RADIOCARBON PROTOCOLS AND FIRST INTERCOMPARISON RESULTS FROM THE CHRONOS ¹⁴CARBON-CYCLE FACILITY, UNIVERSITY OF NEW SOUTH WALES, SYDNEY, AUSTRALIA

Abstract

The Chronos 14Carbon-Cycle Facility is a new radiocarbon laboratory at the University of New South Wales, Australia. Built around an Ionplus 200 kV MIni-CArbon DAting System (MICADAS) Accelerator Mass Spectrometer (AMS) installed in October 2019, the facility was established to address major challenges in the Earth, Environmental and Archaeological sciences. Here we report an overview of the Chronos facility, the pretreatment methods currently employed (bones, carbonates, peat, pollen, charcoal, and wood) and results of radiocarbon and stable isotope measurements undertaken on a wide range of sample types. Measurements on international standards, known-age and blank samples demonstrate the facility is capable of measuring 14C samples from the Anthropocene back to nearly 50,000 years ago. Future work will focus on improving our understanding of the Earth system and managing resources in a future warmer world.

The Application of Pollen Radiocarbon Dating and Bayesian Age-Depth Modeling for Developing Robust Geochronological Frameworks of Wetland Archives

“…The pollen extraction method is summarised in Figure 2. Pollen processing was completed at Chronos, UNSW, following laboratory protocols outlined in Turney et al (2021). Sediment sub-samples were initially dispersed in Milli-Q ® water for 1 hr and mixed with a vortex mixer prior to sieving through a 100 μm pluriStrainer sieve.…”

“…Finally, 1 M HCl was added to each sample and heated for 1 hr at 80ºC. Bulk sediment from Lake Werri Berri and the >100 μm fraction from Welsby Lagoon were pre-treated using standard Acid-Base-Acid (ABA) procedures outlined in Turney et al (2021), yielding a humin fraction. A large charcoal fragment was identified during sieving of the sample at 570 cm depth from Welsby Lagoon.…”

“…A total of 56 14 C samples were pre-treated, graphitised, and measured at the Chronos Facility at the UNSW (Tables 1 and 2). All pre-treated samples were graphitised with an AGE3 system (Ionplus, Switzerland), whereby samples were combusted in an Elemental Analyser with resulting CO 2 passed through a zeolite trap and reduced to graphite with hydrogen over an iron catalyst (Turney et al 2021;Wacker et al 2010). 14 C measurement was undertaken using a MICADAS (Ionplus, Switzerland) accelerator mass spectrometer (Wacker et al 2010), following Turney et al (2021).…”

“…All pre-treated samples were graphitised with an AGE3 system (Ionplus, Switzerland), whereby samples were combusted in an Elemental Analyser with resulting CO 2 passed through a zeolite trap and reduced to graphite with hydrogen over an iron catalyst (Turney et al 2021;Wacker et al 2010). 14 C measurement was undertaken using a MICADAS (Ionplus, Switzerland) accelerator mass spectrometer (Wacker et al 2010), following Turney et al (2021). Table 1 Radiocarbon ages of the different sediment fractions from Lake Werri Berri analyzed in this study.…”

What lies behind radiocarbon intercomparisons and the design of the new intercomparison, GIRI?

“…We have chosen 6 examples of intercomparisons to illustrate their function and diversity. In the first case, an intercomparison was used as part of the commissioning of a new laboratory to allow an evaluation of performance [12]. The second and third examples focus on a specific material, namely bone [13,14], while a fourth study looks at remeasuring of original materials in an evaluation of historical dates made in the late 1940s [14].…”