Limestone and dolomite
Limestone, dolomite, and argillaceous dolomite
Black and greenish-gray shale
Mostly siltstone; lenses of crinodial limestone in upper part. Much cherty and silty limestone and dolomite in northwest. NP, top of New Providence Shale
Mostly shale and sandstone; also includes thin beds of limestone, clay, and coal. B, Buffaloville Coal Member; LB, Lower Block Coal Member
Dolomite, limestone, and argillaceous dolomite
New Albany Shale, Blocher Shale, Sylamore Sandstone, Selmier Shale, Sweetland Creek Shale, Grassy Creek Shale, Saverton Shale, and Louisiana Limestone.
Shale and limestone; upper part of Maquoketa Group in deep buried valleys; Maquoketa to upper part of Knox Supergroup in Kentland area
Sexton Creek Limestone at base in Kentland area and on cross-section
Borden Siltstone, includes Chouteau Limestone in east-central Illinois.
Silurian System undivided, includes Sexton Creek Limestone, St. Clair Limestone, and Moccasin Springs Formation in southern Illinois; includes Wilhelmi Formation, Elwood Dolomite, Kankakee Dolomite, Joliet Dolomite, Sugar Run Dolomite, and Racine Dolomite in northeastern Illinois; includes Mosalem, Tete des Morts, Blanding, Sweeney, Marcus, and Racine Dolomites in northwestern Illinois.
Muscatatuck Group, includes Grand Tower Limestone and St. Laurent (Alto and Lingle) Formation in southern Illinois; includes Detroit River Formation, Wapsipinicon Limestone, and Cedar Valley Limestone in northern and western Illinois.