Angle drilling why?
IMO they have found good results in the first core samples and are now angle drilling to find a true width ...Things are looking good here.
angle holes targeted to intersect steeply-dipping, potentially ore-bearing fault zones and favorable bedrock units.
Each hole is spaced so that the start of one hole corresponds to the end of another hole, so we're covering all of the rocks under the ground basically, we're getting a complete sample."
He says the workers take a sample of rock from each metre drilled.
"About 90 per cent of the sample gets put in a pile on the ground or in a large bag and that's a reference sample if they want to come back and re-check it.
"We take two other smaller samples and they get sent off to an assay laboratory...and they find out how much gold there is in them."
He says it's not obvious when the drill rig strikes gold.
"You really don't know where it's going to pop up. Sometimes you'll drill rock that you think is highly prospective for gold as there's lots of quartz veining in it...and you might think that looks really good for gold and then you can get the assay results back and get nothing.
"You can also drill some rock that's boring as anything and it comes back with lots of gold in it. Gold is highly mobile and you don't know what sort of rock it's going to be in underground."
Testing of potential ?feeder? faults should be carried out with angle drilling
Drill rigs are not called “truth machines” for nothing. No amount of promotion or favorable press will prevent companies from being affected by negative assay results when good ones were anticipated. A selloff takes place immediately, with sophisticated players leading the way. That is why it is important for investors
to understand the economic significance of drilling results, relative to the nature of the
deposit
being explored and where it is situated, You do not want to be the one buying when others are selling, and vice versa.
The first step to analyzing these results is to understand what grades will be economic in a typical mining operation. In general, large deposits capable of being mined by open pit will have lower cutoff grades than will deposits of the same metal that have to be mined by underground methods. For example, the Dome gold mine in northern Ontario operates an open pit with reserves grading 2.3 grams per tonne; its underground reserves grade 4.3 grams.
A 30 meter-drill intersection grading 1 gram gold per tonne, starting at 5 meters below surface, would be of economic interest if it originated from a road-accessible property in Nevada. The state has numerous low-grade deposits mined by less costly open-pit methods, whose gold is recovered by low-cost heap leaching. However, this same drill intersection would not attract much interest on a property in remote northwestern British Columbia owing to a lack of roads and other infrastructure.
A drill intersection showing 0.4% copper would be exciting in the porphyry-copper district of British Columbia, since it approaches the typical grade of the area’s large open-pit mines. In the volcanic belts of northern Ontario, where smaller, higher-grade base metal mines are the norm, the same result would merely merit more work.
Deposits with complex metallurgy will be more costly to mill, so cutoff grades rise accordingly. Off-site costs such as transportation are a major component of total production expenses. This is particularly true for gold and base metal deposits that produce concentrates, which must be shipped to a smelter for processing. Energy costs have a strong influence on a potential operation’s economics, especially when a mill must be built. As a general rule, a mineral deposit in an area where access is poor and costs are high will be less likely to make a mine than an equivalent deposit in a more developed region.
The length of drill intersections is also important, since these give an indication of the kind of mineralization present. Low-grade deposits must be large enough for bulk mining. That means low-grade drill intersections must be long — on the order of tens to hundreds of meters — to show economic potential.
Narrow intersections, on the other hand, must show high grades. A zone’s width is vital to the feasibility of mining operations, and narrow zones may simply not be economic to mine. A mineralized zone only a fraction of a meter wide could not be mined without also extracting large amounts of wall rock, thereby diluting the grade.
Core lengths quoted in press releases can also be misleading. Drill holes that cross a zone of mineralization at nearly a right angle give a better picture of the zone’s true width. Holes that are drilled at shallower angles to the mineralized zone will yield intersections with lengths much greater than the true width of the mineralization.
Keep in mind that a hole drilled to a great depth from surface will often be drilled at a very steep angle, such that if it intersects nearly vertical structures at depth, the true width will be much less than the length of the drill intersection.
There is always the possibility that the company has drilled down the dip or plunge of a mineralized zone rather than across it. This can happen, on occasion, in the early stages of an exploration project when the structure being explored is still poorly understood. A hole drilled in this way will provide no information about the width of the zone, yet the mineralized intersections may run to spectacular, but meaningless, lengths.
Lastly, it is important to consider that narrow zones of high-grade mineralization may carry an intersection. A zone only a meter wide may show a grade of 15% zinc, but a company may average that one-meter intersection with the nearly barren two meters to each side of it, reporting five meters grading 3% zinc.