Micro-invasive method for studying lead isotopes in paintings*

A micro-invasive technique is presented that enables pigment sampling from individual layers of a painting cross-section by obtaining a furrow 10–50 μm wide of chosen length. Combined with increased sensitivity of lead (Pb) isotope analysis using multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) equipped with a 10¹³ Ω resistor or a Pb double-spike technique, the amount of Pb needed for isotopic analysis is drastically reduced, while maintaining a relative 2 SD precision for ²⁰⁶Pb/²⁰⁴Pb of < 0.02%. The methodology proved able to characterize Pb isotope differences within paint layers.     

Probing the provenance of archaeological glaze colorants: Polychrome faunal reliefs of the Ishtar Gate and the Processional Way of Babylon

The polychrome glazes from the Processional Way and the Ishtar Gate of Babylon are among the best preserved from antiquity. Yet, little is known about the logistical choices involved in their production. Variations in isotope ratios can be useful for complementing an archaeological investigation of potential geological sources of raw materials. Consistent with archaeological evidence and ancient texts on trade in metals, Turkish ore deposits are thus tentatively proposed as possible sources of the metal oxide colorants used for the investigated polychrome glazes of three Neo‐Babylonian faunal reliefs that are now part of the collection of the Ny Carlsberg Glyptotek, Copenhagen.     

Considerations on the provenance determination of plant ash glasses using strontium isotopes

Strontium isotopic analysis has been proposed as a suitable method to determine the primary production location of ancient plant ash glasses. The technique is based upon the assumption that Sr enters this glass type with the plant ash used as a flux material, and that the ⁸⁷Sr/⁸⁶Sr ratio of the resulting glass reflects the geological provenance of that flux. In such case, the bulk Sr isotopic composition of the bedrock should be inherited unchanged in the plants growing on that bedrock. Different types of plant ash glasses have been shown to have widely differing ⁸⁷Sr/⁸⁶Sr compositions. In this study, the ⁸⁷Sr/⁸⁶Sr composition of several plant species growing on different bedrock types is measured, and compared to the bulk Sr isotopic composition and petrology of that bedrock. The paper shows that the ⁸⁷Sr/⁸⁶Sr ratio of these plants is a function not only, or even mostly, of the local geology, but also of the Sr isotopic composition of the total water consumed by that plant. This is highly likely to be both plant species dependent and dependent on the small-scale hydrology of the area immediately surrounding the plant. In this way, no definite relation between the isotopic composition of a geological outcrop and the plants growing on this bedrock can be inferred. Hence, the isotopic composition of a plant ash made from such plants is uncertain and moreover species dependent. Though groups of plant ash glasses can certainly be compared in time and space using Sr isotopes, it may prove difficult to ascertain a plant ash glass type to a specific geographical-geological region.     

The use of oxygen,strontium and lead isotopes to provenance ancient glasses in the Middle East

It is sometimes possible to discriminate between glasses made at different factory sites by using chemical analysis. However, this is not necessarily a means of provenancing them unambiguously because glass of slightly different compositions may have been fused using different proportions of the same raw materials. The determination of oxygen, strontium and lead isotopes can provide the possibility of linking the geological sources of the glass raw materials to the production sites on which the glass was fused. Here we consider the possible isotope contributions made to the raw materials thought to have been used in the manufacture of plant ash and natron glasses found at 8th–9th century al-Raqqa, Syria. The isotopic data from al-Raqqa are compared with published results from other Middle Eastern and German glasses. We show that strontium isotopes, in particular, provide a reliable means of distinguishing between the sources of plant ash glass raw materials and that oxygen and lead isotope signatures are less discriminatory.     

