Mid-Pleistocene benthic foraminiferal record in the Southwest Pacific
Fuente:
PANGAEA
Enregistré dans:
| Auteurs principaux: | , , , |
|---|---|
| Format: | Dataset Open Access |
| Langue: | en |
| Publié: |
PANGAEA
2005
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1867171356851830784 |
|---|---|
| author | Hayward, Bruce William Grenfell, Hugh R Sabaa, Ashwaq T Sikes, Elisabeth L |
| author_facet | Hayward, Bruce William Grenfell, Hugh R Sabaa, Ashwaq T Sikes, Elisabeth L |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Benthic foraminiferal faunas from three bathyal sequences provide a proxy record of oceanographic changes through the mid-Pleistocene transition (MPT) on either side of the Subtropical Front (STF), east of New Zealand. Canonical correspondence analyses show that factors related to water depth, latitude and climate cycles were more significant than oceanographic factors in determining changes in faunal assemblage composition over the last 1 Ma. Even so, mid-Pleistocene faunal changes are recognizable and can be linked to inferred palaeoceanographic causes. North of the largely stationary STF the faunas were less variable than to the south, perhaps reflecting the less extreme glacial-interglacial fluctuations in the overlying Subtropical Surface Water. Prior to Marine Isotope Stage (MIS) 21 and after MIS 15, the northern faunas had fairly constant composition, but during most of the MPT faunal composition fluctuated in response to climate-related food-supply variations. Faunal changes through the MPT suggest increasing food supply and decreasing dissolved bottom oxygen. South of the STF, beneath Subantarctic Surface Water, mid-Pleistocene faunas exhibited strong glacial-interglacial fluctuations, inferred to be due to higher interglacial nutrient supply and lower oxygen levels. The most dramatic faunal change in the south occurred at the end of the MPT (MIS 17- 12). with an acme of Abditodentrix pseudothalmanni, possibly reflecting higher carbon flux and lower bottom oxygen. This study suggests that the mid-Pleistocene decline and extinction of a group of elongate, cylindrical deep-sea foraminifera may have been related to decreased bottom oxygen concentrations as aresult of slower deep-water currents. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_705195 |
| institution | PANGAEA |
| language | en |
| publishDate | 2005 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Mid-Pleistocene benthic foraminiferal record in the Southwest Pacific Hayward, Bruce William Grenfell, Hugh R Sabaa, Ashwaq T Sikes, Elisabeth L 181-1119; 181-1125; 90-594_Site; COMPCORE; Composite Core; Deep Sea Drilling Project; DSDP; Glomar Challenger; Joides Resolution; Leg181; Leg90; Ocean Drilling Program; ODP; South Pacific/CONT RISE; South Pacific Ocean Benthic foraminiferal faunas from three bathyal sequences provide a proxy record of oceanographic changes through the mid-Pleistocene transition (MPT) on either side of the Subtropical Front (STF), east of New Zealand. Canonical correspondence analyses show that factors related to water depth, latitude and climate cycles were more significant than oceanographic factors in determining changes in faunal assemblage composition over the last 1 Ma. Even so, mid-Pleistocene faunal changes are recognizable and can be linked to inferred palaeoceanographic causes. North of the largely stationary STF the faunas were less variable than to the south, perhaps reflecting the less extreme glacial-interglacial fluctuations in the overlying Subtropical Surface Water. Prior to Marine Isotope Stage (MIS) 21 and after MIS 15, the northern faunas had fairly constant composition, but during most of the MPT faunal composition fluctuated in response to climate-related food-supply variations. Faunal changes through the MPT suggest increasing food supply and decreasing dissolved bottom oxygen. South of the STF, beneath Subantarctic Surface Water, mid-Pleistocene faunas exhibited strong glacial-interglacial fluctuations, inferred to be due to higher interglacial nutrient supply and lower oxygen levels. The most dramatic faunal change in the south occurred at the end of the MPT (MIS 17- 12). with an acme of Abditodentrix pseudothalmanni, possibly reflecting higher carbon flux and lower bottom oxygen. This study suggests that the mid-Pleistocene decline and extinction of a group of elongate, cylindrical deep-sea foraminifera may have been related to decreased bottom oxygen concentrations as aresult of slower deep-water currents. |
| title | Mid-Pleistocene benthic foraminiferal record in the Southwest Pacific |
| topic | 181-1119; 181-1125; 90-594_Site; COMPCORE; Composite Core; Deep Sea Drilling Project; DSDP; Glomar Challenger; Joides Resolution; Leg181; Leg90; Ocean Drilling Program; ODP; South Pacific/CONT RISE; South Pacific Ocean |
| url | https://doi.org/10.1594/PANGAEA.705195 |