Silurian (ILS;0)

State	Illinois
Name	Silurian
Geologic age	Silurian
Original map label	6700
Comments	The Silurian consists of the following formations: Moccasin Springs Limestone, St. Clair Limestone, Sexton Creek Limestone, and Edgewood Limestone, Racine Dolomite, Waukesha Dolomite, Joliet Dolomite, Kankakee Dolomite, Edgewood Dolomite. The dolomite units occur in the northern part of the state and the limestone units occur in the southern part of the state. Based on the stratigraphic column on the 1967 paper map, the Silurian is about 50% limestone and 50% dolomite.
Primary rock type	dolostone (dolomite)
Secondary rock type	limestone
Other rock types	coral
Lithologic constituents	Major Sedimentary > Carbonate > LimestoneThe Silurian consists of the following formations: Moccasin Springs Limestone, St. Clair Limestone, Sexton Creek, Limestone, and Edgewood Limestone, Racine Dolomite, Waukesha Dolomite, Joliet Dolomite, Kankakee Dolomite, Edgewood Dolomite. The dolomite units occur in the northern part of the state and the limestone units occur in the southern part of the state. Based on the stratigraphic column on the 1967 paper map, the Silurian is about 50% limestone and 50% dolomite. Sedimentary > Carbonate > DolostoneThe Silurian consists of the following formations: Moccasin Springs Limestone, St. Clair Limestone, Sexton Creek, Limestone, and Edgewood Limestone, Racine Dolomite, Waukesha Dolomite, Joliet Dolomite, Kankakee Dolomite, Edgewood Dolomite. The dolomite units occur in the northern part of the state and the limestone units occur in the southern part of the state. Based on the stratigraphic column on the 1967 paper map, the Silurian is about 50% limestone and 50% dolomite.
Map references	Willman, H.B., and others, (compilers), 1967, Geologic Map of Illinois: Illinois State Geological Survey, scale= 1:500,000, paper.
Unit references	Willman, H.B., and others, (compilers), 1967, Geologic Map of Illinois: Illinois State Geological Survey, scale= 1:500,000, paper.
Geographic coverage	Alexander - Boone - Bureau - Calhoun - Carroll - Champaign - Cook - DeKalb - Douglas - DuPage - Ford - Greene - Henry - Iroquois - Jersey - Jo Daviess - Kane - Kankakee - Kendall - Lake - Lee - Livingston - McHenry - Ogle - Pike - Rock Island - Scott - Stephenson - Union - Whiteside - Will