"Fire Stranger" Pyroxene and Young Martian Clay

       Pyroxenes are isosilicates which are one of the most common constituents of the lithosphere of earth. They are also prominent minerals in the uplifted rocks on Mars.

       The name pyroxene comes from the Greek words for fire (πυρ) and stranger (ξένος). Pyroxenes were so named because of their presence in lavas, where they are sometimes present as crystals in volcanic glass. It was originally assumed they were impurities in the glass, hence the name "fire strangers". However, they are merely early-forming minerals that crystallized before the lava erupted.

      The most recent data from Mars show that clay found at impact sites near uplifted pyroxene uplifts is believed to be clay-rich impact melt material (i. e. authigenic), rather than clay pulled to the surface by impacts. This authigenic clay is now dated at 2 billion years or less rather than 3.7 billion years, as previously thought.

Brown University geologists, not affiliated with Coffee ;-), describe their research in a press release yesterday.

And, interestingly a hexagonal pattern shows up in craters on Mars as well:

     Mars and earth seem more and more similar every day. . .

       I am taking a Wild Clay painting class next month with a friend's brother here in Colorado. It may come in especially handy, if I ever go to Mars to check out the melted, wild, young clay.

Ka-O, don't be a fire stranger,
Steph

Bonus: Cliff Palace, Mesa Verde National Park, CO, with 70 lanterns, December 2015

From Microscopic Kaolinite Booklets to Macroscopic Sequence Stratigraphy in the Book Cliffs of Colorado and Utah

          Kaolinite is a clay mineral with a microscopic structure resembling long booklets as seen in this Scanning Electron Micrograph (SEM):

     

           I recently learned that the name is derived from the Chinese Kao-Ling, a village in Jiangxi province, China, where kaolinite was first named. The name entered English in 1727 from the French version of the word, kaolin. Can you read these kaolinite booklets?

          Kaolinite's chemical formula is Al2Si2O5(OH)4. Rocks that are rich in kaolinite are also known as china clay. 

           Kaolinite is used in the production of ceramics, 
as a filler for paint, rubber and plastics, in anti-diarrhearal products, and to produce glossy magazine paper (which brings us to books and the Book Cliffs. . .)

        We now segue from the microscopic to the macroscopic  Book Cliffs of western Colorado and eastern Utah:

           I have spent a fair amount of time in the Book Cliffs studying the sequence stratigraphy described there extensively in the 1980's by Exxon geologists.  Stratigraphy in a chronostratigraphic framework emphasizes unconformities and other time disruptions. 

      Sequence stratigraphy is the alternative to a lithostratigraphic approach which emphasizes similarity of the lithology of rock units rather than time significance. Sequence stratigraphy is a revolutionary change (akin to plate tectonics) in looking at the generation of rock layers. A good primer on sequence stratigraphy is linked here (Motto: The data are in the strata).

       Sequence stratigraphy: can you read it like a book?

Stratigraphically,
Steph