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Gold & gems in N. Dakota
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Author:  Dan&Sally [ Mon Feb 29, 2016 11:14 pm ]
Post subject:  Gold & gems in N. Dakota

Really! are you joking? Actually there have been 3 gold rushes of sorts in ND. The early part of the last century produced gold in gravels at nearly $25 per ton. Its speculated that this is from the black hills and in some past era when rivers flowed north it deposited a very fine flour gold in the gravels of those streams. No mines to my knowledge have operated here since before the 1940s. Gems are very limited here as well, some scattered garnets, agates, agatized wood, chert (flint). It seems odd that this area should be so void of things "precious". Glaciers pushed through many times, giant lakes have come and gone, and left nothing. Layer upon layer of clay hundreds of feet thick an occasional gravel band or coal bed sandwiched in between. A few unlucky dino's stuck in the mud I suppose could be called precious, if you are into those things. Why then are there no Opals, no kimberlite pipes? I feel like the bad kid at xmas, all we got was the lump of coal and its full of sulfer and stinks when it burns. :smt012

Author:  Stephen Challener [ Mon Feb 29, 2016 11:48 pm ]
Post subject:  Re: Gold & gems in N. Dakota

South Dakota has a semi-famous deposit of blue tourmaline, though I don't think it produces anymore. I agree, there must be some good stuff hiding up there--at least you've got agates in the west.

Author:  Dan&Sally [ Tue Mar 01, 2016 2:36 pm ]
Post subject:  Re: Gold & gems in N. Dakota

So far the only prize has been knife river flint. A beautiful root beer semi transparent stone I send to my friends that Knapp flint into stone tools, arrowheads and things of that nature. Not of much use as a stone to facet.

Author:  dchallener [ Tue Mar 01, 2016 7:32 pm ]
Post subject:  Re: Gold & gems in N. Dakota

and of course the famous fossilized turtles.

Author:  Lefty [ Thu Mar 03, 2016 4:08 pm ]
Post subject:  Re: Gold & gems in N. Dakota

I wouldn't be surprised to find something is hiding there Dan. ND looks a bit like Queensland in one respect - sparsely populated over much of it's area. There can be stuff lying around but if there are very few people per square mile to find or stumble across it, it tends to stay hidden. Historically - over here at least - coloured pebbles attracted little interest from gold prospectors who often didn't even record any such finds.

Geologists who have worked on mineral/petroleum/gas exploration would be very interesting to talk to if you could get in touch with any. One of them confirmed to a friend of a friend what I long suspected - there is plenty of gemmy stuff here that no one knows about. Just getting access to it may be the issue.

Some very nice looking agate there

Author:  michael_e [ Thu Mar 03, 2016 6:29 pm ]
Post subject:  Re: Gold & gems in N. Dakota

http://www.dakotamatrix.com/content/pegmatites-of-the-black-hills

Where there are pegmatites, there's bound to be cool stuff. Maybe not enough to mine, but enough get some rough materials. I remember someone a few years back selling some fantastic rose quartz from the Black Hills, not facetable, but fine stars were gotten from much of it.

Author:  Lefty [ Thu Mar 03, 2016 10:37 pm ]
Post subject:  Re: Gold & gems in N. Dakota

michael_e wrote:
http://www.dakotamatrix.com/content/pegmatites-of-the-black-hills

Where there are pegmatites, there's bound to be cool stuff. Maybe not enough to mine, but enough get some rough materials. I remember someone a few years back selling some fantastic rose quartz from the Black Hills, not facetable, but fine stars were gotten from much of it.


That looks like a bit of potential there!

Small deposits may not be of commercial interest but to individual prospectors they can be very worthwhile.

Hopefully my "peace offering" is well received by the lady who owns the property on which the small garnet deposit I am wanting to get my light machinery into exists. Yet another old prospector has confirmed the existence of both rhodolite and good green garnets (among mostly dark pyrope) in the area.

