Environmental processes in Rano Aroi (Ester Island) peat geochemistry forced by climate variability during the last 70 kyr

We analyze the geochemistry of Rano Aroi mire record (Easter Island) using bulk peat composition (C, N, S) and stable isotopes (δ13C, δ15N, δ34S) and major, minor and trace elemental compositions obtained by ICP-AES (Al, Ti, Zr, Sc, V, Y, Fe, Mn, Th, Ba, Ca,Mg and Sr). Peat geochemistry and the poll...

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Autores: Margalef Marrasé, Olga, Martínez-Cortizas, A., Kylander, M., Pla, S., Cañellas Boltà, Núria, Pueyo Mur, Juan José, Sáez, Alberto, Valero Garcés, Blas Lorenzo, Giralt Romeu, Santiago
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2014
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/59734
Acceso en línea:https://hdl.handle.net/2445/59734
Access Level:acceso abierto
Palabra clave:Paleoclimatologia
Polinèsia
Paleoclimatology
Polynesia
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spelling Environmental processes in Rano Aroi (Ester Island) peat geochemistry forced by climate variability during the last 70 kyrMargalef Marrasé, OlgaMartínez-Cortizas, A.Kylander, M.Pla, S.Cañellas Boltà, NúriaPueyo Mur, Juan JoséSáez, AlbertoValero Garcés, Blas LorenzoGiralt Romeu, SantiagoPaleoclimatologiaPolinèsiaPaleoclimatologyPolynesiaWe analyze the geochemistry of Rano Aroi mire record (Easter Island) using bulk peat composition (C, N, S) and stable isotopes (δ13C, δ15N, δ34S) and major, minor and trace elemental compositions obtained by ICP-AES (Al, Ti, Zr, Sc, V, Y, Fe, Mn, Th, Ba, Ca,Mg and Sr). Peat geochemistry and the pollen record are used to reconstruct the environmental changes during the last 70 kyr BP. Principal component analysis on ICP-AES data revealed that three main components account for the chemical signatures of the peat. The first component, characterized by lithogenic elements (combined signal of V, Al, Sc, Y, Cr, Cd, Ti, Zr and Cu), evidences long-term changes in the basal fluxes of mineralmaterial into themire. This component, in combination with stable isotopes and pollen data suggests a link between soil erosion and vegetation cover changes in the Rano Aroiwatershed. The second component is identified by the signal of Fe, Mn, Th, Ba, Zr and Ti, and is indicative of strong runoff events during enhanced precipitation periods. The third component (tied mainly to Ca, Sr and Mg) reflects a strong peat oxidation event that occurred during an arid periodwithmore frequent droughts, sometime between 39 and 31 kyr BP. Correlation coefficients and a multiple regression model (PCR analysis) between peat organic chemistry and the principal components of ICP-AES analysis were calculated. Isotope chemistry of the peat organic matter further contributes to define Rano Aroi environmental history: δ13C data corroborates a vegetation shift documented by the palynological record from C4 to C3 between 55 and 45 cal kyr BP; the δ15N record identifies periods of changes in mire productivity and denitrification processes, while the δ34S peat signature indicates a marine origin of S and significant diagenetic cycling. The geochemical and environmental evolution of Rano Aroi mire is coherent with the regional climatic variability and suggests that climate was the main forcing in mire evolution during the last 70 kyr BP. The coupling of geochemical and biological proxies improves our ability to decipher depositional processes in tropical and subtropical peatlands and to use these sequences for paleoenvironmental and paleoclimate reconstructions.Elsevier B.V.2014info:eu-repo/semantics/articleinfo:eu-repo/semantics/acceptedVersionapplication/pdfhttps://hdl.handle.net/2445/59734Articles publicats en revistes (Dinàmica de la Terra i l'Oceà)reponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaInglésVersió postprint del document publicat a: http://dx.doi.org/10.1016/j.palaeo.2014.09.025Palaeogeography Palaeoclimatology Palaeoecology, 2014, vol. 414, p. 438-450http://dx.doi.org/10.1016/j.palaeo.2014.09.025(c) Elsevier B.V., 2014info:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/597342026-05-27T06:46:51Z
dc.title.none.fl_str_mv Environmental processes in Rano Aroi (Ester Island) peat geochemistry forced by climate variability during the last 70 kyr
title Environmental processes in Rano Aroi (Ester Island) peat geochemistry forced by climate variability during the last 70 kyr
spellingShingle Environmental processes in Rano Aroi (Ester Island) peat geochemistry forced by climate variability during the last 70 kyr
Margalef Marrasé, Olga
Paleoclimatologia
Polinèsia
Paleoclimatology
Polynesia
title_short Environmental processes in Rano Aroi (Ester Island) peat geochemistry forced by climate variability during the last 70 kyr
title_full Environmental processes in Rano Aroi (Ester Island) peat geochemistry forced by climate variability during the last 70 kyr
title_fullStr Environmental processes in Rano Aroi (Ester Island) peat geochemistry forced by climate variability during the last 70 kyr
title_full_unstemmed Environmental processes in Rano Aroi (Ester Island) peat geochemistry forced by climate variability during the last 70 kyr
title_sort Environmental processes in Rano Aroi (Ester Island) peat geochemistry forced by climate variability during the last 70 kyr
dc.creator.none.fl_str_mv Margalef Marrasé, Olga
Martínez-Cortizas, A.
