Holder Formation Explained

Holder Formation
Type:	Formation
Period:	Gzhelian
Prilithology:	Limestone
Otherlithology:	Shale
Namedfor:	Holder Ridge
Namedby:	L.C. Pray
Year Ts:	1954
Region:	New Mexico
Country:	United States
Coordinates:	32.822°N -105.874°W
Underlies:	Bursum Formation
Overlies:	Beeman Formation
Thickness:	850feet

The Holder Formation is a geologic formation in the Sacramento Mountains of New Mexico. It preserves fossils dating back to the late Pennsylvanian.

Description

The Holder Formation consists of limestone, red and gray calcareous shale, sandstone, and conglomerate. The maximum thickness is 850feet. The formation overlies the Beeman Formation 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 NaNfeet 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
• Paleontology in New Mexico

References

• Baars . D. L. . Torres . Andrew M. . Late Paleozoic Phylloid Algae: A Pragmatic Review . PALAIOS . October 1991 . 6 . 5 . 513 . 10.2307/3514989.
• Choh . Suk-Joo . Kirkland . Brenda L. . Sedimentologic role ofin situ Beresellid algal colonies, Holder Formation (Upper Pennsylvanian), New Mexico, U.S.A. . Carbonates and Evaporites . 1 September 2008 . 23 . 2 . 79–88 . 10.1007/BF03176154.
• Encyclopedia: Kues . B.S. . Giles . K.A. . 2004 . The late Paleozoic Ancestral Rocky Mountain system in New Mexico . Mack . G.H. . Giles . K.A. . The geology of New Mexico. A geologic history: New Mexico Geological Society Special Volume 11 . 95–136 . 9781585460106.
• Pray . L.C. . 1954 . Outline of the stratigraphy and structure of the Sacramento Mountain escarpment [Otero County, New Mexico] ]. New Mexico Geological Society Field Conference Guidebook . 5 . 92–107 . 29 July 2020.
• Book: Pray . L.C. . 1959 . Stratigraphic and structural features of the Sacramento Mountain Escarpment, New Mexico . Pray . L.C. . 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 . 86–130.
• Pray . L.C. . 1961 . Geology of the Sacramento Mountains Escarpment, Otero County, New Mexico . New Mexico Bureau of Mines and Mineral Resources Bulletin . 35 . 30 July 2020.