Word Formation

This article is about the geological formation. For the linguistics term, see Word formation.

The Word Formation is a geologic formation in Texas.^[1] It preserves fossils dating back to the Permian period. It is probably named for the Old Word Ranch in the Glass Mountains of Brewster County.^[2]

Word Formation
Stratigraphic range: Roadian-Wordian ~272–265.1 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Fossil from the Word Formation
Type	Formation
Sub-units	Appel Ranch, China Tank & Willis Ranch members
Overlies	Road Canyon Formation
Lithology
Primary	Limestone
Location
Coordinates	30.4°N 103.2°W / 30.4; -103.2
Approximate paleocoordinates	1.6°N 33.0°W / 1.6; -33.0
Region	Texas
Country	United States
Extent	Glass Mountains
Type section
Named for	Old Word Ranch
Word Formation (the United States) Show map of the United States Word Formation (Texas) Show map of Texas

Defining formation

The Wordian age of the Permian Period is named for the Word Formation.^[3]

Subdivisions

The formation is subdivided into three members, from young to old:

• Appel Ranch - Wordian^[4]
• China Tank - Roadian^[5]
• Willis Ranch - Roadian^[6]

Fossil content

The limestone formation contains marine gastropods, brachiopods and ammonites.^[1]

Vertebrate paleofauna

• Helicoprion davisii

See also

• List of fossiliferous stratigraphic units in Texas
• Paleontology in Texas