Anastasia Formation

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Anastasia Formation
Stratigraphic range: Late Pleistocene
Hutchinson Island FL Gilberts HoR beach07.jpg
Part of the formation on Hutchinson Island
Type Geological formation
Lithology
Primary Coquina, sand, sandy limestone
Other Sandy marl
Location
Region South Florida
Country  United States
Extent St. JohnsPalm Beach County
Type section
Named for Anastasia Island
Named by E. H. Sellards, 1912
Location of the Anastasia Formation (red) along the east coast of Florida.

The Anastasia Formation is a geologic formation deposited in Florida during the Late Pleistocene epoch.

Age[edit]

Period : Quaternary
Epoch: Pleistocene ~2.558 to 0.012 mya, calculates to a period of 2.576 million years
Faunal stage: Blancan through early Rancholabrean

Location[edit]

Anastasia Formation overlays The Atlantic Coastal Ridge along the coast from St. John's County southward to Palm Beach County and extends inland as far as 20 miles (32 kilometers) in St. Lucie and Martin County. Blowing Rocks Preserve in northern Palm Beach County is an exposed outcropping along the beach.[1][2]

Composition[edit]

The Anastasia Formation, named by E. H. Sellards in 1912, is composed of interbedded sands and coquina limestones. The formation is an orangish brown, soft to moderately hard, coquina of whole and fragmented mollusk shells within sand often cemented by sparry calcite.[3][4] Coquina obtained from this formation on Anastasia Island was used to construct Castillo de San Marcos during the late 17th century; a local material, it was relatively easy to quarry and proved to be effective for absorbing cannon damage.[5] Sands occur as fossil bearing light gray to tan as well as orangish brown, unconsolidated to moderately indurated. This formation is an integral part of the surficial aquifer system.[3][4]

References[edit]

  1. ^ The Nature Conservancy, Florida Preserves, Blowing Rocks
  2. ^ http://sofia.usgs.gov/publications/reports/mgs_lovejoy1998/ USGS Publications, Classic Exposures of the Anastasia Formation in Martin and Palm Beach Counties, Florida.
  3. ^ a b USGS Publications, Lithostratigraphic Units, Tertiary System, Pleistocene Series
  4. ^ a b Classic Exposures of the Anastasia Formation in Martin and Palm Beach Counties, Florida, Donald W. Lovejoy
  5. ^ Kenworthy, J. P.; Santucci, V. L. (2006). "A preliminary investigation of National Park Service paleontological resources in cultural resource contexts, Part 1: general overview" (pdf). In Lucas, S. G.; Spielmann, J. A.; Hester, P.M.; Kenworthy, J. P.; and Santucci, V. L. (editors). America’s antiquities: 100 years of managing fossils on federal lands. New Mexico Museum of Natural History and Science Bulletin 34. Albuquerque, NM: New Mexico Museum of Natural History and Science. pp. 70–76.