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

doi:10.1016/j.quageo.2014.09.003

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 journal › Article › peer-review

Abstract

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 language	English
Pages (from-to)	49-65
Number of pages	17
Journal	Quaternary Geochronology
Volume	25
Early online date	10 Sept 2014
DOIs	https://doi.org/10.1016/j.quageo.2014.09.003
Publication status	Published - 2015

Keywords

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

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10.1016/j.quageo.2014.09.003

Cite this

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

abstract = "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. ",

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

author = "Beatrice Demarchi and Emily Clements and Mauro Coltorti and {Van De Locht}, Renee and Roland Kr{\"o}ger and Penkman, {Kirsty Elizabeth Helena} and James Rose",

year = "2015",

doi = "10.1016/j.quageo.2014.09.003",

language = "English",

volume = "25",

pages = "49--65",

journal = "Quaternary Geochronology",

issn = "1871-1014",

publisher = "Elsevier",

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T1 - Testing the effect of bleaching on the bivalve Glycymeris

T2 - a case study of amino acid geochronology on key Mediterranean raised beach deposits

AU - Demarchi, Beatrice

AU - Clements, Emily

AU - Coltorti, Mauro

AU - Van De Locht, Renee

AU - Kröger, Roland

AU - Penkman, Kirsty Elizabeth Helena

AU - Rose, James

PY - 2015

Y1 - 2015

N2 - 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.

AB - 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.

KW - Intra-crystalline protein geochronology

KW - (IcPD) / amino acid racemisation (AAR)

KW - Mediterranean

KW - Raised beaches

KW - Glycymeris

KW - SEM

KW - Raman spectroscopy

KW - Last Interglacial

U2 - 10.1016/j.quageo.2014.09.003

DO - 10.1016/j.quageo.2014.09.003

M3 - Article

SN - 1871-1014

VL - 25

SP - 49

EP - 65

JO - Quaternary Geochronology

JF - Quaternary Geochronology

ER -