BOUNDARY CONDITIONS OF ATLANTIC EOCENE OXYGEN MINIMUM ZONES
Biserial heterohelicid foraminifera are paleohydrographic indices for open ocean oxygen minimum zones. Comparison of the depletion of biserial heterohelicid carbon isotope ratios with the carbon isotope contrast through the water column is used to describe the strength of Eocene oxygen minima. Combi...
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| Format: | Article |
| Language: | English |
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Milano University Press
2020-03-01
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| Series: | Rivista Italiana di Paleontologia e Stratigrafia |
| Subjects: | |
| Online Access: | https://riviste.unimi.it/index.php/RIPS/article/view/13186 |
| _version_ | 1797716162308472832 |
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| author | ANNE BOERSMA ISABELLA PREMOLI SILVA |
| author_facet | ANNE BOERSMA ISABELLA PREMOLI SILVA |
| author_sort | ANNE BOERSMA |
| collection | DOAJ |
| description | Biserial heterohelicid foraminifera are paleohydrographic indices for open ocean oxygen minimum zones. Comparison of the depletion of biserial heterohelicid carbon isotope ratios with the carbon isotope contrast through the water column is used to describe the strength of Eocene oxygen minima. Combining stable isotope values and percentages of planktonic foraminiferal index species, we describe the following boundary condition for early, middle and latest Eocene oxygen minimum zones in the Atlantic Ocean. Early Eocene - low meridional and vertical thermal contrasts, reduced upwelling and circulation vigor in a moderately war m, stable thermospheric ocean accompany a poorly developed, spatially restricted oxygen minimum. Middle Eocene - invigorated upwelling, large vertical and spatial thermal contrasts caused by cooling at the bottom but not at the surface together with increased ventilation of the water column accompany a strong, widely developed oxygen minimum; and Late Eocene - in a psychrospheric ocean low meridional and vertical thermal contrasts, reduced equatorial upwelling and atmospheric circulation with decreased current circulation vigor correlate with a homogeneous mixed layer in which an oxygen minimum is poorly developed above the thermocline, but not at mid depths. |
| first_indexed | 2024-03-12T08:17:28Z |
| format | Article |
| id | doaj.art-09a4d9b4dbff445caeb16f07826f43f6 |
| institution | Directory Open Access Journal |
| issn | 0035-6883 2039-4942 |
| language | English |
| last_indexed | 2024-03-12T08:17:28Z |
| publishDate | 2020-03-01 |
| publisher | Milano University Press |
| record_format | Article |
| series | Rivista Italiana di Paleontologia e Stratigrafia |
| spelling | doaj.art-09a4d9b4dbff445caeb16f07826f43f62023-09-02T18:44:24ZengMilano University PressRivista Italiana di Paleontologia e Stratigrafia0035-68832039-49422020-03-01934BOUNDARY CONDITIONS OF ATLANTIC EOCENE OXYGEN MINIMUM ZONESANNE BOERSMA ISABELLA PREMOLI SILVA Biserial heterohelicid foraminifera are paleohydrographic indices for open ocean oxygen minimum zones. Comparison of the depletion of biserial heterohelicid carbon isotope ratios with the carbon isotope contrast through the water column is used to describe the strength of Eocene oxygen minima. Combining stable isotope values and percentages of planktonic foraminiferal index species, we describe the following boundary condition for early, middle and latest Eocene oxygen minimum zones in the Atlantic Ocean. Early Eocene - low meridional and vertical thermal contrasts, reduced upwelling and circulation vigor in a moderately war m, stable thermospheric ocean accompany a poorly developed, spatially restricted oxygen minimum. Middle Eocene - invigorated upwelling, large vertical and spatial thermal contrasts caused by cooling at the bottom but not at the surface together with increased ventilation of the water column accompany a strong, widely developed oxygen minimum; and Late Eocene - in a psychrospheric ocean low meridional and vertical thermal contrasts, reduced equatorial upwelling and atmospheric circulation with decreased current circulation vigor correlate with a homogeneous mixed layer in which an oxygen minimum is poorly developed above the thermocline, but not at mid depths.https://riviste.unimi.it/index.php/RIPS/article/view/13186Paleoceanography; oxygen minimum; planktonic foraminifera; biserial heterohelicids; Eocene; Atlantic Ocean. |
| spellingShingle | ANNE BOERSMA ISABELLA PREMOLI SILVA BOUNDARY CONDITIONS OF ATLANTIC EOCENE OXYGEN MINIMUM ZONES Rivista Italiana di Paleontologia e Stratigrafia Paleoceanography; oxygen minimum; planktonic foraminifera; biserial heterohelicids; Eocene; Atlantic Ocean. |
| title | BOUNDARY CONDITIONS OF ATLANTIC EOCENE OXYGEN MINIMUM ZONES |
| title_full | BOUNDARY CONDITIONS OF ATLANTIC EOCENE OXYGEN MINIMUM ZONES |
| title_fullStr | BOUNDARY CONDITIONS OF ATLANTIC EOCENE OXYGEN MINIMUM ZONES |
| title_full_unstemmed | BOUNDARY CONDITIONS OF ATLANTIC EOCENE OXYGEN MINIMUM ZONES |
| title_short | BOUNDARY CONDITIONS OF ATLANTIC EOCENE OXYGEN MINIMUM ZONES |
| title_sort | boundary conditions of atlantic eocene oxygen minimum zones |
| topic | Paleoceanography; oxygen minimum; planktonic foraminifera; biserial heterohelicids; Eocene; Atlantic Ocean. |
| url | https://riviste.unimi.it/index.php/RIPS/article/view/13186 |
| work_keys_str_mv | AT anneboersma boundaryconditionsofatlanticeoceneoxygenminimumzones AT isabellapremolisilva boundaryconditionsofatlanticeoceneoxygenminimumzones |