Edited by James E. Palmer and Russell R. Dutcher - University of ...

FaciesAbandoneddistributarychannelAbandoneddistributarychanneland marshDistributaryfluvialchannelUpper pointbar (7)Flood plain (?)Interdistributarybay (?IFluvialdistributarychannel(point bar)UnitUNIT 5. Sandstone, light gray, deeply weathered; rusty orangewith purple mottling on weathered surfaces, fine- to mediumgrained,friable, grains subangular to subrounded; bedding is thinto very thin. Contains a few low amplitude symmetrical ripples.UNIT 4. Sandstone, siltstone and shale, deeply weathered;mostly covered by vegetation. Sandstone and siltstone, light tan,weathers dark orange, very finegrained, silty; becomes finertoward top of unit; grains are subangular to subrounded; thinbeddedto laminated. Few low amplitude ripples present. Shale,gray and brown, weathers dark brown, carbonaceous on beddingplanes, with abundant iron oxide concretions as much as 1 '/4 inch(3 cm) in diameter. Thin, discontinuous coal (12 in. or 30 cm) insouth roadcut. May be the Gentry Coal Member. Upper contact isconcealed.UNIT 3. Sandstone, gray-white, orange where weathered,locally purple along joints and bedding planes, medium- to finegrained,grains are subrounded to subangular; arkosic in appearance;poorly indurated. Unit contains trough cross-beddingwith sets filling scours in underlying sets. Paleocurrent trendnorthwest and southwest. Gradational contact with overlyingsandstone and siltstone.UNlT 2. Sandstone, siltstone, and shale; sandstone is purplishwhite, dark orange and purple where weathered, very finegrained;grains are subrounded to subangular. Shale, gray, tan,brown, and gray where weathered; banded in upper one-thirdof the unit; slightly silty. Shale grades laterally into lenticularsiltstone. Sandstone, thin- to thick-bedded, ripple-bedded toripple laminated, with some fine-grained scours into underlyingvery finegrained beds. Sharp erosional contact with overlyingsandstone.UNlT 1. Sandstone and conglomerate, white and light pink,orange-tan with purple and red zones where weathered, mediumtocoarse-grained, becomes finer in upper part, subroundedgrains. Quartz is dominant mineral. Sandstone, planar crossbedded,but with trough cross-bedding in channel fill. No discernablestructure in some units. Conglomerate, white and lightpink to dark tan-brown and reddish where weathered, consists ofwell-rounded, polished, oblate to spheroidal quartz pebbles insandstone matrix. Matrix is similar to adjacent sandstone beds incomposition and texture. Quartz pebbles as much as 2 inch(5 cm) in diameter. Conglomerate is thin- to very thin-beddedand generally occurs as elongate lenses along bedding planesor as fill in channels and scours. Paleocurrent direction northwestand southwest. Trend of two channels is west-southwest.Gradational contact with overlying shale.Figure IL-41. Columnar section and description of units, Caseyville Formation, Lower Roadcut, Interstate 24 (Illinois Stop 10).(After Koeninger, 1978, and Koeninger and Mansfield, 1979.)