Lithological discrimination of altered volcanic rocks based on systematic portable X-ray fluorescence analysis of drill core at the Myra Falls VHMS deposit, Canada

摘要: Portable X-ray fluorescence (pXRF) analyzers can rapidly and inexpensively provide chemical concentrations of a range geologically significant elements, often with instrument detection limits below 10 s ppm. We compiled conventional XRF lithogeochemical data from Myra Falls to assess Ti/Zr discrimination criteria for volcanic-hosted massive sulfide (VHMS) host rocks at Falls. Robust discrete trends coherent volcanic rock types were identified this dataset. To test if pXRF analysis could reproduce these trends, two experiments designed. Single-spot analyses pressed powdered drill core samples three-spot measured directly on the flat, cut surface compared results same sample sets. Our indicate that both sampling methods laboratory based Ti Zr, there is no improvement in accuracy or precision between powders unprepared samples. propose calibration, estimation total measurement uncertainty, reduction procedure systematic improve lithological logging altered types. suggest become routine part lithology providing, some key robust time-efficient be used define important, cryptic, boundaries therefore has ability geological stratigraphic interpretations, which are vital developing mineral exploration models, VHMS deposits other economic systems.