Bluff Formation
| Bluff Formation | |
|---|---|
| Stratigraphic range: | |
Formation | |
| Unit of | San Rafael Group |
| Underlies | Morrison Formation |
| Overlies | Summerville Formation |
| Thickness | 350 ft (110 m) |
| Lithology | |
| Primary | Sandstone |
| Other | Mudstone |
| Location | |
| Coordinates | 37°17′21″N 109°33′06″W / 37.2893°N 109.5518°W |
| Region | Four Corners |
| Country |  United States |
| Type section | |
| Named for | Bluff, Utah |
| Named by | Baker, Dane, and Reeside |
| Year defined | 1936 |
  Bluff Formation (the United States)  Bluff Formation (Utah) | |
The Bluff Formation is a
Period
.
Description
The Bluff Formation consists of massive wind-deposited (
Member. The Recapture Member has been variously assigned either to the overlying Morrison Formation[1] or to the Bluff Formation.[2][3] The Recapture Member is separated from the Salt Wash Member of the Morrison Formation by the regional J-5 unconformity.[4]
History of investigation
The formation was first named as the Bluff Sandstone by A.A. Baker, C.H. Dane, and J.B. Reeside, Jr., in 1938. They assigned it to the lower Morrison Formation.[5][1] J.W. Harshbarger, Charles Repenning, and J.H. Irwin promoted it to formation rank in 1957,[6] but this was not universally accepted.[7][8] Spencer G. Lucas advocated both for formation rank and for assigning the Recapture Member to the Bluff Sandstone.[3] Steven M. Cather agreed with promotion of the Bluff Sandstone to formation rank but advocated leaving the Recapture Member with the Morrison Formation.[9]
References
- ^ .
- ^ Anderson, Orin J.; Lucas, Spencer G. (August 1995). "Base of the Morrison Formation, Jurassic, of northwestern New Mexico and adjacent areas" (PDF). New Mexico Geology: 44–53. Retrieved 31 October 2020.
- ^ a b Lucas, Spencer G. (2020). "Jurassic stratigraphy of the southeastern Colorado Plateau, west-central New Mexico: 2020 synthesis" (PDF). New Mexico Geological Society Special Publication. 14: 135–144. Retrieved 30 October 2020.
- . Retrieved 31 October 2020.
- doi:10.3133/pp183.
- doi:10.3133/pp291.
- ^ O'Sullivan, Robert (1980). "Stratigraphic sections of Middle Jurassic San Rafael group from Wilson Arch to Bluff in southeastern Utah". U.S. Geological Survey Oil and Gas Investigations. OC-102. Retrieved 31 October 2020.
- doi:10.3133/b1633AC.
- ^ Cather, Steven M. (2020). "Jurassic stratigraphic nomenclature for northwestern New Mexico" (PDF). New Mexico Geological Society Special Publication. 14: 145–151. Retrieved 31 October 2020.