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To: Jim 0216
Weren’t there some picture of dredging machines that were sifting gold?

There are many historic postcard pictures of the large floating gold dredge machines at Oroville. The last phase of the gold rush was going after the fine gold in the lower Feather River area using dredges. After all of the river basin area was mined, the leftover material, of 30 to 50 ft high of aggregate rock piles, covered nearly every inch of the basin.

You can see the rock pile tailings in the first photograph (look in the distance between the conveyor & bucket machine. So the gold was long removed many decades ago. The first proposed version of the Oroville dam was an interesting "arch column" tiered massive concrete structure. When costing out the concrete design against an earthen fill design the earthen fill materials were equal to the most competitive concrete design. Since the gold dredge tailings were not far away & ready made for all of the pervious and non-pervious material requirements for a massive earthen fill dam, they chose the latter.

2,563 posted on 03/20/2017 1:05:16 PM PDT by EarthResearcher333
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To: EarthResearcher333; Jim 0216

Yes, they mined for gold with the bucket dredges many years ago and sluiced out the gold, or most of it anyway. But you never get it all. It’s a question if it is economically recoverable.

See how they do it on Discovery Channel’s “Gold Rush.”


2,564 posted on 03/20/2017 1:49:24 PM PDT by abb ("News reporting is too important to be left to the journalists." Walter Abbott (1950 -))
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To: EarthResearcher333

Thanks.


2,568 posted on 03/20/2017 4:36:51 PM PDT by Jim W N
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