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Bedrock Depth Question


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If Bedrock is at 8-10 ft at the level of the stream on my farm and I go up the ridge 50 ft elevation would bedrock be 58-60 ft or would it still be closer to 8-10 ft. Are there any variances for type soil location, etc. I'm in Western North Carolina in South Mtn. gold belt. Any experienced in this area ? If so would appreciate your thoughts.

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You'll need to do a good bit more research probably startin with the North Carolina State Geological Survey and all the different geology maps fer yer state, as well as USGS, 7.5 min. topo maps, all of which only those agencies can provide, would be my suggestion. And thats all just a start.

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In 56+ years I've never seen a norm or any rule thats applicable. Example on Slate creek bedrock was showing 8' from each other with the creek in the middle. 18' deep and quit dredging due to winter. Get a auger to assess your depth is all I can say. Get with a local yokel club of gem/mineral/gold/detecting club to get recent local advise and meet some righteously crazy goldhounds-tons a au 2 u 2 -John

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Geologic maps of the area is very helpful in determining the general makeup of an area.

Bedrock can be like waves on the ocean, it can rise and fall depending on the geologic activity attributed to the area in question. The bedrock "could be" closer to the surface on the hill sides due to errosion filling in the lowlands. Glacial deopsits can leave quite a pile of material on bedrock, and errosion could leave the bedrock closer to the surface in the low areas and deeper in the hill. Even after an in depth study of the area there is no way of really knowing without getting out a shovel. The depth of the bedrock can change in only a few feet.

You could try drilling but then you can be fooled if you happen across a boulder thinking you have reached the elusive bedrock. You could try ground penetrating radar but that is big $$$.

Start with the maps, ask those who have worked in the area, and take your best guess.

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As has already been said ... Only sure way is to dig holes! Lot of work but if you need to know for sure without ground radar that's what you will have to do. AND ... If you are in gold country be sure to run the detector over the dug material.

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Buckshot you didn't say why it's important for you to know....I could see the importance if you were planning on digging

a tunnel....best explanation here that I agree with is it's like the waves on the ocean....you can always bet it's going to

rise or fall....just don't know when or how much....

One of the rivers I was dredging here the bedrock at the North side bank was under three feet of

gravel...not bad....but 20 feet out in the stream the bedrock was at 30 feet....bad news....

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Thanks all for the responses, it about what I thought (UNCERTAIN). I'm always on the lookout for gems & gold, one reason I asked the question was there was testing done along the area of the stream back in the 80's however all was done near the stream some on both sides which indicated bedrock at from 8-10 ft on the average, but none was done on the hillside. I've found rubies & sapphires in a small feeder stream and was going to try and find their source which I think will lead be towards the hillside. I'm looking at purchasing 10 ft split handle post hole diggers so I can test in areas not easily accessible. I borrowed a pair of 8 ft diggers from a utility worker and was pretty satisfied with the depth but would like to get a little deeper with my testing. Thanks again

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There are other methods then digging you can use to check this you know.

Have a Read here.

http://www.epa.gov/esd/cmb/GeophysicsWebsite/pages/reference/methods/Surface_Geophysical_Methods/Electrical_Methods/Induced_Polarization.htm

Here are some actual plots taken by a friend of mine on a site.

GoldenEagle-IP2-S-8FootArrayreply.jpg

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Yup this answered my thoughts

Homey... do you actually understand this stuff?

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If your interested in this stuff this states some good info but the Electronics is more then dated.

http://www.geotech1....1/erm1a_300.pdf

http://www.geotech1.com/cgi-bin/pages/common/index.pl?page=geo&file=projects/erm1/index.dat

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LOL! Being a Woosie Digger, I find it a lot easier.

BTW, This works REALLY GOOD at finding Black Sand Deposits in a Stream or Creek.

Even the Poor White Trailer Trash Version works on the Black Sand Deposits.

Yea, I'm one of those! LOL

http://www.liv.ac.uk/geomagnetism/schools/res.htm

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All of the above suggestions have that bad four letter word associated with them....WORK....I'm going to have a beer

and then a nap and think about this.... :zzzzz:

Hey Don, don't know bout you but I'll make time fer a nap after my funeral when my paul berrers tell me to git back in the box fer we can bury it!
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Hey Homefire, my F-75, in addition to detecting metal, also has incorporated into the computer's software an Fe3O4 bar graph, and in the manual fer the detector, it says that bar graph on the screen will allow me to map out or chart as it be highly mineralized soils, ie; black sands or magnatite, but only so deep as my coil will penetrate, which expains why I bought a 15in. accy. coil along with the 11in. DD that came with it. But I'm guessin your "Earth Resistivity Meter is a good bit more accurate as well as goin really, really deep.

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Black Sand here in New Mexico don't contain that much Ferric Oxide.

The make up is more of other elements like Barrite and other Sulfides and Oxides.

Somethng Strange happened here about 20 million years ago.

This outfit is in Pakistan but we have all the same here.

http://www.perfect-a...Minerals.asp#10

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