Compound-Specific ¹⁴C Dating of IODP Expedition 318 Core U1357A Obtained Off the Wilkes Land Coast, Antarctica

Abstract

This study applied compound-specific radiocarbon analysis (CSRA) to a 186-m-long sediment core (U1357A) taken from Adélie Basin located on the continental shelf off Wilkes Land, East Antarctica. The CSRA targeted C 16 fatty acid as well as C 16 ., fatty acid and cyclopheophorbide- a -enol isolated from the sediment. Due to their high degradation rate, these compounds are expected to occur in low abundances in relict organic matter deposited at this site. Twelve compound-specific (CS) 14 C ages were obtained that are mostly consistent with their stratigraphic order. The CS 14 C results of all samples are Holocene in age (9800 to 440 cal BP). These results suggest that significant sedimentation started ∼10,000 cal BP. Moreover, the data suggest that 14 C measurements of C 16:1 fatty acid and cyclopheophorbide- a -enol are useful for dating sediments from the Southern Ocean.