Nebraska during the Cambrian Period
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Series 3 Epoch
At the start of the Cambrian Period, Precambrian basement rock is exposed and severely eroded, creating an unconformity and relatively flat surface upon which Cambrian rock is deposited. |
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Furongian Epoch
Shallow seas reach Nebraska by the late Cambrian, leaving behind a record of thin beach sand deposits (known as the La Motte Formation)
Atop these sandstones, carbonate rocks (Bonneterre Dolostone) were deposited from the latest Cambrian into the early Ordovician. |
The images above are Paleozoic paleogeographic maps of the central United States (from Dr. Ron Blakey- http://jan.ucc.nau.edu/~rcb7/ ) that are based on observations in the geologic record. Nebraska is outlined in yellow. Click HERE to visit Dr. Blakey's website to learn more about paleogeography and how the continents have changed position throughout geologic time.
| Cambrian and lower Ordovician rocks are thickest in eastern Nebraska and thin westward. They are absent in west-central Nebraska due to later erosion. |
**Image modified after Carlson, M.P., Geology, Geologic Time and Nebraska, Educational Circular No. 10, 1993, University of Nebraska-Conservation and Survey Division, 60p.
