Late Cenozoic stable isotope record of benthic and planktonic foraminifera from the Pacific Ocean
Stable isotopic analyses of Middle Miocene to Quaternary foraminiferal calcite from east equatorial and central north Pacific DSDP cores have provided much new informatlon on the paleoceanography of the Pacific Neogene The history of delta18O change in planktonic foraminifera reflects the changing I...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.710854 2023-05-15T13:42:09+02:00 Late Cenozoic stable isotope record of benthic and planktonic foraminifera from the Pacific Ocean Keigwin, Lloyd D MEDIAN LATITUDE: 15.367260 * MEDIAN LONGITUDE: -124.647720 * SOUTH-BOUND LATITUDE: -1.761700 * WEST-BOUND LONGITUDE: 176.901500 * NORTH-BOUND LATITUDE: 36.868500 * EAST-BOUND LONGITUDE: -85.236000 * DATE/TIME START: 1971-02-12T00:00:00 * DATE/TIME END: 1973-09-19T00:00:00 1979-12-19 application/zip, 5 datasets https://doi.pangaea.de/10.1594/PANGAEA.710854 https://doi.org/10.1594/PANGAEA.710854 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.710854 https://doi.org/10.1594/PANGAEA.710854 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Keigwin, Lloyd D (1979): Late Cenozoic stable isotope stratigraphy and paleoceanography of DSDP sites from the east equatorial and central north Pacific Ocean. Earth and Planetary Science Letters, 45(2), 361-382, https://doi.org/10.1016/0012-821X(79)90137-7 16-157 16-158 32-310 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg16 Leg32 North Pacific/CONT RISE North Pacific/RIDGE South Pacific/RIDGE Dataset 1979 ftpangaea https://doi.org/10.1594/PANGAEA.710854 https://doi.org/10.1016/0012-821X(79)90137-7 2023-01-20T07:31:19Z Stable isotopic analyses of Middle Miocene to Quaternary foraminiferal calcite from east equatorial and central north Pacific DSDP cores have provided much new informatlon on the paleoceanography of the Pacific Neogene The history of delta18O change in planktonic foraminifera reflects the changing Isotopic composition and temperature of seawater at the time of test formation. Changes in the isotopic composition of benthonic foraminifera largely reflect changes m the volume of continental ice. Isotopic data from these cores indicates the following sequence of events related to continental glaciation (1) A permanent Antarctic ice sheet developed late in the Middle Miocene (about 13 to 11.5 m.y. ago) (2) The Late Miocene (about 11.5 to 5 m.y. ago) is marked by significant variation in delta18O of about 0.5‰ throughout, indicating instability of Antarctic ice cap size or bottom-water temperatures (3) The early Pliocene (5 to about 3 m.y. ago) was a time of relative stability in ice volume and bottom-water temperature (4) Growth of permanent Northern Hemisphere ice sheets is referred to have begun about 3 m.y. ago (5) The late Pliocene (3 to about 1.8 m.y. ago) is marked by one major glaciation or bottom-water cooling dated between about 2.1 to 2.3 m.y. (6) There is some evidence that the frequency of glacial-interglacial cycles increased at about 0.9 m.y. There is significant variation in delta13C at these sites but no geochemical interpretation is offered in this paper. The most outstanding feature of delta13C results is a permanent shift of about -0.8‰ found at about 6.5 m.y. in east equatorial and central north Pacific benthonic foraminifera. This benthonic carbon shift may form a useful marker in deep-sea cores recovering Late Miocene carbonates. Dataset Antarc* Antarctic Ice cap Ice Sheet Planktonic foraminifera PANGAEA - Data Publisher for Earth & Environmental Science Antarctic Pacific ENVELOPE(176.901500,-85.236000,36.868500,-1.761700) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
16-157 16-158 32-310 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg16 Leg32 North Pacific/CONT RISE North Pacific/RIDGE South Pacific/RIDGE |
spellingShingle |
16-157 16-158 32-310 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg16 Leg32 North Pacific/CONT RISE North Pacific/RIDGE South Pacific/RIDGE Keigwin, Lloyd D Late Cenozoic stable isotope record of benthic and planktonic foraminifera from the Pacific Ocean |
