Serpentine Bedrock - Hydraulic Area

[AU_Solitude]

I am currently working a smaller hydraulic pit in the sierras that was washed down to bedrock in most places, the bedrock is serpentine but there is also a great deal of ironstone river rock laying around, the ground is incredibly hot. There are areas the SDC struggles with here.

It's no surprise, but there is the usual plethora of iron trash associated with these sites - nails, tin, cans and iron scrap galore. I have been able to pull a few pieces of gold out with the SDC, and I know there is more there, but the SDC is constantly overloading on the scrap iron. VLF's struggle with the ground and have to be fully castrated to the point of being essentially useless to even come close to the serpentine. 

How would you go about detecting such an area? Is my only option to vacate the area of all iron one piece at a time with the PI? All input appreciated.

[Steve Herschbach]

Ah, the classic dilemma! Ground really hot, so you need a PI. But lots of trash, so you need a VLF for discrimination. But the VLF gets no depth so you need the PI. But the PI gets the trash......

Steve's Law Of Target Depletion

[oldmancoyote1]

Since bedrock is mostly exposed, try sweeping the area with an array of super magnets mounted on a pole arranged as if it were a garden rake.  It's certainly not a perfect solution, but it could be a major improvement.

Alternatively, you could build a similar device using an electro-magnet for easy disposal of the trash.  Hope this helps.

Good luck.

[IronDigger]

Trashy areas drive me nuts...only way to deal with it is going back and cleaning it out over a period of time.

[AU_Solitude]

Thanks for the input. Going to have to weed the trash out piece at a time with the SDC.

As to the above suggestions of the electromagnets, sweepers and such, not even close to being practical in the areas I prospect. Only access is by foot. I spend time shaving ounces of weight off my backpack with most of my packs weight being water.

[Steve Herschbach]

I know some spots that are exactly like you are describing. California has some really hot serpentine areas. They are frustrating because they really do call for a PI type detector, but the trash levels mean most of the time is spent digging trash. Or I switch to a VLF, but now half the targets are out of reach. Ultimately it does seem to always boil down to just digging everything. The problem is a time issue. We usually don't have the time to dig everything, but get forced into it anyway. The good news is these are the types of locations where people will keep eking out a few nuggets for a long time. A nugget probably still remains until every metal target is gone.

[Lunk]

Sounds like a job for a GPX with the 5X10 Commander DD coil with Iron Reject on. I’ve had pretty good luck with that setup in heavy trash areas.

[mn90403]

When I first started looking for meteorites I bought one of the shop sweepers and put several super magnets in it because I wanted the hot rock/meteorite to stick to my sweeper.  It turned out to be too big for my job but I was left with a number of super magnets which if you had some could help your job one small area at a time.

You can't clean a huge area and detect it with the time you have left before the snows.  Find your area you are getting the best gold and rake it with a super magnet rake (do a 10'x10') and then with the soil loose run the magnets over it again with them on a rope or stick.  After 30 minutes or so you should have more than half the canslaw, nails and screws out of your way.

The biggest drawback is the cost of the magnets.  Also, be careful with those things around your detectors and fingers.

Mitchel

[geof_junk]

If you use a super magnet it needs to have it exposed surface flush with your pick so that it can be cleared with one wipe with your hand. I managed this by using car bog filler and/or selleys-knead-it multipurpose-epoxy