I would think that a keg of gold, or any heavy amount of gold in anything, let alone a heavy keg to begin with, would sink, and sink and sink and sink, in a swamp or any marsh land, to at least the depth of where it would hit harder ground.
A few years back I used to dream about detecting this area where there was a small pond with old stone seating all around it, right near the old farm that used to be a resort in the 30's. The farm was built in the late 1800's. Anyway, I detected around the farm, found alot of clad and interesting items, etc...I would go past this pond every once in awhile wishing to god I could get in there, knowing it HAD to have plenty of coins in it from the people staying at the resort, treating this pond like a wishing well. This pond was more like a swamp, in that it had a very mucky bottom, ther was also lot's of quicksand in the area (the only lake in the twp was all quicksand on one side)
Well, one day my friend and I were driving past it and I yelled out STOP! The pond was completely dry and I had my detector with me. I walked in thick muck, some pretty scary wetter mucky areas and do you know I didn't get a single beep, nada, nothing ziltch! I figured it had to be because I could never get a reading as deep as any coin that was in there probably had sank.
Moral of the story, there is no way anyone would put something so heavy in a swamp or grounds they sank in. They'd have to know it would sink and be next to impossible to retrieve when they wanted to. Unless it was never their intentions to retrieve it, but just to unload it so they wouldn't go to jail if caught with it, or something like that.
And why would someone say the wood would be preserved? I had/have entire docks in our lake that were made of oak (all types of wood actually) back in the 20's & 30's and there's only fragments left of them. The wood is usually mushy, dilapidated pieces of wood, that when you try to lift them out, they break apart. Even some of the newer treated wood from the 50's does this. I realize some wood stays fairly well preserved (ship wrecks, old boats etc...) but isn't there a difference between sea water and lake water or swamp...and a difference between what lake waters do to wood too?
Not saying this gold doesn't exists, just saying that I wouldn't count on finding anything in that swamp...unless it's changed shape over the years, and it was buried on the dry part way back when. That's the other thing, swamps change shapes too, after many years.
I looked at many ariels of my area ('bout 500 acres) and saw swamps that were there (big one's) back in the 70's that are now gone, and news ones in places where they weren't before. Water sheds and swamps change... Anyway, that's my 25 cents worth (inflation).
