Late Quaternary environmental changes in Misiones, subtropical NE Argentina, deduced from multi-proxy geochemical analyses in a palaeosol-sediment sequence
A 4.5-m-long sediment core from a small basin in the Province of Misiones, NE Argentina, was analyzed in a multi-proxy geochemical approach (major and minor elemental composition, Corg, N, HI, OI, δ13Corg, n-alkanes and compound-specific δ13C analyses of biomarkers) in order to contribute to the rec...
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| Format: | Artículo |
| Language: | Inglés |
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Elsevier
2024
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| Online Access: | http://hdl.handle.net/20.500.12123/19421 https://www.sciencedirect.com/science/article/pii/S1040618208001961 https://doi.org/10.1016/j.quaint.2008.06.006 |
| _version_ | 1855486355904135168 |
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| author | Zech, MIchael Zech, Roland Morras, Hector Moretti, Lucas Martin Claser, Bruno J.R. Zech, Wolfgang |
| author_browse | Claser, Bruno J.R. Moretti, Lucas Martin Morras, Hector Zech, MIchael Zech, Roland Zech, Wolfgang |
| author_facet | Zech, MIchael Zech, Roland Morras, Hector Moretti, Lucas Martin Claser, Bruno J.R. Zech, Wolfgang |
| author_sort | Zech, MIchael |
| collection | INTA Digital |
| description | A 4.5-m-long sediment core from a small basin in the Province of Misiones, NE Argentina, was analyzed in a multi-proxy geochemical approach (major and minor elemental composition, Corg, N, HI, OI, δ13Corg, n-alkanes and compound-specific δ13C analyses of biomarkers) in order to contribute to the reconstruction of the Late Quaternary environmental and climate history of subtropical South America. The results of the elemental analyses and radiocarbon dating indicate different sediment provenances for Unit A—the Holocene, Unit B—the Late Glacial and the Last Glacial Maximum (LGM), and Unit C—the ‘Inca Huasi’ wet phase (before ∼40 ka BP). A sedimentary hiatus after ∼40 ka BP is interpreted as a pronounced pre-LGM dry phase with landscape erosion/deflation. Multi-proxy geochemical characterization of the soil organic matter (SOM) shows that especially (i) the stable carbon isotopic composition (δ13C) of the grass-derived alkanes nC31 and nC33, (ii) the alkane ratio nC31/nC27 and (iii) lacustrine-derived short- and mid-chain alkanes are valuable proxies for the reconstruction of the palaeoenvironment. A transition from C3-tree-dominance to C4-grass-dominance is recorded at the end of the ‘Inca Huasi’ wet phase. In Unit B, the ratio nC31/nC27 documents forest expansion at the beginning of a Late Glacial wet phase. More positive δ13C values in Unit A reflect the increasing contribution of C4-grasses and/or CAM-plants to the SOM during the Holocene and a human impact on the formation of this unit may be possible. The results are in good agreement with other tropical/subtropical palaeoenvironmental records and highlight the importance and temporal variability of the palaeo-South American Summer Monsoon (SASM). |
| format | Artículo |
| id | INTA19421 |
| institution | Instituto Nacional de Tecnología Agropecuaria (INTA -Argentina) |
| language | Inglés |
| publishDate | 2024 |
| publishDateRange | 2024 |
| publishDateSort | 2024 |
| publisher | Elsevier |
| publisherStr | Elsevier |
| record_format | dspace |
| spelling | INTA194212024-09-16T12:23:49Z Late Quaternary environmental changes in Misiones, subtropical NE Argentina, deduced from multi-proxy geochemical analyses in a palaeosol-sediment sequence Zech, MIchael Zech, Roland Morras, Hector Moretti, Lucas Martin Claser, Bruno J.R. Zech, Wolfgang Suelo Soil Environment Medio Ambiente Misiones Environmental Change Geochemical Analyses Cambio Ambiental Análisis Geoquímicos A 4.5-m-long sediment core from a small basin in the Province of Misiones, NE Argentina, was analyzed in a multi-proxy geochemical approach (major and minor elemental composition, Corg, N, HI, OI, δ13Corg, n-alkanes and compound-specific δ13C analyses of biomarkers) in order to contribute to the reconstruction of the Late Quaternary environmental and climate history of subtropical South America. The