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Anastasia Formation

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Type  Geological formation
Country  United States
Region  South Florida
Named for  Anastasia Island
Other  Sandy marl
Named by  E. H. Sellards, 1912
Primary  Coquina
Anastasia Formation wwwgeologicallocationscomassetsphotosanastasi
Extent  St. Johns—Palm Beach County

Anastasia formation 04 08 13


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

Contents

Age

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

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.

Composition

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. 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. 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.

References

Anastasia Formation Wikipedia


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