Kylander, M.
Pla, S.
Cañellas Boltà, Núria
Pueyo Mur, Juan José
Sáez, Alberto
Valero Garcés, Blas Lorenzo
Giralt Romeu, Santiago
author Margalef Marrasé, Olga
author_facet Margalef Marrasé, Olga
Martínez-Cortizas, A.
Kylander, M.
Pla, S.
Cañellas Boltà, Núria
Pueyo Mur, Juan José
Sáez, Alberto
Valero Garcés, Blas Lorenzo
Giralt Romeu, Santiago
author_role author
author2 Martínez-Cortizas, A.
Kylander, M.
Pla, S.
Cañellas Boltà, Núria
Pueyo Mur, Juan José
Sáez, Alberto
Valero Garcés, Blas Lorenzo
Giralt Romeu, Santiago
author2_role author
author
author
author
author
author
author
author
dc.subject.none.fl_str_mv Paleoclimatologia
Polinèsia
Paleoclimatology
Polynesia
topic Paleoclimatologia
Polinèsia
Paleoclimatology
Polynesia
description We analyze the geochemistry of Rano Aroi mire record (Easter Island) using bulk peat composition (C, N, S) and stable isotopes (δ13C, δ15N, δ34S) and major, minor and trace elemental compositions obtained by ICP-AES (Al, Ti, Zr, Sc, V, Y, Fe, Mn, Th, Ba, Ca,Mg and Sr). Peat geochemistry and the pollen record are used to reconstruct the environmental changes during the last 70 kyr BP. Principal component analysis on ICP-AES data revealed that three main components account for the chemical signatures of the peat. The first component, characterized by lithogenic elements (combined signal of V, Al, Sc, Y, Cr, Cd, Ti, Zr and Cu), evidences long-term changes in the basal fluxes of mineralmaterial into themire. This component, in combination with stable isotopes and pollen data suggests a link between soil erosion and vegetation cover changes in the Rano Aroiwatershed. The second component is identified by the signal of Fe, Mn, Th, Ba, Zr and Ti, and is indicative of strong runoff events during enhanced precipitation periods. The third component (tied mainly to Ca, Sr and Mg) reflects a strong peat oxidation event that occurred during an arid periodwithmore frequent droughts, sometime between 39 and 31 kyr BP. Correlation coefficients and a multiple regression model (PCR analysis) between peat organic chemistry and the principal components of ICP-AES analysis were calculated. Isotope chemistry of the peat organic matter further contributes to define Rano Aroi environmental history: δ13C data corroborates a vegetation shift documented by the palynological record from C4 to C3 between 55 and 45 cal kyr BP; the δ15N record identifies periods of changes in mire productivity and denitrification processes, while the δ34S peat signature indicates a marine origin of S and significant diagenetic cycling. The geochemical and environmental evolution of Rano Aroi mire is coherent with the regional climatic variability and suggests that climate was the main forcing in mire evolution during the last 70 kyr BP. The coupling of geochemical and biological proxies improves our ability to decipher depositional processes in tropical and subtropical peatlands and to use these sequences for paleoenvironmental and paleoclimate reconstructions.
publishDate 2014
dc.date.none.fl_str_mv 2014
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/acceptedVersion
format article
status_str acceptedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/59734
url https://hdl.handle.net/2445/59734
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Versió postprint del document publicat a: http://dx.doi.org/10.1016/j.palaeo.2014.09.025
Palaeogeography Palaeoclimatology Palaeoecology, 2014, vol. 414, p. 438-450
http://dx.doi.org/10.1016/j.palaeo.2014.09.025
dc.rights.none.fl_str_mv (c) Elsevier B.V., 2014
info:eu-repo/semantics/openAccess
rights_invalid_str_mv (c) Elsevier B.V., 2014
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Elsevier B.V.
publisher.none.fl_str_mv Elsevier B.V.
dc.source.none.fl_str_mv Articles publicats en revistes (Dinàmica de la Terra i l'Oceà)
reponame:Dipòsit Digital de la UB
instname:Universidad de Barcelona
instname_str Universidad de Barcelona
reponame_str Dipòsit Digital de la UB
collection Dipòsit Digital de la UB
repository.name.fl_str_mv
repository.mail.fl_str_mv
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