| Salem Formation | |
| Type: | Formation |
| Age: | Mississippian |
| Period: | Mississippian |
| Prilithology: | Limestone |
| Namedfor: | Salem, Washington County, Indiana |
| Region: | Illinois, Indiana, Kentucky, and Missouri |
| Country: | United States |
| Unitof: | Sanders Group, Meramec Group |
| Underlies: | St. Louis Limestone |
| Overlies: | Harrodsburg Limestone[1] Warsaw Formation[2] |
The Salem Formation is a geologic formation in Illinois, Indiana, Kentucky, and Missouri. It preserves fossils dating back to the Mississippian subperiod. This formation is quarried and used as a building material, known as "Indiana limestone", also called Bedford limestone.