The Blakely Sandstone is a Middle Ordovician geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. First described in 1892,[3] this unit was not named until 1909 by Albert Homer Purdue in his study of the Ouachita Mountains of Arkansas. Purdue had initially named this unit the Caddo Shale at a 1907 Geological Society of America meeting,[4] but later redefined and renamed the unit as the Ouachita Shale.[5] He again renamed the unit to the Blakely Sandstone in a letter to Edward Oscar Ulrich, to which Ulrich used in a 1911 publication, becoming the first reference using this name.[2] Ulrich assigned the Blakely Mountain in Garland County, Arkansas as the type locality, but did not designate a stratotype. As of 2017, a reference section for this unit has yet to be designated.
| Blakely Sandstone | |
|---|---|
| Stratigraphic range: Ordovician | |
_(8290507503).jpg) Blakely Sandstone (Coleman Quartz Mine, Arkansas) | |
| Type | Formation |
| Unit of | none |
| Sub-units | none |
| Underlies | Womble Shale |
| Overlies | Mazarn Shale |
| Thickness | up to 700 feet[1] |
| Lithology | |
| Primary | Sandstone |
| Location | |
| Region | Arkansas, Oklahoma |
| Country | United States |
| Type section | |
| Named for | Blakely Mountain, Garland County, Arkansas |
| Named by | Albert Homer Purdue[2] |
Paleofauna edit
Conodonts edit
- C. horridus[6]
- H. holodentata[6]
- L. quadratus[6]
- P. costatus[6]
- P. aculeatus[6]
Graptolites edit
See also edit
References edit
- ^ McFarland, John David (2004) [1998]. "Stratigraphic summary of Arkansas" (PDF). Arkansas Geological Commission Information Circular. 36: 19. Archived from the original (PDF) on 2016-12-21. Retrieved 2018-01-08.
- ^ a b Ulrich, E.O. (1911). "Revision of the Paleozoic systems". Bulletin of the Geological Society of America. 22 (1): 677. Bibcode:1911GSAB...22..281U. doi:10.1130/GSAB-22-281.
- ^ Griswold, L.S. (1892). "Whetstones and the novaculites". Annual Report of the Geological Survey of Arkansas for 1890. 3.
- ^ Purdue, A.H. (1909). "Structure and stratigraphy of the Ouachita Ordovician area, Arkansas (abstract)". Geological Society of America Bulletin. 19: 557. doi:10.1130/GSAB-19-513.
- ^ Purdue, A.H. (1909). Slates of Arkansas. Geological Survey of Arkansas.
- ^ a b c d e f Ethington, R.L.; Finney, S.C.; Repetski, J.E. (1989). Biostratigraphy of the Paleozoic rocks of the Ouachita orogen, Arkansas, Oklahoma, west Texas.
- ^ a b c d e f g h Miser, Hugh D.; Purdue, A.H. (1929). "Geology of the De Queen and Caddo Gap quadrangles, Arkansas" (PDF). U.S. Geological Survey Bulletin. 808: 30–31.
 | This article about a specific stratigraphic formation in the United States is a stub. You can help Wikipedia by expanding it. |