Exploring Georgia's Fossil Record & Our History of Paleontology
  • Items of Interest
    • Presentation; Oaky Woods Stratigraphy
    • I, Periarchus (A Fossil's Tale)
    • Coastal Plain Correlation Chart
    • Black & White Sketches
    • Contributing Artists
    • Public Fossil Locations >
      • South Houston County Fossils
      • Updated; Islands of the Savannah River
    • Georgia's Amateurs >
      • Amateur; Jared Dyche, On The Way To A Degree
      • Cam Muskelly, Duluth, GA
      • Kyle Keller, Valdosta, GA >
        • Kyle Keller Returns, Still Rocking!
      • Hank Josey, Dublin
      • Thomas Thurman, Warner Robins, GA
      • Bill Christy; Kamin Performance Minerals Fossils
    • Origins Of This Site
    • Georgia Fossils in the Smithsonian
  • Education Material
    • Georgia's State Fossil; Shark Teeth
    • Taking Georgia's Paleontology To Georgia's Classrooms
    • Georgiacetus Presentation; A Whale for Georgia
    • SW GA RESA 2018 Talk
    • Library & School Presentations
    • An Introduction To Fossils; Presentation
    • Georgia's Fossils Presentation; 500 million years
    • Free Fossils for GA Science Teachers; Crassostrea gigantissima
    • Georgia College Natural History Museum
  • Georgia's Lost Meteorite
  • Evolution in Georgia's Fossil Record
  • 1: Georgia's Oldest Fossils; Archaeocyathids, At 513 Million Years Old
  • 2: Trilobites; 500 Million Years Ago
    • 2A; Murray County Stromatolites
    • 2B; A Trilobite Nest in Georgia
  • 3: Geologic Time
  • 4: Our Oldest Vertebrate?
  • 5: Georgia Before the Dinosaurs
    • 5A; Georgia’s Pennsylvanian Plant Fossils
  • 6: 200 Million Years Ago
    • 6A: Birth of the Atlantic Ocean
  • 7: Cretaceous Georgia, Dinosaurs & more
    • 7A: Georgias Pterosaur
    • 7B: So Many Sharks
    • 7C: Coelecanths
    • 7D: Xiphactinus vetus
    • 7E: Side-necked turtles
    • 7F: Marine Reptiles
    • 7G: Dinosaurs in Georgia
    • 7H: Deinosuchus (Terrible Crocodile)
    • 7I; The Blufftown Formation
  • 8: Suwannee Current, Gulf Trough, & Bridgeboro Limestone
  • 9: The Clayton Formation Report; By Hank Josey
    • 9A: The Georgia Turtle
  • 10: The Eocene; Georgia's Oldest Mammals
    • 10A: The Origins of Whales
  • 11: A Whale For Georgia
  • 12: Basilosaurids; The First Modern Whales
    • 12A: Basilosaurus cetoides
    • 12B: Basilotritus
    • 12C: Cynthiacetus
    • 12D: Chrysocetus
    • 12E: The Redmond Mandible of Albany Ga
    • 12F; Houston County Basilosaurus to the Smithsonian
  • 13: Ziggy and The Museum of Arts & Sciences, Macon, GA
  • 14: Late Eocene
    • 14A: Eocene Fossils & Stratigraphy
    • 14B; Fossils, Impacts & Tektites Dating the Clinchfield Formation
    • 14C: The Tivola Limestone
    • 14D: Twiggs Clay Vertebrates
    • 14E: Ocmulgee Formation Vertebrates
    • 14F; Sandersville Limestone, By Hank Josey
    • 14I: Dating Late Eocene Sediments
    • 14J: Georgia's Tektites; Georgiaites
    • 14K; Shell Bluff; Georgia's Most Historic Paleontology Site
    • 14L; Taylors Bluff, Paleo Paddling the Ocmulgee River
    • 14M; Eocene Terrestrial Mammals From Gordon, GA
    • 14N: Fossil Ridge, A Stratigraphic Study in Oaky Woods Wildlife Management Area
    • 14O; Georgia's First Entelodont
  • 15: Early Oligocene
    • 15A: The Marianna Limestone
    • 15B; The Glendon Limestone
    • 15C: Undiffereniated Oligocene Residuum
    • 15D; Brissus bridgeboroensis; A New Echinoid Species From Georgia’s Bridgeboro Limestone
    • 15E: The Curious Steinkern Sea Biscuits of Red Dog Farm Road
  • 16: Bonaire GA Entelodont
  • 17: The Whale Eating Shark
  • 18: Miocene Epoch; 23.3 to 5.3 Million Years Ago
    • 18A; Miocene Terrestrial Vertebrates
    • 18B; Paul Fell, Rockhouse Cave
  • 19: Pliocene Epoch; 5.3 to 2.5 Million years Ago
  • *NEW* 19A; Two Small Primitive Horses from Taylor County
  • 20: The Ice Ages; Pleistocene & Holocene Epochs
    • 20A; Clark Quarry's Mammoths & Bison
    • 20B: Pleistocene Vertebrate List
    • 20C: Georgia’s Eolian Dunes
    • 20D: Georgia’s Carolina Bays
    • 20E: Late Pleistocene Significant Events
    • 20F: Southeastern Thermal Enclave
    • 20G; Diamond Back Terrapins
    • 20H; A Kaolin Mine Beaver Dam
    • 20I; Pleistocene Vertebrate Fossils On Georgia’s Piedmont
  • *NEW* 20J; Watkins Quarry Pleistocene Vertebrates, Glynn County, GA
  • 21: Humans in Georgia
  • 22: Geology of the Coastal Plain, 1911
    • 22A: 1911 Cretaceous Fossil Locations
    • 22B: 1911 Eocene Fossil Locations
  • 23: Coastal GA Locations (1957)
  • 24: Needed; The Georgia Geologic Survey
15: The Early Oligocene Sediments
​ 33.9 Million Years Ago
The Oligocene Epoch covers 33.9 to 23.03 million years ago.
It breaks down into two stages.
​

