Has anyone ever prospected corrugated storm tubes?

mr_larry

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Jun 22, 2010
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Northern California
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I know a place that had two gold mines in the 1850's. They shut it down because it wasn't particularly profitable, especially since there was all of that gold in the Sierra Mountains.

Anyhow, I know this place holds some gold, and there are a lot of creeks that come down off the mountain. As you drive along the road, there are a bunch of these corrugated tubes that pass under the road to let the streams flow through. I was thinking that they are like a sluice box that has been operating for the last 150 years or so. I'm sure people clean out the tubes of branches and debris, but I really doubt they scrape out the deposits in the riffles.

All of this land is part of a State Park, but I was thinking of sticking my head in some of these tubes and pulling out the concentrates to refine at home.

I was thinking of taking samples from the first few upstream riffles from each tube and putting them into a one-gallon ziploc bag, each labeled individually. I'd label each and attempt to find the gold later from home using methods for separating fine gold.

Is this idea totally crazy or is it worth a shot?

I'm talking about tubes roughly 3-5 feet in diameter, much like the ones pictured below.
 

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Yeah Kaz... I grew up in the foothills outside San Diego and remember the Santa Anna winds. I can honestly say they ain't got nothing on the wind out here at times. I kept expecting some chick from Kansas and her dog to drop in for a visit.
 

Speaking of wind... It's been causing some problems with running the sluice box here. Soon as I get things going the wind picks up and blows the water past the tailings bucket!!! I've got a quick and simple mod I'm going to try this morning and see if it helps with that little problem. If it works like I THINK it should ( I know... Me thinking is dangerous at the best of times) I should be able to run the rest of the materials we got from the culvert at the end of our road. I've already found flour in varying amounts in different portions of the pipe. Now it's just a matter of running and panning down the rest of it.

Yesterday I got the stand made up for my sluice system and it is now at a MUCH better working height. I've got a couple more additions I want to add to it and those should be finished up later this morning. (One must have ones coffee before things get started!!! :coffee2: I need to install an I.V. off the sluice so I don't have to stop for my caffeine fixes)
 

Well the heavies at the upstream end of the culvert seem to be dropping off in quantity. The materials we cleaned out of the corner were just loaded with B.S. and Garnets but the stuff right in front of the pipe seems to be lacking in both. So far we've classified and concentrated down about 60 gallons worth of materials. I've cleaned out a couple of pans worth of the cons and while there was some flour in it, I'm not thinking this is going to be worth continuing. I won't know for sure until i set up the gold wheel and run the rest of the cons through it and see what we get.
 

Thanks for the update GI
So you found the biggest and most plentiful gold near the outside area of the inlet or in the inlet itself? It makes more sense to me because of the redirection midway in the culvert causes turbulence then back up, allowing the heavies drop out in the inlet.
 

Actually Jeff I have hardly even done anything from INSIDE the pipe yet. I've been working the stuff from the hard 90 that leads into the pipe. The back side of the 90 is about 2 feet past the opening of the pipe so it's a MAJOR pooling area. Was getting lots of heavies there but when I moved into the portion right in front of the pipe they have dropped off big time. I'm going to go ahead and continue into the pipe itself this weekend if for no other reason than we want to dissect this pipe in detail just to learn how well it works at different points. That way if we find another one that is like this we'll know which section is the best part to be working on. I'm just not looking forward to having to haul buckets of over burden out of the pipe to get to the "riffles". It's about a foot deep in the bottom of the pipe.

EDIT: I'll try to work up a diagram of how this culvert is set up and post it to the thread so you'll have a better idea of the layout. J.
 

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Here you go Jeff. Keep in mind I'm NOT a computer artist but this should give you the layout.

It's not to scale to say the least. The top of the input retaining is about 6 ft high with a 4 ft diameter pipe. Diameter stays consistent for the entire length but it can't be level as the materials tail off to nothing about 5 ft from the discharge end. Works out well as that's going to slow the flow so heavies drop out of the water stream.

culvert.jpg

I started working the materials in the pipe last night and started finding garnets again so there may be hope for the materials inside the pipe. Haven't done a clean out on the sluice yet so not sure how much if any gold has found its way into the pipe.
 

