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
Blakely Sandstone (Coleman Quartz Mine, Arkansas)
TypeFormation
Unit ofnone
Sub-unitsnone
UnderliesWomble Shale
OverliesMazarn Shale
Thicknessup to 700 feet[1]
Lithology
PrimarySandstone
Location
RegionArkansas, Oklahoma
CountryUnited States
Type section
Named forBlakely Mountain, Garland County, Arkansas
Named byAlbert Homer Purdue[2]

Paleofauna

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C. horridus[6]
H. holodentata[6]
L. quadratus[6]
P. costatus[6]
P. aculeatus[6]
D. euodes[7]
D. manus[7]
D. spinosus[7]
G. echinatus[7]
G. horridus[7]

See also

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References

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  1. ^ 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.
  2. ^ 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.
  3. ^ Griswold, L.S. (1892). "Whetstones and the novaculites". Annual Report of the Geological Survey of Arkansas for 1890. 3.
  4. ^ 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.
  5. ^ Purdue, A.H. (1909). Slates of Arkansas. Geological Survey of Arkansas.
  6. ^ 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.
  7. ^ 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.