The significance of Thor Mining PLC’s (LON:THR) latest drill results might just surprise you.
Thor Mining has received results from 11 holes at its 40%-owned Bonya Tungsten Project, located in Australia’s Northern Territory. These latest results include highlights such as: 20m at 0.24% WO2 from 2m (19RC034); 8m at 0.24% WO2 from 26m (19RC035); 8m at 0.63% WO2 from 62m (19RC037); and 2m at 0.71% WO2 from 11m and 5m at 0.33% WO3 from 17m (19RC039).
Clearly these are some large intercepts, with intersections of mineralisation up to 20m wide, 17m estimated true width. But what about the grades? How significant are they?
Readers that are used to seeing assay results for base metals, such as copper or zinc, might look at these results and think they are low-grade. Which is why context is key, if we compare these drill results to an extensive peer group of tungsten deposits (Figure 1), we can see that tungsten deposit grades vary from 1.026% WO3 to 0.061% WO3.
Figure 1: Grade Curve for Tungsten Deposits
Source: Metals and Mining Research Corporation
High-grade tungsten deposits vary from 1.026% WO3 to 0.326% WO3, while mid-grade tungsten deposits vary from 0.30% WO3 to 0.15% WO3, with low-grade deposits being below 0.15% WO3 (Figure 1).
With this information, we can now give Thor’s drill results the assessment they deserve. With grades that vary between 0.71% WO3 to 0.24% WO3, these drill results from the highlights section of the RNS are clearly high-grade to mid-grade, and as to be expected there are also some smaller intercepts at lower-grades, which can be seen in the summary table of the RNS.
What is really exciting for Thor, is that the White Violet target, within the Bonya project, is only located c. 35km from Molyhil (Figure 2). Molyhil has a total JORC 2012 compliant mineral resource estimate of 4.7mt at a grade of 0.28% WO3, which would give the project a seven-year mine life.
Figure 2: Map of the Molyhil and Bonya Projects
Source: Thor Mining
The tungsten mineralisation at White Violet, and potentially from other targets within the Bonya Project, could with further positive results and metallurgical and economic studies, provide additional feed for the proposed Molyhil mill, extending the mine life beyond seven years, adding significant value to the project.
All this is very positive, but there is one area where investors should be cautious, these drill results are not assay results, they have been obtained from a portable XRF machine, so the accuracy level is not as high as it is with traditional assays. Until we have the assay results investors should treat these results as an intermediate guide to the success of the drill programme, awaiting final confirmation from the assay results.
Thor has now moved the drill rig to the Samarkand target, where drilling is underway and further results will follow. I for one look forward to seeing what comes next.