There's a culvert about 5 minutes from my house where water from the east bay hills comes down a creek. The culvert is under a small bridge that's wide enough for vehicles to cross, but it's mainly a hiking trail. I had seen an episode of Gold Fever where Tom Massie was doing "urban prospecting" and mentioned the culverts acting like a sluice box. I brought a small tupperware container and my snuffer bottle a few days ago just to take samples and see. The culvert is about 30 feet long or so and had just a little water going through it. I walked in about 20 feet from where the water was coming out and noticed where some heavier rocks and gravel were collected. I poked my snuffer bottle around the bottom of the "riffles" in a few various places, and then actually scooped up about 2 fistful sized scoops from the bottom with my trowel to put into my small tupperware container. I went home and panned it out.....and I found small flakes of gold in the snuffer bottle, and in the small amount I scooped up! It wasn't very much, but it was something...especially for how little of material I brought back to test pan. Easiest prospecting ever...and I'm going back tomorrow for more! Hehe, if all the people that walked over that little bridge every day only knew what was beneath them. :laughing7: I'm going to take some advice I read on this thread as well and dig just before the culvert and see if any gold has collected there too. I'll try and remember to bring my camera next time so I can create a better visual to go along with my explanation.
 

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Sounds great Paul, congrats on your secret gold mine! I bet you can come back at least annually to get more after you clean it out. Meanwhile you are doing a public service by cleaning out the culvert!
 

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There's a culvert about 5 minutes from my house where water from the east bay hills comes down a creek. The culvert is under a small bridge that's wide enough for vehicles to cross, but it's mainly a hiking trail. I had seen an episode of Gold Fever where Tom Massie was doing "urban prospecting" and mentioned the culverts acting like a sluice box. I brought a small tupperware container and my snuffer bottle a few days ago just to take samples and see. The culvert is about 30 feet long or so and had just a little water going through it. I walked in about 20 feet from where the water was coming out and noticed where some heavier rocks and gravel were collected. I poked my snuffer bottle around the bottom of the "riffles" in a few various places, and then actually scooped up about 2 fistful sized scoops from the bottom with my trowel to put into my small tupperware container. I went home and panned it out.....and I found small flakes of gold in the snuffer bottle, and in the small amount I scooped up! It wasn't very much, but it was something...especially for how little of material I brought back to test pan. Easiest prospecting ever...and I'm going back tomorrow for more! Hehe, if all the people that walked over that little bridge every day only knew what was beneath them. :laughing7: I'm going to take some advice I read on this thread as well and dig just before the culvert and see if any gold has collected there too. I'll try and remember to bring my camera next time so I can create a better visual to go along with my explanation.

Oh yea, you got it bad:goldpan: welcome to the real Gold Fever show!:icon_thumleft:
 

Be sure to check out the upstream side of that culvert Paul and look for areas that the water would slow down in before entering the actual pipe.

Granted my "art work" in my last post isn't the worlds best but it shows what's there. What I forgot to mention was that the bottom of the pipe was about a 6 inches higher than the "apron" that ADOT built into the setup. The diagonal line is some kind of cement curb that looks to have been part of an old setup that they abandoned when they installed this culvert. Between that and the actual corner it forms a pooling area for water to drop out heavies in.

We grabbed some more materials yesterday (about 35 gallons worth) and the majority of it looks to be over burden. It will be checked out as a research project but the last 5 gallons was from the "riffles" and I spent the majority of the day cleaning it up. (Hey... it's Sunday and I was slackin off for a change!) What little black sands I got came in at about 2 tablespoons worth of true black sands and 4-5 tablespoons worth of Magnetic sands. There was a good amount of flour in the good sands so even though there's a lot of over burden to clear it's going to be worth cleaning out the riffles. Also got about a 1/4 Tsp worth of garnets from the riffle material. We're saving those for an art project I have in mind. When it's finished I'll post a pic of it for those interested.
 

