Uranium-series coral ages from the US Atlantic Coastal Plain–the ‘‘80 ka problem’’ revisited
Uranium series coral ages for emergent units from the passive continental margin US Atlantic Coastal Plain (ACP) suggest sea level above present levels at the end of marine oxygen isotope stage (MIS) 5, contradicting age-elevation relations based on marine isotopic or coral reef models of ice equiva...
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ftunivnebraskali:oai:digitalcommons.unl.edu:usgsstaffpub-1451 2023-11-12T04:22:30+01:00 Uranium-series coral ages from the US Atlantic Coastal Plain–the ‘‘80 ka problem’’ revisited Wehmiller, John F. Simmons, Kathleen R. Cheng, Hai Edwards, R. Lawrence Martin-McNaughton, Jamie York, Linda L. Krantz, David E. Shen, Chuan-Chou 2004-01-01T08:00:00Z application/pdf https://digitalcommons.unl.edu/usgsstaffpub/442 https://digitalcommons.unl.edu/context/usgsstaffpub/article/1451/viewcontent/Simmons_QI_2004_Uranium_series_coral_ages.pdf unknown DigitalCommons@University of Nebraska - Lincoln https://digitalcommons.unl.edu/usgsstaffpub/442 https://digitalcommons.unl.edu/context/usgsstaffpub/article/1451/viewcontent/Simmons_QI_2004_Uranium_series_coral_ages.pdf USGS Staff -- Published Research Earth Sciences text 2004 ftunivnebraskali 2023-10-30T10:48:05Z Uranium series coral ages for emergent units from the passive continental margin US Atlantic Coastal Plain (ACP) suggest sea level above present levels at the end of marine oxygen isotope stage (MIS) 5, contradicting age-elevation relations based on marine isotopic or coral reef models of ice equivalent sea level. We have reexamined this problem by obtaining high precision 230Th/238U and 231Pa/235U thermal ionization mass spectrometric ages for recently collected and carefully cleaned ACPcorals, many in situ. We recognize samples that show no evidence for diagenesis on the basis of uranium isotopic composition and age concordance. Combining new and earlier data, among those ages close to or within the age range of MIS 5, over 85% cluster between 65 and 85 ka BP. Of the corals that we have analyzed, those that show the least evidence for diagenesis on the basis of uranium isotopic composition and age concordance have ages between 80 and 85 ka BP, consistent with a MIS 5a correlation. The units from which these samples have been collected are all emergent and have elevations within ~3–5m of those few units where early stage 5 (~125,000 ka BP) coral ages have been obtained. The ACP appears to record an unusual history of relative sea level throughout MIS 5, a history that is also apparent in the dated coral record for Bermuda. We speculate that this history is related to the regional (near-to intermediate-field) effects of ancestral Laurentide Ice sheets on last interglacial shorelines of the western North Atlantic. Text North Atlantic University of Nebraska-Lincoln: DigitalCommons@UNL |
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University of Nebraska-Lincoln: DigitalCommons@UNL |
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ftunivnebraskali |
language |
unknown |
topic |
Earth Sciences |
spellingShingle |
Earth Sciences Wehmiller, John F. Simmons, Kathleen R. Cheng, Hai Edwards, R. Lawrence Martin-McNaughton, Jamie York, Linda L. Krantz, David E. Shen, Chuan-Chou Uranium-series coral ages from the US Atlantic Coastal Plain–the ‘‘80 ka problem’’ revisited |
topic_facet |
Earth Sciences |
description |
Uranium series coral ages for emergent units from the passive continental margin US Atlantic Coastal Plain (ACP) suggest sea level above present levels at the end of marine oxygen isotope stage (MIS) 5, contradicting age-elevation relations based on marine isotopic or coral reef models of ice equivalent sea level. We have reexamined this problem by obtaining high precision 230Th/238U and 231Pa/235U thermal ionization mass spectrometric ages for recently collected and carefully cleaned ACPcorals, many in situ. We recognize samples that show no evidence for diagenesis on the basis of uranium isotopic composition and age concordance. Combining new and earlier data, among those ages close to or within the age range of MIS 5, over 85% cluster between 65 and 85 ka BP. Of the corals that we have analyzed, those that show the least evidence for diagenesis on the basis of uranium isotopic composition and age concordance have ages between 80 and 85 ka BP, consistent with a MIS 5a correlation. The units from which these samples have been collected are all emergent and have elevations within ~3–5m of those few units where early stage 5 (~125,000 ka BP) coral ages have been obtained. The ACP appears to record an unusual history of relative sea level throughout MIS 5, a history that is also apparent in the dated coral record for Bermuda. We speculate that this history is related to the regional (near-to intermediate-field) effects of ancestral Laurentide Ice sheets on last interglacial shorelines of the western North Atlantic. |
format |
Text |
author |
Wehmiller, John F. Simmons, Kathleen R. Cheng, Hai Edwards, R. Lawrence Martin-McNaughton, Jamie York, Linda L. Krantz, David E. Shen, Chuan-Chou |
author_facet |
Wehmiller, John F. Simmons, Kathleen R. Cheng, Hai Edwards, R. Lawrence Martin-McNaughton, Jamie York, Linda L. Krantz, David E. Shen, Chuan-Chou |
author_sort |
Wehmiller, John F. |
title |
Uranium-series coral ages from the US Atlantic Coastal Plain–the ‘‘80 ka problem’’ revisited |
title_short |
Uranium-series coral ages from the US Atlantic Coastal Plain–the ‘‘80 ka problem’’ revisited |
title_full |
Uranium-series coral ages from the US Atlantic Coastal Plain–the ‘‘80 ka problem’’ revisited |
title_fullStr |
Uranium-series coral ages from the US Atlantic Coastal Plain–the ‘‘80 ka problem’’ revisited |
title_full_unstemmed |
Uranium-series coral ages from the US Atlantic Coastal Plain–the ‘‘80 ka problem’’ revisited |
title_sort |
uranium-series coral ages from the us atlantic coastal plain–the ‘‘80 ka problem’’ revisited |
publisher |
DigitalCommons@University of Nebraska - Lincoln |
publishDate |
2004 |
url |
https://digitalcommons.unl.edu/usgsstaffpub/442 https://digitalcommons.unl.edu/context/usgsstaffpub/article/1451/viewcontent/Simmons_QI_2004_Uranium_series_coral_ages.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
USGS Staff -- Published Research |
op_relation |
https://digitalcommons.unl.edu/usgsstaffpub/442 https://digitalcommons.unl.edu/context/usgsstaffpub/article/1451/viewcontent/Simmons_QI_2004_Uranium_series_coral_ages.pdf |
_version_ |
1782337540112515072 |