that influence mineralization styles within each setting. This study contributes new insights into the distinct mineralization pathways in different geological environments, providing a robust conceptual model that integrates mineralogical and geochemical data. Its findings will refine exploration strategies by highlighting signature features specific to each setting, thereby improving resource prediction accuracy. The research will also advance theoretical understanding of hydrothermal processes, supporting the application of integrated mineralogical and geochemical approaches for mineral deposit delineation. The study concludes that recognizing the differences and similarities in mineralization patterns is crucial for targeted exploration. It recommends adopting a multidisciplinary approach combining petrographic, geochemical, and structural analyses in future exploration endeavors. Further research should focus on expanding sample sizes and exploring additional geological settings to validate and refine the conceptual model, thereby fostering more effective mineral resource management and sustainable extraction practices.