Exploring Georgia's Natural History
  • Natural History & Geology
    • Podcast; The Tivola Whale
    • Coastal Plain Correlation Chart
    • GA Paleo Research by Paul F. Huddlestun PhD >
      • Late Eocene & Older... Coastal Plain Stratigraphy
      • Washington County Core Logs By Paul Huddlestun
      • Coastal Plain Core Logs by Paul F. Huddlestun
    • Presentation; Oaky Woods Stratigraphy
    • Physiographic Map of Georgia
    • Fossils of Oaky Woods
    • Collections & Stewardship of Georgia’s Fossils
    • I, Periarchus (A Fossil's Tale)
    • 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
      • Bill Christy; Kamin Performance Minerals Fossils
    • Public Fossil Locations >
      • South Houston County Fossils
      • Updated; Islands of the Savannah River
    • Georgia Fossils in the Smithsonian
  • Education Material
    • My Field Kit; What You Need In The Field
    • Meet Crassostrea gigantissima, Georgia's Historic Giant Oyster
    • Georgiacetus Presentation; A Whale for Georgia
    • The Natural History & Fossils Record of Houston County, GA
    • Evolution in Georgia's Fossil Record
    • Georgia's State Fossil; Shark Teeth
    • Georgia's Paleontology For Georgia's Classrooms
    • SW GA RESA 2018 Talk
    • Library & School Presentations
    • An Introduction To Fossils; Presentation
    • Georgia's Fossils Presentation; 500 million years
    • Georgia College Natural History Museum
  • Meteorites
    • Did I Find A Meteorite?
    • Georgia's Lost Meteorite
    • Georgia's Witnessed Meteorite Falls
    • The Sardis Iron, Georgia's Largest Meteorite
  • 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
    • 5B: Carpentertypus durhami, Georgia’s Giant Insect, 315 Million Years Ago
  • 6: 200 Million Years Ago
    • 6A: Birth of the Atlantic Ocean
  • 7: Cretaceous Georgia, Dinosaurs & more
    • 7A: Georgias Pterosaur
    • 7C: Coelecanths
    • 7B: So Many Sharks
    • 7D: Xiphactinus vetus
    • 7E: Side-necked turtles
    • 7F: Marine Reptiles
    • 7G: Dinosaurs in Georgia
    • 7I; The Blufftown Formation
    • 7L: Bill Montante's Mega "Gator" Tooth Discovery
    • 7K: The Pio Nono Formation
    • 7J: The Eutaw Formation
    • 7H: Deinosuchus schwimmeri in Recognition of Dr. David Schwimmer
  • 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 (Revised)
    • 12D: Chrysocetus
    • 12E: The Redmond Mandible of Albany Ga
    • 12F; Houston County, GA 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
    • 14F; Sandersville Limestone, By Hank Josey
    • 14E: Ocmulgee Formation Vertebrates
    • 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
    • 14P: Historic Rich Hill
    • 14Q; Bibb County's Christy Hill, Clinchfield Formation Hilltop
  • 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
    • 15F: Early Oligocene Gordian Knot
  • 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
    • 18C: The Marks Head Formation
    • 18D: Miocene Terrestrial Vertebrates of the Marks Head Formation
    • 18E: The Statenville Formation
    • 18F: South Georgia’s Dugong Metaxytherium calvertense
  • 19: Pliocene Epoch; 5.3 to 2.5 Million years Ago
    • 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
    • 20J; Watkins Quarry Pleistocene Vertebrates, Glynn County, GA
  • *NEW* 20K: Pleistocene Vertebrates from Coastal Georgia
  • 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
  • Building This Site
    • Origins Of This Site
    • Contributing Artists
    • Black & White Sketches


​20C: Georgia’s Eolian Dunes

​By Thomas Thurman


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Along the north-eastern banks of many of South Georgia’s rivers there are unusual arched or parabolic sand dune fields, the largest single dune is more than 30 meters (100 feet) high, runs for 7.25 kilometers (4.5 miles) along the river and extends for a width 3.2 kilometers (2 miles) away from the river. 

Along the Ohoopee River they form a continuous chain of sand dunes more than 80 kilometers (50 miles) long. Composed entirely of sand, these are structures which speak of large scale erosion, deposition and wind. 

Crescent shaped, parabolic sand dunes are common in deserts like the Sahara, where there is an ample supply of both sand and wind, but to find them along rivers or streams in water rich parts of the world is very rare. 

Georgia is rich in such rare dunes.

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The parabolic shape is characteristic of a wind created dune, the term “eolian” means “carried or affected by the wind”. (Aeolian is also correct) The name originates from the Greek god of winds; Aeolus.

It would be strange enough if Georgia hosted just one set of such dunes, but where they do occur, they typically occur in sets. Additionally, they aren't along all Georgia rivers. This creates a need for an explanation.

There are series of dunes, varying in size and height, at different distances from a river, clearly showing multiple events of flooding at different levels. There is also stratification within the dunes, obvious evidence of multiple dune building episodes. 

In at least one case, the furthest dune is more than a mile away from the modern banks. 

There are multiple cases where one dune formed its arch, and at a later date a second dune in-filled the hollow of the arch to create a “D” shape.

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The dunes weren’t confirmed as eolian dune chains until the early 1970s when the first satellite images of Georgia became available to Georgia geologists. 

Arguments about their origins continued through the 1970s, 1980s and 1990s with speculations even suggesting that Georgia had been a desert during the glacial maximums and the dunes forming as they do today in the Sahara. 

This was quickly overturned as it was pointed out that if this was the case such dunes would occur everywhere on the Coastal Plain; they don't. 

As early as 1911 they were recognized as Pleistocene, or ice age, structures. Veatch and Stephenson reviewed several of them and concluded that the sand had likely been deposited during ice melt driven floods and the dunes formed at least partly by wind action afterwards; they were absolutely correct. (29)

In 2002 Andrew Ivester with the State University of West Georgia and David Leigh with the University of Georgia investigated several of these dune fields and concluded that they were evidence of repeated cycles of severe river flooding of glacial melt from the retreating glacial fields.

The flooding had been caused by extended torrential rains; the exact opposite of a desert. The torrential were a product of glacial melt, but not directly. The Appalachian Mountains stand between Georgia and the parts of North America once ruled by giant glaciers. Rather, the melting glaciers helped create contemporary monsoon-like weather patterns for Georgia.

It was these rains which eroded the sand and caused it to be deposited in the river beds.  

The sand originated from the weathering of mountains which had stood on Georgia’s Piedmont province, this became suspended in the fast flowing river floods of the flood plain. 

As the flooding abated, vast amounts of sand were left behind in the river beds. 

The sand, which has the consistency of sugar, drains water very quickly so it is difficult for plants to colonize and stabilizes the dunes. 

Even today only drought resistant plants tend to be seen on many of the dunes. Recurring dry seasons during the ice ages left the sand vulnerable to the prevailing east blowing winds which lifted the sand to form these dunes. 

Our strange eolian dunes tell us a little more about conditions in Georgia during the Pleistocene.