Retracing Magna Graecia's silver: coupling lead isotopes with a multi-standard trace element procedure

This study presents the results of compositional and lead isotopic analysis of coinage issued by the Greek colonies of Syracuse, Metapontum, Taras and Thurium in the fifth to third centuries bce . The data suggest that each colony in Magna Graecia, regardless of its motherland roots and despite ongoing conflicts between the cities, had access to the same silver, and that this supply was stable overall throughout their period of minting and issuing coinage. The paper retraces the silver sources of the colonies and points out a potential supply route for the metal. It includes a method development for a multi-standard quantification approach for laser ablation-inductively coupled-mass spectrometry (LA-ICP-MS) analysis of silver.     

Croatian Appoxiomenos alloy composition and lead provenance study

An ancient bronze statue of an athlete with a strigil (known as Apoxiomenos) – was raised from the north Adriatic Sea in 1999. In order to help to determine its place and date of manufacture various scientific techniques were used. ¹⁴C dating performed by the Accelerator Mass Spectrometry (AMS) on the organic material found inside the statue gave calibrated dates between 100 B.C. and 250 A.D. Non-destructive analysis performed by portable X-Ray Fluorescence (XRF) system and external beam Particle Induced X-Ray Emission (PIXE) spectroscopy could not provide representative results for metal alloy composition due to the electrochemical deterioration of the surface of bronze in seawater. This was observed by the analysis of alloy cross-sections performed by the proton microprobe. The analysis showed much higher lead concentrations on the surface of the bronze than inside, confirming that realistic alloy composition can be only performed on samples taken from at least 0.6 mm below the surface. Subsequent micro-PIXE analysis on metal cross-section showed inhomogeneous lead concentrations between 1 and 12%. Lead isotope analysis for provenance investigation has been done on 15 samples using Multi Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS). Analysis showed that lead isotope composition is consistent with some of the lead ores originating either from the Eastern Alps or from Sardinia. Altogether, the results lead to the conclusion that the statue is not of a Greek origin, but most probable it is a Roman copy of the Greek original.     

Roman lead mining in Germany: its origin and development through time deduced from lead isotope provenance studies

High precision lead isotope analysis by Multi Collector Inductively Coupled Plasma Mass Spectrometry was applied to the investigation of more than 240 Roman lead objects from several archaeological sites in Germany, in order to obtain information on the pattern of Roman mining activity and ore processing in the area. Measurements of ore samples from German deposits east (Siegerland, Lahn-Dill, Ems) and west of the Rhine (Eifel, Hunsrueck) were made and supplemented with data from literature to create a data bank of lead isotope ratios of European lead occurrences. Comparing the isotope ratios of lead objects with those from German ore deposits shows that the source of over 85% of the objects is Eifel ore deposits, but that, in the early years, the Romans also imported lead from the Southern Massif Central and later from Britain.     

Determining the provenance of black limestone artifacts using petrography,isotopes and EPR techniques: the case of the monument of Bocco

This paper investigates the provenance of the black limestone of the monument known as Bocco, named after the king of Mauretania who presented Silla with this work as a sign of his submission to the power of Rome. A multi-method approach, comprising petrographic observations, carbon and oxygen isotope composition and electron paramagnetic resonance (EPR) spectra characteristics, was used for this purpose. The monument is part of a reconstruction of a rectangular base (approx. 8 × 2 m) which is likely to have served as the base for a bronze statuary group and is currently composed of six blocks of limestone whose exterior is engraved with a fine frieze. The results of the different analyses were compared with the data of a published database of the most important black limestone quarries exploited during Roman times in the Mediterranean area. The petrographic and physico-chemical parameters did not prove to be very effective in determining the provenance of the black limestone of Bocco; the isotopes result even raised some uncertainty as to whether all six blocks came from the same quarry, though this doubt was dispelled by the EPR data and, above all, by the evident petrographic similarity between them. Differences in the isotopic composition of the various blocks may be due to an in situ rock alteration process caused by interaction with an aqueous fluid. It was, however, impossible to determine with certainty the origin of the material of the stone artifact using the database available; it is possible that the black limestone of Bocco came from an ancient quarry that is likely to be located in north western Africa but has not yet been uncovered. An alternative hypothesis, according to which the limestone used for the monument of Bocco came from the ancient quarry of Ain el Ksir, one of the Tunisian quarries present in the database, is also discussed.     

