Detecting old aluvial workings

[KarlS]

My question is there a point in doing it? Is there any chance to find nugget in quite small aluvial area that has been worked over many times. My two recent prospecting trips were to small creek around Oberon. Aluvial gold has been mined there from about 1860 it was fairly rich deposit. Gold comes from old wash that has been covered by volcanic lava and present creek cut thru basalt cover and redistribute old wash along its banks. Detecting close to the creek is hopeless as you get signal every foot or so. Amount of mosty modern junk there is almost as bad as in the parks around place where I live. Bit higher up along the banks the soil is only few inches deep on bedrock. There I found about dozen .22 bullets, few .22 long cartiges and bits of old rusty iron.
Few test pans produced 1 to 4 flakes of gold, mostly flat and litte bit of flour gold. There is very little of black sand. The wash is mostly small flakes of shale, large water worn black basalt, serpentine rock and some quartz. Am I wasting time trying to find nugget in such a place?
Karl

 

[Goldtarget]

I'll say yes. I'm not familiar with the area but I think of it this way even the heavily hunted gold areas still produce occasionally and Secondly I've seen more than a few tidy pieces come from alluvial diggings. The less frequented and the more nuggets known in the area the better but as long as your putting the machine in the right spots I'd say your a chance. The last nugget I saw over an ounce came out from a heavily worked alluvial area at about 2 inches between holes. No kidding this thing was 10 feet from where the old timers surfaced the hillside in between two diggers holes.

 

[BrisJoe]

My theory on old workings, is rather then go over with a detector, you might have more bang for your buck using either a high banker or dry blower depending on the location or conditions of the area.

Ive found old modern workings near me which was processed by a wet plant in the 70's I took a test pan of the mullock heaps and got 3 specs.

So my plan is as soon as I get my walbanker built I'll go back there and process the dirt.

As far as finding nuggets in the heaps some get very lucky and find piles that hasn't already been detected 1000 times already.

 

[loamer]

Depends where you are for old diggings. There are sites around here with 100s of mullock heaps around one gully x 100s of gullies - do the math. For example, diggings in gully xyz equals 200, of which 90% were duffers.Which ones do you detect or put through a wash? The Inkerman near Moliagul is a classic example - 1000s of holes - where to start and the lead runs for miles and miles and these types of runs are common down here. Wanyarra, Tarnagulla, Dunolly etc etc. Research may show that a certain part of a lead was rich and then rushed - Blackmans near Maryborough Vic is an example, but the majority of the lead was worthless, yet there are 100s of holes. Original source geo maps/commissioners maps provide lots of clues as do the written testimonials at the rewards committees, however,where to start is the big question. I think on big leads, a lot of time can be wasted testing each hole at random in the hope of a throwout or small alluvial gold left behind. There are no magic answers - just a lot or research and local knowledge. I have seen many folk turn up down here, park near the closest mullock heaps and detect with no result - reason? the easiest holes were done years ago.

 

[dave14110]

I'd also say yes the old timers diggings sometimes become less frequent or they stopped digging when the gold per dirt became less. This did not mean the gold had ran out, simple put the nuggets became too far apart & not enough to pay. Gold nugget might have been spread out too much.
The gold may have got deeper or the goldfield may have been left for better location, often diggings had multiple rushes sometimes decades apart. This is only a tiny explanation. I have also seen a nugget over an ounce dug within 20 feet of diggings and 100's of people would of parked their cars on it or very close. In fact this Nugget was in someone else's hole, people really should take their rubbish recheck holes & fill them but that's their lose now.

 

[Lbg dreamer]

If you need a different perspective
I could arrange to meet you out there .
I'm not far away
But I don't frequent that area
Or detect that area .
but I have mates that do
And they do well .

 

[KarlS]

Thanks for answers. This creek is bit peculiar. Most of Mullock heaps has been washed away by the foods. Records show some nuggets were found around this area but it is not clear if it was from this creek or other. Anyhow I will do few more trips there before I move to the next creek.
As BrisJoe suggest, when weather get bit warmer I may try sluice there.
Karl

 

[loamer]

a very good place to check is where the creeks have cut through the old diggings and you can get to very bottom of the old diggers holes.what I am talking about is you can almost see the hole in profile,lmot sliced them in half - find these at many places and well worth a dabble around.

 

[KarlS]

Yes I found hole, more like pit about 103 meters. The remain of Mullock heap is on creek side and whole thing forms kind of creek chanel where water flows during the flood. It is also place where I got most of gold from test pan. As the gold shows only to about 4 inches depth l think it is a new gold deposited in last fifty or so years. I dug down for about another 2 feet, found large bits of shale, but no gold.
Karl