State by State


  • Specimen Number


  • Description

    Square tablet of the cream- and gray-colored sandstone identified by survey staff as the Oriskany Sandstone.  In closeup, the irregular surfaces suggest lack of bedding planes due to turbation by organisms. White  calcite (?) nodules are possibly recrystallized fossils.  Dominantly a calcareous sandstone with grains dominated by quartz. Fizzes in acid. Easily scraped with a knife.

  • Classification

    Sedimentary. Sandstone. Calcareous. Fossiliferous.

  • Location & Occurrence

    Quoting the survey, "likely from the folded mountains in the center of the state or from the northwest corner of the Appalachian Plateau." Search by formation name yields  shallow marine fossiliferous sandstone (USGS).

  • Geologic Age

    Middle Devonian.

  • Geoheritage

    Widespread through Appalachian Basin in NY, PA, OH, WV, MD, VA, KY.  Easily correlated as shoreline transgression over a broad area.

  • Links

    Link to State Geological Map from USGS.  Link to Pennsylvania Department of Conservation and Natural Resources (Geology) .

  • Other

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Specimen stone for Pennsylvania.
Closeup of Pennsylvania stone. Outline map of Pennsylvania. Geol Map of Pennsylvania.