Geochemistry of planktonic foraminifera from DSDP sites in the Atlantic and Pacific Ocean
The lithium content of planktonic foraminiferal calcite has been determined to evaluate temporal variability of seawater Li concentrations over the past 116 m.y. Mean foraminiferal calcite lithium/calcium in each time interval is no more than 16% greater nor 25% less than the mean Li/Ca of all sampl...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.715079 2023-05-15T17:32:34+02:00 Geochemistry of planktonic foraminifera from DSDP sites in the Atlantic and Pacific Ocean Delaney, Margaret Lois Boyle, Edward A MEDIAN LATITUDE: 6.730260 * MEDIAN LONGITUDE: 56.929900 * SOUTH-BOUND LATITUDE: -30.122700 * WEST-BOUND LONGITUDE: -19.851300 * NORTH-BOUND LATITUDE: 32.002200 * EAST-BOUND LONGITUDE: 158.511500 * DATE/TIME START: 1973-05-31T00:00:00 * DATE/TIME END: 1980-07-14T00:00:00 1986-05-15 application/zip, 5 datasets https://doi.pangaea.de/10.1594/PANGAEA.715079 https://doi.org/10.1594/PANGAEA.715079 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.715079 https://doi.org/10.1594/PANGAEA.715079 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Delaney, Margaret Lois; Boyle, Edward A (1986): Lithium in foraminiferal shells: implications for high-temperature hydrothermal circulation fluxes and oceanic crustal generation rates. Earth and Planetary Science Letters, 80(1-2), 91-105, https://doi.org/10.1016/0012-821X(86)90022-1 30-289 32-305 41-366_Site 41-369 41-369A 74-526_Site COMPCORE Composite Core Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg30 Leg32 Leg41 Leg74 North Atlantic/CONT RISE North Atlantic/CONT SLOPE North Pacific/CONT RISE South Atlantic/CREST South Pacific/PLATEAU Dataset 1986 ftpangaea https://doi.org/10.1594/PANGAEA.715079 https://doi.org/10.1016/0012-821X(86)90022-1 2023-01-20T07:31:24Z The lithium content of planktonic foraminiferal calcite has been determined to evaluate temporal variability of seawater Li concentrations over the past 116 m.y. Mean foraminiferal calcite lithium/calcium in each time interval is no more than 16% greater nor 25% less than the mean Li/Ca of all samples. Li/Ca minima are observed for samples from 50-60 m.y. and 80-90 m.y., with Li/Ca about 25% lower than in adjacent time intervals. At no time during the past 40 m.y does mean Li/Ca appear to be higher than that at present. Subject to the limitations imposed by sample coverage and diagenesis, a similar conclusion holds for the past 116 m.y. Coupled with an oceanic mass balance model for Li, these data suggest that: (1) oceanic Li concentrations and, therefore, high-temperature hydrothermal circulation fluxes during the past 40 m.y. (and perhaps the past 100 m.y.) have not been more than perhaps 30-40% greater than at present for intervals any longer than a million years at most, and (2) these fluxes were not a factor of two higher 100 m.y. ago. By inference, variations in oceanic crustal generation rates over these time periods are similarly limited. Decreases in hydrothermal circulation fluxes and crustal generation rates or fluctuations up to 20% in these rates of a few million years duration are not necessarily ruled out by the Li/Ca data. The lack of variability in Li/Ca over time is not unequivocal evidence that hydrothermal fluxes have not varied because the rates of removal processes may be linked to changes in input fluxes. Dataset North Atlantic Planktonic foraminifera PANGAEA - Data Publisher for Earth & Environmental Science Pacific ENVELOPE(-19.851300,158.511500,32.002200,-30.122700) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
30-289 32-305 41-366_Site 41-369 41-369A 74-526_Site COMPCORE Composite Core Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg30 Leg32 Leg41 Leg74 North Atlantic/CONT RISE North Atlantic/CONT SLOPE North Pacific/CONT RISE South Atlantic/CREST South Pacific/PLATEAU |
spellingShingle |
