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Tuesday, October 27, 2015

Columnar Joints: No, NOT in Colorado, But in Svartifoss, Devil's Tower, and Giant's Causeway

     Columnar joints are spectacular, often very long, hexagonal features found in igneous basalts (that's basalts not bathsalts!). Three particularly well-preserved examples are in Svartifoss, Iceland,





Devil's Tower, Wyoming, USA,








and the Giant's Causeway in far northeastern Ireland.






       [To clarify, there are columnar joints in Colorado; they are just not as spectacular as in those three places.]

        The mechanism for creating these six-sided features is seen here where 'C' represents the center of each hexagon:


        

      This two-minute geology video shows columnar jointing from the side and from the top in eastern Washington, USA. The accompanying one minute video shows what happened to a rock hammer atop those hexagonal features!

        The columnar joints in Iceland have inspired architecture for a local church. I still think our first PEOTS field trip ought to be to Iceland.




         More information about this hexagonal packing structure, including T- and Y- junctures, points toward a similarity to the optimally-packed honeycomb:



. . .and to mud cracks. . .



and to carbon rings in chemistry (benzene here):




and to . . .


      Isn't nature mesmerizing?! And more than she's cracked up to be!?

Steph

P.S.

Hmmm, Ethiopia is likely ahead of Iceland in my travel plans, but Iceland is a close second. . .




50 comments:

  1. I would love to go to Iceland! I wish the Smith College Alumnae Chorus were going there next summer rather than Cuba...

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    1. See new p.s. above, although both Cuba and Iceland are intriguing. My mom went to Cuba as a kid and was not all that impressed as it was similar to Florida where she lived in the winter.

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    2. The Black Waterfall looks cool. Too bad it's over 4 hours from the Bridge Between Continents. And the island looks so small on a globe! Think we could get a PEOTS field trip discount on airfare & hotel?

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    3. What if we called ourselves "The PEOTS Colorado Joint Council on Crack"?

      That ought to do it, don't you think?!

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    4. Some Denver Environment Action agents should be knocking on your door any minute now....

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    5. I hear them now. . .Let me open the door a crack. . .

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  2. Wait a minute... that pretty blue and red figure above seems to say that the hexagonal prisms cool from the inside -- "'C' represents the center of cooling". That makes no sense to me; everything else that's hot cools from the outside. And how come all basalts don't form columns? Please explain. Don't bogart that joint information!

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    1. jan, as to your first question, I miswrote; I will fix the text to read "C = center of the hexagon."

      As to your second question, I must Bogart your basalt question just a bit longer. Maizie needs a lunchtime walk. Catch you later with new Colorado joint information. . .

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    2. Here is a good explanation of hexagonal or pentagonal joints.

      All cooling igneous bodies, especially very large ones, be they basalts, ignimbrites or whatever, crack. Hexagonal cracks or joints are nature's preferred crack (and you thought we were only going to discuss joints here).

      Pentagonal cracks are also fairly common.

      Not sure if I've seen septagonal or octagonal cracks. . .Have you?

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    3. And WHY hexagonal cracks?

      And it's heptagonal, not septagonal for 7-sided polygons.

      And, I have, wouldn't you know it, a cracked tooth crown and underlying infection which is keeping me up this night. Kindly kick in, antibiotics!

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  3. Your Giant's Causeway picture reminded me of the hexagonal cells in the miniaturizer in Fantastic Voyage, which rise up from the floor in one scene.

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  4. Replies
    1. I think I need before and after pix to appreciate this. And I though Bighorn Crack was the sound they made when butting heads during rutting season.

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    2. Agreed, jan. These views from farther away give some perspective on the extent of the Bighorn Crack.

      I don't think butting elk heads, even a whole bunch of them, could do that!

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    3. I'm getting a little suspicious, since it doesn't seem that the mainstream press is picking up this story.

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    4. Something fishy in Wyoming. . .

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    5. Huffington Post and ifls have picked up the Bighorn Gash/Crack Story now.

      But, we cracked it here at Partial Ellipsis of the Sun before mainstream media. . .

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  5. Btw, if you see an Amazon or any other ad on PEOTS, if you click through via PEOTS rather than directly through Amazon (or whichever ad), this blog receives a small fee.

