The Juniata is defined as a grayish-red to greenish-gray, thin- to thick-bedded siltstone, shale, and very fine to medium-grained crossbedded sandstone or subgraywacke and protoquartzite with interbedded conglomerate.

[3][4] The Juniata is a lateral equivalent of the Queenston Shale in western Pennsylvania.

Relative age dating of the Juniata places it in the Upper Ordovician period, being deposited between 488.3 and 443.7 (±10) million years ago.

[5] The Juniata is a good source of road material, riprap and building stone.

This article about a specific stratigraphic formation in Maryland is a stub.