Natural concentrations of lead in ancient Arctic and Antarctic ice
Concentrations of Pb and K were determined in a series of veneer layers chiseled in sequence from the outside toward the center of each of the five 1500–5500yr old ice core sections that had been drilled in Greenland and Antarctic ice. They were analogs of very old ice samples analyzed earlier by...
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1981
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ftcaltechauth:oai:authors.library.caltech.edu:8m2dm-v6f65 2024-06-23T07:47:56+00:00 Natural concentrations of lead in ancient Arctic and Antarctic ice Ng, Amy Patterson, Clair 1981-11 https://doi.org/10.1016/0016-7037(81)90064-8 unknown Elsevier oai:authors.library.caltech.edu:8m2dm-v6f65 eprintid:44968 https://doi.org/10.1016/0016-7037(81)90064-8 resolverid:CaltechAUTHORS:20140416-073902631 info:eu-repo/semantics/closedAccess Other Geochimica et Cosmochimica Acta, 45(11), 2109-2121, (1981-11) info:eu-repo/semantics/article 1981 ftcaltechauth https://doi.org/10.1016/0016-7037(81)90064-8 2024-06-12T02:25:05Z Concentrations of Pb and K were determined in a series of veneer layers chiseled in sequence from the outside toward the center of each of the five 1500–5500yr old ice core sections that had been drilled in Greenland and Antarctic ice. They were analogs of very old ice samples analyzed earlier by Herronet al. (1977) and Craginet al. (1975), who reported high concentrations of Pb in them. Lead contamination, existing at exterior concentrations of about 10^6 ng/kg ice, had intruded to the centers of the cores, establishing interior values of at least 1.4 ng/kg ice in three electromechanically drilled Camp Century core sections taken from fluid filled drill holes. Corresponding Pb concentration changes were 3 × 10^4 ng/kg ice to 1.2 ng/kg ice in two thermally drilled New Byrd Station core sections taken from non-fluid filled drill holes. Contamination made the lowest center concentrations serve only as upper limits to the original concentrations of Pb in the ice. Potassium concentrations decreased from exterior values of about 5 × 10^5 ng/kg ice to an interior value of 2 × 10^3 ng/kg ice in the Camp Century core sections and from 8 × 10^4 ng/kg ice to 9 × 10^2 ng/kg ice in New Byrd Station core sections. Potassium contamination effects were not large within the central portions of the cores. These data verify earlier findings by Murozumiet al. (1969) and extend to a broader geographical significance the general validity of their observation of a ~ 300-fold increase of Pb concentrations in the Greenland ice sheet during the past 3000 yr. Our findings refute claims by Herronet al. (1977) and Craguinet al. (1975) that 100-fold excesses of natural Pb exist in 800 yr old Greenland ice above levels contributed by silicate dusts. Our new data also show that average Pb concentrations of 26 ng Pb/kg ice, claimed by Boutron and Lorius (1979) to be natural and present for 60 yr in snow strata in Antarctica, did not exist in old Antarctic ice, and that Pb concentrations have increased at least 10-fold in that ice during ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Arctic Greenland ice core Ice Sheet Caltech Authors (California Institute of Technology) Antarctic Arctic Byrd Byrd Station ENVELOPE(-119.533,-119.533,-80.017,-80.017) Greenland Lorius ENVELOPE(162.350,162.350,-72.467,-72.467) Geochimica et Cosmochimica Acta 45 11 2109 2121 |
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Caltech Authors (California Institute of Technology) |
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unknown |
description |
Concentrations of Pb and K were determined in a series of veneer layers chiseled in sequence from the outside toward the center of each of the five 1500–5500yr old ice core sections that had been drilled in Greenland and Antarctic ice. They were analogs of very old ice samples analyzed earlier by Herronet al. (1977) and Craginet al. (1975), who reported high concentrations of Pb in them. Lead contamination, existing at exterior concentrations of about 10^6 ng/kg ice, had intruded to the centers of the cores, establishing interior values of at least 1.4 ng/kg ice in three electromechanically drilled Camp Century core sections taken from fluid filled drill holes. Corresponding Pb concentration changes were 3 × 10^4 ng/kg ice to 1.2 ng/kg ice in two thermally drilled New Byrd Station core sections taken from non-fluid filled drill holes. Contamination made the lowest center concentrations serve only as upper limits to the original concentrations of Pb in the ice. Potassium concentrations decreased from exterior values of about 5 × 10^5 ng/kg ice to an interior value of 2 × 10^3 ng/kg ice in the Camp Century core sections and from 8 × 10^4 ng/kg ice to 9 × 10^2 ng/kg ice in New Byrd Station core sections. Potassium contamination effects were not large within the central portions of the cores. These data verify earlier findings by Murozumiet al. (1969) and extend to a broader geographical significance the general validity of their observation of a ~ 300-fold increase of Pb concentrations in the Greenland ice sheet during the past 3000 yr. Our findings refute claims by Herronet al. (1977) and Craguinet al. (1975) that 100-fold excesses of natural Pb exist in 800 yr old Greenland ice above levels contributed by silicate dusts. Our new data also show that average Pb concentrations of 26 ng Pb/kg ice, claimed by Boutron and Lorius (1979) to be natural and present for 60 yr in snow strata in Antarctica, did not exist in old Antarctic ice, and that Pb concentrations have increased at least 10-fold in that ice during ... |
format |
Article in Journal/Newspaper |
author |
Ng, Amy Patterson, Clair |
spellingShingle |
Ng, Amy Patterson, Clair Natural concentrations of lead in ancient Arctic and Antarctic ice |
author_facet |
Ng, Amy Patterson, Clair |
author_sort |
Ng, Amy |
title |
Natural concentrations of lead in ancient Arctic and Antarctic ice |
title_short |
Natural concentrations of lead in ancient Arctic and Antarctic ice |
title_full |
Natural concentrations of lead in ancient Arctic and Antarctic ice |
title_fullStr |
Natural concentrations of lead in ancient Arctic and Antarctic ice |
title_full_unstemmed |
Natural concentrations of lead in ancient Arctic and Antarctic ice |
title_sort |
natural concentrations of lead in ancient arctic and antarctic ice |
publisher |
Elsevier |
publishDate |
1981 |
url |
https://doi.org/10.1016/0016-7037(81)90064-8 |
long_lat |
ENVELOPE(-119.533,-119.533,-80.017,-80.017) ENVELOPE(162.350,162.350,-72.467,-72.467) |
geographic |
Antarctic Arctic Byrd Byrd Station Greenland Lorius |
geographic_facet |
Antarctic Arctic Byrd Byrd Station Greenland Lorius |
genre |
Antarc* Antarctic Antarctica Arctic Greenland ice core Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Arctic Greenland ice core Ice Sheet |
op_source |
Geochimica et Cosmochimica Acta, 45(11), 2109-2121, (1981-11) |
op_relation |
oai:authors.library.caltech.edu:8m2dm-v6f65 eprintid:44968 https://doi.org/10.1016/0016-7037(81)90064-8 resolverid:CaltechAUTHORS:20140416-073902631 |
op_rights |
info:eu-repo/semantics/closedAccess Other |
op_doi |
https://doi.org/10.1016/0016-7037(81)90064-8 |
container_title |
Geochimica et Cosmochimica Acta |
container_volume |
45 |
container_issue |
11 |
container_start_page |
2109 |
op_container_end_page |
2121 |
_version_ |
1802638198954786816 |