topic_facet |
16-157 16-158 32-310 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg16 Leg32 North Pacific/CONT RISE North Pacific/RIDGE South Pacific/RIDGE |
description |
Stable isotopic analyses of Middle Miocene to Quaternary foraminiferal calcite from east equatorial and central north Pacific DSDP cores have provided much new informatlon on the paleoceanography of the Pacific Neogene The history of delta18O change in planktonic foraminifera reflects the changing Isotopic composition and temperature of seawater at the time of test formation. Changes in the isotopic composition of benthonic foraminifera largely reflect changes m the volume of continental ice. Isotopic data from these cores indicates the following sequence of events related to continental glaciation (1) A permanent Antarctic ice sheet developed late in the Middle Miocene (about 13 to 11.5 m.y. ago) (2) The Late Miocene (about 11.5 to 5 m.y. ago) is marked by significant variation in delta18O of about 0.5‰ throughout, indicating instability of Antarctic ice cap size or bottom-water temperatures (3) The early Pliocene (5 to about 3 m.y. ago) was a time of relative stability in ice volume and bottom-water temperature (4) Growth of permanent Northern Hemisphere ice sheets is referred to have begun about 3 m.y. ago (5) The late Pliocene (3 to about 1.8 m.y. ago) is marked by one major glaciation or bottom-water cooling dated between about 2.1 to 2.3 m.y. (6) There is some evidence that the frequency of glacial-interglacial cycles increased at about 0.9 m.y. There is significant variation in delta13C at these sites but no geochemical interpretation is offered in this paper. The most outstanding feature of delta13C results is a permanent shift of about -0.8‰ found at about 6.5 m.y. in east equatorial and central north Pacific benthonic foraminifera. This benthonic carbon shift may form a useful marker in deep-sea cores recovering Late Miocene carbonates. |
format |
Dataset |
author |
Keigwin, Lloyd D |
author_facet |
Keigwin, Lloyd D |
author_sort |
Keigwin, Lloyd D |
title |
Late Cenozoic stable isotope record of benthic and planktonic foraminifera from the Pacific Ocean |
title_short |
Late Cenozoic stable isotope record of benthic and planktonic foraminifera from the Pacific Ocean |
title_full |
Late Cenozoic stable isotope record of benthic and planktonic foraminifera from the Pacific Ocean |
title_fullStr |
Late Cenozoic stable isotope record of benthic and planktonic foraminifera from the Pacific Ocean |
title_full_unstemmed |
Late Cenozoic stable isotope record of benthic and planktonic foraminifera from the Pacific Ocean |
title_sort |
late cenozoic stable isotope record of benthic and planktonic foraminifera from the pacific ocean |
publisher |
PANGAEA |
publishDate |
1979 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.710854 https://doi.org/10.1594/PANGAEA.710854 |
op_coverage |
MEDIAN LATITUDE: 15.367260 * MEDIAN LONGITUDE: -124.647720 * SOUTH-BOUND LATITUDE: -1.761700 * WEST-BOUND LONGITUDE: 176.901500 * NORTH-BOUND LATITUDE: 36.868500 * EAST-BOUND LONGITUDE: -85.236000 * DATE/TIME START: 1971-02-12T00:00:00 * DATE/TIME END: 1973-09-19T00:00:00 |
long_lat |
ENVELOPE(176.901500,-85.236000,36.868500,-1.761700) |
geographic |
Antarctic Pacific |
geographic_facet |
Antarctic Pacific |
genre |
Antarc* Antarctic Ice cap Ice Sheet Planktonic foraminifera |
genre_facet |
Antarc* Antarctic Ice cap Ice Sheet Planktonic foraminifera |
op_source |
Supplement to: Keigwin, Lloyd D (1979): Late Cenozoic stable isotope stratigraphy and paleoceanography of DSDP sites from the east equatorial and central north Pacific Ocean. Earth and Planetary Science Letters, 45(2), 361-382, https://doi.org/10.1016/0012-821X(79)90137-7 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.710854 https://doi.org/10.1594/PANGAEA.710854 |
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.710854 https://doi.org/10.1016/0012-821X(79)90137-7 |
_version_ |
1766163427764469760 |