Placer Gold Mining in Colombia
Most of the river beds contain gravels of a depth of from 10 to 30 ft., carrying gold values from the surface dowuwards. These gravels generally average from 5 to 15 and even 20 cents per cubic yard until the last 2 or 3 ft. immediately above the bed rock is reached, when the values rise from $1 to as high as $5 and even $10 per cubic yard. Of ...
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