The Bell Canyon Formation is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

found in the

Delaware Basin The Delaware Basin is a geologic depositional and structural basin in West Texas and southern New Mexico, famous for holding large oil fields and for a fossilized reef exposed at the surface. Guadalupe Mountains National Park and Carlsbad Cav ...

of southeastern

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

and western

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

. It contains fossils characteristic of the

Guadalupian The Guadalupian is the second and middle Series (stratigraphy), series/Epoch (geology), epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico an ...

Age Age or AGE may refer to: Time and its effects * Age, the amount of time someone has been alive or something has existed ** East Asian age reckoning, an Asian system of marking age starting at 1 * Ageing or aging, the process of becoming older ...

of the

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

Period Period may refer to: Common uses * Period (punctuation) * Era, a length or span of time *Menstruation, commonly referred to as a "period" Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (o ...

Description

The formation consists mostly of marine

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

and

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility. Although its permeabil ...

, but with five interfingering tongues of gray

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

. These extend from the Capitan reef into what was then deep, anoxic water deep of the Permian Basin. Total thickness of the formation is .

Fossils

The formation's Lamar Limestone Member of

Guadalupe Mountains National Park Guadalupe Mountains National Park is a national park of the United States in the Guadalupe Mountains, east of El Paso, Texas. The mountain range includes Guadalupe Peak, the highest point in Texas at , and El Capitan used as a landmark by travel ...

has produced fossil

holocephalan Holocephali (Sometimes spelled Holocephala; Romanization of Greek, Greek for "complete head" in reference to the fusion of Palatoquadrate, upper jaw with the rest of the skull) is a Subclass (biology), subclass of Chondrichthyes, cartilaginous fi ...

teeth.

History of investigation

The unit was first designated as a formation by DeFord and Lloyd in 1940, who raised the Delaware Mountain Formation to

group A group is a number of persons or things that are located, gathered, or classed together. Groups of people * Cultural group, a group whose members share the same cultural identity * Ethnic group, a group whose members share the same ethnic iden ...

rank and designed its previously informal members as formations.

Footnotes

References

* * * * {{cite book , last1=Hunt , first1=Rebecca K. , first2=Vincent L. , last2=Santucci , first3=Jason , last3=Kenworthy , year=2006 , chapter=A preliminary inventory of fossil fish from National Park Service units , editor-first1=S.G. , editor-last1=Lucas , editor-first2=J.A. , editor-last2=Spielmann , editor-first3=P.M. , editor-last3=Hester , editor-first4=J.P. , editor-last4=Kenworthy , editor-first5=V.L. , editor-last5=Santucci , title=Fossils from Federal Lands. New Mexico Museum of Natural History and Science Bulletin , volume=34 , pages=63–69 Permian geology of Texas Permian formations of New Mexico Sandstone formations of the United States Limestone formations of the United States Siltstone formations of the United States