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Mineral Resources > Online Spatial Data > Geology > by state > Illinois Geology

Geologic units in Douglas county, Illinois

Spoon Formation (Pennsylvanian) at surface, covers 4 % of this area

Spoon (includes Pa in northeast)

Lithology: shale; sandstone; clay or mud; limestone; coal; black shale

Middle Devonian (Devonian) at surface, covers 4 % of this area

Middle Devonian

Lithology: limestone; shale; dolostone (dolomite); sandstone; evaporite; sedimentary breccia;

Bond Formation (Pennsylvanian) at surface, covers 2 % of this area

Bond Formation

Lithology: limestone; shale; sandstone; clay or mud; coal; black shale

Middle Valmeyeran (Salem, Warsaw, Borden, Springville; includes thin Mvl and Mk in south and east) Series (Mississippian) at surface, covers 6 % of this area

Middle Valmeyeran (Salem, Warsaw, Borden, Springville; includes thin Mvl and Mk in south and east) Series

Lithology: limestone; siltstone; shale

Mattoon Formation (Pennsylvanian) at surface, covers 30 % of this area

Mattoon Formation

Lithology: shale; sandstone; limestone; coal; black shale

Modesto Formation (Pennsylvanian) at surface, covers 18 % of this area

Modesto Formation

Lithology: shale; sandstone; limestone; clay or mud; coal; black shale

Silurian (Silurian) at surface, covers 0.1 % of this area

Silurian

Lithology: dolostone (dolomite); limestone; coral

Carbondale Formation (Pennsylvanian) at surface, covers 33 % of this area

Carbondale Formation

Lithology: shale; limestone; clay or mud; sandstone; coal; black shale

Upper Devonian (Devonian) at surface, covers 3 % of this area

Upper Devonian

Lithology: shale; black shale; limestone; sandstone