Radiocarbon dating of mangrove sediments

Radiocarbon dating is the most widely applied dating technique for understanding past mangrove environments and dynamics. Mangrove sediments contain an abundance of different carbon sources for radiocarbon dating. Creating reliable chronologies, however, is challenging, largely due to contamination from modern root systems. Radiocarbon ages derived from bulk sediments are difficult to link exactly to past environmental changes or events because they are mean ages of an unknown mix of carbon sources. Aboveground surface macrofossil samples and methods that concentrate specific size fractions (e.g., pollen concentrates) will likely provide more control on possible carbon sources and more reliable ages. Ultimately, it is important to carefully consider stratigraphy and likely depositional environments of mangrove sedimentary records to provide the necessary sample context.