| Geological formation|
| Sandy marl|
E. H. Sellards, 1912
| St. Johns—Palm Beach County|
The Anastasia Formation is a geologic formation deposited in Florida during the Late Pleistocene epoch.
Anastasia Formation Wikipedia
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
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.
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.