Drill Results
in response to
by
posted on
Mar 07, 2012 11:15PM
Keep in mind, the opinions on this site are for the most part speculation and are not necessarily the opinions of the company WITHOUT PREJUDICE
Wiser asked the following:
"Could someone give me an example of what good results should look like and what they actually mean?? Like when you guys are talking about 0.53g/t and such...hope this makes sense."
For those who do not know, I submit the following:
The purpose of drilling is to define a mineral deposit in three dimensions (ie: length x width x depth). When an ore-grade intercept is discovered, the drill core will show mineralization over a certain drill-core length. In order to prove continuity and true width, a series of "step out" holes will then be completed by moving out in a series of steps--anywhere from 25m spacings to 100m spacings--in all directions, in order to define the limits of the deposit. By extrapolating the angle of the holes combined with the length of the intercepts and meters of spacing between holes, a three dimensional mass known as a resource footprint appears.
Companies who are defining a deposit will talk about a resource footprint being traced over x-strike length, x-width and x-depth. Now we have a three dimensional mass. If we knew the average grade represented in grams per ton (g/t) we could calculate how many gold ounces the mass contains. Unfortunately, we usually do not know this until the company comes out with an initial resource estimate. This is where the drill hole data gives us some clues.
So what do good results look like?
A company might report drill results like say 153m of 1.5 g/t. This obviously means that over a length of 153 meters they found an average gold grade of 1.5 grams per ton. The higher the grade and the longer the intercepts, the better. Normally long intercepts show lower grade, while oz/t intercepts are usually short. 0.5g/t is often used as a cut-off, anything lower grade being uneconomical. Some companies are going to a 0.3g/t cut-off, but I believe that is too low. When looking at drill holes, you generally want to see intercepts above 1g/t because it will average much lower when calculated into a resource estimate.
In order to know whether a drill result is economic or not, you simply mulitply the length of the intercept by the g/t to get the "drill number" (ie: 153m x 1.5g/t = 229.5). As a rule of thumb, the drill number 100 is usually economic. There are other considerations such as depth, whereby drill numbers under 100 may be economic if high grade and near surface). So 1m of 100g/t, 10m of 10g/t, and 100m of 1g/t may all be economic. High grade is generally more sought after, but rarely comes over long intercepts. CB Gold's Oct 24th intercept of 115m of 7.6 g/t would be considered high grade over a long interval. Their shareprice jumped accordingly, however, they have not been able to duplicate that hit and their shareprice has slid some 40%. On they Feb 27th they reported 24m of 1.3 g/t.