@Sudzie, the below was posted prior to recent results.
With recent holes, particularly 54c1 and 54c2, it is reasonable to assume that high grade mineralization continues to the SW.
PamplonaTrader wrote: In this fourth installment of the series (
pt 1,
pt 2, and
pt 3), we attempt to render a resource calculation for a select portion of the high-grade core within the A2 shear. The scope for this exercise is limited to the area between AR-14-15 and AR-15-44b within the A2 shear given that the area has seen the most drilling activity. As such, a crude estimate may be rendered with a reasonable degree of confidence.
It is very important to note that the following calculation is intended to cover just a fraction of the total mineralized area at Arrow and as a consequence, the total mineral inventory will likely far exceed any figures that are produced. First we contemplate the assumptions.
GRADE
For the purpose of this exercise, I use a conservative blended average of 2% U308. As can be seen in the tables below, 2% U308 is very much on the low end. AR-14-15 averaged 2.29% U308 whereas AR-14-30 and AR-15-44b each averaged 5% U308 or better over longer intervals.
STRIKE AND DEPTH
Conservative dimensions are used in an attempt to capture the volume of ore for which grades are known. I used a strike of 100m to roughly represent the area between discovery hole AR-14-15 and blockbuster hole AR-15-44b. A vertical extent of 250m is established to capture the bulk of ore grading 2% or better. See below:
WIDTH
For width I calculated true thickness and used the averages of AR-14-15 and AR-15-44b. Both using max down-hole ore dilution of 4.5m.
· AR-14-15 was drilled at a dip angle of -70 degrees and returned 54.95m of 2.29%:
54.95m * COS 70 = 18.79m true thickness
· AR-15-44b was drilled at a dip angle of -75 degrees and returned 168.5m of 5.01%:
168.50m * COS 75 = 43.61m true thickness
· The blended average of 18.79m and 43.61m =
31.20m width
Note that as NexGen has drilled down plunge to the SW, the A2 shear widens and may come together with the A3 shear at depth. Please see the graphic below:
DENSITY
The specific gravity of gneiss ranges 2.6 to 2.9 whereas uraninite ranges 6.0 to 10.0. I used the averages of each. At 2% U308, I can use a crude calculation of 98% gneiss (2.75 sg) + 2% uraninite (8.0 sg) to arrive at a blended ore density of
2.86.
It's interesting to note that density for AR-15-44b ran at a specific gravity of
4.00.
CALCULATION
Given the above assumptions we calculate in-situ pounds within our area of interest by using the following formula:
· (Strike * Depth * Width * Density) * Lbs/Tonne * Grade = In-Situ Pounds
(100m * 250m * 31.20m * 2.86) * (2,204.62 lbs/tonne) * (2.00% U308) =
98,361,326 lbs U308
Again, it’s helpful to remember the limited scope of this calculation. The area of interest only covers a
fraction of the
A2 shear which is only one of 3 known shears!
Recall that management believes AR-15-51, which is a 100m step-out from hole AR-15-44b, may have clipped the top of a very large and strongly mineralized system. Below is a sensitivity table assuming varied strike lengths:
Finally, some graphics to put the area of interest in the context of the total mineralized area measuring 645m strike * 820m depth * 215m width. The
green boxes represent the
98.36mm lbs of U308 calculated in the exercise above:
