Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Gold/Mining/Energy : BANDORE -- Ignore unavailable to you. Want to Upgrade?

To: cruncher who wrote (1475)	2/25/1999 9:33:00 AM
From: Just G	Respond to of 1692

cruncher: Not bad, not bad at all, considering the drilling couldn't commence, I shall be one of them checking out the bulk sample at the pda, thanks Cruncher Regards Gopherbroke

To: cruncher who wrote (1475)	2/25/1999 11:08:00 AM
From: E. Charters	Read Replies (1) \| Respond to of 1692

***************************** The Canadian Mining Newsletter Feb 25 1999 *************************** This drilling was supposed to chase up Band Ore's spectacular 54 ounce gold per ton grab sample surface vein discovery. They could not drill on what they thought was the vein continuation in the lake so they had to make do with probing a secondary target. I assume that they believed the structure plunged out into the Lake and they had observed that it nosed out on shore although they did not say that. The drilling returned one hole out of 12 that was in the same character as the vein, 25.5 grams gold or 0.743 ounces gold and 92 grams silver or 2.68 ounces over 1.1 metre (3.608 feet). One would expect the vein to return spotty results as it was high in visible gold. The other holes did return some gold in the .07 ounce per ton range here and there. This is not terribly good information. If the remainder of the vein harbours huge nuggets and that is all then drilling will not catch them. You cannot expect nuggets to be right in line with the drill every 50 feet, After all the drill is only 1.75 inches wide.If nugget clusters are 4 inches square on the average and contain an ounce gold then at one ounce per ton there are 625 of them in 50 feet square. There would be 22500 possible areas that size to hit. That is boxcars, or one chance in 36. If the nugget areas contain one tenth of an ounce, there would be 6250 of them and we are up to one in 3, given even distribution. The distribution is generally given to vertical or plunging shoots, as that is the direction of emplacement, so it is not even. You find similar mineralization most often above and below an ore pocket but not too far laterally from it in a lot of mines. The one in 12 hit rate does not surprise me. In Timmins it was not uncommon to get one in ten to one in three. In those days they just drifted or tunneled to find the ore. Many stopes were supported on 25 feet of rich shoot and the rest of the vein returned low values. What to do here? Well if it's a nugget vein, then drilling will not reveal it very well. The bulk sample is uniformly rich, but we don't really know how much more of that there is to find. That is why in the old days they would just sink a small prospector's shaft and go and look at the vein. Many deposits are too nuggety to drill off effectively. We know of one mine, the Salmita, that had grades of about 0.15 on mining. Most assays returned low and non economic values. Every 10 to 25 samples they returned values of 3 to 5 ounces per ton and that was the rule. It was mineable but not easy at all to sample. This vein is narrow so it would have to be in the 1/2 to one ounce range by continuous sampling to be mineable. It may be that its tenor only yields to large scale sampling. At one time, prospector's shafts were the rule. Mines turned up with fair regularity. Drilling even on our major mines such as the McIntyre, Lakeshore and the Kerr were often inconclusive. During the post war years, when diamond drilling was all companies were willing to do, partly because of the price of gold, there were many disappointing prospects and few mines found. later in the 70's and eighties the massive amount of gold drilling found many deposits but the economics of many were hard to prove to investors. 70 of these deposits sat without "mill money". Later about 20 were developed and due to bad milling methods, bad mining or just plain bad grade calculation many of them were failures. What went wrong? I think that gold does not yield to the current thinking of exploration companies. It needs a step back sometimes to evaluate. It can be devilishly complex to evaluate structurally even to educated geologists. Drilling can fool you. Even when looking at the vein in drifts, its structure may not become clear. 100's of assays can deceive you. Sometimes a body is so nuggety that pervasive assaying on many samples will under-report it by up to 50% of the gold! At the Dome in Timmins the hordes of underground samples when averaged reported about 0.12 ounces per ton but the actual recovered grade was 0.25 ounces! The nuggets slipped by every time. They have mined the Dome for 9 million ounces for 90 years. Drilling would be hopeless. At the Macassa in Kirkland Lake, the grade runs 1/2 ounce per ton. There they say, "drill for structure, drift for grade." They never try to drill the veins to establish their grade. They go out and look at them. --CMN mailto:echarter@mineletter.com mineletter.com ********************************************************************