Hale Formation
Geologic formation in northern Arkansas
From Wikipedia, the free encyclopedia
The Hale Formation is a geologic formation in northern Arkansas that dates to the Morrowan Series of the early Pennsylvanian.[3] The Hale Formation has two named members: the Cane Hill and the Prairie Grove Members. The lower member is the Cane Hill, a primarily sandstone and shale interval that unconformably overlies the Mississippian-age Pitkin Formation. The upper member, the Prairie Grove Member, is predominately limestone and conformably underlies the Bloyd Formation.
| Hale Formation | |
|---|---|
| Stratigraphic range: Pennsylvanian | |
Outcrop of the Cane Hill Member of the Hale Formation | |
| Type | Formation |
| Unit of | none |
| Sub-units | Cane Hill Member, Prairie Grove Member |
| Underlies | Bloyd Formation |
| Overlies | Pitkin Formation |
| Thickness | few feet to over 300 feet[1] |
| Lithology | |
| Primary | Limestone, Sandstone |
| Other | Conglomerate, Shale |
| Location | |
| Region | Arkansas, Kansas |
| Country | United States |
| Type section | |
| Named for | Hale Mountain, Washington County, Arkansas |
| Named by | J.A. Taff[2] |
Nomenclature
Named by J. A. Taff in 1905, the Hale Formation was originally called the "Hale sandstone lentil" of the Morrow Formation after Hale Mountain in Washington County, Arkansas.[2] In the same year, George I. Adams and E. O. Ulrich called it the "Hale sandstone member" of the Morrow Formation. In 1907, Albert Homer Purdue raised the rank to the Hale Formation of the Morrow Group,[4] however, the Morrow Group was later abandoned as a stratigraphic unit in 1961.[5] A stratotype was not designated by J. A. Taff and, as of 2017, no reference section has been designated.
The Cane Hill Member was named after the town of Cane Hill in Washington County, Arkansas in 1953 by Lloyd G. Henbest, who also named its upper member, the Prairie Grove Member, after the town of Prairie Grove, in Washington County, Arkansas.[6] Henbest did not designate a stratotype for either of these members, and as of 2017, neither of them have been designated a reference section.
In the eastern parts of the Ozarks in Arkansas, the Hale Formation becomes undifferentiated with the overlying Bloyd Formation and is called the Witts Springs Formation.
Paleontology
Blastoids
Brachiopods
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Bryozoans
Cephalopods
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Conodonts
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Crinoids
Flora
- Archaeolithophyllum
- A. missouiense[16]
- Asphaltina
- A. cordillerensis[16]
- Eflugelia[16]
- Girvanella[17]
- Stacheoides
- S. spissa[16]
