|Geologic age||Early Ordovician|
Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed)
Sedimentary > Chemical > Chert (Bed)
Sedimentary > Carbonate > Limestone (Bed)
|Comments||Black clay shale with minor thin beds of limestone and chert. Approximatly 1000 ft. maximum thickness|
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.
|Counties||Garland - Montgomery|