Holder Formation

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Holder Formation
Stratigraphic range: Gzhelian
O
S
D
C
P
T
J
K
Pg
N
Type Formation
Underlies Bursum Formation
Overlies Beeman Formation
Thickness850 ft (260 m)
Lithology
Primary Limestone
Other Shale
Location
Coordinates 32°49′19″N105°52′26″W / 32.822°N 105.874°W / 32.822; -105.874
Region New Mexico
Country United States
Type section
Named forHolder Ridge
Named byL.C. Pray
Year defined1954
Usa edcp relief location map.png
Lightgreen pog.svg
Holder Formation (the United States)
USA New Mexico relief location map.svg
Lightgreen pog.svg
Holder Formation (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]

Contents

Description

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]

Fossils

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]

History of investigation

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]

See also

Footnotes

References