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To: Maurice Winn who wrote (22144)	9/8/2007 4:35:08 PM
From: Slagle	Respond to of 218167

Maurice, The Florida Platform is pretty stable, even though no place on earth is perfectly so. But it is very flat, so small sea level changes move the beachlines around a lot. And the nature of the geology here tends to preserve ancient beaches and dunes. If you will look at a sea level map of North America during the Pleistocene you will see that during this period sea levels have been maybe fifty feet higher than they are now and as much as 250 feet lower, at the peak of the several recent glacial maximums. In the last million or so years there have been eight or more glaciations, on about 100,000 year intervals, separated by warm "interglacials" like the one we are enjoying right now. During these interglacials the sea levels rise and when the ice comes back the sea levels fall and the beaches retreat. The belief is that all these fossil beachlines and old sand dunes here in Florida are a product of this current ice age, meaning less than a million years old. So I'm guessing that the sea level rise has put me under water here, probably during the most recent interglacial, maybe around 125,000 years ago. And my sea level at present is probably closer to thirty feet. I think the highest place in the county is not much more than fifty. And that would be about right, time wise for the age of these shells here, considering their condition. Before a million years ago there was no permanent ice at the North Pole. Before forty million years ago there was no permanent ice at the South Pole, so before that the earth was ice free, which is the natural state for the planet, I would think. Of course there were earlier ices ages, including one that nearly froze the earth pole to pole and extinguished life. There is a lot of Pleistocene sea level study of New Guinea, showing that sea levels undulated about the current level over that period. But this is an anomaly, because over this period New Guinea has been subject to rapid uplift. But Florida has been pretty stable during this time period. Slagle

To: Maurice Winn who wrote (22144)	9/8/2007 5:07:12 PM
From: Slagle	Read Replies (1) \| Respond to of 218167

Maurice, From Wikipedia: "The warmest peak of the Eemian interglacial (called the Sangamon here in North America) was around 125,000 years ago. Sea levels were 4-6 meters higher than they are now, indicating greater deglaciation than today, mostly from the partial melting of the ice sheets of Greenland and Antarctica." Six meters could account for the beachline near here, and surely so if there was say a meter or so of uplift to go with it. And this would square with the geology here, which is described as Late Pleistocene. And a bit earlier, though still during the Pleistocene all of Florida was under water, probably during earlier interglacials. Another thing we have here in Florida are lots of limestone caves, many of them now full of water. There is one near here where they have found Indian campsites, indeed a whole village, now submerged, but were high and dry not long ago, probably at the end of the Wisconsin glaciation. Now, six meters of sea level rise would put nearly every coastal city on earth at least partly under water. And this happened as recently as 125,000 years ago. There you have it, the dreaded "global warming" and this ages before the SUV or even the Model T. Slagle