. (2015) Best practice methodology for 14C calibration of marine and mixed terrestrial/marine samples. Quaternary Geochronology, 27, pp. 164-171. Copyright © 2015 Elsevier B.V.A copy can be downloaded for personal non-commercial research or study, without prior permission or charge Content must not be changed in any way or reproduced in any format or medium without the formal permission of the copyright holder(s) This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Abstract: There is a lack of detailed guidance in the published literature on how to calibrate 14 C measurements made on marine or mixed marine/terrestrial (primarily human remains) samples. We describe what we consider to be the best approach towards achieving the most accurate calibrated age ranges, using the most appropriate ΔR and percentage marine diet estimates, and associated, realistic error terms on these values. However, this approach will increase the calibrated age range(s) by fully accounting for the variability in both the model and the material. While the discussion is based on examples from the UK and Iceland, the same fundamental arguments can be applied in any geographic location largely devoid of C 4 plants as the high δ AbstractThere is a lack of detailed guidance in the published literature on how to calibrate 14 C measurements made on marine or mixed marine/terrestrial (primarily human remains) samples. We describe what we consider to be the best approach towards achieving the most accurate calibrated age ranges, using the most appropriate ∆R and percentage marine diet estimates, and associated, realistic error terms on these values. However, this approach will increase the calibrated age range(s) by fully accounting for the variability in both the model and the material. While the discussion is based on examples from the UK and Iceland, the same fundamental arguments can be applied in any geographic location largely devoid of C 4 plants as the high δ 13C values from such plants can make identification of marine intake difficult to determine.
ABSTRACT. Currently, there is significant ongoing research into the temporal and spatial variability of marine radiocarbon reservoir effects (MREs) through quantification of R values. In turn, MRE studies often use large changes in R values as proxies for changes in ocean circulation. R values are published in a variety of formats with variations in how the errors on these values are calculated, making it difficult to identify trends or to compare values, unless the method of calculating the R is explicitly described or all of the data are made available in the publication. This paper demonstrates the large range in R values (+34 to -122) that can be obtained from a single, secure archaeological context when using the multiple paired sample approach, despite the fact that the terrestrial entities were of statistically indistinguishable 14 C ages, as were the marine samples. This demonstrates the inherent variability in the R calculations themselves and we propose that, together with calculation of mean R, the distribution of R values should be displayed, e.g. as histograms in order to illustrate the full data range. This spread is only apparent when employing a multiple paired sample approach as the uncertainty derived on a single pair of samples, taking account only of the errors on the individual 14 C ages, will never truly represent the overall variability in R that results from the intrinsic variability in the population of 14 C ages in samples that might have been used. Consequently, R values and the associated uncertainty calculated from single pairs should be treated with some caution. We propose that, where possible, when using paired archaeological samples, that a multiple paired approach should be employed as it will test the context security of the material used in the R calculations. When summarizing the values by the weighted average, we also propose that the standard error for predicted values should be employed as this will fully encompass the uncertainty of a future R calculation, using different samples for a similar time and location. Finally, we encourage future publishing of R values using the histogram format, making all of the data available. This will help ensure that R values are comparable across the literature and should provide a framework for standardization of publication methods.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.