Lead isotopic analyses of copper ores in the Early Bronze Age central Hexi Corridor,north-west China

This paper explores the possible provenance of ores employed for metallurgical production during the Early Bronze Age in the central Hexi Corridor of north-west China. In total, 78 pieces of copper (Cu) ore samples were collected from five Early Bronze Age sites and one Cu deposit site (the Beishantang Cu deposit) in the Heihe River region of the central corridor. These sites were dated to the late Machang (4100–4000 bp ), Xichengyi (4000–3700 bp ), Qijia (4000–3600 bp ) and Siba (3700–3400 bp ) cultures. After comparing with published lead (Pb) isotopic data from other possible Cu deposits in north-west China, the results show that the Cu ores collected from the Early Bronze Age sites were most likely derived from the adjacent Beishan Cu deposit. More intriguingly, for the first time in Hexi Corridor, a dozen Cu ores were discovered containing highly radiogenic Pb. Though fundamentally different from those in the Central Plains, they illustrate a possible new type of Cu used in Bronze Age western China, and the first-hand materials are significant for further understanding the provenance of raw metals for metallurgical production in the prehistoric Hexi Corridor.     

Origin of deep saline groundwaters in the Vienne granitic rocks (France): constraints inferred from boron and strontium isotopes

As part of a preliminary geological characterization programme to assess the feasibility of an underground laboratory in granitic rock, a series of 17 deep boreholes (maximum depth, 900 m) was drilled by ANDRA in the Vienne district, France. A salinity gradient was demonstrated in the granitic waters with concentrations varying from approximately 1 g L^?1 at 150 m depth at the top of the basement (beneath the sedimentary cover) to 10 g L^?1 in the deeper part (from 400 to 600 m depth). Sr and B isotope ratios were measured in order to better understand the origin of the salinity and to evaluate the degree of water–rock interaction in the system. The results obtained were compared to those of mineral spring waters emerging from the granitic basement in the Massif Central. Evidence in support of a significant marine contribution include: (i) the Cl–Br investigations agree with a marine origin for the saline groundwaters without evolution from seawater; (ii) the ⁸⁷Sr/⁸⁶Sr ratio of the Vienne deep groundwaters (0.7078–0.7084) is in agreement with a palaeo‐seawater isotopic signature; (iii) measured δ¹¹B values for the deepest brine samples are enriched in ¹¹B (up to 36.1‰) relative to the granitic springs. The combined use of δ¹¹B, Cl, B, Br, Sr contents and ⁸⁷Sr/⁸⁶Sr ratios makes it possible to define and quantify a mixing model between marine and crustal end‐members in order to explain the origin of the deep saline groundwaters in the Vienne granitic rocks.     

铅同位素考古研究的可行性问题——浅议“青铜器铅同位素指示意义的范铸实验研究”

国际上对铅同位素示踪方法在青铜器原料产地研究中的应用做过很多探讨。《范铸》一文再次提出有关问题,认为铅同位素分析结果不能确切指示青铜器铜锡铅原料的来源信息。本文考察了其依据的实验数据,它们似乎与其观点互相矛盾,其结论说服力相当有限。     

Reconstructing Neolithic groups in Sarawak,Malaysia through lead and strontium isotope analysis

Heavy stable isotope analysis of mid-late Holocene Neolithic burials from Sarawak (Malaysia) identifies groups not apparent in mortuary treatment or inferred subsistence. Isotope ratios of strontium (⁸⁷Sr/⁸⁶Sr) and lead (²⁰⁸Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb, ²⁰⁶Pb/²⁰⁴Pb) from adult tooth enamel show distinct groups at Niah Cave's West Mouth organized by dietary catchment. Two roughly contemporary sites, Gua Sireh and Lobang Angin, are included to assess regional heterogeneity in northern Borneo. Heavy stable isotope ratios for humans differ from sampled modern plants and archaeological fauna from West Mouth, and suggest a non-local origin for some of the West Mouth human remains. Distinct heavy isotope ratios characterize all three sites and show regional differentiation broadly consistent with geological expectations. Results supplement paleodiet and morphological analyses and have implications for clarifying Niah Cave mortuary use during the mid-late Holocene. Further and more precise geographic placement will follow through additional landscape sampling for strontium and lead isotope values.     

