REVISED TO INCLUDE THE REST OF THE SHAFT. I MAY UPDATE THIS LATER TO REFLECT NEW DETAILS AS THEY BECOME AVAILABLE.
So, when the news comes out that that the LDM mine shaft has started..what then? What should we expect as we head down the shaft on a daily basis? Based on the limited information that is known about the LDM project, the ACA Howe report, and some knowledge about mine shafts in general, I have attempted to determine just that. Enjoy!!! Please note: The schedule does not take into account weekends, holidays, parties, siestas, equipment breakdowns, union/labor troubles, road problems, flash floods, ground water issues, or any other unforeseen problem!
Day 1. We reach a depth of 3 meters and have removed 28 cubic meters of rock weighing about 75.6 tons. All of this material is discarded as it is simply overburden, regolith, and boulders.
Day 2. Depth completed to 6 meters. Material discarded.
Day 3. Depth completed to 9 meters. Material discarded.
Day 4. Depth completed to 12 meters. Starting at 10 meters, we will encounter 20% disseminated pyrite and strong epidote alteration. Gold values average around 1.7 grams gold/tonne. This works out to about 3 ounces of Gold removed! The first 40 meters or so down, in general they will encounter a variably sheared and quartz-carbonate-pyrite veined pyritic siliceous volcanic unit. I would expect all of this material to be placed in the low grade gold pile on the surface
Day 5. Depth completed to 15 meters. About 4.5 ounces of gold mined!
Day 6. Depth completed to 18 meters. Same amount of gold.
Day 7 through Day 13 about the same as previous.
Starting about Day 13, things get a little more interesting. We will reach a depth of 39 meters. At 37 meters of depth, this will correspond to an increase in disseminated pyrite content in the volcanic unit along with strong epidote-diopside-chlorite alteration. Gold values increase to 2.44 grams per tonne. We have finally entered the “shear zone”!
On Day 14, we reach a depth of 42 meters. Several quartz-carbonate pyrite veinlets and stringers will be seen. Gold values increase to 9 grams/tonne. There is a 2 meter wide fault zone that will be encountered between 40 and 42 meters. The miners might consider making a cross-cut drift to follow the gold at this level. Expect this material to be placed in the medium grade gold pile on the surface.
From Day 15 to Day 22 when we will reach a depth of 66 meters-the amount of gold that will be encountered on those days is uncertain since there was no assays taken by Gordon House when it was originally drilled. However, based on remarks from Robert, I believe it will be similar to the 1.7 grams gold/tonne encountered earlier. If you add up all the gold encountered thus far..it would amount to about 100 ounces or about $100,000 worth.
Day 23. The big day!!!! With all the excitement, the miners dig extra hard/long and reach a depth of 73 meters At 66 meters, a significant fault/breccia gouge zone will be intersected and continue to a depth of 73 meters. Bonanza grade gold will be encountered. The exact grade that will be found is unknown as core recovery was extremely poor but as high as 455 grams gold/tonne despite the poor recovery was encountered during the previous drilling. I have decided to assume a conservative 75 grams gold/tonne over the interval of 66 to 73 meters. About 425 ounces or about $425,000 is recovered and placed in the high grade gold pile at the surface. All of this will be immediately placed on a truck and sent directly to Enami for processing.
Day 24. Now what? Do the miners linger at this level or do they proceed with completion of the planned 100 meter vertical shaft? (Note: Miners generally design the vertical shaft to the maximum depth of any expected future workings.) I assume that the horizontal adit will be worked on simultaneously as the vertical shaft. Working on a horizontal adit is easier to do so development of it will exceed that of a vertical shaft. However, the length of it is much longer so it will lag that of the vertical shaft. It doesn’t much sense to complete the vertical shaft well ahead of the adit-the optimum being at the same time. I estimate that the miners have two weeks to kill so they might as well make the best of it! The next thing to consider is the orientation of the vein relative to the vertical shaft. It appears that vein plunges steeply down(and up towards the surface) with about a 30 degree offset from vertical. The miners would likely test both directions. If we assume that stay in the 75 grams gold/tonne material, this will indeed be exciting couple of weeks for Medinah! Each day, they could be pulling out around 200 ounces per day of material. By day 38, another $2.8 million of gold has been extracted. There is now no doubt about it..the LDM project is a success!
Day 39. With the adit quickly moving forward, the miners on the vertical shaft regretfully leave behind the pay zone and work toward completing the rest of their shaft. Below the fault zone between 70 and 80 meters, the miners will encounter bleached breccia and andesite with numerous quartz-carbonate-pyrite-chalcopyrite veinlets and factures. They will then go through a thick sequence of porphyritic andesite with varying amounts of silicification and fine disseminated pyrite along with quartz-carbonate-pyrite and arsenopyrite-chalcopyrite veinlets. Overall, the gold grade will be low. By Day 50, the vertical shaft is complete and miners from the adit and the shaft are able to shake hands through a hole congratulating themselves on a job well done! With the shafts complete, the next month or so will involve completing all the necessary utilities, airflow, material handling, safety issues and like. Beyond that, the miners will go back to the 70 meter level to complete the workings there until that vein is exhausted. Other veins will be targeted as discovered. In particular, the hanging wall of the shear zone near the footwall interface will be high value target. Simultaneously to all of this, one can assume that surface exploration will be on-going such as more IP survey’s and drilling to identify further targets to be exploited. New shafts will be sunk further to the North in the shear zone..with lateral drifts heading back to the South to hook up with the exiting new workings. By the time, all of this taking place, I suspect Medinah will have already been bought out due to a sucessful JV at Lipangue. Either way, it will be exciting/interesting to follow as the project goes forward. Cheers!
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Topic: LDM MINE SHAFT PROJECT (Read 1998 times)