Claibourne Group (ARTc;0)

State	Arkansas
Name	Claibourne Group
Geologic age	Phanerozoic \| Cenozoic \| Tertiary \| Eocene-Middle
Original map label	Tc
Comments	Mainly unconsolidated sand and silty clay/interbedded with carbononaeous clay and lignite. Maximum thickness is 1500 ft. Cyclic marine-nonmarine units formed in a fluvial-deltatic system. Typical delta sequence; Delta Plain:clay and coal, Inner Fringe:sand, Outer Fringe:clay and sand, Pro-Delta:clay, Marine:clay.
Primary rock type	sand
Secondary rock type	clay or mud
Other rock types	coal
Lithologic constituents	Major Unconsolidated > Fine-detrital > Clay (Bed) Unconsolidated > Coarse-detrital > Sand (Bed) Minor Sedimentary > Coal (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	Wilbert, L.J. Jr. 1953, The Jacksonian Stage in southeastern Arkansas: Ark. Res. Devel. Comm., Div. Geology Bull. 19, 125 pp.
Geographic coverage	Ashley - Bradley - Calhoun - Cleveland - Columbia - Craighead - Cross - Dallas - Grant - Jefferson - Lafayette - Miller - Nevada - Ouachita - Poinsett - Pulaski - Saint Francis - Saline - Union