The Beeman 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 the Sacramento Mountains of

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

Kasimovian The Kasimovian is a geochronologic age or chronostratigraphic stage in the ICS geologic timescale. It is the third stage in the Pennsylvanian (late Carboniferous), lasting from to Ma.; 2004: ''A Geologic Time Scale 2004'', Cambridge Unive ...

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 Pennsylvanian

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 Beeman Formation consists of cyclic

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

argillaceous Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al2 Si2 O5( OH)4), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces. Clay mineral ...

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) ...

with some conglomerate. The thickness is . The formation overlies the Gobbler Formation and is overlain by the Holder Formation. The formation is interpreted as cyclic deposition on a

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an islan ...

following rejuvenation of the Pedernal uplift of the

Ancestral Rocky Mountains The geology of the Rocky Mountains is that of a discontinuous series of mountain ranges with distinct geological origins. Collectively these make up the Rocky Mountains, a mountain system that stretches from Northern British Columbia through cen ...

Fossils

The unit contains middle to upper Missourian (Kasimovian)

fusulinid The Fusulinida is an extinct order within the Foraminifera in which the tests are traditionally considered to have been composed of microgranular calcite. Like all forams, they were single-celled organisms. In advanced forms the test wall was d ...

s and

conodont Conodonts, are an extinct group of marine jawless vertebrates belonging to the class Conodonta (from Ancient Greek κῶνος (''kōnos''), meaning " cone", and ὀδούς (''odoús''), meaning "tooth"). They are primarily known from their hard ...

s, including several species of the fusulinid '' Triticites'' and the conodont '' Idiognathodus symmetricus'', related species, and species of ''

Streptognathodus ''Streptognathodus'' is an extinct genus of conodonts from the Late Carboniferous to Early Permian. Use in stratigraphy Late Carboniferous The top of the Kasimovian stage is close to the first appearance of ''Streptognathodus zethus''. The ...

''. These species indicate that the Beeman Formation is entirely Kasimovian in age. The formation has a diverse coprofauna. The formation has also produced a

lacustrine A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from t ...

fauna from one of its shell beds, including the

horseshoe crab Horseshoe crabs are arthropods of the family Limulidae and the only surviving xiphosurans. Despite their name, they are not true crabs or even crustaceans; they are chelicerates, more closely related to arachnids like spiders, ticks, and scor ...

Euproops ''Euproops'' is an extinct genus of xiphosuran, related to the modern horseshoe crab. It lived during the Carboniferous Period. The ''Treatise on Invertebrate Paleontology'' describes ''Euproopidae'' as "small forms with wedge-shaped cardiac lob ...

danae''.

History of investigation

The unit was first named by Lloyd C. Pray in 1954 and a type section was designated in 1959.Pray, L.C., 1959, "Stratigraphic and structural features of the Sacramento Mountain Escarpment, New Mexico", IN Pray, L.C., leader, ''Guidebook for joint field conference in the Sacramento Mountains of Otero County, New Mexico'': Society of Economic Paleontologists and Mineralogists, Permian Basin Section, Field Trip Guidebook, Joint field conference of Society of Economic Paleontologists and Mineralogists, Permian Basin Section, and Roswell Geological Society, Alamogordo, NM, p. 86-130. Pray originally assigned the formation to the Magdalena Group, but the Magdalena Group has subsequently been abandoned.

References

{{Reflist Carboniferous formations of New Mexico Carboniferous southern paleotropical deposits Shale formations of the United States Limestone formations of the United States Conglomerate formations of the United States

Description

Fossils

History of investigation

See also

References