Pole Creek Shale (Upper Ordovician) and Bigfork Chert (Upper and Middle Ordovician)

Polk Creek Shale (Upper Ordovician) and Bigfork Chert (Upper and Middle Ordovician)
State Arkansas
Name Pole Creek Shale (Upper Ordovician) and Bigfork Chert (Upper and Middle Ordovician)
Geologic age Late Ordovician to Middle Ordovician
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > Shale (Bed)
Sedimentary > Chemical > Chert (Bed)
Minor
Sedimentary > Carbonate > Limestone (Bed)
Comments Pole Creek Shale-black shale cherty in parts (300 ft.); Bigfork Chert-thin bedded gray chert inter bedded with limestone and some shale (800 ft.). Approximatly 1100 ft. maximum thickness.
References

Ferguson, J.G., 1920. Outlines of the geology, soils, and minerals of the State of Arkansas: Arkansas State Bureau of Mines, Manufactures and Agriculture,192 pp.

Stone, C.G. and Bush, W.V. 1982, Summary of the geology of the eastern Ouachita Mountains, Arkansas: Guidebook - Arkansas Geological Commission, vol.82-2, 24 pp.

NGMDB product
Counties Garland - Hot Spring - Montgomery - Polk - Pulaski - Saline