• Specimen Number

  36

• 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

Click here for an explanation of categories and illustrations