Author:  Dan&Sally [ Mon Mar 07, 2016 11:51 pm ]
Post subject:  Re: Gold & gems in N. Dakota

When You look at western N. Dakota, the Roosevelt park in particular you see the layering of the clays hundreds of feet thick. You get a better idea of what lays beneath the grass. However Im north east of that, in fact Im north of the Missouri river. That changes things a bit. Glaciers pushed and pulled across here several times and left gravel deposited in layers between the clay sediments. Those close to the surface within a hundred feet of the regional elevation dont contain much of interest to anyone but road crews and cement plants. But I found a gravel bed about 6 ft thick at 200 ft below the regional elevation. A nice sandwich between clay sediments. A small creek has cut through and with water levels low its where I would have been fishing a year ago. Its classic rounded mixed gravels from pebbles to boulders with the clay below it acting as a hard pan it should be an easy prospect. Ice on the river should be going out within a week or 2 and make it Kayak accessible. I vaguely remember thinking it would be a good spawning area when the water was up. Good gravel sizes with random boulders a couple feet across. Funny now that its above water the perspective changes. Looks like I need to find my bucket screens and some empty sand bags. Pretty sure the kayak will stay above water with 500 lbs in it. If not I can always get out and tow it. [-o< please dont sink!

Author:  Dan&Sally [ Thu Mar 10, 2016 12:09 am ]
Post subject:  Re: Gold & gems in N. Dakota

the gravel bed is actually closer to 350' below the regional elevation. What that equates to in terms of whats in the gravel Im not sure. Ive seen some blue agate, quartz, garnet in the area, but it could have been washed in or from a seam higher up the hills. So my thought is to sample only the area where the gravel sits on the clay bed below first. Take my classifier and screen out anything larger than 1/2" first and then screen that down to 1/4" . That will make best use of limited space to transport materials. Bring back 4 sample bags of 25lbs ea. and run that through the pulse jig to concentrate heavies and run the sand through the gold screw to look at the fines. Im not really expecting to find much if anything at all, but it will satisfy my curiosity and get me a little practice in setting up and transporting the equipment before I try and head out to a really remote site. The ritual of the list of things to bring is always fun. Take it all, load it up, unload half. Think about it, unload half again. Bring all that back in the garage. Now unload whats left and repack it so I can carry it uphill both ways, and cuss like the sailor I am because Im not in shape. I really need to put together my prospecting team! Lefty Im jealous that you have bigger toys to dig with, and a crew. :mrgreen:

Author:  Lefty [ Thu Mar 10, 2016 1:59 am ]
Post subject:  Re: Gold & gems in N. Dakota

I think the biggest complicating factor you have there Dan is that you had something that we have never had here, except way down in southern Victoria and Tasmania - glaciers. Here, everything is still where it was aeons ago, albeit very weathered while you could have had entire volcanic provinces and all the goodies they held ripped up and carried away by huge rivers of ice.

Author:  Dan&Sally [ Thu Mar 10, 2016 6:43 pm ]
Post subject:  Re: Gold & gems in N. Dakota

This is true, except the ice stopped here. This was the end of the big conveyor belt . A lot of what is here is sediment from super lakes that formed from the glacial melt. That's why the gravel bed at the -300 ft got my interest. It's possible it could be a river deposit when the lakes were filling or draining, or an area where it was left from another glacier. Either way i'll sample it to see what I can find and satisfy my curiosity

Author:  Lefty [ Thu Mar 10, 2016 10:49 pm ]
Post subject:  Re: Gold & gems in N. Dakota

Oh well, that sounds better! All the goodies from ancient Canada could have been dropped right on your doorstep :)

Author:  Stephen Challener [ Thu Mar 10, 2016 11:02 pm ]
Post subject:  Re: Gold & gems in N. Dakota

Who knows, you might find some jade. Agates are always a good bet since they're so resistent to weathering, no doubt you've already been seeing them around here and there. Diamonds are very rarely but sometimes found. Some other oddball cabbing material can be found in glacial till, things like nicely colored quartzite etc. which are atypical but pretty.

Author:  Dan&Sally [ Fri Mar 11, 2016 12:48 am ]
Post subject:  Re: Gold & gems in N. Dakota

There is something here I find on occasion that is olive green. Sometimes in veins, and as whole stones. River polished to a smooth glassy finish. If you shaped it as an olive it would match perfect color but it has tiny black specks sometimes. I have no idea what it is but it catches the eye in my world of blah stones and red clay.

Author:  Stephen Challener [ Fri Mar 11, 2016 12:56 am ]
Post subject:  Re: Gold & gems in N. Dakota

Sounds interesting. Might be jade, maybe serpentine. Jade tends to build up a white crust but you never know. I'd love to see some pics or poke at a sample if you have a little one.

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