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Wednesday, September 23, 2015

Carbonatite: "Sandcastle" Structures in Calcium Carbonate-Rich Tanzanian Volcano

         Carbonatite lava is quite unusual in that it is dominated by calcium carbonate, rather than silica, as is most of the earth's lava. It creates these delicate structures, reminiscent of giant sandcastles:





        This 2-minute video of  carbonatite lava erupting in Ol Doinyo Lengai Volcano, Tanzania, Africa, shows the extremely liquid, less viscous nature of the carbonatite compared to the thick, ropey, silica-rich pahoehoe lava of Hawaiian volcanoes.



         Ol Doinyo Lengai is the only known, currently erupting carbonatite volcano on earth. It is located in the East Africa rift zone.




          Carbonatites are, almost exclusively, associated with continental rift-related tectonic settings.




         Unfortunately, structures like those seen in the first image above are, like sandcastles, extremely delicate. The structures, as such, are rarely found in the rock record.



     
        Because of its unusual composition, carbonatite is quite literally the coolest lava on earth, erupting at 500-600 degrees Celsius (930 - 1,100 degrees F), compared with 1,160 degrees C (2,120 degrees F) for lava from silica-rich volcanos.

  


How cool is that?!




Field trip to Tanzania, anyone?

Steph










43 comments:

  1. Your link to the volcano video above is broken. Were you thinking of this one, maybe?

    Cool, indeed. I'm surprised by the lack of smoke and steam and Sturm und Drang I usually associate with volcanic eruptions. This Great Rift Valley feature seems sort of just, well, Leakey. And I'm even more surprised by that apparently comfortable sneaker in the frame at one point, right next to the molten lava. How come it wasn't a smoking hotfoot?

    ReplyDelete
    Replies
    1. (Now that I think of it, there are probably plenty of hot Tutsis in the area.)

      (Hutu blame for all these bad puns?)

      Delete
    2. Yes, that's the video. I fixed the link, thanks.

      I saw that sneakered foot, too. 500-600 degrees C is still pretty hot. . .

      Hutu, indeed!

      Delete
    3. Back to that sneaker -- what to do about the apparent coolness of that molten rock? Could it be that the video isn't really showing flowing carbonatite, but maybe just a nearby mud volcano? (For that matter, this is a video found on the Internet -- who can really vouch for its authenticity?)

      Delete
    4. The lava flow pictured is likely fairly significantly far from the center of the volcano. I have seen other images of people jumping over the carbonatite flows:

      not the smartest jumps ever.

      Delete
    5. Makes me feel less stupid for putting my hand in the outflow of the Imperial Geyser in Yellowstone last year, against my wife's advice and posted warnings. (It was only pleasantly warm.)

      Delete
    6. Post about Yellowstone below was meant to go here. . .

      Delete
  2. Not really up for a field trip, but the map makes it seem like Zoë could just tanz over to meet you in Tanzania. Kenya dig it?

    ReplyDelete
    Replies
    1. Tanz on over with tap shoes on?

      It's pretty intriguing. She is planning to travel around the continent as much as possible. . .

      Delete
    2. And, while we're looking at that map, how long does Google say it'll take to drive to Ol Doinyo Lengai?

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    3. Addis Ababa, Ethiopia, to Dar es salaam, Tanzania, (south of the volcano) is a 33 hour drive. . .1000 miles driving around 30 mph. . .That could be a l o n g trip!

      Delete
    4. jan,
      Lengai(nee Lambda)Doinyo is my sister!

      The delicate carbonatite lava structures are reminiscent of a giant sandcastles. Or of giant sanpipers? No, not really close. Perhaps instead giant great blue herons. No, that’s not quite it. More like a giant flamingos.

      FLamego

      Delete
    5. All in the family, Lego!

      Bird wings? Angel wings? When I first saw the image I thought perhaps they were photoshopped. And I remember when Waxman's was just a photo shop. . .

      Delete
  3. "I'll bet that big blue thing on the map, straddling Tanzania, Uganda, and a bit of Kenya is 'Lake Nalubaale'," he said, just trying to be a troublemaker.

