Eccentricity paced paleoenvironment evolution and microbial community structure in the Gulf of Mexico during the outgoing Early Eocene Climate Optimum
Orbital-driven climate fluctuations and associated variations in the carbon cycle over short- and long-term time scales can be recorded in sedimentary archives. Bulk geochemical, biomarker, and stable isotope signatures in sediments deposited at the end of the Early Eocene Climatic Optimum (EECO) re...
| Main Authors: | , , , , , , , |
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| Format: | Journal Article |
| Language: | English |
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ELSEVIER
2022
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| Online Access: | http://purl.org/au-research/grants/arc/DP180100982 http://hdl.handle.net/20.500.11937/90134 |
| _version_ | 1848765334444572672 |
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| author | Wang, Danlei Schwark, Lorenz Ruebsam, W. Holman, Alex Böttcher, M.E. Idiz, E. Coolen, Marco Grice, Kliti |
| author_facet | Wang, Danlei Schwark, Lorenz Ruebsam, W. Holman, Alex Böttcher, M.E. Idiz, E. Coolen, Marco Grice, Kliti |
| author_sort | Wang, Danlei |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Orbital-driven climate fluctuations and associated variations in the carbon cycle over short- and long-term time scales can be recorded in sedimentary archives. Bulk geochemical, biomarker, and stable isotope signatures in sediments deposited at the end of the Early Eocene Climatic Optimum (EECO) recovered from the Chicxulub impact crater in the Gulf of Mexico show a strong relationship with Milankovitch cycles, which play a critical role in controlling climatic and environmental oscillations. Our study represents the first highly spatially-resolved biomarker and bulk geochemical record from the EECO. The bulk δ13Ckerogen data records the Milankovitch eccentricity-paced variability of continental weathering throughout the studied interval. Biomarkers (and indices) indicative of redox conditions [e.g., pristane (Pr)/phytane (Ph) ratios], water column stratification and/or salinity conditions (e.g., Gammacerane Index), photic zone euxinia (e.g., isorenieratane, chlorobactene, and okenane) and those that can differentiate between algal communities such as dinoflagellates (dinosteranes), marine pelagophytes (24-n-propylcholestane), chlorophyte algae (24-iso-propylcholestane), and prasinophytes (C28/C29 sterane ratios) show changes controlled by orbital eccentricity frequencies. In particular, eccentricity maxima were marked by more reducing/salinity stratified water conditions, photic zone euxinic episodes, and higher (relative) abundances of prasinophytes. In contrast, eccentricity minima were marked by more oxic water conditions and an increase in cyanobacterial markers. The δ13C offset observed between phytane and C17–C19 n-alkanes may represent shifts between a predominance of autotrophic vs. heterotrophic communities controlled by orbital eccentricity. The direct response of molecular and isotopic composition of organic matter to orbitally controlled climate change in the early Eocene could be proven here for the first time and may be more prevalent in Paleogene sediments worldwide. |
| first_indexed | 2025-11-14T11:33:36Z |
| format | Journal Article |
| id | curtin-20.500.11937-90134 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:33:36Z |
| publishDate | 2022 |
| publisher | ELSEVIER |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-901342024-11-12T02:43:32Z Eccentricity paced paleoenvironment evolution and microbial community structure in the Gulf of Mexico during the outgoing Early Eocene Climate Optimum Wang, Danlei Schwark, Lorenz Ruebsam, W. Holman, Alex Böttcher, M.E. Idiz, E. Coolen, Marco Grice, Kliti Science & Technology Physical Sciences Geochemistry & Geophysics biomarkers compound specific stable isotope orbital cycles orbital driven paleoenvironmental changes paleoproductivity ASTRONOMICAL CALIBRATION BIOMARKERS SEDIMENTS SEA IDENTIFICATION INDICATORS INSOLATION RECORD VALUES BASIN Orbital-driven climate fluctuations and associated variations