The Significance of Geochemical Data in Enhancing the Accuracy of Geological Mapping for Greenfield Exploration (Yilgarn Craton, Australia)

This thesis introduces an innovative methodology aimed at refining the precision, characterization, and differentiation of lithologies, a task unattainable solely through visual logging assessment. Recognizing the limitations inherent in visual logging, the incorporation of geochemical data emerges as an imperative and complementary tool. The novel approach to augment the accuracy of geological mapping in greenfield exploration project within the Yilgarn Craton involves optimizing Scott Halley’s workflow and the Principal Component Analysis workflow, the latter employed for the validation of the former. In the context of Target 3, while visual logging assessment could distinguish primarily between granite and basalt lithologies, the amalgamation of the methodologies enabled a more nuanced differentiation. Categorizing the tenement into four distinct lithologies: granite, andesite, ultramafic, and basalts. Particularly noteworthy is the capability to discriminate between basalts in the eastern sector and more intermediate rocks prevalent in the western portion of the tenement, a feat unattainable through visual logging alone. Discrimination of ultramafic rocks was facilitated through the analysis of Scandium vs Chromium, Magnesium, Aluminum, and Zirconium, while discrimination between mafic and felsic rocks employed Scandium vs Titanium, Thorium, Vanadium, Zirconium, Yttrium, and Niobium. The outcomes of the Principal Component analysis (PCA) corroborated the distinctions established by the lithogeochemical workflow, notably emphasizing by the discernible presence of andesite in the western segment of the tenement and basalts in the eastern segment. In conclusion, this comprehensive framework underscores the considerable potential of multielement geochemistry, as evinced by the rectification of mislogged data in 41 out of 282 samples, constituting 14.5% of the entire dataset.