Paleontology and geology
The oldest rocks in Missouri are igneous and metamorphic rocks approximately 1.8 billion years old, found in the subsurface of northern Missouri. Slightly younger Precambrian rocks are exposed in the St. Francois Mountain area in the southeastern part of the state. These can be viewed at Elephant Rocks, Taum Sauk, and Johnson’s Shut-Ins State Parks. No fossils are known from these rocks.