Wikimedi'Òc

Gray Slate label.JPG - Amcyrus2012

Bulletin 799 Plate 8A Harpers Schist.jpg - Jstuby

Bulletin 799 Plate 8C Mica Schist from Upper Beds of Chickies Quartzite.jpg - Jstuby

Bulletin 799 Plate 5B Folded Conestoga Limestone.jpg - Jstuby

Bulletin 799 Plate 2A Harpers Schist photomicrograph.jpg - Jstuby

Bulletin 799 Plate 4A Kinzers Pseudoconglomerate.jpg - Jstuby

Magnetite skarn (Early Jurassic; French Creek Mining District, Chester County, Pennsylvania, USA).jpg - Ser Amantio di Nicolao

Greenstone (Catoctin Formation, Neoproterozoic, ~555-568 Ma; between Waynesboro and Liberty Mills, Pennsylvania, USA) 5.jpg - Ser Amantio di Nicolao