A Hylogger-Itrax Core-Scanner Comparison For Multi-Scale High-Resolution Petrophysical Characterisation Workflow

Recent advances in core scanning technologies allow for fast and non-destructive chemical and mineral profiling of rock samples for mineral services and oil and gas exploration. The aim of these automatic core scan methods is to obtain valuable information for profiling drill core cuttings with minimum sample preparation at relatively high speed. In the last decade, a core logging system using an automated infrared-based hyperspectral lineprofiling system, Hylogger, has progressed to become an effective standard for the Australian mineral exploration industry. Its results are used to rapidly obtain mineralogical information allowing the characterisation of different geological formations in near real-time. The interpretation of Hylogger data can be challenging for certain complex mineral mixtures. Here we solve this issue by augmenting the Hylogger interpretation with elemental analysis using the Itrax core scanner equipped with an X-ray fluorescence (XRF) spectrometer. The Itrax core scanner produces high-resolution elemental data of major, minor and trace elements in one dimension. We analyse and compare the Hylogger and Itrax data, with each dataset independently cross-checked using X-ray diffraction (XRD) and thin-section petrology and propose a workflow harvesting the mutual strengths of each method. The recommended workflow consists of rapid screening using Hylogger and XRF analysis, providing new insights into the mineralogy based on comparative multiscale element-mineral analysis. The workflow is tested on four different types of volcanic rock samples, where infrared spectra of individual minerals overlap. We tested tuffaceous ash, basaltic, dolerite, and basaltic-andesitic rocks. Our study shows that embedding Itrax core scanner data into the workflow provides a solution to the challenges of interpreting Hylogger data in complex mineral samples. The proposed workflow provides a total system for multiscale, high-resolution petrophysical analyses and rock property modelling.