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Linnea P

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  1. Linnea P

    Buried Treasure!

    Every prospector must be an optimist to think that he or she can find a bonanza although the odds are not in their favor. Somehow, whether by by their knowledge. skills, tools, system, hard work, luck, or the will of God they will be able to find a deposit that others have overlooked for hundreds of years. Before coming to Alaska about 30 years ago I spent a half hour looking at generalized geologic map of the state and picked 10 targets that I felt had “favorable geology” based on no other information other than my theory that large intrusives into sedimentary rocks such as impure limestones, muddy or limey shales, etc. had the highest potential for precious metal lodes. As my research later showed all 10 areas that I chose had seen historic lode production. Of course with greater knowledge, a little work, and a “better system” I could have further narrowed my search to the what would have to be the mother of all mother lodes - but at that point it would still be a “prospect”. Mineralized rock is just rock and ore needs to be proven. Of the “lodes” mentioned by Geowizard, which one has the highest potential reward to risk ratio? Remember it is better to take risks if you stay close to the road and use other people’s money.
  2. Linnea P

    Buried Treasure!

    Quote from Geowizard There is buried treasure all over Alaska. The State has spent money to do the work. So, if money isn't the issue, then what's keeping so many other prospectors from using this free information? The Alaska Department of Natural Resources has spent and continues to spend Millions of dollars. The information is published online. Geowizard Prospecting targets are not that hard to find but then it takes money and effort to advance a prospect into something of value. Please read “Rule of Thumb” # 101 (below) for another perspective of what it takes to make a mine. Hard Rock Miner's Handbook Rules of Thumb Edition 3 - 2003 Chapter 1 - Exploration Geology and Ore Reserves Rule of Thumb 1.01 Discovery It takes 25,000 claims staked to find 500 worth diamond drilling to find one mine. Source: Lorne Ames 1.02 Discovery On average, the time between discovery and actual start of construction of a base metal mine is 10 years; it is less for a precious metal mine. Source: J.P. Albers 1.03 Discovery On average, the time between discovery and actual start of production of a mine in an established mining district (“brown field”) is seven years. Source: Sylvain Paradis 1.04 Discovery On average, the time between discovery and actual start of production of a mine in a district where there is no previously established mining activity (“green field”) is ten years. Source: Sylvain Paradis 1.05 Costs The amount expended on diamond drilling and exploration development for the purposes of measuring a mineral resource should approximately equal 2% of the gross value of the metals in the deposit. Source: Joe Gerden 1.06 Bulk Sample The minimum size of a bulk sample, when required for a proposed major open pit mine is in the order of 50,000 tons (with a pilot mill on site). For a proposed underground mine, it is typically only 5,000 tons. Source: Jack de la Vergne 1.07 Ore Reserve Estimate The value reported for the specific gravity (SG) of an ore sample on a metallurgical test report is approximately 20% higher than the correct value to be employed in the resource tonnage calculation. Source: Jack de la Vergne 1.08 Ore Resource Estimate To determine an “inferred” or “possible” resource, it is practice to assume that the ore will extend to a distance at least equal to half the strike length at the bottom of measured reserves. Another rule is that the largest horizontal cross section of an ore body is half way between its top and bottom. Source: H. E. McKinstry 1.09 Ore Resource Estimate In the base metal mines of Peru and the Canadian Shield, often a zonal mineralogy is found indicating depth. At the top of the ore body sphalerite and galena predominate. Near mid-depth, chalcopyrite becomes significant and pyrite appears. At the bottom, pyrite, and magnetite displace the ore. Source: H. E. McKinstry 1.10 Ore Resource Estimate Archean aged quartz veins are generally two times as long as their depth extent, but gold zones within these vein systems are 1/5 - 1/10 as long as their depth extent. Source: Gord Yule 1.11 Ore Resource Estimate In gold mines, the amount of silver that accompanies the gold may be an indicator of depth. Shallow gold deposits usually have relatively high silver content while those that run deep have hardly any. Source: James B. Redpath 1.12 Ore Resource Estimate As a rule of thumb, I use that 2P reserves are only such when drill spacing does not exceed five to seven smallest mining units (SMU). Open pit mining on 15m benches could have an SMU of 15m by 15m by 15m. Underground, an SMU would be say 3m by 3m by 3m (a drift round). Source: René Marion 1.13 Ore Resource Estimate Your thumb pressed on a 200-scale map covers 100,000 tons of ore per bench (height assumed to be 50 feet). Source: Janet Flinn 1.14 Strike and Dip The convention for establishing strike and dip is always the Right Hand Rule. With right hand palm up, open and extended, point the thumb in the down-dip direction and the fingertips provide the strike direction. Source: Mike Neumann Rules of Thumb compiled by Jack de la Vergne and McIntosh Engineering Page 1
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