Gastaldello, Maria Elena;
Agnini, Claudia;
Westerhold, Thomas;
Drury, Anna Joy;
Alegret, Laia;
(2024)
Unravelling changes in the productivity regime during the Late Miocene-Early Pliocene Biogenic Bloom: Insights from the western equatorial Pacific (IODP Site U1488).
Marine Micropaleontology
, 191
, Article 102395. 10.1016/j.marmicro.2024.102395.
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Abstract
The Late Miocene-Early Pliocene Biogenic Bloom (9.0–3.5 Ma) is a widespread paleoceanographic phenomenon marked by increased marine biological productivity and by high accumulations of biological components documented at multiple open ocean sites in the Indian, Pacific, and Atlantic oceans. We investigate the expression of the Biogenic Bloom at International Ocean Discovery Program (IODP) Site U1488 in the western equatorial Pacific Ocean. We generated an improved age model based on calcareous nannofossil biostratigraphy and a quantitative benthic foraminiferal record across the Late Miocene to the Early Pliocene. Increased carbonate mass accumulation rates suggest the Biogenic Bloom occurs between 8.1 and 4.0 Ma at Site U1488. We described four intervals with paleoenvironmental significance: Interval 1 (8.1–6.2 Ma), Interval 2 (6.2–5.5 Ma), Interval 3 (5.5–4.5 Ma), and Interval 4 (4.5–3.1 Ma), the Biogenic Bloom spans across Interval 1 and 3. Intervals 1, 3, and 4 are marked by high abundance of phytodetritus exploiting taxa, related to phases of El Niño-like conditions. The highest abundance of these species during Interval 1 has been related to a phase of higher seasonality. In contrast, intervals 3 and 4 show reduced seasonality and a steadier input of food to the seafloor, associated with increased dust supply through wind transport and/or increased continental weathering during the Pliocene. Interval 2 stands out as the sole interval encompassing La Niña-like conditions, marked by a shift in the nutrient composition reaching the seafloor, from labile phytodetritus to refractory organic matter, and possibly a decrease in seasonality.
| Type: | Article |
|---|---|
| Title: | Unravelling changes in the productivity regime during the Late Miocene-Early Pliocene Biogenic Bloom: Insights from the western equatorial Pacific (IODP Site U1488) |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.marmicro.2024.102395 |
| Publisher version: | https://doi.org/10.1016/j.marmicro.2024.102395 |
| Language: | English |
| Additional information: | This work is licensed under a Creative Commons License. The images or other third-party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| Keywords: | Science & Technology, Life Sciences & Biomedicine, Paleontology, Late Miocene, Early Pliocene, Biogenic Bloom, IODP Site U1488, Benthic foraminifera, PLEISTOCENE CALCAREOUS NANNOFOSSILS, SURFACE OCEAN PRODUCTIVITY, DEEP-SEA FORAMINIFERA, BENTHIC FORAMINIFERA, INDIAN-OCEAN, QUANTITATIVE ESTIMATION, INTERMEDIATE WATER, TROPICAL PACIFIC, DISSOLVED-OXYGEN, ZONAL CURRENTS |
| 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.ucl.ac.uk/id/eprint/10207434 |
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