I thought of an eco friendly gold prospecting technique There is a thing called crevicing, where crevices fill up with heavy things like gold, then prospectors dig out the crevices to find nuggets.

Instead, take a log, put thousands or tens of thousands of little crevices on it, then toss it near a river mouth. It gradually accumulates gold nuggets, then pull the log out and harvest the gold. if people forget about it, it is just a log. If the thing accumulates gold at a measurable rate, then the future value could be calculated and the person could get money at the present for the gold accumulating logs laying around
-- beanangel, Oct 10 2016

This is probably not a completely bad idea, [beany].

Issues: (1) Logs have been known to float. Logs that satk at water fast enough to carry gold may also roll. Either of these could have a negative impact on the recovery of gold or, atdeed, of the log.

(2) Logs would be vulnerable to being harvested by unscrupulous people, if there are any such people around. But

(3) I do sort of like the idea of engateeratg a section of river bed to trap gold over the long term.

I'm gonna go [+] on this.
-- MaxwellBuchanan, Oct 10 2016


" WKTE "

Done in Alaska by laying segments of rock in the river at low flow season, and harvesting around them when it comes around again.

Native American tribes did the same game with rocks as well.

But they were not able to spell and punctutate proberly.
-- normzone, Oct 10 2016


Nice. This was his anno to "Gold panning submersible bot".

Only problem I can see is that the log crevices would need to be the lowest crevices available in any given stretch of river.
Logs like to float unless forced not to.
-- 2 fries shy of a happy meal, Oct 10 2016


There's a Captain's log joke in there somewhere...

Logs with crevices pre-impregnated with custard would decrease the floatiness of the logs. Or not.
-- not_morrison_rm, Oct 10 2016


As an alternative, you could just dump about 50-100 cubic metres of mercury in the headwaters, and dig a steep-sided trench across the river mouth. After a few days, just go to the trench and pump out the mercury, along with dissolved gold from the full length of the river.
-- MaxwellBuchanan, Oct 11 2016


Well, the crevices have had thousands of years for the gold to aggregate so your log would 'gain value' very slowly indeed. And it would presumably need to be buried at the bottom of the channel as the gold particles need to fall into the crevices. Having said that, I do believe that some placer miners do harvest gold particles trapped in mossy boulders.
-- AusCan531, Oct 11 2016



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