Langston_Formation
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,[1] weathering to a buff color, often with rounded edges.[2]
Blacksmith Fork is the type locality, and includes more fossils than the Idaho sections.
The Langston Formation includes the fossilerous Spence Shale.