Skip to main content

Assessing Open-System Behavior of 14C in Terrestrial Gastropod Shells

  • Jason A Rech (a1), Jeffrey S Pigati (a2), Sophie B Lehmann (a1), Chelsea N McGimpsey (a1), David A Grimley (a3) and Jeffrey C Nekola (a4)...

In order to assess open-system behavior of radiocarbon in fossil gastropod shells, we measured the 14C activity on 10 aliquots of shell material recovered from Illinoian (~190–130 ka) and pre-Illinoian (~800 ka) loess and lacustrine deposits in the Midwestern USA. Eight of the 10 aliquots yielded measurable 14C activities that ranged from 0.25 to 0.53 percent modern carbon (pMC), corresponding to apparent 14C ages between 48.2 and 42.1 ka. This small level of open-system behavior is common in many materials that are used for 14C 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 14C activities of 1.26 and 1.71 pMC, which correspond to apparent 14C 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 14C 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 14C dating.

    • Send article to Kindle

      To send this article to your Kindle, first ensure is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the or variations. ‘’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Assessing Open-System Behavior of 14C in Terrestrial Gastropod Shells
      Available formats
      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Assessing Open-System Behavior of 14C in Terrestrial Gastropod Shells
      Available formats
      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Assessing Open-System Behavior of 14C in Terrestrial Gastropod Shells
      Available formats
Corresponding author
Corresponding author. Email:
Hide All
Brennan, R, Quade, J. 1997. Reliable late-Pleistocene stratigraphic ages and shorter groundwater travel times from 14C in fossil snails from the southern Great Basin. Quaternary Research 47(3):329–36.
Bruckshen, P, Bruhn, F, Meijer, J, Stephan, A, Veizer, J. 1995. Diagenetic alteration of calcitic fossil shells: proton microprobe (PIXE) as a trace element tool. Nuclear Instruments and Methods Physics Research B 104(1–4):427–31.
Eckberg, MP, Lowell, TV, Stuckenrath, R. 1993. Late Wisconsin glacial advance and retreat patterns in southwestern Ohio, USA. Boreas 22(3):189204.
Evans, JG. 1972. Land Snails in Archaeology. New York: Seminar Press.
Evin, J, Marechal, J, Pachiaudi, C. 1980. Conditions involved in dating terrestrial shells. Radiocarbon 22(2):545–55.
Frye, JC, Willman, HB. 1960. Classification of the Wisconsinan Stage in the Lake Michigan glacial lobe. Illinois Geological Survey Circular 285:116.
Geiger, EC. 2008. Paleoecology of Pleistocene gastropods in glacial lake deposits in southern Illinois/Missouri [Master's thesis]. Southern Illinois University. 138 p.
Goodfriend, GA. 1987. Radiocarbon age anomalies in shell carbonate of land snails from semi-arid areas. Radiocarbon 29(2):159–67.
Goodfriend, GA, Hood, DG. 1983. Carbon isotope analysis of land snail shells: implications for carbon sources and radiocarbon dating. Radiocarbon 25(3):810–30.
Goodfriend, GA, Stipp, JJ. 1983. Limestone and the problem of radiocarbon dating of land-snail shell carbonate. Geology 11(10):575–7.
Goslar, T, Pazdur, MF. 1985. Contamination studies on mollusk shell samples. Radiocarbon 27(1):3342.
Johnson, WH. 1986. Stratigraphy and correlation of the glacial deposits of the Lake Michigan lobe prior to 14 ka B.P. Quaternary Science Reviews 5:1722.
Leighton, MM. 1960. The classification of the Wisconsin Glacial Stage of north central United States. Journal of Geology 68(5):529–52.
Leonard, AB, Frye, JC, Johnson, WH. 1971. Illinoian and Kansan molluscan faunas of Illinois. Illinois State Geological Survey Circular 461.
Miller, BB, Graham, RW, Morgan, AV, Miller, NG, McCoy, WD, Palmer, DF, Smith, AJ, Pilny, JJ. 1994. A biota associated with Matuyama-age sediments in west-central Illinois. Quaternary Research 41(3):350–65.
Nekola, JC. 2005. Geographic variation in richness and shell size of eastern North American land snail communities. Records of the Western Australian Museum Supplement 68:3951.
Pigati, JS. 2002. On correcting 14C ages of gastropod shell carbonate for fractionation. Radiocarbon 44(3):755–60.
Pigati, JS, Quade, J, Shanahan, TM, Haynes, CV Jr. 2004. Radiocarbon dating of minute gastropods and new constraints on the timing of spring-discharge deposits in southern Arizona, USA. Palaeogeography, Palaeoclimatology, Palaeoecology 204:3345.
Pigati, JS, Bright, JE, Shanahan, TM, Mahan, SA. 2009. Late Pleistocene paleohydrology near the boundary of the Sonoran and Chihuahuan deserts, southeastern Arizona, USA. Quaternary Science Reviews 28(3–4):286300.
Pigati, JS, Rech, JA, Nekola, JC. 2010. Radiocarbon dating of small terrestrial gastropod shells in North America. Quaternary Geochronology 5(5):519–32.
Quarta, G, Romaniello, L, D'Elia, M, Mastronuzzi, G, Calcagnile, L. 2007. Radiocarbon age anomalies in pre- and post-bomb land snails from the coastal Mediterranean basin. Radiocarbon 49(2):817–26.
Romaniello, L, Quarta, G, Mastronuzzi, G, D'Elia, M, Calcagnile, L. 2008. 14C age anomalies in modern land snails shell carbonate from southern Italy. Quaternary Geochronology 3(1–2):6875.
Rubin, M, Likins, RC, Berry, EG. 1963. On the validity of radiocarbon dates from snail shells. Journal of Geology 71(1):84–9.
Slota, PJ Jr, Jull, AJT, Linick, TW, Toolin, LJ. 1987. Preparation of small samples for 14C accelerator targets by catalytic reduction of CO. Radiocarbon 29(2):303–6.
Tamers, MA. 1970. Validity of radiocarbon dates on terrestrial snail shells. American Antiquity 35(1):94100.
Veizer, J, Ala, D, Azmy, K, Bruckschen, P, Buhl, D, Bruhn, F, Carden, GAF, Diener, A, Ebneth, S, Godderis, Y, Jasper, T, Korte, C, Pawellek, F, Podlaha, OG, Strauss, H. 1999. 87Sr/86Sr, δ13C and δ18O evolution of Phanerozoic seawater. Chemical Geology 161(1–3):5988.
Wade, BS, Kroon, D. 2002. Middle Eocene regional climate instability: evidence from the western North Atlantic. Geology 30(11):1011–4.
Webb, GE, Price, GJ, Nothdurft, LD, Deer, L, Rintoul, L. 2007. Cryptic meteoric diagenesis in freshwater bivalves: implications for radiocarbon dating. Geology 35(9):803–6.
Willman, HB, Frye, JC. 1970. Pleistocene Stratigraphy of Illinois. Bulletin 94. Champaign: Illinois State Geological Survey. 204 p. 3 plates.
Yates, T. 1986. Studies of non-marine mollusks for the selection of shell samples for radiocarbon dating. Radiocarbon 28(2A):457–63.
Zhou, W, Head, WJ, Wang, F, Donahue, DJ, Jull, AJT. 1999. The reliability of AMS radiocarbon dating of shells from China. Radiocarbon 41(1):1724.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

  • ISSN: 0033-8222
  • EISSN: 1945-5755
  • URL: /core/journals/radiocarbon
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed