High‐Resolution Coccolithophore Morphological Changes in Response to Orbital Forcings During the Early Oligocene
Abstract The global climate of the early Oligocene was characterized by initiated Antarctic glaciation and meridional overturning circulation, which then led to profound eutrophication in the upper ocean. Generating a high‐resolution coccolith record helps to understand the responses of marine phyto...
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ftdoajarticles:oai:doaj.org/article:564dfc78548f46ad80a11b7c4b120a49 2023-12-03T10:11:42+01:00 High‐Resolution Coccolithophore Morphological Changes in Response to Orbital Forcings During the Early Oligocene Ruigang Ma Xiaobo Jin Chuanlian Liu 2023-04-01T00:00:00Z https://doi.org/10.1029/2022GC010746 https://doaj.org/article/564dfc78548f46ad80a11b7c4b120a49 EN eng Wiley https://doi.org/10.1029/2022GC010746 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2022GC010746 https://doaj.org/article/564dfc78548f46ad80a11b7c4b120a49 Geochemistry, Geophysics, Geosystems, Vol 24, Iss 4, Pp n/a-n/a (2023) coccolithophore morphology high‐resolution nutrient Oligocene Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.1029/2022GC010746 2023-11-05T01:35:59Z Abstract The global climate of the early Oligocene was characterized by initiated Antarctic glaciation and meridional overturning circulation, which then led to profound eutrophication in the upper ocean. Generating a high‐resolution coccolith record helps to understand the responses of marine phytoplankton to the newly established environment. Using highly resolved (∼6 kyr time‐resolution) marine sediment samples from Deep Sea Drilling Project Site 522 in the South Atlantic Ocean, we conducted a comprehensive morphological study on coccoliths from the genera Reticulofenestra, Dictyococcites, and Coccolithus, which dominated the study interval between ∼33.1 and 32.8 Ma. Our results showed that the size variations of the three measured genera were significantly correlated (p < 0.01) with each other, indicating homogeneous responses to the environmental changes. Moreover, spectrum analysis on integrated morphologic data of all measured coccoliths showed distinct obliquity (∼40‐kyr) and precession (∼23‐kyr and ∼18‐kyr) cycles. We suggest that these variations were mainly driven by temperate, short‐term ecological fluctuations, which periodically altered the nutrient conditions in the common living habitats of the studied coccolithophores. We proposed two tentative explanations focusing on the obliquity signal. First, the cyclic variation could result from obliquity‐modulated changes in ice volume and variations in ocean circulation intensity, which influenced nutrient export from deep waters to the upper ocean. Alternatively, the changes in coccolith size may indicate the strength of seasonality that influenced upper ocean mixing on the west coast of South Africa. Article in Journal/Newspaper Antarc* Antarctic South Atlantic Ocean Directory of Open Access Journals: DOAJ Articles Antarctic Geochemistry, Geophysics, Geosystems 24 4 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
coccolithophore morphology high‐resolution nutrient Oligocene Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
spellingShingle |
coccolithophore morphology high‐resolution nutrient Oligocene Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 Ruigang Ma Xiaobo Jin Chuanlian Liu High‐Resolution Coccolithophore Morphological Changes in Response to Orbital Forcings During the Early Oligocene |
topic_facet |
coccolithophore morphology high‐resolution nutrient Oligocene Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
description |
Abstract The global climate of the early Oligocene was characterized by initiated Antarctic glaciation and meridional overturning circulation, which then led to profound eutrophication in the upper ocean. Generating a high‐resolution coccolith record helps to understand the responses of marine phytoplankton to the newly established environment. Using highly resolved (∼6 kyr time‐resolution) marine sediment samples from Deep Sea Drilling Project Site 522 in the South Atlantic Ocean, we conducted a comprehensive morphological study on coccoliths from the genera Reticulofenestra, Dictyococcites, and Coccolithus, which dominated the study interval between ∼33.1 and 32.8 Ma. Our results showed that the size variations of the three measured genera were significantly correlated (p < 0.01) with each other, indicating homogeneous responses to the environmental changes. Moreover, spectrum analysis on integrated morphologic data of all measured coccoliths showed distinct obliquity (∼40‐kyr) and precession (∼23‐kyr and ∼18‐kyr) cycles. We suggest that these variations were mainly driven by temperate, short‐term ecological fluctuations, which periodically altered the nutrient conditions in the common living habitats of the studied coccolithophores. We proposed two tentative explanations focusing on the obliquity signal. First, the cyclic variation could result from obliquity‐modulated changes in ice volume and variations in ocean circulation intensity, which influenced nutrient export from deep waters to the upper ocean. Alternatively, the changes in coccolith size may indicate the strength of seasonality that influenced upper ocean mixing on the west coast of South Africa. |
format |
Article in Journal/Newspaper |
author |
Ruigang Ma Xiaobo Jin Chuanlian Liu |
author_facet |
Ruigang Ma Xiaobo Jin Chuanlian Liu |
author_sort |
Ruigang Ma |
title |
High‐Resolution Coccolithophore Morphological Changes in Response to Orbital Forcings During the Early Oligocene |
title_short |
High‐Resolution Coccolithophore Morphological Changes in Response to Orbital Forcings During the Early Oligocene |
title_full |
High‐Resolution Coccolithophore Morphological Changes in Response to Orbital Forcings During the Early Oligocene |
title_fullStr |
High‐Resolution Coccolithophore Morphological Changes in Response to Orbital Forcings During the Early Oligocene |
title_full_unstemmed |
High‐Resolution Coccolithophore Morphological Changes in Response to Orbital Forcings During the Early Oligocene |
title_sort |
high‐resolution coccolithophore morphological changes in response to orbital forcings during the early oligocene |
publisher |
Wiley |
publishDate |
2023 |
url |
https://doi.org/10.1029/2022GC010746 https://doaj.org/article/564dfc78548f46ad80a11b7c4b120a49 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic South Atlantic Ocean |
genre_facet |
Antarc* Antarctic South Atlantic Ocean |
op_source |
Geochemistry, Geophysics, Geosystems, Vol 24, Iss 4, Pp n/a-n/a (2023) |
op_relation |
https://doi.org/10.1029/2022GC010746 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2022GC010746 https://doaj.org/article/564dfc78548f46ad80a11b7c4b120a49 |
op_doi |
https://doi.org/10.1029/2022GC010746 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
24 |
container_issue |
4 |
_version_ |
1784255340077907968 |