We build the side view (VERS - vertical electro-resonance sounding) we take depth soundings at specific points. Those points are selected on the basis of the top view data (e.g. at the centre of the highest intensity responses in the top view data - i.e. indications of richest reserve, and also some at lowest intensity points). Why? The depth sounding process at each point can involve up to two hours site work per data point. So, we don't take as many VERS data points as we do the top view (FSPEF - forming short pulse electromagnetic fields). When clients do their drilling they drill at the same points where we have done both top view and side view data samples with #MFT or #mineralfindertechnology. And yes sometimes those points are widely spaced - because of what I said above - the spread from low to high grade.
Correlation between MFT and Drill Cores involves comparing the core samples (columns of rock including layers of ore) with the MFT virtual cores at the same point. So, we validate the mineralisation layering and depth information in the rock cores with the layering and depth model in the MFT virtual cores. We also correlate the grade variation in each rock core with the grade variation model in the Mineral Finder Technology virtual cores. When we don't have samples for calibration, the correlation can be as low as 94% i.e. the MFT 3D model will be +-6% of the physical core. When we have mineral samples for our lab and field equipment calibration, the correlation will typically be 98.5% i.e. the MFT 3D model will be +-1.5% of the depth and grade measures in the physical core.
The MFT precision or accuracy does not vary with depth. That's because the technology is passive - we don't send signals into the lithosphere, so we are not subject to the skin effect which degrades accuracy with depth.
My new post will explain the two words "skin effect”.
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