| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4456878 | Journal of Geochemical Exploration | 2016 | 9 Pages |
•Drill fines produced diamond drilling are proposed as a new sample medium.•These drill fines are representative of the lithology intersected by the drill hole.•The drill fines are transported fast enough to avoid any lag and the depth is accurate.•The drill fines can be analysed by portable XRF-XRD sensors in near-real time.•The data can be used to constrain lithologies, alteration and ore types in near-real time.
The analysis of drill powders (drill fines) extracted from fluid that is returned during drilling can provide a sampling media that records cm-scale changes in the geochemistry of the rock being drilled through. In addition to being an ideal sample media (~ 78% of particles are < 38 μm; cf. conventionally pulverised samples where ~ 42% of particles are < 38 μm) that is ready for analysis once dried, diamond drill fines may produce a larger sample per meter drilled than recovered by the core itself, and thus be a better representation of the rock that has been drilled through. For an HQ hole size (for rocks with specific gravity = 3100 kg/m3), the mass of drill fines produced in 1 m of drilling is 12.5 kg, whereas, the mass of the 1 m in length of core for the same interval is 9.7 kg. In this contribution we compare high-spatial resolution geochemistry collected by portable X-ray fluorescence (pXRF) and mineralogy collected by portable X-ray diffraction (pXRD) from 12 m of diamond drill core to the corresponding interval of drill fines to highlight the depth fidelity (at the cm-scale) that this sample source may record. We also demonstrate that the drill fines that were previously discarded show high potential to act as a representative sample media of the lithology intersected by the drill hole and can be successfully used for analysis in real time. The integrated pXRF-pXRD data can be used to constrain lithologies and contacts between various units, hydrothermal alteration and ore types.
