RE: Failed to answer the important questions?6 Jul 2021 02:09
Thanks Mr T.
My notes
1. There is a well known trend for discoveries to be of lower grade. Given equal amount of gold ounces, this implies that new deposits will need to be larger volumetrically [this is good for the exploration under cover, as bigger deposits are easier to find than small -albeit high grade ones], which in turn requires more drilling in terms of drill density, and if the deposits are under corver, then each hole will have to drill deeper to define the ore body. Hence it is logical that new discoveries will be far more costly.
2. Given new discoveries will be under cover, that is having little to no surface expression, finding them is going to have a lower probability of success. The industry has appalling discovery rates when the orebodies have some form of surface expression, when this is taken away? I will leave it to your imagination what will happen - in short, exploration will take longer, cost more and have a lower probability of any sort of financial return.
3. If we look at one of the key examples of the above 2 points, the discovery of Olympic Dam, which is an IOCG deposit with no geology or geochemistry expression at the surface, but rather a geophysical expression, it took a very well credenitalled Mining Company (WMC Resources) 10 holes to find the deposit. Here finding means they had a high degree of confidence they had a major mineral deposit (certainly no resources, as the deposit had a foot print of about 7 kms by 4 kms and depth extent still not known). Depth to top of the deposit was 300 meters...so every hole had to be drilled through 300 meters of crud. One of the reasons they thought they were onto something was a gravity anomaly was coincident withthe mineralisation intersected by the "discovery hole". In the hole the mineralisation was denser than the surrounding rock. One calculate the excess mass to cause the positive gravity anomaly and the calculation derived a figure of 10 billion tons.
4. Following the example of Olympic Dam through, drilling started on 400m by 400 m centers and holes down to depths of 800 to 1000 m. Problems correlating between drill holes again! Had to close down to 200 meters. Problems again correlating. Pick a small area where mineralisation was higher grade more consistently. Sink a 500 meter exploratory shaft (think $$$). Make a horizontal exploratory drive (think $$$). Bulk sample, and met test. New shock! Although they had encountered small intersectionsof high grade gold, they did not calculate a gold resource, as nothing correlated between holes [hint all holes were vertical, clue gold was contained in vertical structures]. The bulk sample of the exploratory drive ran of the order of 150 meters + of 6+ gpt Au! There was a high grade gold mineralisation in the vast low grade copper, uranium, REE deposit! WITH TIME AND UNDERGROUND DEVELOPMENT, IT TURNS OUT OLYMPIC DAM CONTAINS 40+ MILLION OUNCES OF GOLD!...now the third largest copper depos