30-289 32-305 41-366_Site 41-369 41-369A 74-526_Site COMPCORE Composite Core Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg30 Leg32 Leg41 Leg74 North Atlantic/CONT RISE North Atlantic/CONT SLOPE North Pacific/CONT RISE South Atlantic/CREST South Pacific/PLATEAU Delaney, Margaret Lois Boyle, Edward A Geochemistry of planktonic foraminifera from DSDP sites in the Atlantic and Pacific Ocean |
topic_facet |
30-289 32-305 41-366_Site 41-369 41-369A 74-526_Site COMPCORE Composite Core Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg30 Leg32 Leg41 Leg74 North Atlantic/CONT RISE North Atlantic/CONT SLOPE North Pacific/CONT RISE South Atlantic/CREST South Pacific/PLATEAU |
description |
The lithium content of planktonic foraminiferal calcite has been determined to evaluate temporal variability of seawater Li concentrations over the past 116 m.y. Mean foraminiferal calcite lithium/calcium in each time interval is no more than 16% greater nor 25% less than the mean Li/Ca of all samples. Li/Ca minima are observed for samples from 50-60 m.y. and 80-90 m.y., with Li/Ca about 25% lower than in adjacent time intervals. At no time during the past 40 m.y does mean Li/Ca appear to be higher than that at present. Subject to the limitations imposed by sample coverage and diagenesis, a similar conclusion holds for the past 116 m.y. Coupled with an oceanic mass balance model for Li, these data suggest that: (1) oceanic Li concentrations and, therefore, high-temperature hydrothermal circulation fluxes during the past 40 m.y. (and perhaps the past 100 m.y.) have not been more than perhaps 30-40% greater than at present for intervals any longer than a million years at most, and (2) these fluxes were not a factor of two higher 100 m.y. ago. By inference, variations in oceanic crustal generation rates over these time periods are similarly limited. Decreases in hydrothermal circulation fluxes and crustal generation rates or fluctuations up to 20% in these rates of a few million years duration are not necessarily ruled out by the Li/Ca data. The lack of variability in Li/Ca over time is not unequivocal evidence that hydrothermal fluxes have not varied because the rates of removal processes may be linked to changes in input fluxes. |
format |
Dataset |
author |
Delaney, Margaret Lois Boyle, Edward A |
author_facet |
Delaney, Margaret Lois Boyle, Edward A |
author_sort |
Delaney, Margaret Lois |
title |
Geochemistry of planktonic foraminifera from DSDP sites in the Atlantic and Pacific Ocean |
title_short |
Geochemistry of planktonic foraminifera from DSDP sites in the Atlantic and Pacific Ocean |
title_full |
Geochemistry of planktonic foraminifera from DSDP sites in the Atlantic and Pacific Ocean |
title_fullStr |
Geochemistry of planktonic foraminifera from DSDP sites in the Atlantic and Pacific Ocean |
title_full_unstemmed |
Geochemistry of planktonic foraminifera from DSDP sites in the Atlantic and Pacific Ocean |
title_sort |
geochemistry of planktonic foraminifera from dsdp sites in the atlantic and pacific ocean |
publisher |
PANGAEA |
publishDate |
1986 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.715079 https://doi.org/10.1594/PANGAEA.715079 |
op_coverage |
MEDIAN LATITUDE: 6.730260 * MEDIAN LONGITUDE: 56.929900 * SOUTH-BOUND LATITUDE: -30.122700 * WEST-BOUND LONGITUDE: -19.851300 * NORTH-BOUND LATITUDE: 32.002200 * EAST-BOUND LONGITUDE: 158.511500 * DATE/TIME START: 1973-05-31T00:00:00 * DATE/TIME END: 1980-07-14T00:00:00 |
long_lat |
ENVELOPE(-19.851300,158.511500,32.002200,-30.122700) |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic Planktonic foraminifera |
genre_facet |
North Atlantic Planktonic foraminifera |
op_source |
Supplement to: Delaney, Margaret Lois; Boyle, Edward A (1986): Lithium in foraminiferal shells: implications for high-temperature hydrothermal circulation fluxes and oceanic crustal generation rates. Earth and Planetary Science Letters, 80(1-2), 91-105, https://doi.org/10.1016/0012-821X(86)90022-1 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.715079 https://doi.org/10.1594/PANGAEA.715079 |
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.715079 https://doi.org/10.1016/0012-821X(86)90022-1 |
_version_ |
1766130747106656256 |