Little bit of gold in thames and they said it was only flower gold. found in low pressure zone.
Oh that looks good.
When you say low pressure zone?
Soutz I am not a hydrodynamic expert but probably like most here have some clues (well i hope so ) so others might explain better but my understanding is low pressure zones are areas where there is less pressure in the water flow, hence material being carried by the river will drop out - based on weight/specific gravity.
The most obvious example might be where gravel bars form on/in a river are typically in low pressure zones, behind a bedrock outcrop or on river bends etc.
To get the idea imagine the river in flood carrying a bunch of material, then the river suddenly widens, the flow pressure will drop, material will drop out of it as the flow slows. If a stringer has a low pressure zone in it you can find nice spots where heavy material accumulates.
Low pressure zones dont always carry gold, there are a lot of “it depends”, but if you are reading a river it def helps to look for these spots. You do have to think about these when the river is in flood not at normal flow, as gold won’t move much without a flood.
I think also big rocks in the middle of the flow can form mini low pressure zones behind them, you can often find nice material just behind a big rock, and indeed occasionally just in front of them.
Anyway hope that helps!
Excellent points to keep in mind
Awesome.thanks for that.
Would the same apply in beach metal detecting after a flood?
A beach would be a very dynamic environment Soutz and well outside my limited understanding. But I would imagine similar principles apply, albeit with tides and storms it might make things a lot more complicated.
I like bedrock very much!
Plenty left over there bud. Good find.
Tararu and Tapu still producing some nice pieces in the sluice