Calling all archaeologists: guidelines for terminology, methodology, data handling, and reporting when undertaking and reviewing stable isotope applications in archaeology.

Alexandre Lucquin,Thomas Larsen,Ricardo Fernandes,Jana Zech,Jillian Swift,Patrick Roberts,Oliver E. Craig

doi:10.1002/rcm.8044

Abstract

Stable isotope analysis has been utilized in archaeology since the 1970s, yet standardized protocols for terminology, sampling, pretreatment evaluation, calibration, quality assurance and control, data presentation, and graphical or statistical treatment still remain lacking in archaeological applications. Here, we present recommendations and requirements for each of these in the archaeological context of: bulk stable carbon and nitrogen isotope analysis of organics; bulk stable carbon and oxygen isotope analysis of carbonates; single compound stable carbon and nitrogen isotope analysis on amino acids in collagen and keratin; and single compound stable carbon and hydrogen isotope analysis on fatty acids. The protocols are based on recommendations from the Commission on Isotopic Abundances and Atomic Weights of the International Union of Pure and Applied Chemistry (IUPAC) as well as an expanding geochemical and archaeological science experimental literature. We hope that this will provide a useful future reference for authors and reviewers engaging with the growing number of stable isotope applications and datasets in archaeology.

Highlights

The archaeological literature has seen an exponential increase in references to stable isotopes over the last half century due to reductions in equipment and sample processing costs, an increasing number of stable isotope laboratories and archaeological science units, and proliferating knowledge of archaeological science applications (Figure 1)
Stable isotope analysis of individual amino acids isolated from bone collagen can be used to determine the proportion of marine versus terrestrial protein in the diet [3]
To make the raw δ values meaningful for cross-study comparison and interpretation, it is essential that the measurements be calibrated to internationally accepted δ scales, using standard reference materials (SRMs) with known isotopic ratios interspersed among samples in each analytical sessions [36,37]

Summary

INTRODUCTION

The archaeological literature has seen an exponential increase in references to stable isotopes over the last half century due to reductions in equipment and sample processing costs, an increasing number of stable isotope laboratories and archaeological science units, and proliferating knowledge of archaeological science applications (Figure 1). Stable isotope analysis of individual amino acids isolated from bone collagen can be used to determine the proportion of marine versus terrestrial protein in the diet [3]. The application of these methods to specific sites, periods, and regions of archaeological interest is increasingly commonplace and often led by archaeologists. While some reviews have touched on a few of these themes in the context of geochemistry as a whole [11,12], and more recently in forensics [13], we have written this article to directly increase information flow to archaeological science practitioners, students, and reviewers less familiar with these techniques We hope this will ensure that archaeologists continue to make substantial contributions to cross-disciplinary advancements of mass spectrometry methods and applications

A NOTE ON TERMINOLOGY

Findings

CONCLUSION