Earth:Mojado Formation
| Mojado Formation Stratigraphic range: Albian | |
|---|---|
| Type | Formation |
| Underlies | Cowboy Spring Formation |
| Overlies | U-Bar Formation |
| Thickness | 5,150–7,800 feet (1,570–2,380 m) |
| Lithology | |
| Primary | Sandstone |
| Other | Shale, limestone, siltstone |
| Location | |
| Coordinates | [ ⚑ ] 31°30′21″N 108°23′14″W / 31.505910°N 108.387181°W |
| Region | New Mexico |
| Country | United States |
| Type section | |
| Named for | Mojado Pass |
| Named by | R.A. Zeller Jr. |
| Year defined | 1962 |
  Mojado Formation (the United States)  Mojado Formation (New Mexico) | |
The Mojado Formation is a geologic formation in southwestern New Mexico. It preserves fossils dating back to the early Cretaceous period.[1][2]
Description
The formation consists mostly of sandstone and shale, with some limestone, and siltstone.[3] It rests conformably on the U-Bar Formation[2] and is unconformably overlain by the Cowboy Spring Formation.The total thickness is 5,150–7,800 feet (1,570–2,380 m).[4]
Lucas and his coinvestigators assigned the formation to the Bisbee Group and divided it into the Fryingpan Spring, Sarten, Beartooth, and Rattlesnake Ridge members.[3]
The Fryingpan Spring Member is interpreted as continental deltaic sedimentation.[5] The Sarten Member is fluvial while the Rattlesnake Ridge Member represents a return to shallow marine conditions.[6]
Fossils
The formation contains fossil mollusks such as gastropods, ammonites, and pelecypod,[2] foraminifera, and scaphopods. These date the formation to the late Albian.[4]
History of investigation
The formation name was first used by Zeller in 1962,[1] but he did not formally name the formation until 1965.[2] In 1998, Lucas and coinvestigators assigned the formation to the Bisbee Group and divided it into the Fryingpan Spring, Sarten, Beartooth, and Rattlesnake Ridge members.[3] However, Lawton abandoned the Beartooth Member in 2004.[6]
See also
- List of fossiliferous stratigraphic units in New Mexico
- Paleontology in New Mexico
Footnotes
- ↑ 1.0 1.1 Zeller 1962.
- ↑ 2.0 2.1 2.2 2.3 Zeller 1965.
- ↑ 3.0 3.1 3.2 Lucas & Estep 1998.
- ↑ 4.0 4.1 Zeller & Alper 1965.
- ↑ Hayes 1970.
- ↑ 6.0 6.1 Lawton 2004, pp. 162–163.
References
- Hayes, P.T. (1970). "Cretaceous paleogeography of southeastern Arizona and adjacent areas". U.S. Geological Survey Professional Paper 658-B: B1–B42. doi:10.3133/pp658B.
- Lawton, Timothy F. (2004). "Upper Jurassic and lower Cretaceous strata of southwestern New Mexico and northern Chihuahua, Mexico". in Mack, G.H.; Giles, K.A.. The geology of New Mexico. A geologic history: New Mexico Geological Society Special Volume 11. pp. 153–168. ISBN 9781585460106.
- Lucas, Spencer G.; Estep, John W. (1998). "Lithostratigraphy and biostratigraphy of the lower-middle Cretaceous Bisbee group, southwestern New Mexico". New Mexico Museum of Natural History and Science Bulletin 14. https://books.google.com/books?id=yF4fCgAAQBAJ&q=Lithostratigraphy+and+biostratigraphy+of+the+Lower-middle+Cretaceous+Bisbee+group,+southwestern+New+Mexico&pg=PA39. Retrieved 5 August 2020.
- Zeller, R.A. Jr. (1962). "Reconnaissance geologic map of southern Animas Mountains [New Mexico"]. New Mexico Bureau of Mines and Mineral Resources Geologic Map 17. https://ngmdb.usgs.gov/Prodesc/proddesc_73069.htm. Retrieved 5 August 2020.
- Zeller, R.A. Jr. (1965). "Stratigraphy of the Big Hatchet Mountains Area, New Mexico". New Mexico Bureau of Mines and Mineral Resources Memoir 16. https://geoinfo.nmt.edu/publications/monographs/memoirs/16/. Retrieved 11 October 2021.
- Zeller, R.A. Jr.; Alper, A.M. (1965). "Geology of the Walnut Wells quadrangle, Hidalgo County, New Mexico". New Mexico Bureau of Mines and Mineral Resources Bulletin 84. https://geoinfo.nmt.edu/publications/monographs/bulletins/downloads/84/B84.pdf. Retrieved 5 August 2020.
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