Improving the detection of shell alteration: implications for sclerochronology
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10773/37303 |
Resumo: | Sclerochronology makes use of (fossil) shell-archives to establish records allowing for investigation of high-resolution environmental dynamics. Nevertheless, this potential can often not be fully exploited due to the interplay between paleoenvironmental variability, vital effects and the potential diagenetic modification of skeletal materials, which often results in highly complex records. A novel dynamic approach, aiming to separate pristine from altered shell material for paleoclimate and paleoenvironmental reconstructions is proposed. Seventeen fossil bivalve shells (requieniid rudists, pectinids and chondrodonts) from two neighbouring Lower Cretaceous (Albian) shallow-water sections (Lusitanian Basin, western Portugal) were analysed for their major and trace elemental compositions using high-resolution quantitative μXRF line scans. Their complex records were subject to a novel statistical analysis protocol, which tested mono- and multi-species datasets, as well as comparing shells from both locations. Characteristic elemental associations reveal the differential impact of early and late diagenetic alteration processes. The incorporation of elements associated with detrital contribution (Fe, Si, Al) is attributed to syn-depositional bioerosion (shell-boring). In clear contrast, shell-portions showing a strong correlation between Fe and Mn are indicative of later diagenetic alteration. The influence of each process is different at each site, revealing local differential alteration pathways. Mono-specific comparisons provides identical geochemical responses, suggesting that intra-specific differences do not control the observed elemental patterns. In contrast, inter-species tests rendered a clear separation in the way elements are incorporated in the shells of pectinids and requieniids (e.g., as evidenced by differences in Mg or Sr content). Such differences can be linked to differential biomineralization pathways, easily detected by the applied method. We present a new, dynamic method for distinguishing pristine from altered shell material, not relying on arbitrary diagenetic thresholds for trace element content. By clearly identifying shell-alteration pathways, syn- to post-depositional processes are recognized. A progressive cleaning of the elemental dataset allows paleoenvironmental studies to be based on the most pristine data, contributing to unravelling the complex interplay between climate, environmental dynamics and their impact on biomineralization processes and sclerochronological archives. |
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Improving the detection of shell alteration: implications for sclerochronologyShellsGeochemistryDiagenesisStatistical analysisPaleoenvironmentSclerochronology makes use of (fossil) shell-archives to establish records allowing for investigation of high-resolution environmental dynamics. Nevertheless, this potential can often not be fully exploited due to the interplay between paleoenvironmental variability, vital effects and the potential diagenetic modification of skeletal materials, which often results in highly complex records. A novel dynamic approach, aiming to separate pristine from altered shell material for paleoclimate and paleoenvironmental reconstructions is proposed. Seventeen fossil bivalve shells (requieniid rudists, pectinids and chondrodonts) from two neighbouring Lower Cretaceous (Albian) shallow-water sections (Lusitanian Basin, western Portugal) were analysed for their major and trace elemental compositions using high-resolution quantitative μXRF line scans. Their complex records were subject to a novel statistical analysis protocol, which tested mono- and multi-species datasets, as well as comparing shells from both locations. Characteristic elemental associations reveal the differential impact of early and late diagenetic alteration processes. The incorporation of elements associated with detrital contribution (Fe, Si, Al) is attributed to syn-depositional bioerosion (shell-boring). In clear contrast, shell-portions showing a strong correlation between Fe and Mn are indicative of later diagenetic alteration. The influence of each process is different at each site, revealing local differential alteration pathways. Mono-specific comparisons provides identical geochemical responses, suggesting that intra-specific differences do not control the observed elemental patterns. In contrast, inter-species tests rendered a clear separation in the way elements are incorporated in the shells of pectinids and requieniids (e.g., as evidenced by differences in Mg or Sr content). Such differences can be linked to differential biomineralization pathways, easily detected by the applied method. We present a new, dynamic method for distinguishing pristine from altered shell material, not relying on arbitrary diagenetic thresholds for trace element content. By clearly identifying shell-alteration pathways, syn- to post-depositional processes are recognized. A progressive cleaning of