Late Oligocene
​     Chattian Stage (Chikcasawhayan) 28.4 to 23.03 mya

Early Oligocene
     Rupelian Stage (Vicksburgian); 33.9 to 28.4 mya 
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​The long, warm Eocene Epoch ended with a glacial event which saw a sea level drop of approximately 55 meters or 180 feet, this unfolded over roughly a two-million-year period. Coastlines retreated from near the Fall Line to the Continental Shelf and a global extinction event occurred.

In Europe this is known as the Grand Coupure, and though moderate by the standards of previous extinction events there was a major turnover in animal and plant species, and this hit freshwater and marine systems hard. Mammals also took some big hits. Many warm climate mammals, including the basilosaurids and brontotheres, met extinction. This allowed cold adapted mammals to become established and diversify.
 
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​We’ve looked at the roughly 34 million year old The Late Eocene Ocmulgee Formation and Tobacco Road Sand in Houston County’s Oaky Woods Wildlife Management Area (See Section 13G of this site) which represents a barrier island environment at the very end of the Eocene Epoch, just before the extinction event.

 
Now we’ll look at Georgia’s fossil record after the extinction event. At 33.9 million years ago the glaciation ended, the global climate warmed again and sea levels ramped up to near previous coastlines. Research shows that coastlines during the Early Oligocene stood well north of the Fall line in western Georgia and at or just south of the Fall line in eastern Georgia.  This return of sea levels marks the opening of the Oligocene Epoch.
 
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  ​
​As the lead Coastal Plain researcher for the Georgia Geologic Survey, Paul F. Huddlestun published an in-depth report over the Oligocene in 1993. (1)

He established the Vicksburgian Group of sediments based on the presence of index fossils restricted to the Early Oligocene. The Vicksburgian Group is diverse in both character and depositional environments but tells us a great deal about the extent and character of sediments after the 
Grand Coupure.
 
Early Oligocene, Rupelian (Vicksburgian) Stage Index Fossils
Clypeaster rogersi
Paraster americanus
Chlamys anatipes
Chamlys duncanensi
Lepidocyclina mantelli 
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References
The Oligocene, A Revision of the Lithostratigraphic Units of the Coastal Plain of Georgia; Paul F. Huddlestun, Bulletin 105, Georgia Geologic Survey, 1993

​Stratigraphic, Paleontology, and Economic Geology of Portions of Perry and Cochran Quadrangles, Georgia; Sam M. Pickering, Bulletin 81, Georgia Geologic Survey, 1970