ADVANCING ANTARCTIC SEDIMENT CHRONOLOGY THROUGH COMBINED RAMPED PYROLYSIS OXIDATION AND PYROLYSIS-GC-MS

• DOI: 10.1017/rdc.2023.116
• Publication Date: 2024-02-08T09:18:42Z
• Authors: Catherine E Ginnane; Jocelyn C Turnbull; Sebastian Naeher; Brad E Rosenheim; Ryan A Venturelli; Andy M Phillips; Simon Reeve; Jeremy Parry-Thom...; Albert Zondervan; Richard H Levy; Kyu-Cheul Yoo; Gavin Dunbar; Theo Calkin; Carlota Escutia; Julia Gutierrez P...
• Keywords: Chronology; Accelerator mass spectrometry

ABSTRACT Radiocarbon ( 14 C) dating of sediment deposition around Antarctica is often challenging due to heterogeneity in sources and ages organic carbon the sediment. Chemical thermochemical techniques have been used separate when microfossils are not present. These generally improve on bulk dates, but they necessitate assumptions about age spectra specific molecules or compound classes chemical separations. To address this, Rafter Laboratory has established parallel ramped pyrolysis oxidation (RPO) pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) systems thermochemically distinct fractions, diagnose composition each fraction, target suitable RPO fractions for radiocarbon dating. Three case studies taken from locations presented demonstrate implementation combined RPO-AMS Py-GC-MS provide more robust determination detrital stratigraphy. three depositional environments good examples analytical interpretive challenges related oceanographic conditions, sources, other factors. Using analyses, we reduce number measurements required, minimize run times, context unexpected C ages, better support interpretations environmental reconstruction.