14C Dating of Humic Acids from Bronze and Iron Age Plant Remains from the Eastern Mediterranean

Author(s)

Eva Maria Wild, Peter Steier, Peter Michael Fischer, Felix Höflmayer

Abstract

Radiocarbon dating of plant remains is often difficult due to the complete dissolution of the samples in the alkaline step of the ABA pretreatment. At the VERA laboratory, this problem was encountered frequently when numerous Bronze and Early Iron Age samples from the eastern Mediterranean were dated in the course of the special research program SCIEM2000 and in other collaborations with archaeologists focused on that area and time period. For these samples, only a 14C age determination of the humic acid fraction was possible. Humic acids from archaeological samples are always assessed as a second-choice material for 14C dating. It is assumed that the 14C ages may be affected by the presence of humic acids originating from other (younger) organic material, e.g. from soil horizons located above a sample. Therefore, when humic acids are dated a verification of the dates is crucial. To address this basic requirement, we started some time ago to date both fractions of charred seeds, wood, and charcoal samples whenever available, i.e. the residue after the ABA treatment and the humic acids extracted from the samples in the alkaline step. The results of this comparison showed that for the investigated eastern Mediterranean archaeological sites, 50 (out of 52) humic acid dates were in agreement with the 14C dates of the respective ABA-treated samples. Statistical analysis of the age differences leads to the conclusion that the extracted humic acids originated from the samples themselves or from contemporaneous material and were not appreciably contaminated by extraneous material of different age.

Organisation(s)

Isotope Physics, Department of Near Eastern Studies

External organisation(s)

Deutsches Archäologisches Institut (DAI), University of Gothenburg

Journal

Radiocarbon

Volume

55

Pages

599-607

No. of pages

9

ISSN

0033-8222

DOI

https://doi.org/10.2458/azu_js_rc.55.16450

Publication date

2013

Peer reviewed

Yes

Austrian Fields of Science 2012

601003 Archaeology, 104020 Radiochemistry, 107001 Archaeometry

Keywords

Portal url

https://ucrisportal.univie.ac.at/en/publications/a56a7777-44d9-4a54-9d21-20dbb18f3f5e