The Castile 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 ...

in west

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

and southeastern

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ker ...

, United States. It was deposited in the

Ochoan The Ochoan is a stage in the Permian stratigraphy (and an age in the geologic timescale) of North America. The Ochoan age is roughly simultaneous with the Changhsingian age in the timescale of the ICS. This post-Guadalupian stage is known for h ...

Stage Stage or stages may refer to: Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly British theatre newspaper * Sta ...

of the

Permian The Permian ( ) is a geologic period and 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 251.9 Mya. It is the last period of the Paleoz ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

Description

The formation consists of up to of

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywall. ...

anhydrite Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the ...

with a few thin beds of

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

. The formation is found within 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 Cavern ...

and was deposited after the formation of the

Capitan Formation The Capitan Formation is a geologic formation found in western Texas and southeastern New Mexico. It is a fossilized reef dating to the Guadalupian Age of the Permian period. The formation underlies El Capitan in Guadalupe Mountains National Park ...

, the fossil reef defining the margins of the Delaware Basin. The formation lies on the

Bell Canyon Formation The Bell Canyon Formation is a geologic formation found in the Delaware Basin of southeastern New Mexico and western Texas. It contains fossils characteristic of the Guadalupian Age of the Permian Period. Description The formation consists mostl ...

and in turn is overlain by the

Salado Formation The Salado Formation is a geologic formation in west Texas and southeastern New Mexico. It was deposited in the Ochoan Stage of the Permian period. Description The formation consists of up to of halite with significant anhydrite, red beds, and p ...

, which is characterized in the subsurface by a thick sequence of

halite Halite (), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, p ...

beds. In locations towards the margins of the Delaware Basin, the Salado Formation is composed mostly of anhydrite and gypsum resembling the Castile, and here the contact is placed at a brecciated bed thought to represent an unconformity between the two formations. The Castile Formation, and the overlying Salado Formation, form an

evaporite An evaporite () is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocea ...

sequence that formed in a very deep basin (over ) from increasingly saline waters. The presence of fine laminations in the formation, which can be traced over great distances, indicate deposition well below wave base. Castile AIII

History of investigation

The unit was first named by

George Burr Richardson George Burr Richardson, MS, PhD (1872 - 1949) was a geologist who, among other endeavors, participated in extensive field work for the United States Geological Survey (USGS) in Alaska, Pennsylvania, California, Texas, Colorado, and Utah. In Texas, ...

in 1904 for exposures in west Texas. The formation was subsequently trace north into the

Pecos River The Pecos River ( es, Río Pecos) originates in north-central New Mexico and flows into Texas, emptying into the Rio Grande. Its headwaters are on the eastern slope of the Sangre de Cristo mountain range in Mora County north of Pecos, New Mexico ...

valley and is extensive in the subsurface. In 1935, Walter B. Lang removed the upper beds of the unit, which include extensive halite beds in the subsurface, into the Salado Formation.

Footnotes

References

* * * * * * {{cite journal , last1=Wilmarth , first1=M.G. , year=1938 , title=Lexicon of geologic names of the United States (including Alaska) , journal= U.S. Geological Survey Bulletin , volume=896 , doi=10.3133/b896 , doi-access=free Permian formations of New Mexico Permian formations of Texas