The Salado 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 ...

. 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

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 ...

with significant

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 ...

red beds Red beds (or redbeds) are sedimentary rocks, typically consisting of sandstone, siltstone, and shale, that are predominantly red in color due to the presence of ferric oxides. Frequently, these red-colored sedimentary strata locally contain ...

, and

polyhalite Polyhalite is an evaporite mineral, a hydrated sulfate of potassium, calcium and magnesium with formula: . Polyhalite crystallizes in the triclinic system, although crystals are very rare. The normal habit is massive to fibrous. It is typically co ...

. 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 Cave ...

and was deposited after 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 A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock out ...

defining the margins of the Delaware Basin. The Salado Formation lies on the Castile Formation and in turn is overlain by the Rustler Formation, and is found almost entirely in the subsurface, with only limited and very poor surface exposures. In locations towards the margins of the Delaware Basin, the Salado Formation is composed mostly of anhydrite and

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. ...

resembling the Castile, and here the

contact Contact may refer to: Interaction Physical interaction * Contact (geology), a common geological feature * Contact lens or contact, a lens placed on the eye * Contact sport, a sport in which players make contact with other players or objects * ...

is placed at a bed of

breccia Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of di ...

thought to represent an

unconformity An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval o ...

between the two formations. The Salado Formation, and the underlying Castile 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.

History of investigation

The beds belonging to this formation were initially included in the Castile Formation of

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 1935, Walter B. Lang removed the upper beds of the Castile, which include extensive halite beds in the subsurface, into the Salado Formation.

Footnotes

References

* * * * * {{cite journal , last1=Richardson , first1=G.B. , author-link1=George Burr Richardson , year=1904 , title=Report of a reconnaissance in Trans-Pecos Texas north of the Texas and Pacific Railway , journal=University of Texas, Mineral Survey Bulletin , volume=9 Permian formations of New Mexico Permian formations of Texas