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Microstructures in relation to temperature-induced aragonite-to-calcite transformation in the marine gastropod Phorcus turbinatus

Mollusk shells represent important archives for paleoclimatic studies aiming to reconstruct environmental conditions at high temporal resolution. However, the shells, made of calcium carbonate in the form of aragonite and /or calcite, can be altered through time which may undermine the suitability f...

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Detalles Bibliográficos
Autores principales: Milano, Stefania, Nehrke, Gernot
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6192573/
https://www.ncbi.nlm.nih.gov/pubmed/30332413
http://dx.doi.org/10.1371/journal.pone.0204577
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author Milano, Stefania
Nehrke, Gernot
author_facet Milano, Stefania
Nehrke, Gernot
author_sort Milano, Stefania
collection PubMed
description Mollusk shells represent important archives for paleoclimatic studies aiming to reconstruct environmental conditions at high temporal resolution. However, the shells, made of calcium carbonate in the form of aragonite and /or calcite, can be altered through time which may undermine the suitability for any reconstruction based on geochemical proxies (i.e., stable isotopes, radiocarbon). At present, the diagenetic processes involved in this chemical and physical deterioration are still poorly understood. The present study aims to shed light on the onset and development of diagenetic alteration in the aragonitic shell of Phorcus turbinatus. To artificially mimic diagenesis, shells of P. turbinatus were exposed to elevated temperatures. The transformation of the mineral phase was monitored by means of Confocal Raman Microscopy whereas the structural changes were investigated using Scanning Electron Microscopy and Atomic Force Microscopy. The results indicate that the two distinct shell layers (prismatic layer and nacre) respond differently to the elevated temperatures, suggesting that the different microstructural organization and organic content may drive the onset and spread of the aragonite-to-calcite transformation. Furthermore, changes in the microstructural arrangement became visible prior to the mineralogical transition. Our results demonstrate that the specific physico-chemical characteristics of structurally different areas within the biogenic carbonates have to be taken into account when studying the phase transformation occurring during diagenesis.
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spelling pubmed-61925732018-11-05 Microstructures in relation to temperature-induced aragonite-to-calcite transformation in the marine gastropod Phorcus turbinatus Milano, Stefania Nehrke, Gernot PLoS One Research Article Mollusk shells represent important archives for paleoclimatic studies aiming to reconstruct environmental conditions at high temporal resolution. However, the shells, made of calcium carbonate in the form of aragonite and /or calcite, can be altered through time which may undermine the suitability for any reconstruction based on geochemical proxies (i.e., stable isotopes, radiocarbon). At present, the diagenetic processes involved in this chemical and physical deterioration are still poorly understood. The present study aims to shed light on the onset and development of diagenetic alteration in the aragonitic shell of Phorcus turbinatus. To artificially mimic diagenesis, shells of P. turbinatus were exposed to elevated temperatures. The transformation of the mineral phase was monitored by means of Confocal Raman Microscopy whereas the structural changes were investigated using Scanning Electron Microscopy and Atomic Force Microscopy. The results indicate that the two distinct shell layers (prismatic layer and nacre) respond differently to the elevated temperatures, suggesting that the different microstructural organization and organic content may drive the onset and spread of the aragonite-to-calcite transformation. Furthermore, changes in the microstructural arrangement became visible prior to the mineralogical transition. Our results demonstrate that the specific physico-chemical characteristics of structurally different areas within the biogenic carbonates have to be taken into account when studying the phase transformation occurring during diagenesis. Public Library of Science 2018-10-17 /pmc/articles/PMC6192573/ /pubmed/30332413 http://dx.doi.org/10.1371/journal.pone.0204577 Text en © 2018 Milano, Nehrke http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Milano, Stefania
Nehrke, Gernot
Microstructures in relation to temperature-induced aragonite-to-calcite transformation in the marine gastropod Phorcus turbinatus
title Microstructures in relation to temperature-induced aragonite-to-calcite transformation in the marine gastropod Phorcus turbinatus
title_full Microstructures in relation to temperature-induced aragonite-to-calcite transformation in the marine gastropod Phorcus turbinatus
title_fullStr Microstructures in relation to temperature-induced aragonite-to-calcite transformation in the marine gastropod Phorcus turbinatus
title_full_unstemmed Microstructures in relation to temperature-induced aragonite-to-calcite transformation in the marine gastropod Phorcus turbinatus
title_short Microstructures in relation to temperature-induced aragonite-to-calcite transformation in the marine gastropod Phorcus turbinatus
title_sort microstructures in relation to temperature-induced aragonite-to-calcite transformation in the marine gastropod phorcus turbinatus
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6192573/
https://www.ncbi.nlm.nih.gov/pubmed/30332413
http://dx.doi.org/10.1371/journal.pone.0204577
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