results of the elemental analyses and radiocarbon dating indicate different sediment provenances for Unit A—the Holocene, Unit B—the Late Glacial and the Last Glacial Maximum (LGM), and Unit C—the ‘Inca Huasi’ wet phase (before ∼40 ka BP). A sedimentary hiatus after ∼40 ka BP is interpreted as a pronounced pre-LGM dry phase with landscape erosion/deflation. Multi-proxy geochemical characterization of the soil organic matter (SOM) shows that especially (i) the stable carbon isotopic composition (δ13C) of the grass-derived alkanes nC31 and nC33, (ii) the alkane ratio nC31/nC27 and (iii) lacustrine-derived short- and mid-chain alkanes are valuable proxies for the reconstruction of the palaeoenvironment. A transition from C3-tree-dominance to C4-grass-dominance is recorded at the end of the ‘Inca Huasi’ wet phase. In Unit B, the ratio nC31/nC27 documents forest expansion at the beginning of a Late Glacial wet phase. More positive δ13C values in Unit A reflect the increasing contribution of C4-grasses and/or CAM-plants to the SOM during the Holocene and a human impact on the formation of this unit may be possible. The results are in good agreement with other tropical/subtropical palaeoenvironmental records and highlight the importance and temporal variability of the palaeo-South American Summer Monsoon (SASM). Instituto de Suelos Fil: Zech, Michael. University of Bayreuth. Chair of Geomorphology and Department of Soil Physics; Alemania Fil: Zech, Roland. University of Bern. Institute of Geography; Suiza Fil: Morras, Héctor J.M. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Suelos; Argentina Fil: Moretti, lucas Martín. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Suelos; Argentina Fil: Glaser, Bruno J.R. University of Bayreuth. Chair of Geomorphology and Department of Soil Physics; Alemania Fil: Zech, Wolfgang. University of Bayreuth. Chair of Geomorphology and Department of Soil Physics; Alemania 2024-09-16T12:11:33Z 2024-09-16T12:11:33Z 2009-03-01 info:ar-repo/semantics/artículo info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/20.500.12123/19421 https://www.sciencedirect.com/science/article/pii/S1040618208001961 1040-6182 1873-4553 https://doi.org/10.1016/j.quaint.2008.06.006 eng info:eu-repo/semantics/restrictedAccess http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) application/pdf Elsevier Quaternary International 196 (1-2) : 121-136. (March 2009) |
| spellingShingle | Suelo Soil Environment Medio Ambiente Misiones Environmental Change Geochemical Analyses Cambio Ambiental Análisis Geoquímicos Zech, MIchael Zech, Roland Morras, Hector Moretti, Lucas Martin Claser, Bruno J.R. Zech, Wolfgang Late Quaternary environmental changes in Misiones, subtropical NE Argentina, deduced from multi-proxy geochemical analyses in a palaeosol-sediment sequence |
| title | Late Quaternary environmental changes in Misiones, subtropical NE Argentina, deduced from multi-proxy geochemical analyses in a palaeosol-sediment sequence |
| title_full | Late Quaternary environmental changes in Misiones, subtropical NE Argentina, deduced from multi-proxy geochemical analyses in a palaeosol-sediment sequence |
| title_fullStr | Late Quaternary environmental changes in Misiones, subtropical NE Argentina, deduced from multi-proxy geochemical analyses in a palaeosol-sediment sequence |
| title_full_unstemmed | Late Quaternary environmental changes in Misiones, subtropical NE Argentina, deduced from multi-proxy geochemical analyses in a palaeosol-sediment sequence |
| title_short | Late Quaternary environmental changes in Misiones, subtropical NE Argentina, deduced from multi-proxy geochemical analyses in a palaeosol-sediment sequence |
| title_sort | late quaternary environmental changes in misiones subtropical ne argentina deduced from multi proxy geochemical analyses in a palaeosol sediment sequence |
| topic | Suelo Soil Environment Medio Ambiente Misiones Environmental Change Geochemical Analyses Cambio Ambiental Análisis Geoquímicos |
| url | http://hdl.handle.net/20.500.12123/19421 https://www.sciencedirect.com/science/article/pii/S1040618208001961 https://doi.org/10.1016/j.quaint.2008.06.006 |
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