Group II Kimberlite (Orangeite) Mining Review
(Based on a paper entitled: Kimberlite Dyke Mining in South Africa
by: J.J Gurney & M.B. Kirkley
Africa Geoscience Review, Vol.3, No.2, pp191-201, 1996
1. Dykes can persist along strike for over 5 kilometers
For the 5 localities reviewed by Gurney et al that have sustained mining for over 40 years:
2. No evidence of dykes cutting out at depths over 600 meters below surface
3. Consistent and uniform grades as evidenced over 40 years of mining without recorded reduction of grade with depth
4. Percentage of gem can range up to 90-95% as at Bellsbank
5. Average stone size can be large in comparison to pipes (eg. 6 stones per carat at Bellsbank)Note that this is very similar to the average stone size at Snap Lake -.16 carats.
6. The dykes have no direct association with major kimberlite pipes, therefore , may represent feeders to pipes that have eroded away OR volatile contents were too limited for pipe development OR intrusions into host rock structures which were not conducive to pipe development.
So....what might this mean for Snap Lake?....IMO, I see no reason why the grade shouldn't stand up at Snap Lake, if not improve to about 1.5 carats per tonne.....Also, given the reported stone size distribution (about 30 % by weight is over 1 carat in size), some 20 to 30 carat stones should show up in the 6000 tonne bulk, and there is a chance for a stone up to 100 carats in size showing up....if anything is suggested by the size of the mini-bulk sample, it is that Winspear was un lucky given the results they got.....a larger sample like the 6000 tonne bulk will recover some larger stones which should have the effect of increasing the average price per carat valuation and implied value per tonne....as for the percentage of gem diamond?....we know from other Group II kimberlite dykes being mined for over 40 years that Percentage of gem can be as high as 90-95%.....I see absolutely no reason what so ever that the implied percentage of gem from the mini-bulk should change.....in other words, what what we got on the mini-bulk will likely be what we get on the 6000 tonne sample....
IMO, there are going to be a few shocked folks out there when the grades and valuations come in.....but this is just my "arm chair analysis" folks......now maybe this clarifies why the insiders were so keen to take down the private placement themselves and have been noticably absent from the insider reports as big sellers, and why I have added to my position and am sitting tight for the results.
regards,
teevee |
