Primate ....... thanks for making the first effort publicly in attempting to make an estimate of tonnages, grades & averages. Unlike yourself, I am a later primate perhaps of the Tertiary period, so between us, we might be able to make some sense here for the readers here ! LOL
Lets start with your prism and subsequent determinations.
1. The mineralised zone is Dloerite, not Diorite. Book SG of Dolerite is 3.0 Fractionated or otherwise, whereas Diorite is approx 2.6 - 3.0 The Metallurgical testwork has confirmed that the SG of the mineralised zone hosting the gold is 3.0
2. I am inclined to make the surface width of the open pit at 125m at this stage. That will change your cubic meterage.
3. Because of the shallow nature of the richest section of this system is defined somewhere between 9m - 50m I would consider the volume at those levels, and then tonnages on the SG of 3.o The economics of these depths are enormous !
4. The open pit angles can be compared and followed on the western side of the mineralised zone, following the easterly dipping Keith Kilkenny Fault, at 60 degrees.
5. Calculate the same angle from the eastern side of the mineralisation, dip the open pit wall at 60 west as well, and starting at 125m width at surface. A new volume will appear.
6. Terminate that pit at 50m & 100m depths with a flat floor, calculate volume to both levels, that is 50m and 100m.
7. In doing so, I believe that because we are looking at the richest part of the overall formation, some staggering numbers will be revealed in terms of grams per vertical metre of open pitting. Overall tonnage will be smaller, yes, but the economics will be overwhelmingly staggering. To me that means cash ! After all, why would BRB be looking at a full scale gravity plant so early before a JORC. The numbers really do stack up to the two Directors of BRB who are both graduates with MSc in Economic Geology. Very important IMO.
8. So getting back to your original calcs of volume, I now say that your 18.2M cubic metres and of which I am comfortable with, (from your calcs using that bloody horrible formula) will result in 54.6Mt
9. I have been trying to Average Vertical Depths in terms of Au / m. There are so many holes, lots of work to do, and being a former explorer/miner, only eight and a half fingers left from which to wrk with. Now thats a handicap, not your bottle of Christmas wine ! LOL
10. Lets have a look at just one or two holes only, to see if we can get an average of Au per vertical metre, rather than g/t as seen in the assays.
(a) Hole BBRC0644 which interesects from 120 -147m, an amazing 27m @ 12.37g/t
Lets say that the economic grade at that depth is 2g (which is ridiculously over conservative to say the least), then 12.37g/t needs to be divided by 6 to achieve that 2g/t economic value. So if you divide the Assay by 6, then the intersection length must also be adjusted by multiplying it by 6. So now in the JORC, and using the (wine bottle formulas-no polygons here) we now have 27m x 6 = 162m of economic grade to a depth of 162m.
Now, do that with every hole drilled so far, what do we get? We get some staggering numbers to 50m depth, even more and greater interesctions widths to 100m, and beyond that, as Tom ha said previously, mineralising systems of this nature "keep on giving" ....... and I assume at depth for underground mining at economic depths.
(b) Hole BBRC0487 which intersects from 68 - 87m an amazing 19m @ 6.65/t
Do the same exercise as in (a) above, divide 6.65g/t by 3 = 2.2g ((which is now still well and truly up and above conservative grades at that depth) and multiply the intersection width by x 3 = 57m of Economic Grade. So to 57m of that intersection diddnt quite reach the intersection depth of 87m, so do we leave the last few metres out of the JORC. Whats below it is so important in terms of depth in the long run. Yes, dont leave it there, target the open pit at the same time.
11. In concluding, I feel that it is well worth any investor doing the economic sums to both 50m depth and 100m depth. That is the difference between an Economic Greenfields Discovery and a Non-Economic Discovery.
Lake Roe is Extremely Economic to 100m from my calcs, but, if anyone would like to throw some more holes into the equation, you are most welcome to assist.
So a query to my new found BRB friend here "Primate", would you be able to calculate a volume to say 50m firstly, on an open pit length of 1 kilometre (125m wide). Then if I am not asking for too much, a volume along strile again of 1 kilometre, but to a depth of 100m ? In appreciation I thank you. (I have run out of wine to do those further calculations ! LOL) But....... "Perdant" has been keeping up the supply here prior to Christmas hoping that I would get stuck into those calcs !
In concluding ....... if our "Primate" friend can calculate my a few new figures as of above, and then from new volumes, we can start estimating some new numbers in terms of MOz's, either above or below 50m to 100m.
After all, the value of a Resource is determined basically by DEPTH & GRADE !
AND BRB Have it ALL +++++ Metallurgy ........ SO SIMPLE .......... that ALL adds up to $$$$$$$ 's ............ the medium/long term Investors DREAM !
IMO, BRB is a hold, both medium & long term. Dont let the daily/monthly,yearly glitches frighten you rom BRB. The Gold is still there, it is not going anywhere, other than thru a Crushing/Plant owned by BRB !!!!
GLTAH
Cheers
