Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-19T06:10:06.200Z Has data issue: false hasContentIssue false

Implications for the Dating of Wisconsinan (Weichselian) Late-Glacial Events of Systematic Radiocarbon Age Differences between Terrestrial Plant Macrofossils from a Site in SW Ireland

Published online by Cambridge University Press:  20 January 2017

Chris S.M. Turney
Affiliation:
Centre for Quaternary Research, Department of Geography, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, United Kingdom
G. Russell Coope
Affiliation:
Centre for Quaternary Research, Department of Geography, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, United Kingdom
Doug D. Harkness
Affiliation:
NERC Radiocarbon Laboratory, Scottish Enterprise Technology Park, East Kilbride, Glasgow, G75 0QU, United Kingdom
J. John Lowe
Affiliation:
Centre for Quaternary Research, Department of Geography, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, United Kingdom
Michael J.C. Walker
Affiliation:
Department of Geography, University of Wales, Lampeter, Ceredigion, Wales, SA48 7ED, United Kingdom

Abstract

AMS radiocarbon dates were obtained from Salix herbacea leaves, Carex seeds, and bulk organic detritus from a lake sediment profile of Wisconsinan (Weichselian) Lateglacial age in SW Ireland. There is a systematic age difference between the dated series from the two types of macrofossils, with ages obtained from Salix herbacea leaves being 900 to 1500 14C years younger than those obtained from Carex seeds. The latter tend to be more in accord with dates from the total organic detritus in the lake sediment, although the bulk organic fraction invariably registered the older ages. Intact survival of the fragile Salix leaves indicates that they are unlikely to have been physically transferred within the sediment matrix and/or otherwise reworked from the surrounding catchment. Hence, these macrofossils are the more likely to be contemporaneous with the time of deposition. However, there is no significant correlation between measured 14C age and depth in the Salix values, which scatter over a range of 700 14C years. In contrast, the age/depth relationship for Carex shows a significant reversal, possibly reflecting the redeposition of these macrofossils, and therefore giving radiocarbon ages that are anomalously old. The data have important implications for the dating of lake sediment sequences by AMS radiocarbon measurement of terrestrial plant macrofossils.

