Cub Mountain Formation
The Cub Mountain Formation is a geologic formation in southern New Mexico. It preserves fossils dating back to the Eocene epoch.[1]
| Cub Mountain Formation Stratigraphic range: Eocene | |
|---|---|
| Type | Formation |
| Lithology | |
| Primary | Sandstone, mudstone |
| Other | Conglomerate |
| Location | |
| Coordinates | 33.520700°N 105.914505°W |
| Region | New Mexico |
| Country | United States |
| Type section | |
| Named for | Cub Mountain |
| Named by | H.R. Weber |
| Year defined | 1964 |
  Cub Mountain Formation (the United States)  Cub Mountain Formation (New Mexico) | |
Description
The formation consists of interbedded gray to red sandstone and mudstone with minor conglomerate with a total thickness of 730 meters (2,400 ft). The formation disconformably rests on the Mesaverde Group and conformably underlies unnamed volcanic debris beds. In the vicinity of Sierra Blanca, the formation is intruded by dikes with K-Ar ages of 47.7 +/-2.9 Ma (million years ago).[1]
The formation is interpreted as deposited in a braided stream environment.[1]
Fossils
Fossil turtles have been found towards the base of the formation. These are characteristic of the Wasatchian-Bridgerian boundary at about 50 Ma.[1]
History of investigation
The first definition of the formation was credited to H.R. Weber in a publication by M.W. Bodine, Jr., in 1956,[2] but Weber did not publish a type section until 1964. The formation is named after an isolated peak in southern New Mexico.[1]
Kenneth Segerstrom and his coinvestigators argued in 1979 that the beds of the Cub Mountain Formation properly belong to the Cretaceous McRae Formation.[3] Spencer G. Lucas and his coinvestigators disagreed on the basis of fossil evidence, placing the formation in the Eocene.[1]
References
- Bodine, M.W., Jr. (1956). "Geology of the Capitan coal field, Lincoln County, New Mexico" (PDF). New Mexico Bureau of Mines and Mineral Resources Circular. 35. Retrieved 2 August 2020.
- Lucas, S.G.; Cather, S.M.; Sealey, Paul; Hutchison, H.C. (1989). "Stratigraphy, paleontology, and depositional systems of the Eocene Cub Mountain Formation, Lincoln County, New Mexico; a preliminary report" (PDF). New Mexico Geology. 11 (1): 11–17. Retrieved 2 August 2020.
- Segerstrom, Kenneth; Stotelmeyer, R.B.; Williams, F.E. (1979). "Mineral resources of the White Mountain Wilderness and adjacent areas, Lincoln County, New Mexico". U.S. Geological Survey Bulletin (1453). Retrieved 2 August 2020.