Diatoms as indicators of provenance in Finnish sub-neolithic pottery

The clays of Finland originated from glacial deposits formed during the deglaciation of the Weichselian ice-sheet and during the different stages of the Baltic Sea. The analysis of the fossil diatom flora is of central importance in the study of its developmental history. The diatoms in the clay indicate its sedimentary environment, which can be linked to the stages of the Baltic Sea. The siliceous valves of diatoms tolerate heating up to 1400°C and can consequently be identified in ceramics fired at lower temperatures. Several diatom analyses have been made in Finnish Sub-Neolithic comb ware pottery in order to determinate the origin of their clay materials. According to the results of these studies, prehistoric potteries used clays deposited during the Yoldia and the Ancylus stages. The criteria used in selecting raw materials were identical to those of modern ceramic industries. Further details as to provenance of clay materials have been illustrated in connection with research on pottery from the Aland Islands. In the example from Kymi, South-eastern Finland, changes in the composition of the diatom flora have been found to correlate with changes in pottery decoration styles.     

Elemental analysis of pottery in the study of its provenance: A review

Elemental analysis of pottery is a valuable scientific approach to investigation of its provenance. Increasing use is being made of the approach, and this paper presents a critical review of the basic methodology and experimental procedures. Genenal problems and limitations of the technique are discussed, and the procedures involved in each of the four main stages of such studies are described. These stages are: (1) selecting specimens of pottery for analysis, (2) obtaining samples from the specimens, (3) analysing the samples, and (4) interpreting the results. For each stage, suggestions are made for generally useful procedures and experimental precautions, and for aspects on which further study seems desirable. Much of the discussion is also relevant to the analysis and typing of artifacts of other materials, e.g., metal and stone objects.     

Origin of palaeo‐waters in the Ordovician carbonates in Tahe oilfield,Tarim Basin: constraints from fluid inclusions and Sr,C and O isotopes

Petrographic features, isotopes, and trace elements were determined, and fluid inclusions were analyzed on fracture‐filling, karst‐filling and interparticle calcite cement from the Ordovician carbonates in Tahe oilfield, Tarim basin, NW China. The aim was to assess the origin and evolution of palaeo‐waters in the carbonates. The initial water was seawater diluted by meteoric water, as indicated by bright cathodoluminescence (CL) in low‐temperature calcite. The palaeoseawater was further buried to temperatures from 57 to 110°C, nonluminescent calcite precipitated during the Silurian to middle Devonian. Infiltration of meteoric water of late Devonian age into the carbonate rocks was recorded in the first generation of fracture‐ and karst‐filling dull red CL calcite with temperatures from <50°C to 83°C, low salinities (<9.0 wt%), high Mn contents and high ⁸⁶Sr/⁸⁷Sr ratios from 0.7090 to 0.7099. During the early Permian, ⁸⁷Sr‐rich hydrothermal water may have entered the carbonate rocks, from which precipitated a second generation of fracture‐filling and interparticle calcite and barite cements with salinities greater than 22.4 wt%, and temperatures from 120°C to 180°C. The hydrothermal water may have collected isotopically light CO₂ (possibly of TSR‐origin) during upward migration, resulting in hydrothermal calcite and the present‐day oilfield water having δ¹³C values from ?4.3 to ?13.8‰ and showing negative relationships of ⁸⁷Sr/⁸⁶Sr ratios to δ¹³C and δ¹⁸O values. However, higher temperatures (up to 187°C) and much lower salinities (down to 0.5 wt%) measured from some karst‐filling, giant, nonluminescent calcite crystals may suggest that hydrothermal water was deeply recycled, reduced (Fe‐bearing) meteoric water heated in deeper strata, or water generated from TSR during hydrothermal water activity. Mixing of hydrothermal and local basinal water (or diagenetically altered connate water) with meteoric waters of late Permian age and/or later may have resulted in large variations in salinity of the present oilfield waters with the lowest salinity formation waters in the palaeohighs.     

