RE:Drill Interval CalculatorBoss & BXJU, this may help you understand what Grade Smear is and why you should use the interval calculator. FIRST, let me say, I am glad BGM is providing the high grade intercepts within drill holes. This would be when a company Has the including. IF you see a company list a long high grade intercept, and they don’t break out the grades, you should have a concern. I would call and ask if a hole did have high grade within the long intercept. For example, lets use the most recent P/R from BGM first. The first hole CM11-83 reported the following:
12.2m @ 9.46g/T
Including 9.1m @ 12.49 g/T
AND including 6.1m @ 18.11. The high grade intercept contributing to the 12.2m @ 9.46 g/T. If you plug these numbers into the interval calculator, you get these results.
Using the 9.1m value you get a residual of 3.1m @ 0.565 g/T, meaning the grade of the core outside of the 9.1m. (9.1m +3.1m). As you can see, the 12.2m is not looking so good anymore because the grade outside the high grade is marginal or may be marginal.
Using the 6.1m value you get a residual of 6.1m @ 0.81 g/T.
Here is hole:
CM11-102 from the 2011 P/R using Fire Assay ( this is only part of the hole data)
- 62.3 m (204.5 feet) of 14.2 g/T (0.415 oz/t) gold between 58.8 and 121.1 meters (192.8' and 397.3')
- including 34.7 meters (113.9 feet) of 25.2 g/T (0.735 oz/t) gold between 70.3 and 105.1 meters (230.8' and 344.7') and
- including 0.9 meters (3.0 feet) of 858.1 g/T (25.023 oz/t) gold between 77.4 and 78.3 meters (254.0' and 257.0')
Using the 62.3m interval first and the high grade of 0.9m @ 858.1 g/T you get the following:
Residual 61.4m @ 1.83 g/T. Now, 1.83 g/T is not bad, but you actually see why it is important to understand what it really means. The actual values will be blocked out in the model, they will not use the 62.3m @ 14.2, they will actually break it down as per the intervals of high grade. It is actually amazing to play with these numbers on Pretium Gold’s P/R. You will see why issues have come up. BTW, I love PVG, I just see when it actually gets down to final mining time, the amount of tons per day may be smaller than the PEA suggested. I think it is highly likely the widths of mining may shrink when the FS is completed… JMO.
SO Boss, it has nothing to do with believing, it has to do with what the DATA TELLS YOU. All I can do is read what is provided.