Nannofossil assemblag and geochemistry of IODP Site 356-U1463
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| Format: | Dataset Open Access |
| Sprache: | en |
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PANGAEA
2019
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| _version_ | 1867169516523356160 |
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| author | Auer, Gerald De Vleeschouwer, David Smith, Rebecca Bogus, Kara A Groeneveld, Jeroen Grunert, Patrick Castañeda, Isla S Petrick, Benjamin F Christensen, Beth A Fulthorpe, Craig S Gallagher, Stephen John Henderiks, Jorijntje |
| author_facet | Auer, Gerald De Vleeschouwer, David Smith, Rebecca Bogus, Kara A Groeneveld, Jeroen Grunert, Patrick Castañeda, Isla S Petrick, Benjamin F Christensen, Beth A Fulthorpe, Craig S Gallagher, Stephen John Henderiks, Jorijntje |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | The Pliocene was characterized by a gradual shift of global climate toward cooler and drier conditions. This shift fundamentally reorganized Earth's climate from the Miocene state toward conditions similar to the present. During the Pliocene, the progressive restriction of the Indonesian Throughflow (ITF) is suggested to have enhanced this shift toward stronger meridional thermal gradients. Reduced ITF, caused by the northward movement of Australia and uplift of Indonesia, impeded global thermohaline circulation, also contributing to late Pliocene Northern Hemisphere cooling via atmospheric and oceanographic teleconnections. Here we present an orbitally tuned high‐resolution sediment geochemistry, calcareous nannofossil, and X‐ray fluorescence record between 3.65 and 2.97 Ma from the northwest shelf of Australia within the Leeuwin Current. International Ocean Discovery Program Site U1463 provides a record of local surface water conditions and Australian climate in relation to changing ITF connectivity. Modern analogue‐based interpretations of nannofossil assemblages indicate that ITF configuration culminated ~3.54 Ma. A decrease in warm, oligotrophic taxa such as Umbilicosphaera sibogae, with a shift from Gephyrocapsa sp. to Reticulofenestra sp., and an increase of mesotrophic taxa (e.g., Umbilicosphaera jafari and Helicosphaera spp.) suggest that tropical Pacific ITF sources were replaced by cooler, fresher, northern Pacific waters. This initial tectonic reorganization enhanced the Indian Oceans sensitivity to orbitally forced cooling in the southern high latitudes culminating in the M2 glacial event (~3.3 Ma). After 3.3 Ma the restructured ITF established the boundary conditions for the inception of the Sahul‐Indian Ocean Bjerknes mechanism and increased the response to glacio‐eustatic variability. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_903728 |
| institution | PANGAEA |
| language | en |
| publishDate | 2019 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Nannofossil assemblag and geochemistry of IODP Site 356-U1463 Auer, Gerald De Vleeschouwer, David Smith, Rebecca Bogus, Kara A Groeneveld, Jeroen Grunert, Patrick Castañeda, Isla S Petrick, Benjamin F Christensen, Beth A Fulthorpe, Craig S Gallagher, Stephen John Henderiks, Jorijntje Calcium carbonate; Carbon; Expedition 356; Indonesian Throughflow; Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP; M2-event; Nannoplankton; Pliocene; Sulfur The Pliocene was characterized by a gradual shift of global climate toward cooler and drier conditions. This shift fundamentally reorganized Earth's climate from the Miocene state toward conditions similar to the present. During the Pliocene, the progressive restriction of the Indonesian Throughflow (ITF) is suggested to have enhanced this shift toward stronger meridional thermal gradients. Reduced ITF, caused by the northward movement of Australia and uplift of Indonesia, impeded global thermohaline circulation, also contributing to late Pliocene Northern Hemisphere cooling via atmospheric and oceanographic teleconnections. Here we present an orbitally tuned high‐resolution sediment geochemistry, calcareous nannofossil, and X‐ray fluorescence record between 3.65 and 2.97 Ma from the northwest shelf of Australia within the Leeuwin Current. International Ocean Discovery Program Site U1463 provides a record of local surface water conditions and Australian climate in relation to changing ITF connectivity. Modern analogue‐based interpretations of nannofossil assemblages indicate that ITF configuration culminated ~3.54 Ma. A decrease in warm, oligotrophic taxa such as Umbilicosphaera sibogae, with a shift from Gephyrocapsa sp. to Reticulofenestra sp., and an increase of mesotrophic taxa (e.g., Umbilicosphaera jafari and Helicosphaera spp.) suggest that tropical Pacific ITF sources were replaced by cooler, fresher, northern Pacific waters. This initial tectonic reorganization enhanced the Indian Oceans sensitivity to orbitally forced cooling in the southern high latitudes culminating in the M2 glacial event (~3.3 Ma). After 3.3 Ma the restructured ITF established the boundary conditions for the inception of the Sahul‐Indian Ocean Bjerknes mechanism and increased the response to glacio‐eustatic variability. |
| title | Nannofossil assemblag and geochemistry of IODP Site 356-U1463 |
| topic | Calcium carbonate; Carbon; Expedition 356; Indonesian Throughflow; Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP; M2-event; Nannoplankton; Pliocene; Sulfur |
| url | https://doi.org/10.1594/PANGAEA.903728 |