Mulitregional vs Out of Africa

[ravenwing5910]

Seems I have recently read something about a super continent previous to pangea. I am sure it must have been one of the links that one of you gentlemen posted.

[Digit]

Well it started ok Monk, but the only item missing towards the end was Atlantis.

[Minimalist]

Plate tectonics not only explains continental drift but also is a pretty good explanation for earthquake and volcano zones.

As "theories" go, it seems to have a lot going for it.

[Digit]

Once the continents started moving Min the theory pretty well fits the known and observed facts. What it doen't answer, and doesn't attempt to, is what started the continents moving.
There doesn't seem to be any logical reason as why the continents formed in one lump, unless they are an impact phenomenum, and once formed why split?
We're a long way off thread here!

[Forum Monk]

That's your problem Digit. You're always asking questions. It tends to screw up perfectly good theories.

[Digit]

Ah shucks!

[Cognito]

There doesn't seem to be any logical reason as why the continents formed in one lump, unless they are an impact phenomenum, and once formed why split?

I have never seen anyone take on that obvious question. Doesn't anyone think the answer to that would be important?

[Digit]

You watch a TV programme Cog about, dinosaurs, for example. Do they ever say 'this is only our opinion'?
The best you can hope for, 'the causes are not fully understood', bull for we haven't got a clue but aren't going to admit it.
As I said earlier the drift theory does a good job of explaining what we have but offers no explanation for the start, and the attitude is, 'it doesn't matter how it started just so as we know what is happening now.'
From a practical viewpoint that's true, but it's a bit like saying it doesn't matter whether HSS bred with HSN because we are what we are. Again true, but both ignore that we are what we are because we ask these questions.
What Monk said about me earlier has been said to me before but I'm often surprised that somebody else hasn't seen fit to ask before me.
I can offer two possible explanations to my questions but I'll wait and see if anybody else has the same ideas first.

[Minimalist]

This animtion, from Berkeley, suggests that the continents came together to form Pangea and then broke up again.

http://www.ucmp.berkeley.edu/geology/tecall1_4.avi

[Digit]

Given the time scale I can see no reason why the continents, in various guises, have not been around the globe several times.

[Minimalist]

Sort of like a gigantic game of slow-motion bumper cars.

[Beagle]

http://www.normanspencer.co.nz/PsEarthS ... erica.html


Since we're engaging in all this fun thinking, you'll enjoy this theory. Here is a picture regarding the "Expanding Earth Theory"

I'll go get the text.

[Beagle]

http://www.expanding-earth.org/

This theory has been out there for quite a while, as an alternative to the plate tectonics theory/fact.

[Minimalist]

Kind of like blowing up a beachball.

[Cognito]

Eventually Mankind will be forced to migrate to a new home on Mars before Earth grows to the size of Neptune. Today's global warming is an early warning to Mankind.

Now down to important matters. Will drinking beer on Mars provide the same or better rush due to differences in atmospheric pressure, CO2, oxygen content, etc. In other words, we have a perfect opportunity now to terraform Mars for a perfect buzz. Let's not let this pass by!