Age model, geochemistry, XRF core scanning elemental data and benthic foraminifera from IODP Site 371-U1506

DOI

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 (IODP) Site 371-U1506 in the Tasman Sea, where we provide an integrated age model based on orbital tuning of the Natural Gamma Radiation (NGR), 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 Ma to 6.7 Ma, seafloor conditions were characterized by episodic nutrient supply, perhaps related to seasonal phytoplankton blooms. From 6.7 Ma 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.

Identifier
DOI https://doi.org/10.1594/PANGAEA.953692
Related Identifier https://doi.org/10.1029/2022PA004565
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.953692
Provenance
Creator Gastaldello, Maria Elena ORCID logo; Agnini, Claudia ORCID logo; Westerhold, Thomas ORCID logo; Drury, Anna Joy ORCID logo; Sutherland, Rupert ORCID logo; Drake, Michelle K ORCID logo; Lam, Adriane R ORCID logo; Dickens, Gerald Roy ORCID logo; Dallanave, Edoardo ORCID logo; Burns, Stephen J ORCID logo; Alegret, Laia
Publisher PANGAEA
Publication Year 2023
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Resource Type Bundled Publication of Datasets; Collection
Format application/zip
Size 9 datasets
Discipline Earth System Research
Spatial Coverage (161.740 LON, -28.662 LAT)
Temporal Coverage Begin 2017-08-03T09:48:00Z
Temporal Coverage End 2017-08-05T19:35:00Z