Processing and Interpretation

The HCI-3 system produces unprecedented mineral and textural map products, in respect to both their spatial and spectral scale and sensitivity. The HCI-3’s ability to spectrally image drill core and cuttings at sub-millimetre resolution offers distinct advantages in the processing, analysis and interpretation of spectra as well as in the derivation of trends in both the alteration assemblages and the chemical variations of individual minerals.

Distribution of Illite (high abundance in red, low abundance in blue)

Unlike traditional spectral systems used in rock sampling (generally hand-held/lab-based commercial spectrometers used to measure single points along lengths of core at set distances), the fine spatial resolution and continuous imaging capacity of HCI-3 is able to capture a large number of pure pixels providing a comprehensive and easily determined group of end member minerals that are subsequently mapped throughout the borehole.

The Mapping Process 

  • Mineral mapping is done using in-house proprietary software
  • Much of this process is automated leading to fast turnaround times for delivery of mapping products
  • Through an initial testing and consultation process, our spectral geologists create a site-specific library for each deposit or reservoir, often dividing this further into type-domain libraries for resource zones
  • Such libraries are used throughout the mapping of the deposit or reservoir and provide a definitive record of project mineralogy
  • The imaging nature of the data means spatial relationships (eg. disseminated, veined, intra-fracture, etc.) are immediately apparent

Corescan image and data prodcuts

The high spectral resolution and SNR of HCI-3 also allows for confident mapping of compositional parameters of individual alteration minerals present throughout a section of core.

  • Variations of these parameters (such as degree of crystallinity, amount of aluminum, iron, magnesium etc.) may relate to pre- and syn- mineralisation phases which can be distinguished from those parameters relating to post-mineralisation events
  • Such parameters may also say something about formation temperatures, reservoir chemistry (in oil/gas and geothermal applications) and source fluids



Semi-Quantitative Downhole Mineralogy

The calculated mineral map for a section of core (or cuttings) can be used to compute quantitative down-hole mineralogy. This digital mineralogical assay data is easily exported for use in third party 3D visualisation software for mine or reservoir planning or into logging software for comparison with traditional down-hole data (eg. metals assay, temperature, conductivity, etc.)Quantitative downhole mineralogy 

  • The quantitative nature of the data allows for rigorous statistical analysis of mineralogical data using third party software
  • While done in the past with traditionally logged data, the consistent mineralogical data from Corescan comes closest to real, unbiased input data for such models
  • Ultimately improves the accuracy and consistency of ore/resource projections for exploration, mineral process and metallurgical studies

Textural Mapping

Both physical and mineralogical textures are also easily tracked with the HCI-3 system. General texture such as degree of veining or dissemination can be identified using the hyperspectral-derived mineral maps. This differs greatly from historic methods that utilise simple photography and basic mineral colour; a method prone to high levels of error and subjectivity.

Physical texture, such as faults, fractures and qRQD (quick RQD) are performed using the high resolution laser profiler data. The combination of derived mineralogy with texture produces sophisticated new products with particular application in the geotechnical and mineral process fields. Automated rock quality measurements by Corescan bring new efficiencies and accuracy to an important but expensive and time-consuming process.

Quick RQD Image
Automated rock quality measurements for geotechnical and mineral process applications