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Showing posts with label lithostratigraphic vs. time sequences. Show all posts
Showing posts with label lithostratigraphic vs. time sequences. Show all posts

Tuesday, February 17, 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