Re: Florida Man
"Hmm... This change from rise to drop wouldn't happen to roughly coincide with a world war and mass use of leaded fuels would it? "
Some years ago I watched a documentary about excavations at some ancient site in the UK - it may have been at Stonehenge.
Anyhoo, they discovered the skeletons of a woman and two or three young children which were duly dated to confirm they were contemporary with the structure they were found beside. Once that had been done, and isotope analysis was carried on the teeth out to find out where they had been born and lived and to try and benchmark how much lead modern children take in from leaded petrol and other evil things in modern society.
Unfortunately this came to naught, as the children's teeth contained as much lead (within the accuracy limitations of the instruments used) as a modern child's did at the time the documentary was made.
So now we know - when places like Stonehenge were built technology was primitive, so all the trucks, cranes and earth movers they used to build it had petrol engines rather than diesels, which obviously hadn't been invented yet..