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 Cavern ...

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

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , Offi ...

. 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 In the geologic timescale, the Kungurian is an age or stage of the Permian. It is the latest or upper of four subdivisions of the Cisuralian Epoch or Series. The Kungurian lasted between and million years ago (Ma). It was preceded by the Art ...

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

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 Pale ...

Period.

Description

The formation consists of dark gray deep marine

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 wh ...

interbedded with

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especia ...

and

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates ...

interpreted as

turbidite A turbidite is the geologic 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 Turbidites w ...

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 Cutoff Formation is a geologic formation in Texas and New Mexico, US. It preserves fossils dating back to the Permian period. Description The Cutoff Formation consists of feet of thin limestone beds interbedded with dark shale and sa ...

. The formation grades laterally into the

Victorio Peak Formation The Victorio Peak Formation is a geologic formation found in the Delaware Basin in Texas and New Mexico. It preserves fossils dating back to the Leonardian Age of the Permian Period.Kues and Giles 2004 Description The formation consists of l ...

. The uppermost shale beds of the formation have been assigned to the Avalon Shale.

Fossils

The formation contains fossils of the

brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan 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 end, ...

s '' Productus leonardensis'', ''

Marginifera ''Marginifera'' is an extinct genus of brachiopod belonging to the order Productida. Specimens have been found in Carboniferous to Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Pe ...

cristobalensis'', ''

Pugnoides ''Pugnoides'' is an extinct genus of brachiopod belonging to the order Rhynchonellida and family Petasmariidae. Specimens have been found in Devonian to Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 mil ...

texanus'', ''P. bidentatus'', and ''

Composita mexicana ''Composita'' is an extinct brachiopod genus that lived from the Late Devonian to the Late Permian.

''; the

ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttle ...

s ''

Peritrochia Peritrochia is an extinct genus of ammonite belonging to the order Goniatitida and family Vidrioceratidae. Specimens have been recovered from Permian beds in North America and East Timor East Timor (), also known as Timor-Leste (), offic ...

erebus'', '' Paracelites elegans'', '' Agathiceras texanum'', and '' Perrinites''.

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 presenc ...

s with estimated reserves in 1997 of 300,000–375,000

bbl A barrel is one of several units of volume applied in various contexts; there are dry barrels, fluid barrels (such as the U.K. beer barrel and U.S. beer barrel), oil barrels, and so forth. For historical reasons the volumes of some barrel units ...

. The formation lies deep in the subsurface in the Delaware Basin, where its shale facies is known as the Avalon Shale.

Footnotes

References

* * * * * * * * * * * {{cite journal , last1=Stolz , first1=Dustin J. , last2=Franseen , first2=Evan K. , last3=Goldstein , first3=Robert H. , title=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 , journal=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

Description

Fossils

History of investigation

Economic geology

See also

Footnotes

References