Zooming in on Heinrich layers
Theories explaining the origin of the abrupt, massive discharges of ice-rafted detritus (IRD) into the glacial North Atlantic (the Heinrich layers (HLs)) generally point to the Laurentide ice sheet as the sole source of these events, until it was found that the IRDs also originated from Icelandic an...
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2001
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Online Access: | https://doi.org/10.1029/2000PA000559 https://archimer.ifremer.fr/doc/00221/33190/31786.pdf https://archimer.ifremer.fr/doc/00221/33190/ |
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fttriple:oai:gotriple.eu:10670/1.qn7gq9 2023-05-15T16:41:15+02:00 Zooming in on Heinrich layers Grousset, Fe Cortijo, E Huon, S Herve, L Richter, T Burdloff, D Duprat, J Weber, O 2001-01-01 https://doi.org/10.1029/2000PA000559 https://archimer.ifremer.fr/doc/00221/33190/31786.pdf https://archimer.ifremer.fr/doc/00221/33190/ en eng Amer Geophysical Union doi:10.1029/2000PA000559 10670/1.qn7gq9 https://archimer.ifremer.fr/doc/00221/33190/31786.pdf https://archimer.ifremer.fr/doc/00221/33190/ other Archimer, archive institutionnelle de l'Ifremer Paleoceanography (0883-8305) (Amer Geophysical Union), 2001-06 , Vol. 16 , N. 3 , P. 240-259 geo envir Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ 2001 fttriple https://doi.org/10.1029/2000PA000559 2023-01-22T17:06:23Z Theories explaining the origin of the abrupt, massive discharges of ice-rafted detritus (IRD) into the glacial North Atlantic (the Heinrich layers (HLs)) generally point to the Laurentide ice sheet as the sole source of these events, until it was found that the IRDs also originated from Icelandic and European ice sheets [Bond and Lotti, 1995; Snoeckx er al., 1999; Grousset et al., 2000]. This apparent contradiction must be reconciled as it raises fundamental questions about the mechanism(s) of HL origin. We have analyzed two similar to 12 cm thick HLs in an ultrahigh-resolution mode (1-2 century intervals) in a mid-Atlantic ridge piston core. The delta O-18 record (N. pachyderma left coiling) reveals strong excursions induced by the melting of the icebergs; these excursions are associated with a strong decrease in the amount of planktic foraminifers and with a 30 degreesC cooling of the surface waters. Counts of coarse detrital grains reveal that IRD are deposited according to a typical sequence (I) volcanic glass, (2) quartz and feldspars, (3) detrital carbonate, that implies a chronology in the melting of the differentpan-Atlantic ice sheets. Sr and Nd isotopic composition confirm that in both Heinrich layers H1 and H2, "precursor" IRD came from first Europe/Iceland, followed then by Laurentide-derived IRD. An internal cyclicity can be identified: during H1 and H2, about four to six major, abrupt discharges occurred roughly on a century timescale. The delta C-13 and delta N-15 records reveal that dominant inputs of continent-derived organic matter are associated with IRD within the HLs, hiding the plankton productivity signal. Text Ice Sheet Iceland North Atlantic Unknown Mid-Atlantic Ridge Paleoceanography 16 3 240 259 |
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language |
English |
topic |
geo envir |
spellingShingle |
geo envir Grousset, Fe Cortijo, E Huon, S Herve, L Richter, T Burdloff, D Duprat, J Weber, O Zooming in on Heinrich layers |
topic_facet |
geo envir |
description |
Theories explaining the origin of the abrupt, massive discharges of ice-rafted detritus (IRD) into the glacial North Atlantic (the Heinrich layers (HLs)) generally point to the Laurentide ice sheet as the sole source of these events, until it was found that the IRDs also originated from Icelandic and European ice sheets [Bond and Lotti, 1995; Snoeckx er al., 1999; Grousset et al., 2000]. This apparent contradiction must be reconciled as it raises fundamental questions about the mechanism(s) of HL origin. We have analyzed two similar to 12 cm thick HLs in an ultrahigh-resolution mode (1-2 century intervals) in a mid-Atlantic ridge piston core. The delta O-18 record (N. pachyderma left coiling) reveals strong excursions induced by the melting of the icebergs; these excursions are associated with a strong decrease in the amount of planktic foraminifers and with a 30 degreesC cooling of the surface waters. Counts of coarse detrital grains reveal that IRD are deposited according to a typical sequence (I) volcanic glass, (2) quartz and feldspars, (3) detrital carbonate, that implies a chronology in the melting of the differentpan-Atlantic ice sheets. Sr and Nd isotopic composition confirm that in both Heinrich layers H1 and H2, "precursor" IRD came from first Europe/Iceland, followed then by Laurentide-derived IRD. An internal cyclicity can be identified: during H1 and H2, about four to six major, abrupt discharges occurred roughly on a century timescale. The delta C-13 and delta N-15 records reveal that dominant inputs of continent-derived organic matter are associated with IRD within the HLs, hiding the plankton productivity signal. |
format |
Text |
author |
Grousset, Fe Cortijo, E Huon, S Herve, L Richter, T Burdloff, D Duprat, J Weber, O |
author_facet |
Grousset, Fe Cortijo, E Huon, S Herve, L Richter, T Burdloff, D Duprat, J Weber, O |
author_sort |
Grousset, Fe |
title |
Zooming in on Heinrich layers |
title_short |
Zooming in on Heinrich layers |
title_full |
Zooming in on Heinrich layers |
title_fullStr |
Zooming in on Heinrich layers |
title_full_unstemmed |
Zooming in on Heinrich layers |
title_sort |
zooming in on heinrich layers |
publisher |
Amer Geophysical Union |
publishDate |
2001 |
url |
https://doi.org/10.1029/2000PA000559 https://archimer.ifremer.fr/doc/00221/33190/31786.pdf https://archimer.ifremer.fr/doc/00221/33190/ |
geographic |
Mid-Atlantic Ridge |
geographic_facet |
Mid-Atlantic Ridge |
genre |
Ice Sheet Iceland North Atlantic |
genre_facet |
Ice Sheet Iceland North Atlantic |
op_source |
Archimer, archive institutionnelle de l'Ifremer Paleoceanography (0883-8305) (Amer Geophysical Union), 2001-06 , Vol. 16 , N. 3 , P. 240-259 |
op_relation |
doi:10.1029/2000PA000559 10670/1.qn7gq9 https://archimer.ifremer.fr/doc/00221/33190/31786.pdf https://archimer.ifremer.fr/doc/00221/33190/ |
op_rights |
other |
op_doi |
https://doi.org/10.1029/2000PA000559 |
container_title |
Paleoceanography |
container_volume |
16 |
container_issue |
3 |
container_start_page |
240 |
op_container_end_page |
259 |
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1766031686669172736 |