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
- 20 January 2000
- journal article
- Published by Cambridge University Press (CUP) in Quaternary Research
- Vol. 53 (1) , 114-121
- https://doi.org/10.1006/qres.1999.2087
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 14 C 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 14 C age and depth in the Salix values, which scatter over a range of 700 14 C 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.Keywords
This publication has 26 references indexed in Scilit:
- The Late Devensian Lateglacial palaeoenvironmental record from Whitrig Bog, SE Scotland. 2. Chironomidae (Insecta: Diptera)Boreas, 1997
- The Late Devensian Lateglacial palaeoenvironmental record from Whitrig Bog, SE Scotland. 1. Lithostratigraphy, geochemistry and palaeobotanyBoreas, 1997
- Stable carbon isotope variations in northwest Europe during the last glacial–interglacial transitionJournal of Quaternary Science, 1997
- Chironomid-based Lateglacial climatic reconstruction for southeast ScotlandJournal of Quaternary Science, 1997
- The chronology of the last termination: A review of radiocarbon-dated, high-resolution terrestrial stratigraphiesQuaternary Science Reviews, 1996
- Oxygen‐isotope record of Late‐Glacial climatic change in western IrelandBoreas, 1996
- AMS dating Swedish varved clays of the last glacial/interglacial transition and the potential/difficulties of calibrating Late Weichselian ‘absolute’ chronologiesBoreas, 1993
- The Devensian (Weichselian) Lateglacial palaeoenvironmental record from Gransmoor, East Yorkshire, EnglandQuaternary Science Reviews, 1993
- Late Weichselian Environmental History in Southeastern Sweden during the Deglaciation of the Scandinavian Ice SheetQuaternary Research, 1987
- Coleoptera from the “Arctic Bed ” at Barnwell Station, CambridgeGeological Magazine, 1968