Direct AMS 14C analysis of carbonate

Quan Hua, Vladimir Levchenko, Matthew Kosnik

    Research output: Contribution to journalConference paperpeer-review

    Abstract

    We have investigated the possibility of direct accelerator mass spectrometry radiocarbon (AMS 14C) measurement of carbonate samples at ANSTO using the STAR 2 MV tandem accelerator. Each carbonate sample was powdered, mixed with metal powder and pressed into an aluminum cathode for direct carbonate measurement by AMS 14C. Of the three high-purity metal powders (Fe, Nb, and Ag) used in our investigation, Nb was found to be the best metal, which delivered higher carbon beam currents and lower background. Beam currents for targets containing the optimal carbonate mass of 1.5–2.0 mg were ∼8% of those obtained from graphite targets of standard size (>0.5 mg C). Typical measured blank for Carrara marble (IAEA-C1) of ∼40 ka was obtained. Background-corrected 14C values of carbonate targets agreed well with their associated values obtained from high-precision analysis of graphite targets within 2σ uncertainties. Typical precision of this rapid AMS analysis was ∼1% for samples <8 ka. Despite lower precision for carbonate target ages (compared to standard graphite target ages), these ages are useful for palaeobiological applications where a large number of dates are required, such as time-averaging studies.
    Original languageEnglish
    Pages (from-to)1431-1440
    Number of pages9
    JournalRadiocarbon
    Volume61
    Issue number5
    Early online date15 Apr 2019
    DOIs
    Publication statusPublished - Oct 2019
    EventInternational Radiocarbon Conference (23rd : 2018) - Trondheim, Norway
    Duration: 17 Jun 201822 Jun 2018

    Keywords

    • carbonate
    • radiocarbon AMS dating
    • shells
    • Sydney Harbour
    • time-averaging

    Fingerprint

    Dive into the research topics of 'Direct AMS <sup>14</sup>C analysis of carbonate'. Together they form a unique fingerprint.

    Cite this