The Lipeón Formation is a Telychian to Pridoli geologic

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondar ...

of southern Bolivia and northwestern Argentina. The formation comprises

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) ...

s 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.Blatt ''et al.'' 1980, p ...

s. Plant fossils comprising rhyniophytes (specifically ''

Aberlemnia ''Aberlemnia'' is a genus of extinct vascular plants of the Early Devonian (around ), which consisted of leafless stems with terminal spore-forming organs (sporangia). Fossils found in Scotland were initially described as ''Cooksonia caledonica ...

'', ''

Steganotheca ''Steganotheca'' is a genus of bushy, probably vascular plants with branched axes, known from upper Silurian strata. It has terminal sporangia A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be comp ...

'', '' Tarrantia'', ''

Hostinella ''Hostinella'' is a form genus, used for bare dichotomously branching stems (axes) which have not been found in association with spore-forming organs or sporangia and so cannot be assigned to a more precise genus or species. Specimens assigned t ...

'' and '' Cooksonia'') are scattered throughout, with some abundant concentrations on micaceous bedding plains. The fossil flora is the oldest of South America.Jarcas stream, Negra Muerta, Sella Valley, Tarija
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.orgPadcaya, Tarija
at

.org Also present were quite diverse small, irregularly branching fragments possibly the tips of algae such as '' Buthotrephis'' or '' Hungerfordia''.Edwards et al., 2015, pp.16-17

Correlations

The Lipeón Formation is laterally equivalent to the Kirusillas Formation.Veizaga Saavedra et al., 2014, p.96Hacienda de Tapacari, 10 km from Huari, 120 km S of Oruro
at

.org The formation is a potential

source rock In petroleum geology, source rock is rock which has generated hydrocarbons or which could generate hydrocarbons. Source rocks are one of the necessary elements of a working petroleum system. They are organic-rich sediments that may have been depos ...

for

shale oil Shale oil is an unconventional oil produced from oil shale rock fragments by pyrolysis, hydrogenation, or thermal dissolution. These processes convert the organic matter within the rock (kerogen) into synthetic oil and gas. The resulting oil ca ...

and shale gas.Veizaga Saavedra et al., 2014, p.99

Fossil content

The formation has provided the following fossils: * '' Ornatosinuitina reyesi'' * '' Slimonia boliviana''Kjellesvig-Waering, 1973 * '' Styliolina sp.'' * Lingulata indet. ;Flora * ''

'' * '' Cooksonia'' * ''

'' * ''

'' * '' Tarrantia''

References

Bibliography

* * *

Correlations

Fossil content

See also

References

Bibliography

Further reading