in the carbon cycle over short- and long-term time scales can be recorded in sedimentary archives. Bulk geochemical, biomarker, and stable isotope signatures in sediments deposited at the end of the Early Eocene Climatic Optimum (EECO) recovered from the Chicxulub impact crater in the Gulf of Mexico show a strong relationship with Milankovitch cycles, which play a critical role in controlling climatic and environmental oscillations. Our study represents the first highly spatially-resolved biomarker and bulk geochemical record from the EECO. The bulk δ13Ckerogen data records the Milankovitch eccentricity-paced variability of continental weathering throughout the studied interval. Biomarkers (and indices) indicative of redox conditions [e.g., pristane (Pr)/phytane (Ph) ratios], water column stratification and/or salinity conditions (e.g., Gammacerane Index), photic zone euxinia (e.g., isorenieratane, chlorobactene, and okenane) and those that can differentiate between algal communities such as dinoflagellates (dinosteranes), marine pelagophytes (24-n-propylcholestane), chlorophyte algae (24-iso-propylcholestane), and prasinophytes (C28/C29 sterane ratios) show changes controlled by orbital eccentricity frequencies. In particular, eccentricity maxima were marked by more reducing/salinity stratified water conditions, photic zone euxinic episodes, and higher (relative) abundances of prasinophytes. In contrast, eccentricity minima were marked by more oxic water conditions and an increase in cyanobacterial markers. The δ13C offset observed between phytane and C17–C19 n-alkanes may represent shifts between a predominance of autotrophic vs. heterotrophic communities controlled by orbital eccentricity. The direct response of molecular and isotopic composition of organic matter to orbitally controlled climate change in the early Eocene could be proven here for the first time and may be more prevalent in Paleogene sediments worldwide. 2022 Journal Article http://hdl.handle.net/20.500.11937/90134 10.1016/j.epsl.2022.117857 English http://purl.org/au-research/grants/arc/DP180100982 http://creativecommons.org/licenses/by-nc-nd/4.0/ ELSEVIER fulltext |
| spellingShingle | Science & Technology Physical Sciences Geochemistry & Geophysics biomarkers compound specific stable isotope orbital cycles orbital driven paleoenvironmental changes paleoproductivity ASTRONOMICAL CALIBRATION BIOMARKERS SEDIMENTS SEA IDENTIFICATION INDICATORS INSOLATION RECORD VALUES BASIN Wang, Danlei Schwark, Lorenz Ruebsam, W. Holman, Alex Böttcher, M.E. Idiz, E. Coolen, Marco Grice, Kliti Eccentricity paced paleoenvironment evolution and microbial community structure in the Gulf of Mexico during the outgoing Early Eocene Climate Optimum |
| title | Eccentricity paced paleoenvironment evolution and microbial community structure in the Gulf of Mexico during the outgoing Early Eocene Climate Optimum |
| title_full | Eccentricity paced paleoenvironment evolution and microbial community structure in the Gulf of Mexico during the outgoing Early Eocene Climate Optimum |
| title_fullStr | Eccentricity paced paleoenvironment evolution and microbial community structure in the Gulf of Mexico during the outgoing Early Eocene Climate Optimum |
| title_full_unstemmed | Eccentricity paced paleoenvironment evolution and microbial community structure in the Gulf of Mexico during the outgoing Early Eocene Climate Optimum |
| title_short | Eccentricity paced paleoenvironment evolution and microbial community structure in the Gulf of Mexico during the outgoing Early Eocene Climate Optimum |
| title_sort | eccentricity paced paleoenvironment evolution and microbial community structure in the gulf of mexico during the outgoing early eocene climate optimum |
| topic | Science & Technology Physical Sciences Geochemistry & Geophysics biomarkers compound specific stable isotope orbital cycles orbital driven paleoenvironmental changes paleoproductivity ASTRONOMICAL CALIBRATION BIOMARKERS SEDIMENTS SEA IDENTIFICATION INDICATORS INSOLATION RECORD VALUES BASIN |
| url | http://purl.org/au-research/grants/arc/DP180100982 http://hdl.handle.net/20.500.11937/90134 |