Edith Formation
The Edith Formation is a fluvial gravel Late Pleistocene geologic formation exposed near Albuquerque, New Mexico.[1][2]
| Edith Formation Stratigraphic range: Late Pleistocene (Wisconsian) ~0.01 Ma | |
|---|---|
| Type | Formation |
| Overlies | Arroyo Ojito Formation, Sierra Ladrones Formation |
| Thickness | 10–40 feet (3.0–12.2 m) |
| Lithology | |
| Primary | Gravel |
| Location | |
| Coordinates | 35.152°N 106.658°W |
| Region | New Mexico |
| Country | United States |
| Type section | |
| Named for | Edith Boulevard in Albuquerque, New Mexico |
| Named by | P.W. Lambert |
| Year defined | 1968 |
  Edith Formation (the United States)  Edith Formation (New Mexico) | |
Description
The Edith Formation consists of a single upward fining sequence, with a gravel base and overlying sandy to muddy floodplain deposits. It is poorly to moderately consolidated and locally cemented brown gravel, sand, and sandy clay. A typical composition for the basal gravel is 30% quartzite and 40% volcanic rock, with smaller amounds of granite and metamorphic and sedimentary rocks. It contains sparse clasts of densely welded Bandelier Tuff.[1]
The formation extends at least from near Algodones to Albuquerque and forms a distinctive regional marker bed, cropping out along the inner valley escarpment of the Rio Grande river. Its thickness is 10–40 feet (3.0–12.2 m). Its upper contact is marked by a diatomite bed and it unconformably rests on the Arroyo Ojito and Sierra Ladrones Formations, with a weakly developed paleosol at the contact. The base of the formation defines a prominent strath some 40–80 feet (12–24 m) above the Rio Grande floodplain.[1]
The formation is interpreted as a late Pleistocene terrace of the most recent glaciation.[3]
Formations
The Edith Formation contains fossils characteristic of the Rancholabrean, including Bison, Mastodon, Camelops, and Equus.[2]
History of investigation
The unit was first defined by P.W. Lambert in his dissertation on the Quaternary geology of Albuquerque in 1968, and named for nearby Edith Boulevard.[3]
References
- Connell, Sean D.; Love, David W. (2001). "Stratigraphy of middle and upper Pleistocene fluvial deposits of the Rio Grand (post-Santa Fe Group) and the geomorphic development of the Rio Grande Valley, Northern Albuquerque Basin, Central New Mexico" (PDF). New Mexico Burea of Geology and Mineral Resources Open File Reports. 454B: 167–178. Retrieved July 31, 2020.
- Lambert, P.W. (1968). Quaternary stratigraphy of the Albuquerque area, New Mexico [Ph.D. dissertation]. Albuquerque: University of New Mexico.
- Lucas, S.G.; Williamson, T.E.; Sobus, J. (1988). "Late Pleistocene (Rancholabrean) mammals from the Edith Formation, Albuquerque, New Mexico". The New Mexico Journal of Science. 28 (1): 51–58.