I thank you for suggesting this weekend's foray into musing and research. There is not much meaning in making SP estimates IMO but putting numbers on levels of success is not too outrageous. Know what you mean about the bigger dream it's a bit like imagining winning Lotto. There will be another Sirius out there one just has to be lucky to find it and survive the ride. AZY is a possible IMO.
As mentioned in my previous post here are some cogitations on Calibre North.
I checked through the thread for 16 Dec 2015 Ann of the last drill results for Calibre and didn’t find any rough estimates of the size for the data provided. As an exercise to find out the potential magnitude of the northern extension of the main Calibre deposit any estimates must be viewed as simplistic and not reliable. Apologies if already covered. DYOR
The announcement gives the following dimensions:
Some 80m of cover
in excess of 770m of strike length,
up to 160m width, and
some 50-100m of drilled vertical extent at least which is wide open at depth.
Grades to date appear to have been higher than in the main part of Calibre but even if the bulk Au Cu grades are similar to those to the south it would be a minimum of 0.56g/t Au and 0.17% cu which would be less likely IMO & disappointing.
From the general figures above (plus a low density estimate of 2.5) a basic calculation for Calibre north gives a back of the envelope, wild estimate:
800X150X100x2.5 is roughly 30Mt.
This estimate is only meant to give an idea of the order of the possible tons per 100m at Calibre North and nothing more. DYOR IMO etc etc.
Grade is more difficult to guesstimate but given the visually higher grades a reasonable wild guess might be between 1 and 1.5g/t Au eq. Using 1.5 g/t Au eq and 30Mt would give around 1.5 Moz contained gold equivalent.
There are existing JORC resource for both Calibre ( 47.8Mt @ 0.56g/t Au ) and Magnum (16.1Mt @ 0.66 g/t Au) both with Cu Ag potential credits (AZY projects page).
As mentioned by a poster (16634619 ) on the thread 16.Dec 15 the 80m of overburden, while significant, can readily be removed and an open pit developed. If mineralization continues uniformly down dip (it won’t), and such a pit were developed on Calibre North alone to a depth of say 380m below surface, the above calculations suggest a resource of 4.5Moz at some 1.5 g/t Au eq.
Whether such a resource would be economic depends on many factors only two of which I am willing to comment on.
If the grade comes in at the 2+ g/t Au eq then the economics will improve dramatically. On the other hand the 2006 NCM Minyari resource estimate I posted last weekend ( 18232932) surprised some HC readers by being on the low side for grade and tonnage which suggests it can be very difficult to estimate the size and grade of the resource without rigorous calculations.
Rock properties: About 10 years ago I chatted with drillers who had worked in the Telfer area and they told me tales of very hard rock and slow drill penetration. Looking at the core photos in AZYs presentation (back ground to header) IMO they are of highly silicified lithologies with stringer sulphides. If they come from Calibre or Magnum then mining and milling costs could be high. Boddington has been having issues with hard ore for years (recent chat with a supervisor) - hopefully the same won't be the case at Citadel if there is ever any development.
At present Calibre North IMO represents the obvious place to focus the next round of Citadel drilling to expand an already exciting exploration target. Beyond that there are some very tantalizing IP targets which IMO may be drill prioritized more by how shallow they are than intensity or potential size. Then again the geophysical interpretation of some of the deeper ones may outweigh the increased cost and risk of deep drilling.
If one or more of the IP anomalies prove to be mineralized enough to be a mine then Rio IMO certainly has the access to finance and experience to open pit or block cave as is necessary.
Minyari first results in the next two weeks. Then a couple of more rounds of results announcements from there through to September. IMO there will be an ANN this quarter regarding a drilling campaign at Citadel. A promising news flow through to Christmas is likely.
This news flow will impact on the SP estimates in my post 18287428 and hopefully create a positive feedback loop to increase the price as “boxes get ticked”.
(20min delay)