Gastaldello, ME;
Agnini, C;
Westerhold, T;
Drury, AJ;
Sutherland, R;
Drake, MK;
Lam, AR;
... Alegret, L; + view all
(2023)
The Late Miocene-Early Pliocene Biogenic Bloom: An Integrated Study in the Tasman Sea.
Paleoceanography and Paleoclimatology
, 38
(4)
10.1029/2022pa004565.
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Abstract
The Late Miocene-Early Pliocene Biogenic Bloom (∼9–3.5 Ma) was a paleoceanographic phenomenon defined by anomalously high accumulations of biological components at multiple open ocean sites, especially in certain regions of the Indian, and Pacific oceans. Its temporal and spatial extent with available information leaves fundamental questions about driving forces and responses unanswered. In this work, we focus on the middle part of the Biogenic Bloom (7.4–4.5 Ma) at International Ocean Discovery Program Site U1506 in the Tasman Sea, where we provide an integrated age model based on orbital tuning of the Natural Gamma Radiation, benthic foraminiferal oxygen isotopes, and calcareous nannofossil biostratigraphy. Benthic foraminiferal assemblages suggest changes in deep water oxygen concentration and seafloor nutrient supply during generally high export productivity conditions. From 7.4 to 6.7 Ma, seafloor conditions were characterized by episodic nutrient supply, perhaps related to seasonal phytoplankton blooms. From 6.7 to 4.5 Ma, the regime shifted to a more stable interval characterized by eutrophic and dysoxic conditions. Combined with seismic data, a regional change in paleoceanography is inferred at around 6.7 Ma, from stronger and well-oxygenated bottom currents to weaker, oxygen-depleted bottom currents. Our results support the hypothesis that the Biogenic Bloom was a complex, multiphase phenomenon driven by changes in ocean currents, rather than a single uniform period of sustained sea surface water productivity. Highly resolved studies are thus fundamental to its understanding and the disentanglement of local, regional, and global imprints.
| Type: | Article |
|---|---|
| Title: | The Late Miocene-Early Pliocene Biogenic Bloom: An Integrated Study in the Tasman Sea |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1029/2022pa004565 |
| Publisher version: | https://doi.org/10.1029/2022pa004565 |
| Language: | English |
| Additional information: | © 2023. The Authors. This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10168123 |
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