Langston Formation (original) (raw)

The Langston Formation is a geologic formation in Idaho and Utah. It preserves fossils dating back to the Cambrian period. The formation is composed of bluish-gray limestone, weathering to a buff color, often with rounded edges. Blacksmith Fork is the type locality, and includes more fossils than the Idaho sections. The Langston Formation includes the fossilerous Spence Shale.