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Missouri Mountain Shale and Baylock Sandstone

Missouri Mountain Shale and Baylock Sandstone - The Baylock Sandstone is present only in the Cross, Cossatot, and Trap Mountains. Missouri Mountain Shale is mapped with Polk Creek Shale and Bigfork Chert in the area between Paron, Saline County, and Little Rock
State Arkansas
Name Missouri Mountain Shale and Baylock Sandstone
Geologic age Phanerozoic | Paleozoic | Silurian
Comments Missouri Mtn. Shale-argillitic shale with minor sandstone and conglomerate (250 ft.); Baylock Sandstone-sandstone with minor siltstone and shale (1000 ft.) Approximately 1250 ft. maximum thickness. Summary- 75% sandstone, 20% shale, 5% other
Primary rock type sandstone
Secondary rock type shale
Other rock types conglomerate; siltstone
Lithologic constituents
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Mudstone > Shale (Bed)
Sedimentary > Clastic > Conglomerate (Bed)
Sedimentary > Clastic > Siltstone (Bed)
Map references
Haley, B. R., Glick, E. E., Bush, W. V.; Clardy, B. F.; Stone, C. G.; Woodward, M. B., Zachry, D.L., 1993, Geologic Map of Arkansas: U.S.Geological Survey Special Geologic Map. Scale 1:500K
Unit 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.
Counties Garland - Hot Spring - Montgomery - Pike - Polk - Pulaski - Saline