Martian Topography

[dragon04]

Rather than hijack the Mars Ocean thread, I have questions about the presence or absence of evidence that would indicate whether or not there was ever tectonic plate activity as we know it here on Earth.<br /><br />I've looked at topo maps of Mars, and can't see with my admittedly untrained eye any evidence of features that would either directly identify or infer past plate tectonic activity on mars.<br /><br />No underwater ridges, no mountain ranges like the Himalayas or Rockies, etc.<br /><br />Given that current estimates state that Mars has been "dry" for billions of years, and that Mars hasn't had a significantly dense atmosphere for a long time, would erosion as we know it be a satisfactory explanation for the absence of such large features?<br /><br /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[dragon04]

I dislike bumping threads I make, but I really would like some expert answers to my questions. <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[billslugg]

MGS here found magnetized bands similar to the ones on Earth's ocean floor, suggesting plate tectonics in the distant past. <div class="Discussion_UserSignature"> <p> </p><p> </p> </div>

 

[MeteorWayne]

Dragon,<br />I didn't have time to do any research yesterday, between following the ISS saga, Shuttle repair, and cooking for the NJAA Bar-B-Q.<br />I'll see what I have in my pile o' stuff today.<br /><br />Don't complain too much about slow responses or you'll get yelled at like I did last week <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

But you might be in luck...I see JonClarke is back <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[exoscientist]

Valles Marineris has been compared to the Great Rift Valley in Africa, a plate tectonics feature:<br /><br />Great Rift Valley.<br />http://en.wikipedia.org/wiki/Great_Rift_Valley<br /><br /> Go to the NASA ADS astronomy server to look up articles both for and against the idea of plate tectonics on Mars:<br /><br />Smithsonian/NASA ADS Astronomy Query Form.<br />http://adsabs.harvard.edu/abstract_service.html<br /><br /> In the box for searching in the abstract type in: Mars, plate tectonics. Make sure the "AND" option box is selected. <br /><br /><br /> Bob Clark<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[JonClarke]

That's a good question. Given that parts of the Martian surface are 4 billion years old I would say that had Mars ever had plate tectonics we would see evidence of it in the gross landforms and composition. Large scale features like island arcs, mid ocean rifts, subduction zones, continental and oceanic crust, fold belts etc. should be preserved. There is little or no evidence for any of these.<br /><br />Rifts - as Bob points out, we have the Vallis Marineris system. But that is it.<br /><br />Island arcs - Apart from the arcuate mountain range of Thaumasia, there is nothing that looks like an island arc. Structurally Thaumasia is a fold belt, and lacks the andesitic volcanics of an island arc.<br /><br />Fold belts - Just the one,Thaumasia, as mentioned. This lies south of Vallis Marineris and may be where the crustal extension of that rift is taken up by matching crustal shortening.<br /><br />Continental/oceanic crustal dichotomy - there is the hemispheric dichotomy in elevation on Mars, which would match the eleveation dichotomy between oceanic and continental crust on Earth. But the composition is wrong. The Martian highlands are basaltic in composition, not granitic. The very few granites are local differentiates, not wide spread masses as on Earth.<br /><br />Subduction zones - no sign.<br /><br />Mid ocean ridges - no sign.<br /><br />Magnetic striping anomalies - very local and have alternate explanations like parallel dykes emplaced during periods of differing magnetic polarity (we see these on Earth as well).<br /><br />All in all I would say that at most Mars shows signs of having had incipient plate tectonics, but did not develop the full condition.<br /><br />As to why not, who knows? We don't really understand why Earth is the only planet with full blown plate tectnoncs, and there is still debate as to when it actually started here. <br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[exoscientist]

Just found this link that also allows you to search Lunar and Planetary Science Conference abstracts:<br /><br />Search the LPI Abstract Collection.<br />http://www.lpi.usra.edu/publications/absearch/<br /><br /><br /> Bob Clark<br /> <div class="Discussion_UserSignature"> </div>

 

[3488]

Was not the Vallis Marineris formed due to the stretching of the crust of Mars, by the <br />formation of the Tharsis Rise?<br /><br />Like Jon Clarke, I too have found no evidnece for spreading or subduction.<br /><br />Jon, did you have a good time???<br /><br />I hope you did.<br /><br />Thanks Bob, for your link. Its an interesting read.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[JonClarke]

