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Tuesday, February 4, 2014

Ooids, Pisoids, and Kidney Stones: Concentrate Concretely!


     The trip to Iceland with a discussion of plate tectonics and mid-oceanic rifts has been postponed due to snow. This week's blog will migrate to some more tropical sedimentary features like these ooids (from the Greek for egg-like). I never wondered why Dr. Allen Curran of Smith College chose to study them in the Bahamas:





and pisoids (from the Greek word for pea-like).





      I tried to play the word ooid in a recent Scrabble game; the Official Scrabble Dictionary says it is not a word. Oo id is! Pisoid is also not acceptable~~and it's such a fun word.  .  .

 
     The main difference between the two sedimentary concretions is their size. Ooids are less than 2 millimeters in size and pisoids are 2 millimeters and greater in size. Ooids and pisoids are spheroidal, layered or coated grains, usually composed of calcium carbonate (CaCO3). Some pisoids and ooids contain iron (siderite for you Latin fans) or phosphates as well. They form as a series of concentric layers (see thin section below--crossed nicols or not--you be the judge!) around a nucleus of a crystal, shell fragment, or other small grain in shallow seas where the water is highly concentrated in calcium carbonate.






     And if you use a scanning electron microscope (SEM) to view ooids you will see not only the concretions that mark the growth of ooids, but also the pitting and cracking of the grains caused by various microbes:


     
      Three interesting things you should know about ooids and pisoids:

      (1) They have formed under different conditions called calcite seas (where low-magnesium calcite is the primary CaCO3 precipitate and which occurred during my favorite period, the Jurassic, and the Ordovician period) or aragonite seas (where aragonite and high magnesium calcite is the primary CaCO3 precipitate during most of the rest of geologic time, including now)Thus, the calcite seas are found in the early Paleozoic time period when life was relatively new and during the middle of the Mesozoic (sometimes called the Age of Dinosaurs). Both of these time periods were time periods of rapid sea-floor spreading. (Ok, a wee bit of plate tectonics today).

       (2) Ooids and pisoids generally require microbial action in their formation.

       (3) They cannot form in areas where a great deal of river runoff occurs as the ooids and pisoids need greatly concentrated waters full of CaCO3 to form. This brings us to the kidney stone tie in:





       It had not occurred to me until today that the process of ooid and pisoid concretion is similar to kidney stone formation (It even says so in Wikiipedia :-)). Kidney stones tend to form in patients with concentrated urine (no extra fresh water running in). 


       Oh, a fourth item:

       (4) Ooids and pisoids ought to be Scrabble-acceptable words. 


       And to bring this concentrated topic concretely back in focus, this view of pisoids shows the highlighted concreted layers that have been colorized to show the structure of the layers.

        



        Looking forward to your crystallized, concentrated comments, diluted not at all by your new-found enthusiasm for the ooid and the pisoid :-)


        Ooidally (but not pisoidally this evening),

        Word Woman (Scientific Steph)

 

29 comments:

  1. Ooids cemented together form the rock oolite and pisoids cemented together form pisolite. Oolite and pisolite are both Scrabble-acceptable words!

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  2. If you'd like to read more about the contributions of micro bacteria as catalysts to the ooid/pisoid precipitation process this article by Robert L. Folk is a good place to start:

    http://jsedres.sepmonline.org/content/63/5/990.short

    Welcome to newest readers from France and Nigeria. PEOTS has now been read in every continent except South America and Antarctica.

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    1. SS,
      Here is a winter-time comfort food suggestion, ooid/pisiod division:
      http://southernfood.about.com/od/peas/r/bl30426j.htm
      Goes good with oolong tea and pistachio nuts.
      Are ooid and pisiod pronounced Oh-oid and Pis-oid? Or trisyllabically, Oh-schwa-id and Pis-schwa-id?

      I agree that these are Scrabble-worthy words. Mary gave me the “Words with Friends” board game for Christmas. It’s Scrabble, but by another name. How do the WWF people get away with that? Don’t the Scrabble people have copyright attorneys?

      \Pisoid is a fun word because of the whole piss/pee/pea scatology/punnery. Ooid is a fun word because.… well, because it starts with oo-.

      Your fourth illustration, the SEM shot, looks like something sent back to earth from a moon probe.

      LeggsandpeasOoohh…

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    2. Lego, thanks for the green edible suggestion. I believe ooid can be pronounced either way, though ew-ids is much more fun for me. I have wondered about the Scrabble/Words with Friends issue but, I don't have an answer.

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    3. So those "moon probe" looking ooids could have pits and cracks on them by either the physical process of movement or by microbes or both...Back to the life in other places discussion ;-).

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    4. One possible explanation for the lack of Words With Friends v. Scrabble litigation if that there seems to be a cooperative relationship. The WWF board game is produced by Zenga and Hasbro, under the "Hasbro Gaming" imprint. Hasbro owns the rights to Scrabble.

      My wife and I sometimes play WWF while I'm at work, and use the built-in messaging system (since I don't usually send enough texts to justify an unlimited-messaging plan for my phone). If someone figured out how to sext with that feature, they could call it Words With Friends With Benefits...

