Vanishing Beach Targets

So I got out for a couple of hours on the beach yesterday and had three targets disappear on me, this has happened before but three is enough to make me ask why ?

The usual scenario is that I'll hit a solid signal say 13 or 14 (Nox 600) that says its 8 or more inches deep. One scoop out and the signal is more like a 10 to 12, another scoop and its 8 or 10 and a lot weaker, by the time I'm at depth there is a weak 5 or 6 signal, one more scoop and the signal is gone. Nothing in the spoils pile, nothing in the hole.

Would this be like a mineral concentration ? it only seems to happen in quite wet sand.

Thanks
Steve

I had similar, have a look here.

https://www.prospectingaustralia.com/forum/viewtopic.php?pid=481929#p481929

Unable to get it to go #1, starts at #5, just go back to #1 to read the original question I posted.

Graham

Cheers Graham, At least its a semi consistent issue and not just me :8
I'll try lifting the coil next time to see if that helps.

maybe remnants of a hook that has corroded away but the iron oxide is still present (just not solid rust bits), but separates as you dig it up?

Could be a combination of mineral layers and a high sensitivity setting

But if it pinpoints clearly at depth, with those target ids I would say a very small piece of aluminium can that has turned on its side once out of the hole, or a heavily rusted beer bottle cap or very small bit of rusted iron giving false numbers

Next time put in all metal and pinpoint mode and see what happens, toggle across modes and see if the target pinpoint location changes location and what the ID variation is, if it is jumpy it is most likely one of the above fuggets

Would your detector pick up a small concentration of minerals sands that might disperse when disturbed i.e. rutile, illmenite and zircon (?. They were mined along the beaches around Newcastle area.

yes. where I am we have ilmenite (with above mentioned content) in our beach sand. The MXT Pro seems to pick it up when there's enough of it, especially when wet, & of course especially if the gain is a bit high. The Rutile (Iron Oxide) & Zircon (Zirconium ore) are most likely the chief culprits, although the Monazite which has Thorium in it (the radioactive stuff) may contribute as well if there is enough of it.
But, it gives a broad area signal, or patch, cant really pinpoint it

Thanks Wally,
I've been running on standard beach 1 mode. Pin point is clear but i'll be honest I haven't reached for all metal mode in these scenarios as the initial signal is strong and clear (I have learnt with help from members here to use all metal mode when I'm getting mixed or multiple target tones (this has really help me with the bottle top identification)). The small Aluminium is possible but I do spread the spoils pile out a couple of times and rescan. I know the nox gets very excited with small aluminium targets but I generally retrieve even the smallest bits of foil (and have found that in high foil areas that the pinpoint covers a much wider area)

The most confusing bit for me is that the ID lowers with each dig which seems counter intuitive if i'm getting closer to the target .
The tiny bit of iron (with false ID) seems sensible and as Ded Driver suggests this may well be a fully corroded hook as I was picking up a few small lead sinkers in the same area.

Ded Driver said:

may contribute as well if there is enough of it.
But, it gives a broad area signal, or patch, cant really pinpoint it

Click to expand...

I've had this experience too on the same beach but with being unable to pinpoint the target have moved on without digging.

curious stuff Po8. If you can positively pinpoint it, I'd reckon on a heavily corroded piece of steel or aluminium