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    Replies
    1. 'Trouble' and 'Truth' are your middle names, Paul.

      Delete
  4. And if a sneakered foot is that close to a 500-600 degrees C source, shouldn't it be a simple procedure to siphon off a megawatt or so?

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    Replies
    1. Maybe not so simple. . .but certainly doable. If Yellowstone NP can harness the natural geothermal power why not Ol Doinyo Lengai? (I enjoy saying that name!)

      Delete
  5. Replies
    1. Thanks, jan. Made me laugh. And feel spacey. Ha!

      Delete
    2. Weird.__ Looks like blogger "corrected" my double spaces.__Stop it!

      Delete
  6. Replies
    1. These people (Triebold Paleontology) have worked with the Black Hills Institute of Geological Research, the for-profit fossil hunters that were the subject of Dinosaur 13, the movie we discussed here last year.

      Interesting that Ava is named for Avaceratops, which was named for its discoverer's wife, Ava.

      Delete
    2. It sounds like it ought to be a flying dinosaur.

      Delete
  7. We discovered the " Boiling River " spot along the Yellowstone River in 1980 thanks to a park employee. My parents, brothers and sister and I were the only ones there in early August.

    We shared the spot with one other family when I returned with my kids in June, 2007.

    The secret is out.

    {Oh, internet :-( , for some things I really miss word of mouth. . .}

    ReplyDelete
    Replies
    1. ^^^Gardner River, not the Yellowstone River.

      Delete
  8. Replies
    1. Okay, Steph, let me get this straight. You are wishing us a belated Happy Punctuation Day... that is, you are being not punctual about wishing us us a Happy Punctuation Day!

      If my keyboard only had an irony mark I would type one!

      LegoOnceLeftAnIronyMarkOnHisTrousersAfterForgettingToTurnOffTheHotIronOnHisIroningBoard!

      Delete
    2. I know! Ah the Fe-y! Weekend in the mountains with two dear Smithies is really no excuse.

      Hmmm. . .So Tina Fey is just all about irony then, , ,

      Delete
  9. More on __.

    And let us celebrate the ellipsis, too. . .

    ReplyDelete
    Replies
    1. Yes, and do not forget a punctuation mark I did not see on the Punctuation Day! mental_floss link. It is one I created years ago -- the "commapsis."

      It looks like this: ,,,

      A commapsis is defined as "the omission of one or more words that are obviously understood but that must be supplied to make a construction grammatically complete, but which tend to give one pause, give one pause, give one pause,,,"

      LegoPunctRocker

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    2. Comma, comma, comma, chameleon. . .I like it, Lego!

      Delete
  10. Isn't carbonatite that stuff that Han Solo gets frozen in a block of at the end of the second Star Wars movie?

    ReplyDelete
    Replies
    1. Close. It was carbonite.

      From WOOKIEEPEDIA "Carbonite was a metal alloy that was made from carbon. It was mixed with tibanna gas, compressed, and flash-frozen into blocks for transportation."

      Got any tibanna gas floating around?

      Delete
  11. You know what seems odd to me?

    Numbers that aren't divisible by two.

    ReplyDelete
  12. Liquid water? Really? It's either water, steam, or ice! Who writes these Headlines?!

    ReplyDelete
    Replies
    1. Hmm ...
      I think i'm exhaling some 'dry steam' right now, but I wonder what 'dry water' looks like. (Actually, I've never seen 'dry ice', either. I know, I've lived a sheltered life.)

      Delete
    2. Is there liquid water on Mount Denali?

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    3. Ha! They changed the headline. . .but I have a screen shot. . .Dunt dunt dunt. . .

      Really, Paul, you need to get out more. No dry ice at a Halloween party?!

      Delete
  13. New post on "Stromatolites: Fossil and Living Cyanobacteria Algal Mounds that Resemble a Cross between a Cauliflower and a Rock" is up. Our two-year anniversary post features a pop quiz and a poetry challenge (POETS for PEOTS).

    Thanks for your support of Partial Ellipsis of the Sun (POETS).

    Swimming Stromatolite Steph

    ReplyDelete