Radiocarbon dating of archaeological textiles at different states of preservation

Abstract

Archaeological textiles are suitable material for radiocarbon dating as they are mainly made of organic matter, such as plant and/or animal fibres. Radiocarbon dating provides objective age estimates of archaeological finds, based on measurements of the carbon-14 isotope present in the organic matter against an internationally used reference standard. However, the quantity and quality of carbon present in the organic matter of archaeological textiles can be affected either by the conditions under which the find was preserved (such as carbonisation, chemical change of organic matter to carbon, and mineralisation, which is the gradual replacement of organic matter by metal degradation products), or by the application of certain interventive methods of conservation (such as, consolidation and the application of organic adhesives that add foreign organic matter/carbon to the textile). Six case studies of archaeological textiles dated using the carbon-14 method are presented here. Two carbonised textile finds, two which were mineralised (one treated with adhesives in the past), and a final two which come from inhumation burials (similar to the textile previously treated with adhesives). This paper includes a discussion and review of the dating method, focusing on sample selection, sample preparation, and by evaluating the efficiency of the technique on textile finds at various states of preservation. This study shows that efficiency of the technique is highly dependable on the amount of carbon present in the finds, which does not seem to be affected by carbonisation, but is greatly affected by mineralisation and the incorporation of foreign organic matter, like synthetic consolidants.