State by State
- Specimen Number
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.
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
Widespread through Appalachian Basin in NY, PA, OH, WV, MD, VA, KY. Easily correlated as shoreline transgression over a broad area.
Link to State Geological Map from USGS. Link to Pennsylvania Department of Conservation and Natural Resources (Geology) .