Optical dating of the anastasia formation, northeastern florida, USA

The single-aliquot regenerative-dose (SAR) procedure was used to obtain optically stimulated luminescence ages to determine the depositional age of the upper part of the Anastasia Formation. This unit, which crops out along the east coast of Florida, is one of the most culturally and economically important coquina deposits in North America. Rock samples from the upper three meters of exposure at three locations were collected. Additional materials for paleontological analysis were also taken. Based on our samples, the luminescence ages of the Anastasia Formation are well within marine isotope stage 5, which is supported by the results of Osmond et al. (1970) based on U/Th ages. The associated fossil assemblages support our luminescence age determinations. Associated fossils fall within the Rancholabrean North American Land Mammal Age (300 10 ka) and the fossil mollusk assemblage consists entirely of modern species.