I'll see if I can get Robi to break out her little digital camera and get some shots oh impatient Grasshopper. I shoot on (Dare I say it?) FILM!!! Only digital camera I have is the little POS one on my phone. Then they charge me to e-mail it to myself to top it all off.

Today I took a break from the culvert and headed out to the wash where I had been working before. I went to where I had dug down to bedrock and followed my line I was working. Well the bedrock decided to take a dip down and it formed a nice little pocket that I cleared out. Got two buckets worth and drug them back to the house. So far I've only had a chance to run about 1/2 of one bucket through the sluice. When I did the first pan of the classified material I found over forty garnets in it!!!! I've either hit what could be a really good pocket or have found the source for all the garnets in the world! I still have to finish running the rest of the bucket before I clean out the sluice but if the garnets are any indication I should do better than just flour gold for a change. That or I'll have enough flour to bake a loaf of bread. ;)
 

Sounds great Paul, congrats on your secret gold mine! I bet you can come back at least annually to get more after you clean it out. Meanwhile you are doing a public service by cleaning out the culvert!

Thanks! I will also make sure to continue with my public service and keep this culvert clean. There are at least 2 others I know of within a 5 to 10 minute walk from this one.....which I'll be taking care of after this one. I believe the other ones are just concrete though and don't have "riffles". I'm sure they have some sort of crevices that I can clean out though.


Oh yea, you got it bad:goldpan: welcome to the real Gold Fever show!:icon_thumleft:

Haha, I know!! ....and I wouldn't have it any other way. So much fun hunting for this elusive yellow metal, and even thinking about doing it is almost just as fun! The only bummer is that I have zero friends and family interested in it....except my 4 year old daughter who goes almost everywhere with me. That's why I'm soooo glad I found Treasurenet recently!!


And spiders, never what kind'a piezunous critters you'll find in those pipes!

No worries. I'm not afraid of snakes or spiders in the least, and grew up having plenty of them as pets, from black widows and Goliath bird eating tarantulas to boas and rattlesnakes. Yeah, there were dangling webs in the culvert....but what made me rush a little quicker was looking down at my arm and seeing about 4 Mosquitos simultaneously eating lunch.


Be sure to check out the upstream side of that culvert Paul and look for areas that the water would slow down in before entering the actual pipe.

Oh yes, I will definitely be doing that!
 

So, I went back yesterday to collect more material from that culvert. Here's the bridge that sits on top of it.
The Bridge.jpg


Here's the entrance
Culvert entrance.jpg


....and here's my giant, personal sluice box about 10 feet in. Had to use the camera flash since it's pretty dark in here.
about 10 feet in.jpg


Here's the spot on the upstream side where the most heavy material has collected. I took samples from different spots, but the majority was taken from right here. Each scoop was taken from the very bottom with my trowel scraping the bottom of the culvert.
The material.jpg


Here's what I brought back with me. It's about 5 times what I brought back last time. It's still not a whole lot, but I wanted to pan this out and see what I got this time before I REALLY clean that culvert out good. I'll let ya know what I find in here....
Material.jpg
 

Sounds like a plan Paul. Although you're SUPPOSED to be cleaning out the culvert, I'd leave that trunk in there as it may help slow the flow so heavies can drop out even during the "Wet Season". I I do have to ask one question though. What the heck is all that green stuff in that area? Could they be real trees? I seem to remember something like that but I've been in the desert for so long now..... ;) We expect a report on the findings soonest.

Grasshopper: Garnets are a good sign that you're getting close to an area that will catch gold. Gold has an average specific gravity of about 17.6 but can range from 16 to 19.3. Garnets Range from 3.6 to 4.2. Between their S.G and shape, anyplace that will trap garnets is also likely to be able to trap gold. There are certain varieties of Garnets that are worth a lot of money. We're talking $1,00s of dollars per caret. Needless to say I'm keeping my eyes open for some of those puppies!!! My main problems with this area are that it's a flash flood wash so it doesn't follow "The Rules" on gold and water flow and that there's no way to get a vehicle in there to haul stuff out. I have to go dig and classify it into buckets, then haul it back to the house to process it.
 

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