Provenance of archaeological wool textiles: new case studies

Abstract

In the last two decades, measurements of strontium (Sr) isotopes in archaeological bone tissues/skeletons have shown to be an effective technique for the characterisation of human and animal mobility in prehistory. More recently, this tracing system is also being applied to the investigation of archaeological textile's provenance. The importance of ancient textiles has been often underestimated, however research of archaeological textiles is currently experiencing an extremely increasing interest as the development of new methodologies, conducting experimental studies and lancing of new projects are providing an unreached amount of new information, knowledge and impressive data sets which together build the basis of novel thinking and interpretations. This manuscript aims at summarising two of the most recently developed methods that focus on the extraction of Sr from ancient non-dyed and organic-dyed wool threads from archaeological textiles in an attempt to identify if the raw materials are local or non-local to the sites. In particular, this study presents two case studies which rely on the use of these chemical protocols. The first example deals with a wool/fur sample from a modern Greenlandic Musk ox. The purpose of this study is to characterise wool from an exotic animal on the one side, and to try to establish a link between this wool and a geologically-seen ancient and very special terrain (Archaean basement rocks from the Kangerlussuaq area of Western Greenland) on which this musk ox was grazing. Our interest was focused on whether the bioavailable Sr fraction from this terrain impacted on the composition of the wool from the animal. The second case study deals with three thread samples from four ancient wool textile pieces recovered from one and the same pre-Roman Iron Age peat bog site at Krogens Mølle (Denmark). Some of these textiles have proven to be dyed with organic dyestuffs. This study therefore aimed at applying a novel pre-cleaning methodology developed for dyed (by organic dyestuffs) wool threads from ancient textiles. The outcome of these two particular studies revealed both the potential of these novel methodologies for retrieving the original Sr isotope signature of the raw material wool, and their limitations.

Bronze Age wool: provenance and dye investigations of Danish textiles

“…cross-disciplinary analytical methodologies has made a particularly important contribution. These include: the refinement of wool fibre identifications; different chemical extraction methods for the identification of organic dyestuffs; and new developments in the fields of aDNA and strontium isotope analysis (Benson et al 2006;Frei et al 2009Frei et al , 2010Vanden Berghe et al 2009;Brandt et al 2011;Gleba 2012;Rast-Eicher & Bender Jørgensen 2013;Frei 2014).…”

“…Following the results of dye identification analyses (HPLC), the textile samples were subjected to pre-cleaning processes, prior to dissolution. This ensured the removal of exogenous strontium (as described by Frei 2014;Frei et al 2015a). The authors have successfully applied their pre-cleaning protocols to wool textiles in a large number of previous studies (described in Frei et al 2009), and are therefore confident in applying this methodology.…”

Tracing the dynamic life story of a Bronze Age Female

“…Recent advances in tracing techniques at the individual level provide us with methodologies to map individual mobility during different life stages 1 2 3 4 5 6 7 8 9 10 11 12 13 14 . However, the limited preservation of coexisting hard and soft human tissues often impedes the diachronic investigation of a single individual.…”

Strontium isotope investigations of the Haraldskær Woman – a complex record of various tissues

“…New achievements in the ield of ancient wool textile and human hair analyses (Font et al, 2012, Frei et al, 2015Frei 2014, Frei et al, 2009a, Frei et al, 2010Lynnerup, 2007), have for the irst time made it possible to conduct a complete provenance investigation of a bog body (including teeth, scalp hair and garments) using the strontium isotope tracing system. he exceptional preservation of the Haraldskaer ind provides a unique opportunity to build a sequence of time-snapshots indicating where the woman lived and where her garments were produced (Table 1).…”

“…Recent advances in methodological strontium isotopic tracing techniques in keratin-rich animal and human tissues, provide us with new possibilities to investigate both archaeological textiles as well as ancient human hair (Frei et al, 2015 ;Frei et al, 2009a ;Frei et al, 2010). hese studies focus on developing pre-cleaning procedures that enable the recovery of the nutritional strontium fraction in hair (Font et al, 2012;Frei et al, 2015;Frei, 2014;Lynnerup, 2007). he present study applies these chemical protocols.…”