While Gork takes a breather I'll take a stab at answering some of the questions posed. Keep in mind I'm an Oregon miner and the Klondike is completely different territory.
Judging from the pictures shown here, and what we all see on TV, most of the gold is finer flakes. There is an old saying "Nuggets are nice, but the fines are your bread and butter".
That being said, most of the sluice setups I've seen on here and on the show are set up for volumes of material. If they're actually catching 60% to 70% of the fines present, I'd say they were doing pretty damned good. I believe Gork mentioned the guys up there aren't too concerned with losing a million dollars worth of gold if they're catching a lot more than that.
Going by Todd's numbers..... once they finally got set up and running, they were running 100 yards an hour, for a ten hour run and recovered 4 ounces. That's pretty pathetic in my opinion. Either their recovery was piss-poor or the ground was, take your pick. That's .004 ounces per yard, recovered.
When I'm out dredging, a pennyweight or more a yard is not uncommon at all. But then again, I'm running concentrated material, not bank run yardage. Big difference.
With fines, you can count on pay layers. Not necessarily on the bedrock, although your bigger stuff will be down there. You've heard of 100 year floods? Those are the layers you're looking for when going after fines. Maybe there wasn't enough water to scour everything right down to bedrock. So you will see cemented gravels pre-flood, with a layer of new deposit on top of it, and another on top of that, and so on. Hence moving yardage and lots of it. You really can't cherry pick with big equipment like you can with a dredge. I do test holes and track the layers for pay, then run what I think is best. Sometimes it turns out just skimming the surface is the best pay, don't even bother working your way down to bedrock.
Gork, you can count me among the ones who want to pick your brain as well. Don't assume T net is like a lot of other sites and give these guys a little break. One day I hope to move as much material as you and the other big timers!
I wince at posting this- but this was my bit for ICMJ a few years ago
Scott was a heckuva nice guy for even publishing it, let alone coming to our rally.