Removal of natural organic dyes from wool–implications for ancient textile provenance studies

Ancient wool textiles recovered from archaeological sites are in many cases originally dyed with natural organic dyestuffs from vegetable sources. These include among others woad (Isatis tinctoria L.), weld (Reseda luteola L.), and madder (Rubia tinctorum L.). These dyestuffs could be a threat to the use of the strontium isotopic system as a tracer for provenance studies of ancient wool, because they could potentially contaminate the signature of the textile's raw material. We present a novel method which allows for efficient removal of organic dyestuffs in wool prior to strontium isotopic analysis. Our method is based on an oxidative release of the dyestuff constituents by ammonium peroxodisulfate [(NH₄)₂S₂O₈] solution, combined with hydrofluoric acid (HF) that has shown to effectively remove/dissolve adhering dust micro-particles. Our multi-analytical results show that such a pretreatment is capable of removing >98% of the originally present organic dyestuffs without significantly destroying the wool structure. The strontium isotopic ratios of the residual wool fraction after the application of the pretreatment are sensitive to the origin and, therefore, can be used as tracers for the provenance of the raw material. We propose to apply this method to ancient wool textiles in which positive identification of organic dyestuff constituents by High Performance Liquid Chromatography (HPLC) was made.     

Late Holocene Neotropical agricultural landscapes: phytolith and stable carbon isotope analysis of raised fields from French Guianan coastal savannahs

This paper summarizes phytolith analyses from four pre-Columbian agricultural raised-field sites of the coastal savannahs of French Guiana—Savane Grand Macoua, Piliwa, Bois Diable and K-VIII—and carbon isotope analyses from the first-named site. The combined phytolith and ¹³C isotope analyses evidence the transformation of the landscape from a relatively homogeneous wetland vegetation comprised of a mixture of C4 and C3 plants (the latter including Cyperaceae and other herbaceous monocots such as Marantaceae and Heliconia, Oryzoideae grasses, and other plants typical of frequently flooded areas) to the construction of raised fields that were dominated by C4 plants (maize and other Panicoideae grasses). Our analysis proves the utility of phytoliths for tracing the agricultural history of landscapes, showing that, as in other parts of the Central and South American lowlands, maize (Zea mays) was one important crop cultivated in raised fields. We also estimated the productivity of raised-field agriculture, showing that in combination with other subsistence activities, it certainly had the capacity to sustain sizeable populations.     

Stable nitrogen isotopic examination of Norse sites in the Western settlement of Greenland

To continue to explore the impact of past human activity on the stable nitrogen isotope ratios of modern vegetation, we have measured the δ¹⁵N values of plants now growing on several ancient farmsteads in the Western Settlement of Norse Greenland. Although this new test area is some 400 km north and in a different ecoregion from the previous study area, the same isotopic effect was observed. A clear isotopic signature was found on the ancient farms which could be directly correlated to past activity areas; in particular, the infields. Further, the magnitude of the δ¹⁵N values was found to be similar between study areas, indicating the same interpretative framework can be applied in widely separate geographic regions. A first test of different plant species showed that although the magnitude differed greatly the same basic information was found for functionally different plants. These observations provide additional information to aid in future archaeological application of this newly observed phenomenon.     

Romita pottery revisited: a reassessment of the provenance of ceramics from Colonial Mexico by LA-MC-ICP-MS

The origin of Romita pottery has been a controversial topic during the last three decades of Colonial Mexico archaeological studies. Lead isotopic analyses of glaze coatings of Spanish and Mexican pottery, and Romita ceramics unearthed from the archaeological site of the Metropolitan Cathedral in Mexico City provide evidence that support a Mexican origin.     

Lead isotope and chemical signature of copper from Oman and its occurrence in Mesopotamia and sites on the Arabian Gulf coast

Lead isotope data, together with an evaluation of previously published results for the chemical composition of Omani ores and copper‐base artefacts are used to define a material signature of Omani copper. Absent from our group of Bronze Age metal (Umm an Nar and Wadi Suq periods) are the signature of ores from Masirah Island and also from the vast deposits in north Oman inland from Suhar. Contemporaneous copper from Bahrain and from Tell Abraq on the Gulf coast is consistent in its material signature with Omani copper; a derivation from Omani ores of this copper is highly likely. A few exceptions at Tell Abraq point to Faynan/Timna in the southern Levant as a possible source region. Among Mesopotamian artefacts the signature of Omani copper is encountered during all cultural periods from Uruk at the end of the fourth millennium BC to Akkadian 1000 years later. Oman/Magan appears to have been particularly important during Early Dynastic III and Akkadian when about half of the copper in circulation bears the Omani signature.     

