I found the new .pdf presentation exciting! I can hardly wait to go through the Powerpoint as well. They / V.P. Brian Maher described the situation very well.

grams/ton and gram*meters

There is widespread use of gram*meters or g*m on mining plots. Thanks to Brian for making it clear for me. For anyone who is fuzzy on it, perhaps I could be useful explaining the best I can. Forgive me if I belabour the point - if you know all this then just skip it. I was originally confused too and I figured we might as well all be on the same page with this.

First mistake I made - I had assumed that it's complicated, somehow involving densities of quartz and cross-multiplication of units. Forget all that. I hope it's not a huge disappointment, but the g*m thing is about as complicated as working a Bic pen - i.e. it's utterly simple.

When you look at a vertical cross-section of a gold zone - for example the multicoloured cross-section of the Golden Mile that's on Page 16 of the current .pdf presentation, the whole point of using g*m to colour the various cross-section areas is to describe the total amount of gold in a particular place on the cross-section (at a particular depth x distance-along-strike). At a given place, how much total gold?

One way of getting it clear is this: when you get to mining the gold ore out, it makes little difference whether you have a certain amount of gold in one thick vein, or whether instead you have the same gold hosted in a bunch of thin veins arrayed all right next to each other. The idea is to be able to have a measure for how much total gold is at one location, and also to be able to directly compare it to another location, even if the veins in each place happen to be thick or thin or tapered or wiggly or whatever.

Within reason, looking at a particular area of the cross-section (for a particular depth x particular strike), you are taking all the rock from the cross-section face right there out to the mill anyways, so the total gold you recover for each square meter of the cross section is the same with one vein vs. the same total gold in a few thin veins. I am oversimplifying, but that's the idea.

Some Number Examples

First example: Still looking at a vertical cross-section of your gold zone, suppose you have a vein that just by chance happens to be 1 meter thick (looking laterally into the cross-section rock face), and that you have a particular grade there in grams/ton. In this case, the grams/ton and g*m numbers are the same. Both numbers are telling you that for a 1m thickness (the vein just happens to be that thick), you have so many grams of gold to recover.

With real numbers: at a depth of zzz meters (doesn't matter) and xxx meters along strike (doesn't matter), assays show a 1 meter thick vein with a grade of 30 grams/ton. In this case the g*m number is also 30 g*m. Same number. At the cross-section face at this location, a area of 1m depth x 1m strike of the cross-section produces 30 grams of gold.

Second example: At a particular cross-section location (depth/strike), you have a grade of 15 grams/ton in one vein that is 0.5m thick, and parallel to and next to the first vein you also have a grade of 15 grams/ton in a second vein that is 1.5m thick. When you mine you will take out both veins side by side.

You have 2 meters of vein thickness in total, and they both have the same grade of 15 grams/ton. 2 meters at 15 grams/ton gives the same gold as 1 meter at 30 grams/ton. The total amount of gold you have is the same as in the "first example", but it's spread out over 2 meters thickness instead of 1. You have to mine the whole 2 meter thickness anyways, just to get the machinery in, so what you get out of the mill for that location is the same amount of gold either way.

For a 1m x 1m area of the cross-section, you mine 2 meters thickness and you get 30 grams of gold total, same as in the first example. You can also write 15 grams/ton x 2m = 30 g*m. The grade is less but the veins are thicker overall, so you get the same 30 grams gold.

Third example: Obviously the above examples are a bit contrived. The usefulness of the g*m comes into its own when you have all odd numbers for grades and thicknesses. It's the only practical way to answer "for mining a given depth-range and strike-length of my gold-zone, how much total gold comes out?

Suppose in area A you have grades and vein thicknesses of 40g/t : 0.5m and 27g/t : 3m. The g*m figure is 40 x 0.5 + 27 x 3 = 101 g*m. For each 1m x 1m area of mining at the cross-section rock face, you get 101 grams of gold.

