Radiocarbon-calibrated multiple amino acid geochronology of Holocene molluscs from Bramble and Rib Reefs (Great Barrier Reef, Australia)

Matthew A. Kosnik, Darrell S Kaufman, Quan Hua

Research output: Contribution to journalArticle

24 Scopus citations


Calibrated amino acid racemisation methods allow paleobiologists to quantify the age distributions of fossil assemblages. Focussing on 110 Scissulina dispar and 110 Liloa sp. specimens collected from Bramble and Rib Reefs (central Great Barrier Reef, Australia), we create calibration curves for seven amino acids for each taxon. Using these curves we calculate seven quasi-independent age estimates for each specimen. We evaluate each calibration curve for consistency and use the weighted mean and uncertainty of the quasi-independent ages as the specimen age for geochronological analyses. We extend the ". Y" criterion for screening specimens and describing the precision of an AAR dataset from two amino acids to any number of amino acids. Using weighted mean ages and Y < 0.2 we demonstrate that the top 1.4 m of Bramble and Rib Reefs preserve remarkably well-mixed shell assemblages spanning from living to ∼3400 years old with median ages of 373 and 326 years old, respectively.

Original languageEnglish (US)
Pages (from-to)73-86
Number of pages14
JournalQuaternary Geochronology
StatePublished - Apr 2013



  • Amino acid geochronology
  • Carbon-14
  • Carbonate sediments
  • Holocene
  • Mollusca
  • Time-averaging

ASJC Scopus subject areas

  • Geology
  • Earth and Planetary Sciences (miscellaneous)
  • Stratigraphy

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