Dating Recent Peat Accumulation in European Ombrotrophic Bogs

Abstract

Dating recent peat accumulation in European ombrotrophic bogsvan der Plicht, J.; Yeloff, D.; van der Linden, M.; van Geel, B.; Brain, S.; Chambers, F.M.; Webb, J.; Toms, P. Published in: Radiocarbon DOI:10.2458/azu_js_rc.55.16057 Link to publication Citation for published version (APA):van der Plicht, J., Yeloff, D., van der Linden, M., van Geel, B., Brain, S., Chambers, F. M., ... Toms, P. (2013). Dating recent peat accumulation in European ombrotrophic bogs. Radiocarbon, 55(2-3), 1763-1778. DOI: 10.2458/azu_js_rc.55.16057 General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. ABSTRACT. This study compares age estimates of recent peat deposits in 10 European ombrotrophic (precipitation-fed) bogs produced using the 14 C bomb peak, 210 Pb, 137 Cs, spheroidal carbonaceous particles (SCPs), and pollen. At 3 sites, the results of the different dating methods agree well. In 5 cores, there is a clear discrepancy between the 14 C bomb peak and 210 Pb age estimates. In the upper layers of the profiles, the age estimates of 14 C and 210 Pb are in agreement. However, with increasing depth, the difference between the age estimates appears to become progressively greater. The evidence from the sites featured in the study suggests that, provided aboveground plant material (seeds, leaves) is selected for dating, the 14 C bomb peak is a reliable dating method, and is not significantly affected by the incorporation of old carbon with low 14 C content originating from sources including air pollution deposition or methane produced by peat decomposition. 210 Pb age estimates that are too old may be explained by the enrichment of 210 Pb activity in the surface layers of peat resulting from a hypothesized mechanism where rapidly infilling hollows, rich in binding sites, may scavenge 210 Pb associated with dissolved organic matter passing through the hollow, as part of the surface drainage network. Until further research identifies and resolves the cause of the inaccuracy in 210 Pb dating, age estimates of peat samples based only on 210 Pb should be used with caution. INTRODUCTIONThe increased human impact on the environment and climate during the last few centuries has given added importance to the reconstruction of environmental change during this period. In addition, the overlap between the environmental monitoring programs of the last 50-100 yr and paleoenvironmental data provides the opportunity to calibrate paleoenvironmental records (Charman and Garnett 2005). The high-precision dating of recen...

The ‘Little Ice Age’ in the Southern Hemisphere in the context of the last 3000 years: Peat-based proxy-climate data from Tierra del Fuego

“…For example, although the dry period from c. ad 1675-1770 is close both in time and duration to that of the Maunder Minimum (ad 1645-1715), limitations of the method preclude more precise dating of the mire data, because the dating of the peat that accumulated during recent centuries is compromised by the acknowledged 'fuzziness' of the calibration (see Figure 2) and the failure of 210 Pb dating at this site. Indeed, it is unfortunate that some other methods to help date the top of the core, which can be used in Europe (Van der Plicht et al, 2013), could not be applied here. Nevertheless, the closeness of fit of the driest episodes in the mire with cold episodes noted elsewhere and with solar minima is striking, even allowing for imprecision in calibrated ages (and therefore possible inaccuracy in dating) in this part of the core.…”