Characteristics of the burial environment related to quartz SAR-OSL dating at St. Vincent Island, NW Florida, USA

Abstract

St. Vincent Island, on the northwest Gulf coast of Florida, USA, preserves a well-developed beach ridge plain that began to form ∼4000 years ago based on inferred ages of pottery artefact assemblages. Seven vibra cores up to 2.88 m in length (uncompacted sediment) were retrieved from six ridges across the island. The single-aliquot regenerative-dose (SAR) procedure was used to obtain two optically stimulated luminescence (OSL) ages per core at different depths within each core. The geographically youngest ridges gave ages of 370±50–1900±300 years, yielding an inter-ridge accumulation time of ∼150 years assuming uniform sediment accumulation. The oldest ridge sets yielded ages of 2700±400–2800±300 years. Dating results are evaluated in terms of equivalent dose ( D E) distributions and other characteristics in relation to aspects of the burial environment, including pedogenesis.