The Dubuque Formation is a geologic formation in Illinois, Iowa, Wisconsin and Minnesota. It preserves fossils dating back to the Ordovician period.
See also
References
|
---|
Ph | Cz | Q |
- Glacial and post-glacial unconsolidated deposits
|
---|
|
---|
Mz | K | Upper |
- unnamed Upper? Cretaceous formations, western and southeastern Minnesota
|
---|
|
---|
|
---|
Pz | |
---|
|
---|
pЄ | |
---|