Is Australia the old Antarctica?

wingedelm

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Is Australia the old Antarctica?

Submitted by wingedelm on Fri, 02/27/2009 - 12:52.

I have been studying magnetism lately and started putting the effects on a global scale. Seems that Pangaea actually formed around the north pole as it is pulling the + continental material towards it. Antarctica gave me pause until I realized that the south pole would be forcing continental material up and out (thus the lack of subduction zones around antarctica where ocean floor spreads northward-always wondered why) creating new continental material. Also at the north pole the continental material is pulled down so Pangaea would have had a huge dip in the middle at the pole (Mediterranean Sea?) and a ring of subduction mountains on the outer rim (the now ring of fire and south Africa). So my theory is that Australia was Pangaea's Antarctica with Ayers rock as the S pole. Maybe when the meteor hit off the Yucatan in Mexico it shifted the magnetic pole since something that huge would be a major attractor and the subsequent wobble effect and the impact split up Pangaea and displaced the south pole which erupted out the beginnings of Antarctica we know over thin ocean crust. As the poles moved back to stasis Australia was suddenly adrift and now heading toward the north pole. Went further today and I think that the India plate was the even older south pole with possibly the large mesa due south of Gwalior and sw of Jhansi as the possible Ayers rock type polar formation. Anyway, if anyone has any data that can help with this theory or any suggestions as to how it might be better proved, all comments are welcome

al8301

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I think you may be getting a

Mon, 03/02/2009 - 17:17

I think you may be getting a little confused about paleomagnetism and the effect of the magnetic field on the crust.

As I understand it you are postulating that: continental crust is drawn northwards to the pole due to magnetic attraction and that a depression is formed around the pole itself. This state of events is interupted by a catacylsmic event (meteor impact) until it re-establishes itself and the whole process begins anew.

Please forgive me if I have misunderstood the above.

Interesting theory though it is I'm afraid that is simply not how the earth works. Tectonic plates move due to mantle convection. The energy source for mantle convection is nuclear fission in the earth's core. Palaeomagnetism measures the orientation and inclination of 'dipoles' within igneous rock. As the rock cools below the materials Curie point (500-600C) then the orientation of the 'dipole' is fixed. The inclination of the 'dipole' can be correlated to the latitude at which the rock passed the Curie point - this is one technique used in recreating ancient supercontinents like Pangaea, Laurasia, Gondwanaland etc).

For further evidence of plate tectonics you may wish to consult the information elsewhere on the site. I'm unsure if there is guidance on palaeomagnetism but a quick search should resolve this.

The other side of the argument is to contest your evidence:

There is a subduction zone south of New Zealand so crust is being subducted (relatively) close to the Antarctic.

Pangaea had already split before the Yucatan impact 65Ma (I can't spell Chicxulub!)

The Yuacatan impactor is estimated at being 10km across - pretty devastating for life on earth but not an overly big deal for the planet given that imapcts this size are estimated to occur every 100million years on average.

And I suppose the big argument against is that the poles of the earth switch every 1-2million years (north becomes south and vice versa) which, if your theory was correct, would prevent continental crust from gathering at either pole.

Bye,

wingedelm

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Thanks for your comments,

Mon, 03/02/2009 - 23:56

Thanks for your comments, just read a paper on paleomagnetism and it cleared up all my lingering questions. Looks like my hypothesis was disproved, glad to say, because I was starting to attempt to link up the Snake River lava flow and Yosemite with magnetic pole reversals, very glad to drop this line of thinking, thank you.

GeologyRocks