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Tuesday, September 29, 2015

Stromatolites: Fossil and Living Cyanobacteria Algal Mounds that Resemble a Cross between a Cauliflower and a Rock

     Stromatolites are mounds of cyanobacteria and sediment that have been found in the fossil record since 3.5 billion years ago in the Archean time period. The mounds resemble a cross between a cauliflower and a rock:

      Living stromatolites were not discovered until 1956 in Shark Bay off the west coast of Australia (There's some poetry to accompany this stromatolite tour). These present-day algal mounds are also found in the Bahamas.

      "Stromatolite" is derived from stroma, Latin for layer, and it is easy to see why. The laminae are particularly well-defined, especially in thin section.

       Shark Bay is the site of discovery of 
chlorophyll f, a type form of chlorophyll that absorbs further in the infrared light part of the spectrum (red) than other chlorophylls. (Are you blue-green with envy?)

     Chlorophyll f's discovery was made by scientists at the University of Sydney led by Dr. Min Chen. It is the first discovery of a new form of chlorophyll since about the time stromatolites were discovered in Shark Bay. 

        Pop Quiz:

1) Where are these stromatolites? (They are poetically called "Petrified Sea Gardens.")

2) Based on today's post, what are these organic structures called?

3)  Where are these stromatolites? Hint: maple syrup is big here.

4) Let out your inner POETS for PEOTS: Write your best stromatolite haiku, limerick, or any other poetry form. Help celebrate two years of scientists who like to write and writers who like science. . .

Peeling those (not-always round) onion layers,

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?


Thursday, September 17, 2015

Coprolite Happened: Poo, Poop, Do, Dung, Scat; Do-Diddly-Be-Bop-Scat

        Coprolite happened! Not happens. Ah, but we quibble.

     Fossil excrement is a thing of the past. Coprolite, meaning dung stone, did indeed happen all over the world. And not just dinosaur scat although dinosaur poo gets the most notoriety.

        Most coprolites are primarily composed of calcium phosphate with minor quantities of organic matter. Dung beetles did enjoy their dinosaur dung. These trace fossils were a big hit with kindergartners at Dinosaur Ridge Tuesday. They uncovered an herbivore dinosaur skeleton, as well as the carnivore dinosaur tooth in her spine, her nest, and, of course, the coprolite.

        There are coprolite cabochons or cabs:

          And there's Cab Calloway, an early jazz scat singer:

           Jazz scat is a humorous, non-word way of singing, wonderfully sung by Cab, Ella Fitzgerald, and many others.

            Dinosaur scat is a humorous trace fossil. Right?

            Scat. Scat. Cab. Cab. A coincidence? I think not. . .What do you think?

          And, finally, a coprolite controversy: Is this a coprolite or Faux Poo?

                           The END.


P.S. I am bracing myself for Close Encounters of the Turd Kind and other poo puns. Pun on if you are feeling fair to midden. . .

                    The BEGINNING

     Zoe's Peace Corps Swearing-in Ceremony on Friday in Ethiopia:

"We use what we have, where we are, while we can."

Wednesday, September 9, 2015

The Unsinkable Molybdenum Brown: Atomic Number 42 (The Answer to Absolutely Everything Revealed)

     Field work on Tuesday--yeah!

      My trusty assistant, Maizie, was on the job as we hiked around and above the Henderson Molybdenum Mine near Empire, Colorado.

      The mine is surrounded by U.S Forest land of the Arapahoe National Forest.

      Yes. It is a tough job. And yes, we were happy to do it.

     Molybdenum, known informally as Moly or Molly, is a chemical element with the symbol Mo and atomic number 42. The atomic number alone is enough to endear this shiny silvery-gray (OK, it's not really brown, like Molly Brown of Titanic fame) metal to the Douglas Adams' fans of the Universe.

        The name molybdenum is derived from Neo-Latin molybdaenum, from Ancient Greek Μόλυβδος or molybdos, meaning lead. Molybdenum, the element, was discovered in 1778 by Carl Scheele. 
      Molybdenum does not occur naturally as a free metal on earth, but rather in various oxidation states in minerals. The free element has the 6th-highest melting point of any element and readily forms hard, stable carbides in alloys. Because of this high melting point, most of the production of molybdenum is in making steel alloys, including high strength alloys and superalloys.

         The red arrow below marks the location of the Henderson Mine buildings; the conical orangeish peak to the right is the "glory hole" which is the result of collapsing of the peak during underground mining:

     We also explored the area between the Henderson Mine and the Urad Lake reclaimed area (the surrounding vegetation appears to now be thriving after moly, uranium, and vanadium mining clean-up). We were met with a few raised eyebrows and stern looks along this road but, we persevered, in the name of science:

We saw moly slag ponds, super-secret buildings,

a boreal toad-crossing sign,

and lots of waterbars* (though our thirst was never quenched).

       *a ridge made across a hill road to divert rain water to one side.

        And sadly, we also saw the rocks we had to leave behind. . . 

         Here's a one-minute video from our Tuesday in the mountains, mounts, and peaks:

              Field "Work" above Timberline

         Looking for your best moly, waterbar, or glory hole stories. I heard wonderful moly, angelite (anhydrite), nephrite (jade), and other stories from rockhound Jack Sleimers of Moss Rock Shop in Chief Hosa, CO, today (Sunday, 9/13).

          A man and his moly:

All in the name of science,

Wednesday, September 2, 2015

Cryptobiotic Soil Crusts: Take Nothing but Photos and Don't Leave Any Footprints!

     The cryptobiotic soil crusts of Arches National Park, Utah, are the inspiration for this week's post. 

    Cryptobiotic soil crusts are communities of living organisms on the soil surface in arid and semi-arid ecosystems. They are found worldwide.

        Cryptobiotic soil crusts perform important ecological roles including carbon fixation, nitrogen fixation, soil stabilization, altering soil albedo and affecting germination and nutrient levels in vascular plants. 

        The "crypto" part of the name refers to the hidden nature of the crusts. The crusts form very slowly and can look like surrounding soil in the first few decades. A footprint on these soils can cause damage that may take 250 years to recover in low rainfall areas like Arches' Fiery Furnace.

     A Scanning Electron Microscope (SEM) image of this crust reveals a complex array of cyanobacteria (the bacteria formerly known as blue-green algae), lichen (see our 100th post on litmus and lichen), and mosses.

     This one-minute video shows the effect water has on part of the mosses in the cryptobiotic soil crust.

     Yes, a very delicate organism surrounds much of Delicate Arch in Arches N.P. and all over Utah. Treading lightly on marked trails will preserve these important, complex cryptobiotic soil crusts.

      Have you encountered cryptobiotic soil crust at Arches or elsewhere? May you have photos but no footprints to share. . .

      I am also curious about whether reddish-orange landscapes are more appealing to each of you than the green and blue ones. I grew up in the greener landscapes of New England (NE!) but I have learned to love the red-oranges after living in the west for more than half my life. The blue-greens are beautiful, too, of course.

Crustily and cryptically,

Arches: Delicate Arch and La Sal Mountains

Bryce: Peakaboo Trail

Zion: Near Angel's Landing Trail