COMPOUND-SPECIFIC 14C DATING OF IODP EXPEDITION 318 CORE U1357A OBTAINED OFF THE WILKES LAND COAST, ANTARCTICA

This study applied compound-specific radiocarbon analysis (CSRA) to a 186-m-long sediment core (U1357A) taken from Ad lie Basin located on the continental shelf off Wilkes Land, East Antarctica. The CSRA targeted C-16 fatty acid as well as C-16:1 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) C-14 ages were obtained that are mostly consistent with their stratigraphic order. The CS C-14 results of all samples are Holocene in age (9800 to 440 cal BP). These results suggest that significant sedimentation started similar to 10,000 cal BP. Moreover, the data suggest that C-14 measurements of C-16:1 fatty acid and cyclopheophorbide-a-enol are useful for dating sediments from the Southern Ocean.