Testing the effect of bleaching on the bivalve Glycymeris: a case study of amino acid geochronology on key Mediterranean raised beach deposits

Beatrice Demarchi, Emily Clements, Mauro Coltorti, Renee Van De Locht, Roland Kröger, Kirsty Elizabeth Helena Penkman, James Rose

Research output: Contribution to journalArticlepeer-review


Part of an extensive assessment of the suitability of the Intra-crystalline protein diagenesis (IcPD) dating approach for classic shells used in classic amino acid racemisation (AAR) studies in the Mediterranean, this work focuses on the bivalve Glycymeris.
We present results obtained on both modern shells, artificially degraded at high temperature, and fossil shells from Last interglacial deposits in Sardinia (Calamosca), Mallorca (Palma Bay) and Tunisia (Hergla). We conclude that although bleaching is effective in isolating an intra-crystalline fraction of proteins, this may not behave as a closed system, as verified here in a number of fossil Glycymeris. High levels of natural variability certainly impact on time resolution, but we also want to draw attention to a fundamental methodological issue: dating the shells is not sufficient to distinguish the age of clearly different sedimentary units, but containing derived molluscan fauna.
Original languageEnglish
Pages (from-to)49-65
Number of pages17
JournalQuaternary Geochronology
Early online date10 Sept 2014
Publication statusPublished - 2015


  • Intra-crystalline protein geochronology
  • (IcPD) / amino acid racemisation (AAR)
  • Mediterranean
  • Raised beaches
  • Glycymeris
  • SEM
  • Raman spectroscopy
  • Last Interglacial

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