From its inception until January 23, 1919, this formation was named the Volunteer Army.

The formation is named for the community of Llewellyn in Schuylkill County.

The formation is named after the Judith River in Montana.

This formation is named Catena Sumner after the nearby crater.

Near the northwestern end is the crater Rheita, for which this formation was named.

The age and the formation are both named after the Belgian river Rupel.

The formation is named after the Belgian capital, Brussels.

The formation is named after the town of Opglabbeek in Limburg.

Geologic formations are typically named for the geographic area in which they were first described.

The formation is named after the town of Lede in East Flanders.