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Mars as a pre-tectonic model for Earth?

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  1. Sep 5, 2011 #1

    cph

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    Might Mars serve as a pre-tectonic model for Earth? For example, no continents, no mountain building nor deep oceans? And does homogeneity of Valles marinaris, as opposed to Grand Canyon, suggest homogeneity for Earth's pre-tectonic environment?
     
  2. jcsd
  3. Sep 7, 2011 #2
    I don't think so. You have the Martian dichotomy with the comparatively high, thick crusted, heavily cratered, old southern half and the younger, lightly cratered, thinly crusted northern plains.

    You have strong residual magentism, with some evidence supporting early spreading ridges. There is the volcanism of the Tharsis bulge. And a host of other distinctive features.

    I don't see these as being primitive in character - certainly not most of them - so it just doesn't speak to me as being an analog for an early Earth.
     
  4. Sep 7, 2011 #3
    If you look at the magnetic signature of Mars you will note a spreading center (marked by reversals in Mars' magnetic field) was present prior to whatever event caused the Martian Crustal Dichotomy.

    http://jmars.asu.edu/download
     
  5. Oct 18, 2011 #4
    Bingo!

    Not to mention Olympus Mons, the largest known mountain, which is an extinct volcano.

    Mars is POST-tectonic, not pre tectonic.

    Perhaps the fact that Mars is 40% of the mass of Earth might explain this fact, as the energy radiating from the Martian core and mantle had less mass to pass through on its way to outer space than on Earth, in addition to there (likely) having been less of such energy to begin with.
     
  6. Oct 18, 2011 #5
    OOH!

    Actually, I just thought of something.

    What does it mean to be tectonically active?

    Does it require plates to be crashing into one another, or spreading away from one another, or does it simply require my usual definition of "crunchy on the outside, gooey on the inside"?

    Am I misusing the term, and should I really be substituting the term "volcanically active" for my customary usage of the term?

    Anyways, this observation doesn't change my original statement, as the evidence of tectonic spreading on Mars indicated by Ophiolite and Shootist clearly exemplifies tectonic activity in the more usual sense in Mars' past.
     
    Last edited: Oct 18, 2011
  7. Oct 18, 2011 #6
    Ophiolite:

    Sorry! I didn't mean to ignore you, but I read through this thread rather quickly, and I didn't realize that my first post to this thread post (post #4) was, in some respects, a duplicate of yours, even though Olympus Mons isn't technically part of the Tharsis Bulge (though it's near enough that it might be a product of the same hot spot).
     
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