Gold is heavy and is generally found at the bottom of mining strata. It strikes me as being odd, the bucket you scoop pay dirt up with has ten inch teeth on it and i figure there must be a considerable amount of pay dirt left on the bedrock unprocessed which never gets to go through the trammel.
Surely it would make sense to use a high pressure hose to blast the last of the pay dirt off the bed rock into a holding pit and use a vacuum pump to suck up the last of the pay dirt from there and feed it into the trammel.
Once the bedrock is exposed you could then use the hose to blast gold out of the cracks and fissures before abandoning the site.
This is what we call alluvial mining in Australia.moreless