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  • Specimen Number


  • Description

    Broken slab of red petrified wood. with clear contrast between outer bark and inner replacement.  Rings of trees not visible. Red stain is hematite. Identified by state survey staff.

  • Classification

    Sedimentary. Fossil (without matrix). Petrified Wood.

  • Location & Occurrence

    From state survey and search. Chinle Formation. Likely from Petrified Forest National Park. Paleoenvironment is terrestrial lowland  forest in fluvial, lacustrine, palustrine and eolian settings.  Silica replacement of plant tissue likely from groundwater high in dissolved silica, likely from volcanic tephra source in vadose groundwater zone. Red stain related to strong oxidation in continental monsoonal climate of late Pangea.

  • Geologic Age
  • Chinle formation. Late Triassic.  202-218 Ma based on U-Pb ages (Irmis et al, 2011).

  • Geoheritage

    Arguably the most widely recognized (famous) rock in the collection. Very well sourced.  Reveals the importance of paleobotany as part of geology.  Hematite staining is beautiful. Collected before site became a national park.

  • Links

    Link to State Geological Map from USGS.  Link to Arizona  Geological Survey.

  • Other

    Hartford Daily Courant article in 1937 identifies this specimen as a  "petrified tree."

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Specimen stone for Alaska.
Closeup Outline Map Arizona Geo Map