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flintgreasewood

Life At The Bottom Of A 64' Shaft

29 posts in this topic

Late December last year I began digging a 6' x 6' prospect shaft about 100' downstream from the original Cobb prospect shaft. Armed with a 30 lb electric jack hammer, a couple of shovels and my nifty 1/2 size home made "Fairbanks self dumping bucket" system I worked my way down through frozen muck and eventually a 10' gravel layer to bed rock at 62'. On my way down I encountered layers of tangled branches and trees up to 6" in diameter. After 40+ feet I hit fine sand and scattered patches of gravel, fossil bone fragments, then complete bones. I was anticipating these finds but the excitement of actually finding them was intense. The first chunk of mammoth tusk nearly put me over the top. Progressing downward, the bones became less frequent and the pay gravel more dense. I had been told that a jack hammer would be ineffective in frozen gravel. Good I don't listen to everything I hear; it busted up almost as easy as the muck. The gravel graded into fractured and decomposed bed rock and I knew I had finally reached my goal...10 months after starting the project. Before freeze up I was able to wash 5 yards of pay and the result was encouraging. I'll have to wait till late spring to resume processing what I brought up before and what I can hoist this winter.

Now it's late November and all is solidly frozen above as well as below ground. Since bottoming out in the shaft I've been devoting most of my time to upgrades above the shaft in preparation for winter work. Also I had to take a part time job in town to help pay for the added expense of moving to a small cabin also in Fairbanks. What little time I've been able to devote to underground efforts have been to expand my working space. On the way down I managed to increase the dimensions of the shaft from 6' x 6' to over 7' square. The plan is to continue out to 10' square before I begin pushing the drifts across the valley.

Jack hammering straight down is relatively easy compared to working horizontally and even vertically. Sufficient pressure is difficult to exert out of position so I began working on ideas to free the gravel other than by the traditional steaming or blasting to reduce the great amount of physical labor involved with jack hammering. Suffice it to say, I'm making good progress in those efforts. I'll report on this process in months to come.

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Thanks, Doug I hope my efforts serve as an encouragement to other current and future drift miners. I'm hoping to develop simple systems that can be utilized by even just one person to successfully mine underground.

B O'Berry likes this

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Kurt.....glad to hear you finally got to the bottom of that thing!  I was wondering how you are going to protect the shaft from filling up during the winter?  I realize it will be inevitable that you will get moisture inside but what type of steps will you take to minimize it so that you can hit the ground running again in the spring?   

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JR, Good to hear back from you. The seepage into the shaft ended shortly after freeze up. All is nice and dry down below. I'll be digging a substantial trench up stream this spring to hopefully divert any flow into the shaft next summer. Let's hope it works.

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I'm sure its all socked in with snow now, but I hope the melt doesnt create problems.

Assuming its not much work to re-open this coming spring, will you start drifting out horizontally?

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Hi Chris

It's almost February and I'll soon be starting my cross valley drifts.  In anticipation of increased material removal I am beefing up and enlarging my hoisting system. Should be an exciting season. Good luck to you

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Good luck to you!

I'm looking forward to hearing more about your progress. I hope you hit a nice rich paystreak.

Still a bit cold here for detecting in Northern Nevada / Northern California, but it wont be too many weeks until I am out there digging.

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Kurt, I want to see what the gravels look like that you will be pulling out of that thing.  From the blog that you have posted, I envision you down on ancient riverbed approaching bedrock?  You've mentioned you got to the gravels, but have you also discovered how far down bedrock is under the gravels? 

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Hey guys

   I have approximately 10 feet of gravel on top of bed rock.  I'm only beginning to run my drifts across valley so I'm not able to say what the angle of bed rock is yet.  Now I'm recovering from back surgery [relatively minor] but it's going to keep me from any vigorous mine work for several weeks.  Ahhh, patience!

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I can certainly relate to the back pain thing - sorry you had to have surgery. No surgery for me as mine is not that bad but I know it can certainly slow you down.

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Kurt, got to think the weather up there is about to turn if it hasn't already.  We didn't hear from you all summer and wanted to see how your project is goin?  Hope all is well?

JR

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JR   Thanks for your continued interest.  I'm back in town for the fall and winter[back on line] so I can update easier.  It was a slow season for pushing the drifts in my shaft.  I spent much of the summer upgrading infrastructure, as it were...new gin pole, new shaft deck, new dead man, etc.  Also had water issues that have been so aggravating I just didn't want to be down in all the wet.  I did get some thawing done and am very pleased with the performance of my home made thawing rods.  I'll start back in the drift as soon as things freeze up good.  We're also prospecting an old mine's dump piles [not tailings] and will try to keep that going even after freeze up.  Got a couple of young guys helping me out now.  Sure nice to have the extra muscle, enthusiasm and company.

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Hey guys, sorry for taking so long to respond.  I'm back down in the hole where it's much warmer than top side. Finally got all systems working well enough to initiate another round of drilling and thawing in my main drift.  Unfortunately, my heat rods weren't working like I had hoped they would and produced an uneven thaw.  Consequently I had a fairly thick wall of frozen gravel on the face and well thawed gravel behind which necessitated a good bit of jack hammering to clean it all out.  So I brought all the rods home and reworked them so they'll heat more evenly and also run a good bit hotter.  I'll be testing them over the next two days.

My young help disappeared when the snow and cold hit and put an end to above ground work.  I may get them back soon.  The began putting down a new shaft about 150' from my shaft which I'll eventually connect to via my drift.  We're thinking the main pay streak is much closer to being below the new  shaft.

I'm developing a system for operating my hammer drill that allows me to simply set up the various support members, position the drill and then just turn a crank handle to either pull the drill  bit into the wall or retract it.  I've already drilled about 20 holes using the system and now I'm just simplifying it.  Hopefully soon I can include some videos and photos of the operation.  Well, that's about it for now.  Stay tuned.

 

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Im glad every thing is going well next summer when we go to our claims up the steese highway maybe we could get together for lunch or coffee be careful down there

Doug

 

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Kurt, good to hear from you.  Sounds like you got your hands full and a solid plan moving forward.  Good luck, look forward to your updates.

JR

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Not an awful lot to report.  I'm about 9' in my drift which is about 5' wide and 5' 6" high at the top of an arch.  My gravel is very atypical with large lenses of pure muck in between a jumble of chunky, fine and ground up shist bedrock, large cobbles, angular and rounded quartz and a smattering of intrusives.  There's no bedding or layering except for the muck and I even have bones almost to bed rock, one of those being a young mammoth jaw complete with two teeth found 2' off bed rock.  It's quite a conundrum.  And the gold is not primarily just off bed rock but spotty and scattered throughout the entire column.  Got any ideas?  Heavy flood event??   I'm also continually making changes to my heat rods for the gravel thawing.  My latest iteration should be ready to test out in about 2 weeks.  From calculations and prior experience I'm expecting some really effective thawing.  I'm also improving my drilling system making it faster and  less labor intensive.   My bucket hoist has been working nearly flawlessly.  I'm ready for the cold to leave though I'm not looking forward to fighting with runoff again this year.  Got some ideas  how to mitigate it.   More soon.  Thannks all for your continued interest.

JR BOI, truckeegirl and Got the bug like this

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