Mars as a pre-tectonic model for Earth?

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Discussion Overview

The discussion explores whether Mars can be considered a pre-tectonic model for Earth, examining geological features and characteristics of both planets. Participants analyze aspects such as the absence of continents, mountain building, and oceanic structures on Mars, as well as the implications of its geological history for understanding early Earth.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants propose that Mars, with its lack of continents and mountain building, might serve as a pre-tectonic model for Earth.
  • Others argue against this idea, citing the Martian dichotomy, which features a high, thick crusted southern hemisphere and a younger, thinly crusted northern plains, as evidence of complex geological processes.
  • One participant highlights the presence of a magnetic signature indicating a spreading center on Mars, suggesting tectonic activity prior to the crustal dichotomy.
  • Another participant asserts that Mars is post-tectonic rather than pre-tectonic, pointing to features like Olympus Mons and the implications of Mars' lower mass affecting its geological activity.
  • A participant questions the definition of tectonic activity, pondering whether it should encompass plate interactions or simply volcanic activity, while maintaining that evidence of tectonic spreading exists on Mars.
  • One participant acknowledges a duplication in their earlier post regarding Olympus Mons and its relation to the Tharsis Bulge.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding Mars as a pre-tectonic model for Earth, with no consensus reached on the validity of this comparison.

Contextual Notes

Participants discuss various geological features and their implications without resolving the definitions of tectonic activity or the relevance of Mars' geological history to early Earth.

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?
 
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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.
 
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
 
Shootist said:
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

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.
 
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:
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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