Assessing Amino Acid Racemization Variability in Coral Intra-Crystalline Protein for Geochronological Applications
Available online at www.sciencedirect.com Geochimica et Cosmochimica Acta 86 (2012) 338–353 www.elsevier.com/locate/gca Assessing amino acid racemization variability in coral intra-crystalline protein for geochronological applications Erica J. Hendy a,b, Peter J. Tomiak a, Matthew J. Collins c, John Hellstrom d, Alexander W. Tudhope e, Janice M. Lough f, Kirsty E.H. Penkman c,⇑ a School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, United Kingdom b School of Biological Sciences, University of Bristol, Bristol, BS8 1UG, United Kingdom c BioArCh, Departments of Archaeology and Chemistry, University of York, York, YO10 5DD, United Kingdom d School of Earth Sciences, University of Melbourne, Melbourne, VIC 3010, Australia e School of GeoSciences, University of Edinburgh, Edinburgh EH9 3JW, UK f Australian Institute of Marine Science, PMB3, Townsville M.C., QLD 4810, Australia Received 12 September 2011; accepted in revised form 15 February 2012; available online 1 March 2012 Abstract Over 500 Free Amino Acid (FAA) and corresponding Total Hydrolysed Amino Acid (THAA) analyses were completed from eight independently-dated, multi-century coral cores of massive Porites sp. colonies. This dataset allows us to re-evaluate the application of amino acid racemization (AAR) for dating late Holocene coral material, 20 years after Goodfriend et al. (GCA 56 (1992), 3847) first showed AAR had promise for developing chronologies in coral cores. This re-assessment incor- porates recent method improvements, including measurement by RP-HPLC, new quality control approaches (e.g. sampling and sub-sampling protocols, statistically-based data screening criteria), and cleaning steps to isolate the intra-crystalline skel- etal protein.
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