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Tuesday, March 31, 2015

Slab Melting: Quite Continental!

       Plate tectonics theory has generally espoused that all continental crust, rich in silica, has been recycled. 

     Virginia Technical University geologists have published research today indicating some of that continental crust may actually be new or "juvenile" crust.

       Some of the type areas for this discovery are in Costa Rica and Panama:

The March 31, 2015, research includes this description of continental and oceanic crust:

     "The researchers used geochemical and geophysical data to reconstruct the evolution what is now Costa Rica and Panama, which was generated when two oceanic plates collided and melted iron- and magnesium-rich oceanic crust over the past 70 million years."

      "Melting of the oceanic crust originally produced what today are the Galapagos islands, reproducing Achaean-like conditions to provide the "missing ingredient" in the generation of continental crust."

     "The researchers discovered the geochemical signature of erupted lavas reached continental crust-like composition about 10 million years ago. They tested the material and observed seismic waves traveling through the crust at velocities closer to the ones observed in continental crust worldwide."

        The study continues "It raises questions about the global impact newly generated continental crust has had over the ages, and the role it has played in the evolution of not just continents, but life itself. 

        For example, the formation of the Central American land bridge resulted in the closure of the seaway, which changed how the ocean circulated, separated marine species, and had a powerful impact on the climate on the planet."

        Older names for continental and oceanic crust are SIAL and SIMA, respectively. Sial is a short for silica aluminum (or aluminum silicate) and sima is short for silica magnesium (or magnesium silicate). The sial is less dense than the sima. And now, researchers have shown that some of that sial is juvenile. 




Tuesday, March 24, 2015

A Picture a Day Picnic: Down the NASA Rabbit Hole with the Pelican Nebula and Opals

     Today I discovered this "A Picture a Day" site from NASA. Today's post on the Powers of Ten includes an intriguing video moving away and inward from a picnic by the powers of ten. Each post includes extraordinary images and descriptions by astronomers.

          The past posts from the NASA site lead you down many a fascinating rabbit hole. Click on the "Discover the Cosmos" link at the NASA site to enjoy exploring!

           The March 4, 2015, image from the NASA site of pillars and jets in the Pelican Nebula is particularly striking:

          And this particular Rabbit Hole led me to the Rabbit Hole Mine in Black Desert, Nevada, (red pin below) near the Burning Man Festival site. Based on what I know about the Burning Man Festival, their proximity cannot be an accident!

          The Rabbit Hole Mine is rich in sulphur, alunite, cinnabar, gypsum and opal.

           The powers of ten may also provide a colorful journey from opals to nebulae . . .and back, via the rabbit hole.

            Let me know your favorite past image on the NASA site. . .and do enjoy your trip down the rabbit hole. Please--come back!

Enjoy the ride,

Tuesday, March 17, 2015

Wearin' o' the Green: Malachite and Mallows

          On this St Paddy's day, malachite, especially this form of the copper carbonate  hydroxide replacing the limestone of stalactites or stalagmites, is our featured green mineral.

          Malachite's name derives from the Greek Μολοχίτης λίθος molochitis lithos, "mallow-green stone", from μολόχη molōchē, variant of μαλάχη malāchē, "mallow". The mineral was given this name due to its resemblance to the leaves of the mallow plant. You've likely seen these (marsh) mallows ;-) before:

            The resembance to other forms of malachite is remarkable:

           Malachite is fairly common and was used as a mineral pigment in green paints from antiquity until the 19th century. The pigment is moderately light-fast, very sensitive to acid, and varies in color.  

        It has also been used extensively in jewelry (with no shellacking ;-)):

          One of the greatest occurrences of malachite is in the Ural Mountains in Russia. It is mined fairly easily with other copper minerals, especially azurite.

           Uploading images on Blogger has been hiccuping here all night--must be the green beer at the local Irish pub.

              Enjoy all the green today and all the way into spring!

Happy St Paddy's Day all ye Malachites!


And footware for 3/17 is now easy as pi:

Tuesday, March 10, 2015

SpongeBob SquarePants Fungi (Really!) and Possible Sponge Precursor

          Spongiforma squarepantsii is a species of fungus, genus Spongiforma. It was found and described in 2011 in Malaysia. It produces sponge-like, rubbery orange fruit bodies that have a musky or fruity odor.

      And the name comes from the cartoon character SpongeBob SquarePants, of course.

      Like a sponge, these fungi resume their original shape if water is squeezed out. The spores, produced on the surfaces of the hollows of the sponge, are almond-shaped. 

       I discovered the Spongiforma squarepantsii fungi in researching this microfossil which may be a precursor [put your cursor in front ;-)] to the sponge family itself:

      This well-preserved 600-million-year-old fossil shows actual cells that make it an excellent candidate for an ancestor of sponge animals.

      The new discovery, named Eocyathispongia qiania, is a single fossil found in China. Yet its three tubular chambers arising from a base and its visible parts of cells resemble sponges according to  Zongjun Yin et al of the Chinese Academy of Sciences in Nanjing  in the yesterday's Proceedings of the National Academy of Sciences.

         Looking at the fossil with X-rays and scanning electron microscopy (SEM), the researchers saw cells that resemble modern sponges’ outer structural elements, called pinacocytes (still looking for a pinacolada connection there via pineapple bract structure ;-) ). 

          The link to the Science News article includes this description of this possible sponge ancestor:

         "Some surface cells are signs of pores, like those that let water swoosh into modern sponges. And a patch inside one of the tubes has pits encircled by raised collars. These could be an early version of the cells called choanocytes, distinctive cells in modern sponges that move water through the animal."

           Further examples and connections are needed to make a definitive connection from this single microfossil to the sponges. . .perhaps to SpongeRobert SquarishPants?

SBSP to all you fun guys,



Tuesday, March 3, 2015

Light: Particle/Wave? . . .Topographic Map?

      The first-ever image of light behaving as both a particle and a wave was published yesterday in Nature Communications and is shown below:

      This short summary article from Science Daily describes the procurement of the image by researchers at Ecole Polytechnique Fédérale de Lausanne. Quantum mechanics in bright , primary colors!

      The first thing I noted was the similarity to contour lines on topographic maps:

        Closing all those circles from contour lines/waves into pinnacles/particles brought me to Topo Gigio's brother, a quantum mechanic ;-) :


            Off to enjoy time with my brothers, my son, and my mom. 

            Happy March! Enjoy March fo(u)rth tomorrow, the most assertive day of the year and the anniversary of my son's beginning of his first trip around the sun. 

March Forth and Prosper,