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Showing posts with label Silurian. Show all posts
Showing posts with label Silurian. Show all posts

Wednesday, August 31, 2016

One-Syllable State of Maine Rocks: Underappreciated Silurian Age Stones

     
      Take a close look at these exquisite Silurian rocks from the state of Maine, USA. (How did I just realize Maine is our only monosyllabic state?) The Silurian, an underappreciated time period, without the cachet of say, the younger Jurassic, is part of the Paleozoic era between the Ordovician and Devonian. Silurian rocks are 443 million years to 416 million years old.




     
A significant evolutionary milestone during the Silurian was the diversification of jawed and bony fishes. 



   
       Life also began to appear on land during the Silurian in the form of moss-like, vascular land plants that grew beside bodies of water. Small terrestrial arthropods also began to appear.




       These Maine rocks of the Kittery Formation are old. They show the results of millions of years of deposition, igneous activity, faulting, tectonics, and metamorphism. 





      However, in researching this week's topic, I discovered the "Silurians," a fictional race of reptile-like humanoids in the long-running British science fiction tv series Doctor Who? Those first Silurians are depicted as prehistoric and scientifically advanced sentient humanoids who predate the evolution of man.





      The creatures were called Silurians, after their supposed origins in the Silurian period. However, author John Pertwee claims that "properly speaking", the Silurians should have been called the "Eocenes" (part of the much more recent Cenozoic era.)
     Perhaps Dr. Who needed a geologic consultant to the tv show. E. O. Seen and heard? Background music by Diana Ross and the Eocenes?!

Just call me,
Silurian Steph

Bonus question: without googling or duck duck going, name all current countries of only one syllable.



Wednesday, November 4, 2015

Bioturbation: The Worms Crawl In, The Worms Crawl Out

       Bioturbation is the reworking of soils and sediments by animals (including worms, snakes, trilobites, and crustaceans) or plant roots. The worms crawl in, the worms crawl out in these churned, turned over and under soils: check out this bioturbation video and watch the burrowing worms in action.


         These ancient dirt churners were recently determined to have taken much longer to bioturbate than originally thought, by millions of years.





       "For years, scientists thought bioturbation commenced in earnest with the Cambrian Explosion, 541 million years ago, when the complexity and diversity of animal species began to expand dramatically."

        "But that wasn’t the case. In a new study published in the journal Nature Geoscience, researchers found that major bioturbation did not occur until at least 120 million years later, during the late Silurian Period."



      Dr. Lidya Tarhan and researchers at Yale University propose that "Delayed bioturbation may have been responsible for regulating marine sulfate and atmospheric oxygen levels. A previously proposed drop in surface oxygen levels may be tied to the onset of extensive bioturbation, given that “oxygen is directly tied to the burial of organic carbon,” Tarhan said. “Less burial of organic carbon, due to bioturbation, means that more oxygen is used to respire or burn through that carbon, and thus oxygen decreases.”"



      Thank heavens for worms and other bioturbators!

     And of course, there's evidence of mass bioturbation (wait for it. . .):




As the Worm Turns,
Steph

       I am not especially fond of the color pink, but I do like these kindergartners' style for our "NOVEMBER is CHEMISTRY MONTH" experiment with Chromatography and ROY G BIV.