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    5. That makes sense. Repackage Scrabble with a hipper, younger-sounding name. I imagine Words With Friends With Benefits is the next iteration

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  3. Just one correction to your statement that "kidney stones also have plenty of microbial action going on in their location." Urine in the kidneys, ureters and bladder is usually sterile. One particular kind of kidney stone -- struvite stones, which are not most common -- is associated with bacterial infection.

    Could you fill us in a bit more about the role of microbes in the formation of ooids and pisoids (which really ought to be in the Scrabble dictionary)?

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    1. Thanks, Jan. I knew that. Scratch number (2) on the list as a definitive ooid/pisoid connection as there is some controversy about the role of microbes.

      This article from 2012 is a good place to start:
      https://www.google.com/url?sa=t&source=web&rct=j&ei=r3PyUvKBFeiMyAG9wYG4CQ&url=http://www.cameca.com/download/pacton-freshwater-ooid-geology-june2012.pdf&cd=1&ved=0CCcQFjAA&usg=AFQjCNEaI7Jdlyn8BS48SojpwrgJEjrI5g&sig2=hPW8cyjRaOXqPFMid_lMpA

      It was generally thought that ooid/pisoid formation required a fairly high energy environment. The role of microbes in starting or continuing this movement is debated in the article (concerning freshwater ooids).

      You know more about kidneys and kidney stones than I do but it makes sense to me that movement in the kidneys combined with high calcium oxalate concentration could form the stones. And struvite kidney stones could be the more unusual counterpart.

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    2. Geologists are mostly concerned about the high-energy/low-energy issue as a depositional model for sediments in geologic history.

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    3. Good points all around. And here I thought, when I saw the pictures of pretty round white stones and those nice concentric cross sections, that you would be mentioning pearls, and talking about how an irritant can sometimes produce a gem, and devolve into a discussion of your fellow bloggers...

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    4. This is getting a little scary. I did think of mentioning that exact observation but thought perhaps it might be more appropriate on another, unnamed blog :-).

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  4. This really belongs with the spider blog post from a couple of weeks ago, but better late than never.

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  5. Well, we may be ready for that trip to Iceland next week after all now that the mythical Viking Sunstone or Iceland Spar has been discovered:

    http://www.businessinsider.com/viking-sunstone-discovered-2013-3#ixzz2MlemaIS3

    It would be a good idea to review calcite optics before we go ;-) : http://www.nordskip.com/calciteoptics.html#scree

    More next week.


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    Replies
    1. Interesting, though not surprising. Birds and insects have been shown to use polarized light as well as the Earth's magnetic field for navigation.

      If I want to use a rock for navigation, though, I'll start with some silicon, dope it appropriately, and make a GPS receiver, thanks.

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    2. Yeah, but how do the birds and insects have the strength to carry around those soap-bar-sized pieces of calcite? ;-)

      I mean, Iceland spar is apparently just scattered about in the scree up there, but still. . .

      Buzz kill. Get your hands on a really fine piece of calcite; you'll never go back to GPS again ;-).

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    3. > Yeah, but how do the birds and insects have the strength to carry around those soap-bar-sized pieces of calcite?

      Depends. Is that an African or a European swallow we're talking about?

      Scree is such a nice word. Don't mean to be a heel, but talus just doesn't cut it.

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  6. Monty Python reference?

    I agree on scree. As to talus, I have never seen you put your foot in your mouth yet!

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  7. > Monty Python reference?

    Of course.

    I see we're talking calcite again. Wouldn't Nichols be pleased? And, speaking of wooden nickles...

    I once attended a talk by Niklaus Wirth, the computer scientist who designed the Pascal language. He remarked that Americans tended to pronounce his name, "Nickles Worth", while Europeans correctly pronounced it "Niklaus Virt", and that therefore, he concluded that Europeans favored Call-By-Name, and Americans Call-By-Value. (These are evaluation strategies you'll need to choose between if you ever want to design a programming language.)

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  8. Nicols! Nicols! Ack!

    That was a long way to go for that story, jan, but maybe it was worth it. I am sure it would have killed at a springtime programmers' conference, Pasc(h)al lamb and all. Move the 'h' from our fine crossed fellow to make the object of this story. Ok, I am treading in unfamiliar territory here so best stop. END

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    1. Couldn't just pass over a little typo, eh?

      Well, as long as we're splitting hairs about crossed Nicols, and talking about spider silk, as we were, how about a nickle's worth of wandering in hyperspace for a story on crosshairs, blonde, Brown, Black Widow, and otherwise? Don't remember what led me to this article the other day, but I thought it was interesting.

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    2. Only because I made such a big deal of fixing the NAME typo last week. For my nickel, that was a fascinating link! Blonde hair sure has some interesting properties for meteorological instruments. I did read that the cross hairs were probably etched on the glass...Fascinating stuff.

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  9. Speaking of lambs, Legolambda, are you busy launching?

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  10. Fie. Fie, I say, on these brrrr optics

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    1. Paul, I thought you might be beaming coldly, but beaming nonetheless. . . and with an evanescent wave.

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    2. Cooler than the Beatles on February 9, 1964. Thanks for sharing, Paul.

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