Oklahoma Geologic Map

Oklahoma resembles other midwestern states in having Paleozoic sedimentary rocks folded up against the ancient Appalachian mountain belt, only the mountain belt runs east-west. The small colorful areas in the south and the deeply folded area in the southeast are, from west to east, the Wichita, Arbuckle and Ouachita Mountains. These represent a western extension of the Appalachians that also appears in Texas.

The westward sweep of gray to blue represents sedimentary rocks of Pennsylvanian to Permian age, most of them laid down in shallow seas. In the northeast is part of the uplifted Ozark Plateau, which preserves older rocks of Mississippian down to Devonian age.

The strip of green in southernmost Oklahoma represents Cretaceous-age rocks from a later incursion of the sea. And in the western panhandle are still younger layers of rock debris that were shed from the rising Rockies in Tertiary time, after 50 million years ago. These have been eroded in more recent time to reveal deep-seated older rocks in the farthest west end of the state in the High Plains.

Learn much more about Oklahoma's geology at the Oklahoma Geological Survey site.

More about Oklahoma Geology

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