(Table 1) Age model of DSDP Site 72-516
Changes in ocean circulation are often credited as the primary control on large-scale climate change during the Miocene. This study investigates the latest Oligocene to middle Miocene evolution of Southern Ocean circulation by evaluating stable isotopic trends of shallow- and deep-dwelling planktoni...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.848096 2023-05-15T14:03:05+02:00 (Table 1) Age model of DSDP Site 72-516 Pagani, Mark Arthur, Michael A Freeman, Katherine H MEDIAN LATITUDE: -30.276400 * MEDIAN LONGITUDE: -35.285100 * SOUTH-BOUND LATITUDE: -30.276500 * WEST-BOUND LONGITUDE: -35.285200 * NORTH-BOUND LATITUDE: -30.276300 * EAST-BOUND LONGITUDE: -35.285000 * DATE/TIME START: 1980-03-11T00:00:00 * DATE/TIME END: 1980-03-11T00:00:00 * MINIMUM DEPTH, sediment/rock: 71.1 m * MAXIMUM DEPTH, sediment/rock: 246.0 m 2000-07-14 text/tab-separated-values, 36 data points https://doi.pangaea.de/10.1594/PANGAEA.848096 https://doi.org/10.1594/PANGAEA.848096 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.848096 https://doi.org/10.1594/PANGAEA.848096 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Pagani, Mark; Arthur, Michael A; Freeman, Katherine H (2000): Variations in Miocene phytoplankton growth rates in the southwest Atlantic: Evidence for changes in ocean circulation. Paleoceanography, 15(5), 486-496, https://doi.org/10.1029/1999PA000484 72-516 72-516F Age model paleomag Berggren et al (1985) Ageprofile Datum Description Deep Sea Drilling Project DEPTH sediment/rock DRILL Drilling/drill rig DSDP Event label Glomar Challenger Leg72 South Atlantic/CONT RISE Dataset 2000 ftpangaea https://doi.org/10.1594/PANGAEA.848096 https://doi.org/10.1029/1999PA000484 2023-01-20T09:06:10Z Changes in ocean circulation are often credited as the primary control on large-scale climate change during the Miocene. This study investigates the latest Oligocene to middle Miocene evolution of Southern Ocean circulation by evaluating stable isotopic trends of shallow- and deep-dwelling planktonic foraminifera, as well as epsilon-p records reconstructed from the carbon isotopic composition of diunsaturated alkenones in the southwestern Altantic Ocean (Deep Sea Drilling Project site 516). Changes in epsilon-p at site 516 closely paralleled the opening and deepening of the Drake Passage as inferred from seafloor magnetic anomalies. A large negative shift in epsilon-p at ~20.3 Ma is interpreted to reflect an increase in upper water column nutrient concentrations, caused by the onset or strengthening of the Antarctic Circumpolar Current (ACC). Measurable alkenone concentrations disappear by ~17 Ma, prior to a collapse in surface-to-thermocline d18O and d13C gradients. This is interpreted as reflecting a severe decrease in mixed layer nutrient concentrations and reduced proto-Antarctic Intermediate Water influence. The d18O gradient was reestablished by 14.5 Ma, coincident with the hypothesized East Antarctic ice sheet expansion, suggesting a direct relationship between increased strength of the ACC and the largest climate shift of the middle Miocene. Dataset Antarc* Antarctic Drake Passage Ice Sheet Planktonic foraminifera Southern Ocean PANGAEA - Data Publisher for Earth & Environmental Science Antarctic Southern Ocean The Antarctic Drake Passage East Antarctic Ice Sheet ENVELOPE(-35.285200,-35.285000,-30.276300,-30.276500) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
72-516 72-516F Age model paleomag Berggren et al (1985) Ageprofile Datum Description Deep Sea Drilling Project DEPTH sediment/rock DRILL Drilling/drill rig DSDP Event label Glomar Challenger Leg72 South Atlantic/CONT RISE |
spellingShingle |
