Mazarn Shale

The Mazarn Shale is an Early Ordovician geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. This interval was first described in 1892,[3] but remained unnamed until 1918 as part of a study by U.S. Geological Survey geologist Hugh Dinsmore Miser.[2]

Mazarn Shale Stratigraphic range: Ordovician
Type	Formation
Unit of	none
Sub-units	none
Underlies	Blakely Sandstone
Overlies	Crystal Mountain Sandstone
Thickness	1000 to 2500+ feet[1]
Lithology
Primary	Shale
Location
Region	Arkansas, Oklahoma
Country	United States
Type section
Named for	Mazarn Creek, Montgomery County, Arkansas
Named by	Hugh Dinsmore Miser[2]

Paleofauna

Graptolites

Caryocaris C. wrighti[4] Cryptograptus C. antennarius[4] Didymograptus D. caduceus[4] D. caduceus nana[4] D. extensus[4][5] D. filiformis[4] D. nitidus[4] D. similis[4] Diplograptus[4]

Glossograptus G. hystrix[4] Mesograptus[4] Phyllograptus P. typus[4] Retiograptus[4] Tetragraptus [5] T. clarkei[4] T. fruticosus[4] T. quadribrachiatus[4] T. pendens[4] T. serra[4] T. similis[4]

See also

• List of fossiliferous stratigraphic units in Arkansas
• Paleontology in Arkansas

References

1. McFarland, John David (2004) [1998]. "Stratigraphic summary of Arkansas" (PDF). Arkansas Geological Commission Information Circular. 36: 18. Archived from the original (PDF) on 2016-12-21. Retrieved 2018-01-08.
2. Miser, H.D. (1918). "Manganese deposits of the Caddo Gap and De Queen quadrangles, Arkansas". U.S. Geological Survey Bulletin. 660-C: 68.
3. Griswold, I.S. (1892). "Whetstones and the novaculites". Annual Report of the Geological Survey of Arkansas for 1890. 3.
4. Miser, Hugh D.; Purdue, A.H. (1929). "Geology of the De Queen and Caddo Gap quadrangles, Arkansas". U.S. Geological Survey Bulletin. 808: 27–28.
5. Pitt, William D.; Cohoon, Richard R.; Lee, Harry C.; Robb, Marion G; Watson, John (January 1961). "Ouachita Mountain core area, Montgomery County, Arkansas". Bulletin of the American Association of Petroleum Geologists. 45 (1): 79–80. Retrieved 8 January 2018.