Mifflintown Formation
Geology
Members: unnamed (2), Keefer (1), McKenzie (1)
Lithologies: "shale" (2), rudstone (1), framestone (2)
Paleoenvironments: reef, buildup or bioherm (2), marginal marine indet. (2)
Age range: Wenlock or 433.40000 to 427.40000 Ma