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Tuesday, January 28, 2014

Petrographic Thin Sections, Deadlines, and Nature's Stained Glass

     Deciding on this week's Partial Ellipsis of the Sun topic was harder than usual. The genetically modified organisms (GMOs) we saw on the western side of Kaua'i, guarded by several people, trucks and barbed wire, was an option. I decided that topic needed more research than driving past miles of corn (in various developmental stages) where sugar cane and pineapples used to grow ten years ago and reading a few articles. I will also read Frankenstein's Cat: Cuddling up to Biotech's Brave New Beasts by Emily Anthes before addressing this topic. (Great suggestion, Jan).

     So...deadlines to deadliness :-), on this Tuesday I decided to write about petrographic thin sections because they are something I know and they are amazing beautiful.

      Here's a piece of olivine, a magnesium iron silicate (called peridot when of gem quality):


     Amazingly beautiful, right? How about cutting a nice, clean, thin slice of this and attaching it to a glass slide. And then, how about looking at this thin slice of rock (or thin section) under a petrographic microscope? Still not impressed?

      Well, how about under crossed Nicols filters (see below) under a petrographic microscope, in thin section?

      The  two polarizing filters on a petrographic microscope work similarly to polarizing sunglasses. Each filter allows light vibrating at one particular orientation to pass through. One of the two filters is fixed. The other can be moved in and out of the light path. That filter's  polarizing direction is perpendicular to the fixed filter. 

      If you put a thin section of a rock in between the two polarizing filters (referred to as looking at the section under "crossed Nicols") it creates the stunningly beautiful portraits we see above of olivine and below of  zircon: 

     The uncrossed filter photograph of zircon, a nesosilicate, is below:

       Here's one more crossed Nicols thin section of basalt, a fast-cooling, fine-grained volcanic rock from Thailand with two large spectacular olivine crystals in the center.

       And, for completeness, a sample of basalt:

           I will end this week's illustration-rich blog with a photo of one of my favorite thin sections of gabbro, coarser-grained (i.e. slower cooling), intrusive igneous rock found near mid-oceanic rift zones (under crossed Nicols):

         The brightly colored orthopyroxene crystals are surrounded by striped plagioclase feldspar. Slower cooling produces some amazing crystals.

          Stained glass: made by nature.

          Enjoy! Next stop, a field trip to Iceland to see the mid-Atlantic ocean ridge on land to see that basalt and gabbro up close!

Petrographically yours,

Word Woman (Scientific Steph)


Tuesday, January 21, 2014

Fossilized Jurassic Spiders, Other Chelicerata, and Impractical Jokes

     Two weeks ago the horseshoe crab, a marine arthropod, was the topic of Partial Ellipsis of the Sun. This week, another member of the Chelicerata, the spider,  will be the focus.

      Besides the smooth transition from one arthropod to another, I was entranced by this recent large spider discovery from fine volcanic ash beds in Daohugou, China (in Inner Mongolia):

      The giant Jurassic (201-145 million years ago) male spider's body length is 1.65 centimeters long, and its first leg length is 5.82 centimeters, the largest fossilized spider found to date (as of January 8, 2014).  It was significantly different, according to researchers from the University of Kansas, from the female of the species, Nephila jurassica, to warrant an entirely new genus and family. Lots of room for discussion there! :-)

      The researchers believe that this male spider is one of the first orbweaver spiders after a detailed look at foot claws, hairs and genital organs, using a Scanning Electron Microsope (SEM). 

       The full article featuring Paul Selden of the U of Kansas is linked here:

                                     GIANT JURASSIC SPIDER IN VOLCANIC ASH

      So, how to get to impractical jokes from this giant Jurassic spider? Via the Jumping Spider, of course:



     Jumping spiders make up 13 percent of the entire air-breathing chelicerates. While the marine horseshoe crabs rely on external fertilization, air-breathing spiders use internal (but usually indirect) fertilization. 

      The jumping spider is likely the closest to what I was like after a very impractical joke involving the Jurassic time period.

       I worked on an extensive project using aerial photography and Landsat imagery for one of our biggest clients, Amoco Oil Corporation. I wrote a very detailed 200-page, single-spaced, report on the geologic basin (in the days where we had secretaries to type everything from scratch, no computers of course, and no global replace feature).

       The President of our company, Chuck, called me in one day and showed me a letter, written on very fancy, thicker-than-regular-paper AMOCO Oil Company letterhead. It was addressed to him and said something like: "On page 143 of your report we have just received, I see that Jurassic is misspelled as Jurrassic. Jurassic does not have two r's in it. I cannot believe such unprofessional work is coming to us from your company."

