Type Formation Thickness 10 to 100 ft. Country United States Overlies Cape Formation | Underlies Thebes Formation Other Limestone Primary Slate | |
The Maquoketa Formation is a geologic formation in Illinois, Indiana. Iowa, Kansas, Minnesota, Missouri, and Wisconsin. It preserves mollusk, coral, brachiopod and graptolite fossils dating back to the Ordovician period.
References
Maquoketa Formation Wikipedia(Text) CC BY-SA