The Holder 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
late Pennsylvanian
The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, on the ICS geologic timescale, the younger of two subperiods of the Carboniferous Period (or the upper of two subsystems of the Carboniferous System). It laste ...
.
Description
The Holder Formation consists of
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) ...
, red and gray calcareous
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 ...
,
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 ...
, and
conglomerate. The maximum thickness is . The formation overlies the
Beeman Formation
The Beeman Formation is a geologic formation in the Sacramento Mountains of New Mexico. It preserves fossils dating back to the Kasimovian Age of the Pennsylvanian Period.
Description
The Beeman Formation consists of cyclic shale and argillac ...
and is overlain by the
Laborcita Formation.
The formation is interpreted as a shallow-shelf marine formation of Virgilian (latest Pennsylvanian) age during a global ice age.
Fossils
Bioherms are present at the base of the formation. These are up to thick. They are composed of uncalcified cup-shaped phylloid (leaf-like) algae surrounded by masses of
beresellid algae.
History of investigation
The unit was first named by Lloyd C. Pray in 1954 and a type section was designated in 1959. Pray originally assigned the formation to the Magdalena Group, but the Magdalena Group has subsequently been abandoned.
See also
*
List of fossiliferous stratigraphic units in New Mexico
This article contains a list of fossil-bearing stratigraphic units in the state of New Mexico, New Mexico, U.S.
Sites
See also
* Paleontology in New Mexico
References
*
{{DEFAULTSORT:Fossiliferous stratigraphic units in New Mexico
...
*
Paleontology in New Mexico
Paleontology in New Mexico refers to paleontological research occurring within or conducted by people from the U.S. state of New Mexico. The fossil record of New Mexico is exceptionally complete and spans almost the entire stratigraphic column. ...
Footnotes
References
*
*
*
*
*
* {{cite journal , last1=Pray , first1=L.C. , year=1961 , title=Geology of the Sacramento Mountains Escarpment, Otero County, New Mexico , journal=New Mexico Bureau of Mines and Mineral Resources Bulletin , volume=35 , url=https://ngmdb.usgs.gov/Prodesc/proddesc_90717.htm , accessdate=30 July 2020
Carboniferous formations of New Mexico
Carboniferous southern paleotropical deposits
Limestone formations of the United States
Shale formations of the United States