    And. . .Thank you!

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  6. The worship space at my old school in Collegeville. It's a honey of a church.

    LegoAndIHaveGoneBack,Often

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    Replies
    1. Wow, great honeycomb architecture, Lego! Sweet. . .

      And you can't go wrong with Steely Dan...

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  7. Back to our field trip to Iceland: Picture a gaggle of gleeful geologists.

    Don't miss the embedded drone footage.

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  8. We tutored at the high school today with "Anonymous," a funny, spunky young woman who eventually told us her name was really J'Maria (pronounced "Jay Marria") and Tsain, from Addis Ababa, Ethiopia! That was very satisfying and fun; we worked on functions.

    When I told J'Maria about the flat, originally-thought-to-be-seas maria on other planetary bodies she asked " Say, how do you know that?!"

    "I studied geology in college."

    "That's what I wanna do. Maria--cool."

    From the way she introduced herself, I had the sense she was a bit embarrassed about her name. So glad she knows a cool association with it now.

    I truly love these ninth graders! It's lively, for sure.

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    1. Upon further reflection, I think J'Maria wanted me to earn her trust before she told me her name.

      This week, I brought seaweed, candy, and fruit to share with any interested Math MoJoers in tutoring. Guess the biggest hit?

      Yup, seaweed.

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  9. Replies
    1. Very cool. Especially for Colorado geologists? ;-}

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    2. I bought one of the little stone notebooks at the Japanese stationery store in New York where I discovered them. The sheets are very smooth, and take ink and pencil readily. They deform a bit with pressure, like you're writing on a thin sheet of polyethylene, which they are, except for the "stone" (calcium carbonate). The sheets don't tear easily, and are indeed waterproof (you can even write on them underwater). They do burn (in case you're dealing with classified documents, which you wouldn't want to set in stone anyway...), leaving a waxy smell and a fine, crumbly ash. Interesting product.

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    3. I want to try those out!

      We used to have small, waterproof field notebooks at field camp and for field studies. . .but I don't believe stone was involved. . .

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    4. "The sheets don't tear easily," ...but can you cut them with scissors?

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    5. Ha -- yeah, it's a lot more paper-like than rock-like. More soft rock than Steph's acid rock experiments.

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    6. Say, that reminds me. . .

      How did they cut the Roman Empire in half?


      .
      .
      .
      .
      .
      .
      .
      .
      .
      .
      They used a pair of Caesars. . .
      .
      .
      .
      .
      .
      .
      .
      .
      :-)

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    7. That took a lot of Gaul.

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  10. Replies
    1. Indeed. Zoe's high school team name was the Angels, which was often misspelled as East High Angles!

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  11. Another interesting map.


    (I'm suspicious, though: one of those labels actually translates as "Homeland is racist".)

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  12. And, before your Devil's Tower picture fades into the archives, I'm surprised no one mentioned this all week.

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  13. Interesting perspective on the White House NSCI Workshop. Full disclosure: I used to babysit Doug and his brother, Bob, while their mom, Ann Burger, taught geology labs at Smith.

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    1. "CMOS is coming to an end"? Bull. Are all the billions of CMOS devices out there going to quit working? Is no one else going to think of anything clever to do using current VLSI rules? No. What he means is, he can't foresee how to make CMOS devices much smaller than they are now.

      "There is no replacement for CMOS devices within the next ten years." Again, no replacement is needed. But, what about those carbon nanotube field-effect transistors we've been hearing about?

      First he says "No new computational models outside of quantum, neuromorphic and approximate computing were discussed", and then, in the next breath, "The scale and explosive growth rate of the cloud market was surprising". Yeah, as we've learned, making predictions is hard, especially when you're talking about the future. But there are a lot of smart people out there trying to figure out how to make money on new technologies; I have a feeling today's iPhones and laptops aren't the end of the line.

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    2. Truthfully, I understood very little of Doug's article. . .I'm still not sure I do.

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  14. David, how was your trip to Arches?

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  15. I am working on "Bioturbation: The Worms Crawl In, The Worms Crawl Out" for this week's post.

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  16. Three Jefferson County, CO, School Board members recalled-yeah!

    Close race on Denver School Board too!

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