Speculators in minerals exploration face real difficulties while attempting to interpret drill information when important pieces are missing from company press releases. Most common amongst our problems is determining what a drill interval grades when higher grade intersections are removed—essentially the residual grade. With that in mind, Corebox and Exploration Insights have jointly developed a drill hole interval calculator that provides that residual grade; we are making it available to anyone interested. This will hopefully prove popular with investors (and drive them to our respective websites).
Often news releases that announce drill results report a long interval grading ‘X’ grams per tonne gold (or any metal) over ‘Y’ meters. The Y interval may contain smaller, higher grade intervals within; this is generally indicated by a statement such as: ‘Including __ grams per tonne gold over ___ meters.’ Although this is useful information it only tells half the story. We also need to know what the rest of the interval grades when the high grade intervals are excluded. Would the excluded interval make money (ore) or lose money (waste) if it were mined?
To use our Drill Hole Interval Calculator, simply fill in the data for the long interval and then the smaller or ‘including’ intervals. You are left with the average grade of the drill interval excluding the higher grade sections. If the company has posted the results on Corebox you will be able to visually walk through the property section by section or view it in 3-D. Putting this data into geologic and economic context requires experience and understanding – that is what Exploration Insights is all about.
I hope you find this useful and good luck out there,
Although this calculator is by no means the final word on grade, I think you will find it a useful tool in your exploration research. Have fun and pass it around.