Chlorine stable isotope ratios as tracer for pore‐water advection rates in a submarine gas‐hydrate field: implication for hydrate concentration

At Ocean Drilling Program Site 997 in Blake Ridge gas‐hydrate field in West Atlantic, pore‐water studies revealed a pronounced downward depletion of the heavy chlorine isotope to nearly ?4‰δ³⁷Cl at approximately 750 m below sea floor (mbsf) associated with a 10% downward chlorinity decrease. This is one of the stronger ³⁷Cl depletions hitherto reported for marine pore waters. Chlorinity reductions in hydrate‐bearing sediments commonly result from fresh‐water release by hydrate melting. However, in situ measurements at Site 997 suggest that >50% of the chlorinity reduction occurred prior to hydrate dissociation. Modeling the chlorinity profile shows that advection of a strongly ³⁷Cl‐depleted, low‐chlorinity water (506 mm ) from below the drilled sequence can explain the reduction prior to sampling. Fitting the model to the δ³⁷Cl curve yielded an advection rate of 0.18 mm year^?1. Diffusive mixing with near‐0‰‐δ³⁷Cl paleo‐seawater with maximum chlorinity at shallow subsurface depths (561 mm at approximately 20 mbsf) produced the smooth, steady trend. Separating that part of the freshening caused by advection and diffusion from that due to hydrate dissociation allowed estimation of average hydrate concentrations of 3.8% of the pore space (up to 24.5% in hydrate‐rich layers; near‐100% in rare massive hydrate layers). The deep‐seated source of the ³⁷Cl‐depleted, low‐chlorinity water remains unknown and might be located below the sedimentary section in the oceanic basement.     

Human and animal diet at Conchopata, Peru: stable isotope evidence for maize agriculture and animal management practices during the Middle Horizon

This paper reports δ¹³C and δ¹⁵N values for human and animal skeletal remains from the Middle Horizon (AD 550–1000) site of Conchopata in the Peruvian highlands. The data indicate that maize was the dietary staple for both humans and the majority of animals at this urban site. Camelids at the site segregated into two groups according to δ¹³C values, reflecting two distinct animal management strategies. Human infants were found to have elevated δ¹⁵N values, reflecting the trophic level effect of breastfeeding. No sex based differences in diet were observed.     

Beyond the grave: variability in Neolithic diets in Southern Germany?

Carbon and nitrogen stable isotope analyses were undertaken on human and faunal remains from two Neolithic sites in Southern Germany; the LBK settlement at Herxheim and the middle Neolithic cemetery at Trebur. Stable isotope data were used to reconstruct the diets of individuals buried at these sites and to look at dietary variation between groups classified by their sex, age, grave goods and cultural affiliation. Overall there was surprisingly little variation in the diet between the groups, as described by the stable isotope analysis, despite significant differences in the composition of grave goods. Also surprising, considering the archaeological evidence for extensive grain cultivation in this region during the Neolithic, was that the majority of individuals had δ¹⁵N values consistent with the consumption of significant amounts of animal protein.     

Bone chemistry and paleodiet

Bone chemistry paleodietary studies are emerging as important research areas in archaeology, biological anthropology, and paleontology. With appropriate controls, the inorganic and organic chemical composition of bones and teeth can provide information about past diet and habitat use. Chemical signatures are used to address individual dietary variability in early hominid fossils, paleontological remains, and more recent human and faunal populations.     

Other ways to examine the finances behind the birth of Classical Greece

Although the birth of Classical Greece is often attributed to the constitutional reforms of Cleisthenes (508/507 BCE), the achievement of an economically minded government under the Peisistratid tyrant Hippias (527–510 BCE) potentially paved the way by advancing Athenian silver for exportation in international trade. It is proposed here that new silver technology, which initiated the transition from acquiring silver from ‘dry’ silver ores to silver-bearing lead ores, was introduced to Greece during the time of the Peisistratids (561–510 BCE). Massive exploitation of silver-bearing lead ores at Laurion in Attica, which later financed the construction of a war navy, appears evident in the lead pollution records of Greenland ice, lead isotopic analyses of sixth-century BCE Attic silver coins and late Iron Age Levantine hacksilver, and is reflected in the numbers of lead votive figurines at sanctuaries in Sparta. Against the backdrop of the threat of war with Persia and an imminent Spartan invasion which resulted in the overthrow of Hippias (510 BCE), it is considered that a political transition occurred because Greece was both geologically and politically disposed to adopt this labour-intensive silver technology which helped to initiate, fund and protect the radical social experiment that became known as Classical Greece.