Hi Andrew<br /><br />Yep, I have read that The formation of Vallis Marineris was due to the formation of the Tharsis Bulge. I am not sure what the current preferred theory is. Even so, it is still possible for Thaumasia to be related, via gravity sliding.<br /><br />BTW, did you know that Tharsis, the biblical Tarshish, is ancient name for Spain?<br /><br />Yes, I had a good time in Echuca. Here I am unbogging the truck <img src="/images/icons/smile.gif" /><br /><br />Jon<br /> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[3488]

Hi Jon, I did hear that from somewhere referring to the name of Tharsis!!<br /><br />I too think that Thaumasia is related.<br /><br />Glad you had a good time. See you got bogged down!!<br /><br />I suppose on a trip like that, it was inevitable!!<br /><br />Will talk again later.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[JonClarke]

Yep, we dug 25 soil pits, each big enough, in the words of my colleague, to bury a baby. Despite getting bogged in most places the clay was so hard that the mattock bounced off.<br /><br />Apparently Thaumasia is named after the ancient Arabian cloud god Thaumas.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[exoscientist]

Is that what they call a billabong?<br /><br /> - Bob Clark <div class="Discussion_UserSignature"> </div>

 

[3488]

Hi Bob,<br /><br />I do believe that is a Billabong. There are loads where Jon Clarke went.<br /><br />Tricky & slow going as the photograph clearly shows.!!<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[centsworth_II]

<font color="yellow">"...we dug 25 soil pits, big enough, in the words of my colleague, <br />to bury a baby."</font><br /><br />I thought the dingo ate it.<br /><br />Seriously.. Your colleague might want to change that description<br />to "big enough to bury a rugby ball" in the future. <div class="Discussion_UserSignature"> </div>

 

[dragon04]

Thanks very much for the answer. <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[JonClarke]

There were billabongs in that area. Are semi-permanant water holes in abandoned channels and channel oxbows. That particular incident was on a flood plain. Gunbower island to be precise. A world significance wetland but dry as a bone at the moment - except for the odd mud hole on the track.<br /><br />Jon<br /><br /> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[JonClarke]

Nah, my colleague takes rugby far too seriously for that. me, I would be happy to bury a rugby ball. <img src="/images/icons/smile.gif" /><br /><br />But it is a very pretty area, as this Gunbower Creek sunset shows. <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[h2ouniverse]

aw Jon<br />Sorry for the pedantic minute but afaik Thaumas was in Greek mythology the son of Pontus, elemental god of water (pre-Zeus&Poseidon) and of Gaia. Thaumas was a sea god.<br />A good pick for a new planet or planetary moon btw.<br />Best regards.

 

[JonClarke]

That's interesting - I got my information from the Mars Gazetteer on the USGS site. I must say your atribution sounds more plausible as Thaumasia is a significant albedo feature and almost all of these had classical names. The use of multi-cutural names on mars is a post Mariner 9 custom.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[exoscientist]

This report to be given at the 7th International Conference on Mars discusses rifts seen on Mars and whether plate tectonics are required to explain them:<br /><br />MARTIAN RIFTING IN THE ABSENCE OF PLATE TECTONICS?<br />M. Grott, E. Hauber, Institute of Planetary Research,<br />German Aerospace Center (DLR), Berlin, Germany (****@dlr.de, ****@dlr.de), P. Kronberg, Institute of Geology,<br />Technical University of Clausthal, ClausthalZellerfeld,<br />Germany.<br />Seventh International Conference on Mars.<br />"Recently, Martian candidate analogues to terrestrial continental<br />rifts have been investigated in detail and it has been<br />shown that the Tempe Fossae [3], Acheron Fossae [4] and<br />Thaumasia Highland Rifts [5][6] bear many structural similarities<br />to continental rifts on Earth. However, the question of<br />the rift formation process has so far not been addressed and<br />an active mechanism involving mantle plumes and local doming<br />has usually been assumed. Furthermore, the connection<br />of Martian rifts to plate tectonic forces has so far not been<br />discussed, although rifts are sometimes thought to be at least<br />indirect evidence for plate tectonics [7]."<br />http://www.lpi.usra.edu/meetings/7thmars2007/pdf/3077.pdf<br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>