       I was a bit concerned, as a newly-minted 23-year-old geologist.

       "What should we do about this, Steph?" asked my boss, looking very serious. "Termination?"  

       It was only then that I heard the crowd of geologists laughing outside Chuck's door. One of my fellow geologist's girlfriend had gotten the AMOCO stationery from her work there and helped with the elaborate impractical joke.

       Jumping Spider indeed!

        How about you? What are some of the best practical or impractical jokes ever played on you? Did any of them involve words, spiders, or other arachnids?

Jurassically Yours,

Word Woman (Scientific Steph)




Tuesday, January 14, 2014

Kaua'i, Okina, A'a

     Aloha from Hanalei Bay in Kaua'i.

     Due to technical difficulties, Partial Ellipsis of the Sun will be taking the week off.

     There were wonderful things about the okina (the unicameral glottal stop of a "backward apostrophe"), the original unicase or unicameral Hawaiian language (ron, jan---you were made for Hawaiian), and the a'a lava here... but my iPad is not cooperating and will only work in HTML mode. Also, I've been swimming with large sea turtles, fish and eels and need to get back there for the afternoon Anini swim ;-).

     However, there is an interesting NPR story link on the first land-walking fish, Tikaalik (which does incorporate that a'a). :

    Until next week, I shall try to embed a few photographs here. We'll see how it goes.


                                                           Hanalei Bay "downtown" 


                                                              Hibiscus flower


                                                           Anini (not Wanini) Beach

                                                   Hanalei Bay, dragon head to tail...

                                                                  Palm trees, of course

   View from our lanai. . .

  And, lastly, wild roosters everywhere on the island:


Word Woman (Scientific Steph)

Tuesday, January 7, 2014

Blue-blooded Horseshoe Crabs, Hemocyanin, and Kenneth Marshall Gordon

     The blood of horseshoe crabs (as well as cuttlefish, squid, lobster, and a variety of other marine animals) contains hemocyanin, which is copper-based, rather than hemoglobin, which is iron-based. They are the blue-bloods of the animal kingdom and their blood has amazing anti-bacterial properties. The blood sloshes around in their bodies, rather than being carried in veins and arteries.

        And their blood has powerful acti-bacterial properties that release a mass of blood-clotting granules that instantaneously clot to seal out the bad bacteria, preventing further infection. It is so valuable that pharmaceutical companies are harvesting the horse shoe crabs, removing some of their blood,


and then returning them to the sea. The link to the full NPR article (including a video of the process) is here:

     Paleontologist Richard Fortey describes the 450,000,000-year-old creatures as being akin to a Volkswagen Beetle:
"I saw a damaged horseshoe crab still trundling gamely onwards, even with a great hole punched right though its head. Looking over the beach more carefully, I noticed a lot of these war veterans; lumps out of the thorax, broken tail spikes — clearly, it must take a lot to finish these creatures off."

      Indeed, the amazing blue-blood properties of these relatives of trilobites are what have likely kept the horseshoe crab around for so many millions of years. They have lasted through the massive extinctions at the end of the Paleozoic, Mesozoic, and Cenozoic eras when massive extinctions wiped out large, sweeping amounts of their cousins.

       I don't have a wonderful segue to this next portion. We are all still a bit in shock here in Colorado about Ken Gordon's death last month.

       Today was the memorial service for Kenneth Marshall Gordon, one of Colorado's most respected members of the Colorado House for 8 years and then the Senate for another 8 years. 

     Ken was our neighbor when he first ran in Colorado in 1992 and my son and I put up yard signs for him. Ken introduced my then three-year-old son to then Governor Romer. Ken took no PAC money--ever. He was respected, well-liked, and he listened to everyone. He believed in the power of every voice. The Temple was packed with over 500 people from both sides of the political aisle, with friends, family, and our current Governor Hickenlooper. Ken was one of the really, really good guys.

     I learned at the service today that Ken was from a somewhat "blue-blood" Michigan family but that he preferred to make his own way, working long hours in a meat-packing plant, before he became a lawyer. He did not want help from his family. And, sadly, rather than asking his family for help to get medical care, he drove himself to the local hospital and died, of a massive heart attack, in the parking lot. Ken was 63 years old.

      This is the way I'll remember Ken--out there walking, like the horseshoe crabs. Ken walked across the state of Colorado in support of referenda for education.  If only he'd had the staying power of the horseshoe crab to be able to work more on his life's work, to love and be a loved a little more...and to walk a little further.


And the walking man walks (James Taylor),

Word Woman (aka Scientific Steph)