In area B you have 100g/t : 0.3m and 15g/t : 4.7m, and you want to know - is this area of the cross-section less worthwhile to mine or more worthwhile? 100 x 0.3 + 15 x 4.7 = 100.5 g*m. For each 1m x 1m area at the cross-section rock face, you get 100.5 grams of gold. So area B is essentially the same as area A, 100.5 vs. 101 grams.

Further notes: Even then, I have significantly oversimplified the whole business. There are lots of valid concerns in using g*m and Kodiak obviously addresses these. For example, a core with an extremely high grade e.g. 500 grams/ton is most likely thrown out of the calculation, because you can't be sure that it represents enough of the vein to know the vein is really that rich. Better to be conservative. Ditto a super-low grade of 0.05 g - you'd have to remove too much of such rock to make it worthwhile, so that vein is considered to hold nothing so far as the calculation of g*m is concerned. Kodiak has taken other precautions that are too much to get into here, but the bottom line is that it's a useful and reliable method.

The magic comes out of it when you go to estimate the overall gold resources of a particular zone. In calculating g*m, so long as you use conservative methods, you have described an equivalent vein that is 1 meter thick all over your cross-section rock face. The 1m thick equivalent vein has various g*m figures as you move deeper or move along the strike. You can tally up all the values and come up with, for example - how much gold can we see in the first 3 km of the Golden Mile explored so far?

An adjustment coefficient is used to reduce the number you first calculate, because there are lots of factors involved in mining it that mean you won't get all the gold out. First off, of course you will be removing some thicknesses of rock with no gold in them, between the valuable veins. Also, you might only economically pursue xxx% of the available gold out of a structure you've identified. You might start with a dazzling number for total grams of gold and then cut it by 3 or 5 or whatever the appropriate number is, and still have a glowing g*m number, but one you can more likely take to the bank.

At this point you can do your own back of the envelope calculations from the Golden Mile map, taking xxx meters strike and up to zzz meters depth, the 1-meter-thick equivalent-vein, and after using an adjustment factor you can multiply by an average of bbb g*m of gold. That gives you so many grams of gold in total from mining that area, you divide by 31 grams/ounce and dad-gummit you're rich!

Okay, reality check. "Professional drivers only," "performed on a closed circuit," "may induce giddyness" and all that. People can bandy about numbers until the cows come home, and I'm sure they will (ask Ganalane).

The point of the coloured zones on Page 16 of the new Kodiak .pdf issued today is that moderately deep down there are large new purple-coloured tongues of high-grade gold ore with values of 20-50 g*m, each 50 meters long along strike, and so far drilled, assayed and located between 150-400 meters depth. They are further open at depth and getting bigger as you go deeper. So in the first 400 meters down, that is a Good Thing (plus, the few even-deeper holes continue to show the high grades). For each of those purple tongues, that means for every 1m x 1m area at the cross-section rock face, you have 20-50 grams or 0.6 to 1.6 ounces of gold in the veins there.

On Page 19 of the .pdf, Red Lake is shown for comparison. Note that most of the gold came from 1500 to 2500 meters depth. At Red Lake depths comparable to what's been demonstrated so far at Kodiak's Golden Mile, the amount of gold was also good, but at greater depth it was a lot richer. The Golden Mile is also shown to be getting better as it goes deeper. Very good.

Of course with all the excitement (well, I'm excited anyways) people will be asking "why doesn't Kodiak drill 25 really deep holes now? If it's getting better as it gets deeper, I want to see what's down there!".

Brian Maher pointed out that drilling each deep hole takes a long time and burns up a lot of money. A 1 km long hole takes weeks to drill and costs in the ballpark of $100,000 even at good rates. In the meanwhile half the 9 km Golden Mile is still covered in bush. Who knows what's under there as well? Need to find that out. If it's even richer somewhere else in the same zone, might as well sink the deep holes over there. I am happy Kodiak is using their money wisely (thanks, Bill).

I got the impression that the drilling is very strategic, and at the same time I'm also bubbling over a bit that we've seen these great grades come from depth, just as we'd all hoped.

Time for me to go figure how many g*m of strawberry jam I'm spreading on my stack of toast. Pardon me if the whole discussion here was too plodding, hope it was maybe useful, and thanks for reading this far / cedar