Jackson Group (ARTj;0)

State	Arkansas
Name	Jackson Group
Geologic age	Phanerozoic \| Cenozoic \| Tertiary \| Eocene-Late
Original map label	Tj
Comments	Mainly marl- fossiliferous calcareous glauconitic clay/interbedded with fossiliferous argillaceous sand and silty clay. White Bluff FM dominates over Redfield FM in thickness and extent. Transgressional marine-nonmarine sequence. Marl refers to loosley consolidated calcareous clays, silts and sands containing glauconite. Includes White Bluff FM (marine)- Caney Point member, Pastoria Sand member, Rison Clay member and Redfield FM (nonmarine) fossiliferous lignitic silt and sand.
Primary rock type	mixed clastic/carbonate
Secondary rock type	silt
Other rock types	sand
Lithologic constituents	Major Unconsolidated > Marl (Bed) Minor Unconsolidated > Coarse-detrital > Sand (Bed) Unconsolidated > Fine-detrital > Silt (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 - Cleveland - Drew - Grant - Jefferson - Lincoln