The Bone Spring 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 ...

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 ...

and

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 ...

. It preserves

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

dating back to the Leonardian

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 of dark gray deep marine

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) ...

interbedded with

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

and

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 ...

interpreted as

turbidite A turbidite is the geologic Deposition (geology), deposit of a turbidity current, which is a type of amalgamation of fluidal and sediment gravity flow responsible for distributing vast amounts of clastic sediment into the deep ocean. Sequencing ...

s. The total thickness is about . The base of the formation is largely concealed in the subsurface, and the formation is overlain by the Cutoff Shale. The formation grades laterally into the Victorio Peak Formation. The uppermost shale beds of the formation have been assigned to the Avalon Shale.

Fossils

The formation contains fossils of the

brachiopod Brachiopods (), phylum (biology), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear e ...

s ''

Productus ''Productus subaculeatus'' is an extinct species of brachiopods. Its fossils are present in the Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the ...

leonardensis'', '' Marginifera cristobalensis'', '' Pugnoides texanus'', ''P. bidentatus'', and '' Composita mexicana''; the

ammonite Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

s '' Peritrochia erebus'', '' Paracelites elegans'', ''

Agathiceras ''Agathiceras'' is a subglobose goniatitida, goniatitid from the family Agathiceratidae, widespread and locally abundant in Lower Pennsylvanian to Middle Permian sediments, e.g. the Urals, Sicily, and Texas (Blaine Formation). ''Agathiceras'', n ...

texanum'', and ''

Perrinites Perrinitinae is one of two subfamilies of the Perrinitidae family. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloid Nautiloids ar ...

''.

History of investigation

The formation was first designated the Bone Springs Limestone by Blanchard and Davis in 1929. It has subsequently been demoted to membership as the Bone Canyon Member of the Leonard Formation, renamed the Bone Spring Limestone, and most recently redesigned the Bone Spring Formation. The Cutoff Shale was removed as a separate formation in 1964.

Economic geology

The sandstones of the Bone Spring Formation are important

petroleum reservoir A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the prese ...

s with estimated reserves in 1997 of 300,000–375,000 bbl. The formation lies deep in the subsurface in the Delaware Basin, where its shale facies is known as the Avalon Shale.

Footnotes

References

* * * * * * * * * * * {{cite book , last1=Stolz , first1=Dustin J. , last2=Franseen , first2=Evan K. , last3=Goldstein , first3=Robert H. , chapter=Character of the Avalon Shale (Bone Spring Formation) of the Delaware Basin, West Texas and Southeast New Mexico: Effect of Carbonate-rich Sediment Gravity Flows , title=Proceedings of the 3rd Unconventional Resources Technology Conference , date=2015 , doi=10.15530/urtec-2015-2154681, isbn=978-0-9912144-2-6 Permian geology of Texas Permian formations of New Mexico Limestone formations of the United States Shale formations of the United States Sandstone formations of the United States

Description

Fossils

History of investigation

Economic geology

See also

Footnotes

References