72-516 72-516F Age model paleomag Berggren et al (1985) Ageprofile Datum Description Deep Sea Drilling Project DEPTH sediment/rock DRILL Drilling/drill rig DSDP Event label Glomar Challenger Leg72 South Atlantic/CONT RISE Pagani, Mark Arthur, Michael A Freeman, Katherine H (Table 1) Age model of DSDP Site 72-516 |
topic_facet |
72-516 72-516F Age model paleomag Berggren et al (1985) Ageprofile Datum Description Deep Sea Drilling Project DEPTH sediment/rock DRILL Drilling/drill rig DSDP Event label Glomar Challenger Leg72 South Atlantic/CONT RISE |
description |
Changes in ocean circulation are often credited as the primary control on large-scale climate change during the Miocene. This study investigates the latest Oligocene to middle Miocene evolution of Southern Ocean circulation by evaluating stable isotopic trends of shallow- and deep-dwelling planktonic foraminifera, as well as epsilon-p records reconstructed from the carbon isotopic composition of diunsaturated alkenones in the southwestern Altantic Ocean (Deep Sea Drilling Project site 516). Changes in epsilon-p at site 516 closely paralleled the opening and deepening of the Drake Passage as inferred from seafloor magnetic anomalies. A large negative shift in epsilon-p at ~20.3 Ma is interpreted to reflect an increase in upper water column nutrient concentrations, caused by the onset or strengthening of the Antarctic Circumpolar Current (ACC). Measurable alkenone concentrations disappear by ~17 Ma, prior to a collapse in surface-to-thermocline d18O and d13C gradients. This is interpreted as reflecting a severe decrease in mixed layer nutrient concentrations and reduced proto-Antarctic Intermediate Water influence. The d18O gradient was reestablished by 14.5 Ma, coincident with the hypothesized East Antarctic ice sheet expansion, suggesting a direct relationship between increased strength of the ACC and the largest climate shift of the middle Miocene. |
format |
Dataset |
author |
Pagani, Mark Arthur, Michael A Freeman, Katherine H |
author_facet |
Pagani, Mark Arthur, Michael A Freeman, Katherine H |
author_sort |
Pagani, Mark |
title |
(Table 1) Age model of DSDP Site 72-516 |
title_short |
(Table 1) Age model of DSDP Site 72-516 |
title_full |
(Table 1) Age model of DSDP Site 72-516 |
title_fullStr |
(Table 1) Age model of DSDP Site 72-516 |
title_full_unstemmed |
(Table 1) Age model of DSDP Site 72-516 |
title_sort |
(table 1) age model of dsdp site 72-516 |
publisher |
PANGAEA |
publishDate |
2000 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.848096 https://doi.org/10.1594/PANGAEA.848096 |
op_coverage |
MEDIAN LATITUDE: -30.276400 * MEDIAN LONGITUDE: -35.285100 * SOUTH-BOUND LATITUDE: -30.276500 * WEST-BOUND LONGITUDE: -35.285200 * NORTH-BOUND LATITUDE: -30.276300 * EAST-BOUND LONGITUDE: -35.285000 * DATE/TIME START: 1980-03-11T00:00:00 * DATE/TIME END: 1980-03-11T00:00:00 * MINIMUM DEPTH, sediment/rock: 71.1 m * MAXIMUM DEPTH, sediment/rock: 246.0 m |
long_lat |
ENVELOPE(-35.285200,-35.285000,-30.276300,-30.276500) |
geographic |
Antarctic Southern Ocean The Antarctic Drake Passage East Antarctic Ice Sheet |
geographic_facet |
Antarctic Southern Ocean The Antarctic Drake Passage East Antarctic Ice Sheet |
genre |
Antarc* Antarctic Drake Passage Ice Sheet Planktonic foraminifera Southern Ocean |
genre_facet |
Antarc* Antarctic Drake Passage Ice Sheet Planktonic foraminifera Southern Ocean |
op_source |
Supplement to: Pagani, Mark; Arthur, Michael A; Freeman, Katherine H (2000): Variations in Miocene phytoplankton growth rates in the southwest Atlantic: Evidence for changes in ocean circulation. Paleoceanography, 15(5), 486-496, https://doi.org/10.1029/1999PA000484 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.848096 https://doi.org/10.1594/PANGAEA.848096 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.848096 https://doi.org/10.1029/1999PA000484 |
_version_ |
1766273586075533312 |