the elemental dataset allows paleoenvironmental studies to be based on the most pristine data, contributing to unravelling the complex interplay between climate, environmental dynamics and their impact on biomineralization processes and sclerochronological archives.Elsevier2023-04-24T09:25:51Z2020-12-01T00:00:00Z2020-12-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10773/37303eng0031-018210.1016/j.palaeo.2020.109968Coimbra, RuteHuck, Stefande Winter, Niels J.Heimhofer, UlrichClaeys, Philippeinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-02-22T12:11:58Zoai:ria.ua.pt:10773/37303Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:07:55.493832Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Improving the detection of shell alteration: implications for sclerochronology |
title |
Improving the detection of shell alteration: implications for sclerochronology |
spellingShingle |
Improving the detection of shell alteration: implications for sclerochronology Coimbra, Rute Shells Geochemistry Diagenesis Statistical analysis Paleoenvironment |
title_short |
Improving the detection of shell alteration: implications for sclerochronology |
title_full |
Improving the detection of shell alteration: implications for sclerochronology |
title_fullStr |
Improving the detection of shell alteration: implications for sclerochronology |
title_full_unstemmed |
Improving the detection of shell alteration: implications for sclerochronology |
title_sort |
Improving the detection of shell alteration: implications for sclerochronology |
author |
Coimbra, Rute |
author_facet |
Coimbra, Rute Huck, Stefan de Winter, Niels J. Heimhofer, Ulrich Claeys, Philippe |
author_role |
author |
author2 |
Huck, Stefan de Winter, Niels J. Heimhofer, Ulrich Claeys, Philippe |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Coimbra, Rute Huck, Stefan de Winter, Niels J. Heimhofer, Ulrich Claeys, Philippe |
dc.subject.por.fl_str_mv |
Shells Geochemistry Diagenesis Statistical analysis Paleoenvironment |
topic |
Shells Geochemistry Diagenesis Statistical analysis Paleoenvironment |
description |
Sclerochronology makes use of (fossil) shell-archives to establish records allowing for investigation of high-resolution environmental dynamics. Nevertheless, this potential can often not be fully exploited due to the interplay between paleoenvironmental variability, vital effects and the potential diagenetic modification of skeletal materials, which often results in highly complex records. A novel dynamic approach, aiming to separate pristine from altered shell material for paleoclimate and paleoenvironmental reconstructions is proposed. Seventeen fossil bivalve shells (requieniid rudists, pectinids and chondrodonts) from two neighbouring Lower Cretaceous (Albian) shallow-water sections (Lusitanian Basin, western Portugal) were analysed for their major and trace elemental compositions using high-resolution quantitative μXRF line scans. Their complex records were subject to a novel statistical analysis protocol, which tested mono- and multi-species datasets, as well as comparing shells from both locations. Characteristic elemental associations reveal the differential impact of early and late diagenetic alteration processes. The incorporation of elements associated with detrital contribution (Fe, Si, Al) is attributed to syn-depositional bioerosion (shell-boring). In clear contrast, shell-portions showing a strong correlation between Fe and Mn are indicative of later diagenetic alteration. The influence of each process is different at each site, revealing local differential alteration pathways. Mono-specific comparisons provides identical geochemical responses, suggesting that intra-specific differences do not control the observed elemental patterns. In contrast, inter-species tests rendered a clear separation in the way elements are incorporated in the shells of pectinids and requieniids (e.g., as evidenced by differences in Mg or Sr content). Such differences can be linked to differential biomineralization pathways, easily detected by the applied method. We present a new, dynamic method for distinguishing pristine from altered shell material, not relying on arbitrary diagenetic thresholds for trace element content. By clearly identifying shell-alteration pathways, syn- to post-depositional processes are recognized. A progressive cleaning of the elemental dataset allows paleoenvironmental studies to be based on the most pristine data, contributing to unravelling the complex interplay between climate, environmental dynamics and their impact on biomineralization processes and sclerochronological archives. |
publishDate |
2020 |
dc.date.none.fl_str_mv |
2020-12-01T00:00:00Z 2020-12-01 2023-04-24T09:25:51Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10773/37303 |
url |
http://hdl.handle.net/10773/37303 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
0031-0182 10.1016/j.palaeo.2020.109968 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Elsevier |
publisher.none.fl_str_mv |
Elsevier |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
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1799137733192450048 |