home   Printer friendly version Add to site
Advanced search
Time & Space Fossil Gallery Famous Flora & Fauna
Careers Resources K-12 Collections PaleoPeople

Louisiana, US



Choose a time period:

Dates (mya)
Time Scale Legend

State Fossil:
State fossil from Louisiana

During the Oligocene (~ 33-23 million years ago), forests and swamps covered the northern half of the state. When these “palm” trees died and were buried, silica in the water gradually replaced the organic matter, leaving the original wood preserved as a glassy rock.

Search the fossil gallery

Paleontology and geology

The Precambrian: There are no Precambrian rocks known from Louisiana. Louisiana, as such, did not exist until later, when North and South America separated during the breakup of Pangea.

The Paleozoic: Paleozoic rocks older than the Devonian appear to be absent from Louisiana, even in the subsurface. Any sediment that might have accumulated in the marine environment that occupied this region from the mid-Cambrian through the Silurian has been pushed north and out of the state by later mountain building. Devonian and Carboniferous rocks are present well below the surface, but are primarily igneous and metamorphic. Gravels brought down into Louisiana by rivers and streams contain molds of molluscs, crinoids, brachiopods, and trilobites of Late Paleozoic age, indicating that shallow seas covered the general area at this time.

The Mesozoic: Shallow seas covered Louisiana throughout the Mesozoic. The Gulf of Mexico began to develop as the supercontinent of Pangea split apart, forming a sea with restricted flow to the main ocean. Evaporation rates were high, particularly during the Jurassic, and thick layers of salt formed on the sea floor. Most Mesozoic units are known only from drill cores; however, a few Cretaceous outcrops exist and shark teeth have been recovered from these.

The Cenozoic: Cenozoic deposits cover most of Louisiana. These deposits were formed as the sea advanced and retreated several times during this interval, producing a complex interfingering of marine and non-marine beds. Over the course of the Cenozoic, the state was built farther and farther out into the widening Gulf of Mexico, providing large areas of coastal plain habitat for camels, mastodons, and other mammals.

Links to more on Louisiana paleontology



Museums (showing 1 of 1 listings)

Louisiana Museum of Natural History: Information on visiting the museum, along with links to the museum's collections databases.

top Top of List

Government Agencies (showing 1 of 1 listings)

Louisiana Geological Survey: Homepage for the Louisiana Geological Survey, with information on the state's geology and geological resources of economic importance.

top Top of List

Texas State Map
Mississippi State Map
Arkansas State Map