Type
Research Article
Copyright
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ahlberg, K., Almgren, E., Wright, H.E. Jr., Ito, E., Hobbie, S., (1996). Oxygen–isotope record of Late-Glacial climatic change in western Ireland. Boreas 25, 257267.CrossRefGoogle Scholar
Andrieu, V., Huang, C.C., O'Connell, M., Paus, A., (1993). Lateglacial vegetation and environment in Ireland. First results from four western sites. Quaternary Science Reviews 12, 681706.Google Scholar
Ashworth, A.C., (1972). A Late-glacial insect fauna from Red Moss, Lancashire, England. Entomologica Scandinavica 3, 211224.Google Scholar
Atkinson, T.C., Briffa, K.R., Coope, G.R., Joachim, M.J., Perzy, D.W., (1986). Climatic calibration of coleopteran data. Berglund, B.E., Handbook of Holocene Palaeoecology and Palaeohydrology Wiley, Chichester.851858.Google Scholar
Atkinson, T.C., Briffa, K.R., Coope, G.R., (1987). Seasonal temperatures in Britain during the past 22,000 years reconstructed using beetle remains. Nature 352, 587592.Google Scholar
Björck, S., Kromer, B., Johnsen, S., Bennike, O., Hammarlund, D., Lemdahl, G., Possnert, G., Rasmussen, T.L., Wohlfarth, B., Hammer, C.U., Spurk, M., (1996). Synchronized terrestrial–atmospheric deglacial records around the North Atlantic. Science 274, 11551160.Google Scholar
Björck, S., Möller, P., (1987). Late Weichselian environmental history in southeastern Sweden during the deglaciation of the Scandinavian ice sheet. Quaternary Research 28, 137.CrossRefGoogle Scholar
Björck, S., Walker, M.J.C., Cwynar, L., Johnsen, S.J., Knudsen, K.L., Lowe, J.J., Wohlfarth, B., (1998). An event stratigraphy for the Last Termination in the North Atlantic based on the Greenland Ice Core record: A proposal by the INTIMATE group. Journal of Quaternary Science 13, 283292.3.0.CO;2-A>CrossRefGoogle Scholar
Björck, S., Wohlfarth, B., Possnert, G., (1995). 14C AMS measurements from the Late Weichselian part of the Swedish Time Scale. Quaternary International 27, 1118.CrossRefGoogle Scholar
Boutton, T.W., Wong, W.W., Hachey, D.L., Lee, L.S., Cabrera, M.P., Klein, P.D., (1983). Comparison of quartz and pyrex tubes for combustion of organic samples for stable carbon itotope analysis. Analytical Chemistry 55, 18321833.Google Scholar
Brooks, S.J., Mayle, F.E., Lowe, J.J., (1997). Chironomid-based lateglacial climatic reconstruction for southeast Scotland. Journal of Quaternary Science 12, 161167.3.0.CO;2-T>CrossRefGoogle Scholar
Brooks, S.J., Lowe, J.J., Mayle, F.E., (1997). The Late Devensian Lateglacial palaeoenvironmental record from Whitrig Bog, S.E. Scotland. 2. Chironomids. Boreas 26, 297308.CrossRefGoogle Scholar
Bryant, R.H., (1974). A late-Midlandian section at Finglas River, near Waterville, Kerry. Proceedings of the Royal Irish Academy 74, 161178.Google Scholar
Coope, G.R., (1968). Coleoptera from the “Arctic Bed” at Barnwell Station, Cambridge. Geological Magazine 105, 482486.Google Scholar
Coope, G.R., Dickson, J.H., McCutcheon, J.A., Mitchell, G.F., (1979). The Lateglacial and Early Postglacial Deposit at Drumurcher, Co. Monaghan. Proceedings of the Royal Irish Academy B79, 6385.Google Scholar
Cwynar, L.C., Watts, W.A., (1989). Accelerator mass spectrometer ages for Late-glacial events at Ballybetagh, Ireland. Quaternary Research 31, 377380.CrossRefGoogle Scholar
Donahue, D.J., Linick, T.W., Jull, A.J.T., (1990). Isotope ratio and background corrections for accelerator mass spectrometry radiocarbon measurements. Radiocarbon 32, 135142.Google Scholar
Lewis, C.A., (1977). South and South-west Ireland. Geo Abstracts Ltd, Norwich.Google Scholar
Lowe, J.J., (1991). Stratigraphic resolution and radiocarbon dating of Devensian Lateglacial sediments. Quaternary Proceedings 1, 1926.Google Scholar
Lowe, J.J., Coope, G.R., Harkness, D.D., Sheldrick, C., Walker, M.J.C., (1995). Direct comparison of UK temperatures and Greenland snow accumulation rates, 15–12,000 calendar years ago. Journal of Quaternary Science 10, 175180.Google Scholar
Lowe, J.J., Birks, H.H., Brooks, S.J., Coope, G.R., Harkness, D.D., Mayle, F.E., Sheldrick, C., Turney, C.S.M., Walker, M.J.C., (1999). The chronology of palaeoenvironmental changes during the last glacial–Holocene Transition: Towards an event stratigraphy for the British Isles. Quarterly Journal of the Geological Society of London 156, 397410.Google Scholar
Mangerud, J., Anderson, S.T., Berglund, B.E., Donner, J.J., (1974). Quaternary stratigraphy of Norden, a proposal for terminology and classification. Boreas 3, 109126.Google Scholar
Mayle, F.E., Lowe, J.J., Sheldrick, C., (1997). The Late Devensian Lateglacial palaeoenvironmental record from Whitrig Bog, S.E. Scotland. 1. Lithostratigraphy and palaeobotany. Boreas 26, 279295.CrossRefGoogle Scholar
Mayle, F.E., Bell, M., Birks, H.H., Brooks, S.J., Coope, G.R., Lowe, J.J., Sheldrick, C., Li Shijie, , Turney, C.S.M., Walker, M.J.C., (1999). The history of climate variations in Britain during the last glacial–Holocene transition and comparison with the GRIP ice-core record. Quarterly Journal of the Geological Society of London 156, 411423.CrossRefGoogle Scholar
Slota, P.J., Jull, A.J.T., Linick, T.W., Toolin, L.J., (1987). Preparation of small samples for 14C accelerator targets by catalytic reduction of CO. Radiocarbon 29, 303306.CrossRefGoogle Scholar
Stuiver, M., Polach, H.A., (1977). Discussion: Reporting of 14C data. Radiocarbon 19, 355363.CrossRefGoogle Scholar
Sutherland, D.G., (1980). Problems of radiocarbon dating of deposits from newly deglaciated terrain: Examples from the Scottish Lateglacial. Lowe, J.J., Gray, J.M., Robinson, J.E., Studies in the Late-glacial of North-west Europe Pergamon Press, Oxford.139149.Google Scholar
Törnqvist, T.E., de Jong, A.F.M., van der Borg, K., (1992). Accurate dating of organic deposits by AMS 14C measurement of macrofossils. Radiocarbon 34, 566577.CrossRefGoogle Scholar
Turney, C.S.M., (1998). Isotope stratigraphy and tephrochronology of the last glacial–interglacial transition (14-9 ka 14C BP) in the British Isles. University of London, .Google Scholar
Turney, C.S.M., Beerling, D.J., Harkness, D.D., Lowe, J.J., Scott, E.M., (1997). Stable carbon isotope variations in NW Europe during the last glacial-interglacial transition. Journal of Quaternary Science 12, 339344.3.0.CO;2-4>CrossRefGoogle Scholar
Walker, M.J.C., Coope, G.R., Lowe, J.J., (1993). The Devensian (Weichselian) Lateglacial palaeoenvironmental record from Gransmoor, East Yorkshire, England. Quaternary Science Reviews 12, 659680.Google Scholar
Wohlfarth, B., (1996). The chronology of the Last Termination: A review of radiocarbon-dated, high-resolution terrestrial stratigraphies. Quaternary Science Reviews 15, 267284.Google Scholar
Wohlfarth, B., Björck, S., Possnert, G., Lemdahl, G., Brunnberg, L., Ising, J., Olsson, S., Svensson, N.O., (1993). AMS dating Swedish varved clays of the last glacial/interglacial transition and the potential difficulties of calibrating Late Weichselian ‘absolute’ chronologies. Boreas 22, 113128.Google Scholar