Holder Formation

Holder Formation
Stratigraphic range: Gzhelian PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Formation
Underlies	Bursum Formation
Overlies	Beeman Formation
Thickness	850 ft (260 m)
Lithology
Primary	Limestone
Other	Shale
Location
Coordinates	32°49′19″N 105°52′26″W / 32.822°N 105.874°W / 32.822; -105.874
Region	New Mexico
Country	United States
Type section
Named for	Holder Ridge
Named by	L.C. Pray
Year defined	1954
Holder Formation (the United States) Show map of the United States Holder Formation (New Mexico) Show map of New Mexico

The Holder Formation is a geologic formation in the Sacramento Mountains of New Mexico. It preserves fossils dating back to the late Pennsylvanian.^[1]

The Holder Formation consists of limestone, red and gray calcareous shale, sandstone, and conglomerate. The maximum thickness is 850 ft (260 m).^[1] The formation overlies the Beeman Formation^[1] and is overlain by the Laborcita Formation.^[2]

The formation is interpreted as a shallow-shelf marine formation of Virgilian (latest Pennsylvanian) age^[3] during a global ice age.^[4]

Bioherms are present at the base of the formation.^[1] These are up to 50–75 feet (15–23 meters) thick.^[3] They are composed of uncalcified cup-shaped phylloid (leaf-like^[5]) algae surrounded by masses of beresellid algae.^[4]

The unit was first named by Lloyd C. Pray in 1954^[1] and a type section was designated in 1959.^[6] Pray originally assigned the formation to the Magdalena Group, but the Magdalena Group has subsequently been abandoned.^[3][2]

• List of fossiliferous stratigraphic units in New Mexico
• Paleontology in New Mexico

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