Limestone and shale. Limestone is light gray to dark gray, yellowish gray to pale yellowish brown. Two limestones in the upper part are thin bedded to medium bedded, argillaceous, cherty and fossiliferous; two limestones in the lower part are medium to massive bedded, very cherty, and fossiliferous. Shale is gray, green, red, redish brown, calcareous, arenaceous, fossiliferous; locally fissile. Approx. max thickness 300 ft.
Shale and interbedded limestone. Shale is gray, green, red, reddish brown, or maroon, sandy, calcareous, fossiliferous, locally fissile; several fissile black shale beds are in lower 75 feet. Interbedded dark- to light-gray, medium- to thick-bedded, argillaceous, cherty limestone beds are very fossiliferous and locally contain shale partings. Approx. max thickness 300 ft
Upper part is white, light-gray, brownish-gray, yellow, redish-brown, and red sandstone and shale. Sandstone is very fine to coarse grained, friable, micaeous, crossbedded, and lenticular; locally contains gravel near base. contains numerous zones of ironstone and siltstone concretions of variable thickness. Middle part is light-gray, yellow, red brown and dark-gray, sandy carbonaceous shale; commonly contains a zone of concretions near top. Lower part is sandstone similar to that in upper except there are zones of siderite concretions and, locally a basal zone of chert pebbles. Approx. max thickness 600 ft.
Shale and interbedded limestone. Shale is dark gray to light gray, brown, red, or green, sandy, calcareous, and fossiliferous. Interbedded dark- to light-gray, very thin to medium bedded, argillaceous, very fossiliferous limestone beds. Near top of unit a fine-grained, micaceous sandstone bed underlies a stromatolite limestone bed which has distinctive lobate bedding. Approx. max thickness 150 ft