{
"USGS Publications Warehouse": {
"@context": "https://schema.org",
"@type": "Article",
"additionalType": "Journal Article",
"name": "Assessing open-system behavior of 14C in terrestrial gastropod shells",
"identifier": [
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"@type": "PropertyValue",
"propertyID": "USGS Publications Warehouse IndexID",
"value": "70036384",
"url": "https://pubs.usgs.gov/publication/70036384"
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"value": 70036384
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"propertyID": "DOI",
"value": "10.1017/S0033822200056587",
"url": "https://doi.org/10.1017/S0033822200056587"
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"propertyID": "ISSN",
"value": "00338222"
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],
"journal": {
"@type": "Periodical",
"name": "Radiocarbon",
"volumeNumber": "53",
"issueNumber": "2"
},
"inLanguage": "en",
"isPartOf": [
{
"@type": "CreativeWorkSeries",
"name": "Radiocarbon"
}
],
"datePublished": "2011",
"dateModified": "2021-05-20",
"abstract": "In order to assess open-system behavior of radiocarbon in fossil gastropod shells, we measured the\u00a014C activity on 10 aliquots of shell material recovered from Illinoian (~190\u2013130 ka) and pre-Illinoian (~800 ka) loess and lacustrine deposits in the Midwestern USA. Eight of the 10 aliquots yielded measurable\u00a014C activities that ranged from 0.25 to 0.53 percent modern carbon (pMC), corresponding to apparent\u00a014C ages between 48.2 and 42.1 ka. This small level of open-system behavior is common in many materials that are used for\u00a014C dating (e.g. charcoal), and typically sets the upper practical limit of the technique. Two aliquots of gastropod shells from the Illinoian-aged Petersburg Silt (Petersburg Section) in central Illinois, USA, however, yielded elevated\u00a014C activities of 1.26 and 1.71 pMC, which correspond to apparent\u00a014C ages of 35.1 and 32.7 ka. Together, these results suggest that while many fossil gastropods shells may not suffer from major (>1%) open-system problems, this is not always the case. We then examined the mineralogy, trace element chemistry, and physical characteristics of a suite of fossil and modern gastropod shells to identify the source of contamination in the Petersburg shells and assess the effectiveness of these screening techniques at identifying samples suitable for\u00a014C dating. Mineralogical (XRD) and trace element analyses were inconclusive, which suggests that these techniques are not suitable for assessing open-system behavior in terrestrial gastropod shells. Analysis with scanning electron microscopy (SEM), however, identified secondary mineralization (calcium carbonate) primarily within the inner whorls of the Petersburg shells. This indicates that SEM examination, or possibly standard microscope examination, of the interior of gastropod shells should be used when selecting fossil gastropod shells for\u00a014C dating.",
"description": "11 p.",
"publisher": {
"@type": "Organization",
"name": "Cambridge University Press"
},
"author": [
{
"@type": "Person",
"name": "Rech, J.A.",
"givenName": "J.A.",
"familyName": "Rech"
},
{
"@type": "Person",
"name": "Nekola, J.C.",
"givenName": "J.C.",
"familyName": "Nekola"
},
{
"@type": "Person",
"name": "Pigati, Jeffrey S. jpigati@usgs.gov",
"givenName": "Jeffrey S.",
"familyName": "Pigati",
"email": "jpigati@usgs.gov",
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"propertyID": "ORCID",
"value": "0000-0001-5843-6219",
"url": "https://orcid.org/0000-0001-5843-6219"
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"affiliation": [
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"@type": "Organization",
"name": "Geosciences and Environmental Change Science Center",
"url": "https://www.usgs.gov/centers/geosciences-and-environmental-change-science-center"
}
]
},
{
"@type": "Person",
"name": "Lehmann, S.B.",
"givenName": "S.B.",
"familyName": "Lehmann"
},
{
"@type": "Person",
"name": "McGimpsey, C.N.",
"givenName": "C.N.",
"familyName": "McGimpsey"
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{
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"name": "Grimley, D.A.",
"givenName": "D.A.",
"familyName": "Grimley"
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