Lead isotopes of feldspar in North Atlantic Ocean sediments
The provenance of ice-rafted debris (IRD) deposited in the North Atlantic before, during, and after Heinrich event 2 has been determined through measuring the lead isotopic composition of single feldspar grains and multiple-grain composites from the larger than 150-µm size fraction, from cores from...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.786112 2023-05-15T16:30:28+02:00 Lead isotopes of feldspar in North Atlantic Ocean sediments Gwiazda, Roberto H Hemming, Sidney R Broecker, Wallace S MEDIAN LATITUDE: 50.179723 * MEDIAN LONGITUDE: -39.754333 * SOUTH-BOUND LATITUDE: 43.400000 * WEST-BOUND LONGITUDE: -59.450000 * NORTH-BOUND LATITUDE: 62.516670 * EAST-BOUND LONGITUDE: -22.270000 * DATE/TIME START: 1966-08-15T00:00:00 * DATE/TIME END: 1970-10-18T00:00:00 1996-07-16 application/zip, 2 datasets https://doi.pangaea.de/10.1594/PANGAEA.786112 https://doi.org/10.1594/PANGAEA.786112 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.786112 https://doi.org/10.1594/PANGAEA.786112 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Gwiazda, Roberto H; Hemming, Sidney R; Broecker, Wallace S (1996): Tracking the sources of icebergs with lead isotopes: The provenance of ice-rafted debris in Heinrich layer 2. Paleoceanography, 11(1), 77-93, https://doi.org/10.1029/95PA03135 Dataset 1996 ftpangaea https://doi.org/10.1594/PANGAEA.786112 https://doi.org/10.1029/95PA03135 2023-01-20T07:32:36Z The provenance of ice-rafted debris (IRD) deposited in the North Atlantic before, during, and after Heinrich event 2 has been determined through measuring the lead isotopic composition of single feldspar grains and multiple-grain composites from the larger than 150-µm size fraction, from cores from the eastern and western North Atlantic and from the Labrador Sea. Single-grain analyses are used to identify the specific continental sources of the IRD, whereas composite samples are used to assess the relative IRD contributions from different sources. All single grains from Heinrich layer 2 (H 2) as well as H 2 composites plot along a correlation line on a 207Pb/204Pb versus 206Pb/204Pb diagram characteristic of the Churchill province of the Canadian shield. This is yet another strong piece of evidence that this Heinrich event was dominated by a massive iceberg discharge of the Laurentide ice sheet lobe located over Hudson Bay. In contrast, single grains from the ambient glacial sediment (above and below H 2) have multiple sources: many of them also lie along the correlation line with H 2 grains, but many others have Pb signatures consistent with derivation from the Grenville province and the Appalachian range in North America and possibly from Scandinavia and Greenland. Composites from the ambient sediment generally lie well to the right of the H 2 reference line in agreement with the results of the single-grain analyses. The evidence provided by lead isotopes regarding the dominant role played by the Hudson Bay lobe of the Laurentide ice sheet in the development of the Heinrich events lends support to the binge/purge model advanced by MacAyeal [1993a, b] that invokes trapping of geothermal heat by the base of the icecap and subsequent basal melting as the mechanism that triggered the Heinrich events. Dataset Greenland Hudson Bay Ice Sheet Labrador Sea North Atlantic PANGAEA - Data Publisher for Earth & Environmental Science Hudson Bay Greenland Hudson ENVELOPE(-59.450000,-22.270000,62.516670,43.400000) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
description |
The provenance of ice-rafted debris (IRD) deposited in the North Atlantic before, during, and after Heinrich event 2 has been determined through measuring the lead isotopic composition of single feldspar grains and multiple-grain composites from the larger than 150-µm size fraction, from cores from the eastern and western North Atlantic and from the Labrador Sea. Single-grain analyses are used to identify the specific continental sources of the IRD, whereas composite samples are used to assess the relative IRD contributions from different sources. All single grains from Heinrich layer 2 (H 2) as well as H 2 composites plot along a correlation line on a 207Pb/204Pb versus 206Pb/204Pb diagram characteristic of the Churchill province of the Canadian shield. This is yet another strong piece of evidence that this Heinrich event was dominated by a massive iceberg discharge of the Laurentide ice sheet lobe located over Hudson Bay. In contrast, single grains from the ambient glacial sediment (above and below H 2) have multiple sources: many of them also lie along the correlation line with H 2 grains, but many others have Pb signatures consistent with derivation from the Grenville province and the Appalachian range in North America and possibly from Scandinavia and Greenland. Composites from the ambient sediment generally lie well to the right of the H 2 reference line in agreement with the results of the single-grain analyses. The evidence provided by lead isotopes regarding the dominant role played by the Hudson Bay lobe of the Laurentide ice sheet in the development of the Heinrich events lends support to the binge/purge model advanced by MacAyeal [1993a, b] that invokes trapping of geothermal heat by the base of the icecap and subsequent basal melting as the mechanism that triggered the Heinrich events. |
format |
Dataset |
author |
Gwiazda, Roberto H Hemming, Sidney R Broecker, Wallace S |
spellingShingle |
Gwiazda, Roberto H Hemming, Sidney R Broecker, Wallace S Lead isotopes of feldspar in North Atlantic Ocean sediments |
author_facet |
Gwiazda, Roberto H Hemming, Sidney R Broecker, Wallace S |
author_sort |
Gwiazda, Roberto H |
title |
Lead isotopes of feldspar in North Atlantic Ocean sediments |
title_short |
Lead isotopes of feldspar in North Atlantic Ocean sediments |
title_full |
Lead isotopes of feldspar in North Atlantic Ocean sediments |
title_fullStr |
Lead isotopes of feldspar in North Atlantic Ocean sediments |
title_full_unstemmed |
Lead isotopes of feldspar in North Atlantic Ocean sediments |
title_sort |
lead isotopes of feldspar in north atlantic ocean sediments |
publisher |
PANGAEA |
publishDate |
1996 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.786112 https://doi.org/10.1594/PANGAEA.786112 |
op_coverage |
MEDIAN LATITUDE: 50.179723 * MEDIAN LONGITUDE: -39.754333 * SOUTH-BOUND LATITUDE: 43.400000 * WEST-BOUND LONGITUDE: -59.450000 * NORTH-BOUND LATITUDE: 62.516670 * EAST-BOUND LONGITUDE: -22.270000 * DATE/TIME START: 1966-08-15T00:00:00 * DATE/TIME END: 1970-10-18T00:00:00 |
long_lat |
ENVELOPE(-59.450000,-22.270000,62.516670,43.400000) |
geographic |
Hudson Bay Greenland Hudson |
geographic_facet |
Hudson Bay Greenland Hudson |
genre |
Greenland Hudson Bay Ice Sheet Labrador Sea North Atlantic |
genre_facet |
Greenland Hudson Bay Ice Sheet Labrador Sea North Atlantic |
op_source |
Supplement to: Gwiazda, Roberto H; Hemming, Sidney R; Broecker, Wallace S (1996): Tracking the sources of icebergs with lead isotopes: The provenance of ice-rafted debris in Heinrich layer 2. Paleoceanography, 11(1), 77-93, https://doi.org/10.1029/95PA03135 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.786112 https://doi.org/10.1594/PANGAEA.786112 |
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.786112 https://doi.org/10.1029/95PA03135 |
_version_ |
1766020190906089472 |