Holder Formation | |
---|---|
Stratigraphic range: | |
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 |
Region | New Mexico |
Country | United States |
Type section | |
Named for | Holder Ridge |
Named by | L.C. Pray |
Year defined | 1954 |
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]