Can be many reasons. Getting down to bed rock generally is the go, but bed rock in the pay streak is the best. It mite only be a foot wide! Two feet off it and get zip in comparison.
If the area is an old worked site, chances are the did strip back, and whats there now could be overburden mixed in with a bit of later flood gold. Hence some spots might only have gold at the top layer. Overburden dumped in the creek can hold a false clay layer at times too. This is from tailings and un wantecd top soil etc being dumped and washed into the creek over years from them digging the top soil away to get down to the old wash.
Thus on the upper flood level on the bend you will often see a wide flat band of silty sand etc. Im sure this is just left over waste from them digging obove.
I have found gold in this sandy stuff. Low yield, but it was quick and easy to dig, and the high banker (back then) could handle a high volume feed as it processed so easily. But mostly fine gold.
The orange colored tailings i mentioned can be messy to pan off, but if you can use a high banker in your state, use spray bars with finer slots, and less of them, this improves cutting power.
at a higher pressure, the volume of water can be made up in a higher pressure. Put this stuff on the classifier, and let it break down at its own pace, dont force it through,. If your are
seeing the color of the clay stripping off in the water up top, all is good. If you dont see colour from the clay spraying around the hopper, it isnt wanting to be broken down and the clay level amount is too high. Flick out, wasting your time with it.
I wont waste my time with the grey clean clay.
The punched sheet we have today was almost unheard of then. A few holes punched through a sheet of tin was pretty standard back then as a classifier. And no high pressure pumps either.
So a lot was missed within this orange clay.
It just ran over the top if they didnt puddle it.
Where the gold was good, it was a case of greed and speed,
and my best two nuggets I've found in my sluice came from Chinese tailings.... in the orange clay.... and they say they missed nothing!
:Y:
