A delightful afternoon with Mr. Tilsley
in response to
by
posted on
Jul 02, 2010 12:08PM
New Discovery Resulting in a 20KM Mineralized Gold Belt
I had the pleasure of spending the better part of Wednesday afternoon with Jim Tilsley at his beautiful home in Aurora. Jim was kind enough to invite me over to discuss the effects of small sample size (ie the current drill core) on the underestimation of grade and his strategies for developing an accurate correction factor (multiplier) that can be applied to the drill results at the time of a resource estimation. I think the real take-home message for me was the stunningly large number of misses (assay values of 0 g/t) that we should expect to get before we can accurately determine the true gold grades in this type of deposit. These sampling-size generated zeros are expected, and almost celebrated by Tilsley in his review of the data for this deposit. Ironically, if there was evenly distributed fine gold in every core sample, this deposit would likely have been mined out by now and he would not be having the time of his life. I won't go into explaining how the sampling/subdivision of the already small core sample during assay preparation creates an even greater probability of getting more zeros, but the term that Jim uses is that we are "over-powered by sampling zeros". OK so now combine the high chance of getting a zero in each metre (5 kg) of core with the fact that when you do get a hit, it is likely to look fantastic because of small core size and the nuggety/nugget cluster distribution in this deposit, and you begin to develop an appreciation for why this property has provided such a challenge for previous claim holders who didn't have Jim's knowledge of sample size effects on low event number statistics.
Jim admits that he doesn't quite yet know the size distribution of the gold particles in the deposit (although they have some clues from the -80 Mesh data used in their assays) but that once he has that information that modeling the expected tonnage of the resource will be much easier. He expects to determine this empirically over the next several months.
The last bit of information I will share will be about Jim's perception of the culture at GNH. He described the company environment as almost family-like at all levels of GNH. The entire crew is awash with excitement and even after returning from a long day in the field they have an amazing amount of energy. As for Jim's excitement level, he often reminds the younger geologists on the crew "Don't expect your next job to be as rewarding as this one. This is a one in a lifetime opportunity" I don't know about you - but that's good enough for me.
Have a great weekend everyone!
Scott