Black limestones used in antiquity: the petrographic,isotopic and EPR database for provenance determination

We compiled a database of some of the most important black limestone quarries used in Roman times to be able to determine the provenance of ancient artifacts. For this purpose, we adopted a multimethod approach using the techniques commonly applied to study the provenance of white marbles: petrographic observations, carbon and oxygen isotope composition, electron paramagnetic resonance (EPR) spectra characteristics. Few black limestones were quarried and traded in ancient times; indeed, the importance of most of these quarries was restricted to the areas in which they were located. In this work, we selected a limited number of quarries that produced material believed to have been exported and used throughout the Mediterranean area; most of the quarries selected are found in northern Tunisia, i.e. the Roman proconsular Africa: Djebel Oust, Djebel Azeiz, Ain al Ksir and (presumably) Thala. The “Nero Chiota” limestone quarried on the Aegean island of Chios (Greece) was also included in the database.     

A computerized system to determine the provenance of finds in archaeological sites using acoustic signals

Some archaeological excavations require the accurate determination of the provenance of finds (three-dimensional location and orientation) for a subsequent spatial analysis. The traditional manual measurement using a grid reference is not a very efficient registration method. Some proposed computerized solutions based on total stations, photogrammetry and DGPS, are more effective but have some limitations. This paper presents a new acoustic localization system (3D-LOCUS) for measuring the three-dimensional position of finds in archaeological sites. The system can also be used for registering the size, shape and orientation of artifacts. 3D-LOCUS basically consists of a set of wireless rod-like pointing devices that are localized with a network of intelligent nodes installed above the excavation site. Archaeologists use the pointing device as a stylus to locate and outline the object under study. The main technological characteristics of the system are: omnidirectional wideband acoustic transducers, Bidirectional Time-Of-Arrival (BTOA) estimation, redundant ranging and robust trilateration. 3D-LOCUS achieves an accurate registration, even if used simultaneously to the digging labor, or in noisy or turbulent airflow conditions. We tested the system in the Gran Dolina archaeological site (Atapuerca, Spain). The typical location accuracy is below 10 mm in natural conditions, and the achieved resolution is 5 mm, which allows us sketching objects with enough detail.     

青铜器铅同位素指示意义的范铸实验研究

铅同位素比值作为探索青铜器产地和矿料来源的指示剂而被广泛采用,为论证这种方法的可行性,进行了仿古范铸实验。测试分析表明,长江中、下游出土古铜锭含铅量大多在1％以下,样品中添加铅的含量远高于铜、锡料所带入的微量铅。结果证明,青铜器铅同位素的指示意义是不确定的,并且在冶铸过程中可能存在铅同位素的分馏。     

Nitrogen isotopes and the trophic level of humans in archaeology

Human and domesticate animal bone collagen δ¹⁵N values in prehistory differ generally by 3‰ or more from Neolithic to post- Roman times in Northwest Europe, leading to an assumed dietary animal protein fraction of 60–80% using a standard interpretation of δ¹⁵N values. We examine the assumptions on which this model rests and the limitations of our knowledge in the analysis of δ¹⁵N values in archaeology. We have developed a set of models which, with small changes made in assumptions (on the order of 1‰), can produce substantially lower estimates of the dietary animal protein fraction for given δ¹⁵N values. We consider the implications of various dietary animal protein fractions on agricultural carrying capacities and human population densities in prehistory.     

A study of the glazing techniques and provenances of Tang sancai glazes using elemental and lead isotope analyses

This study discusses the elemental compositions and lead isotope ratios of Tang sancai glazes unearthed from the Huangpu kiln, Huangye kiln and two Tang sancai tomb sites. The various glazes feature distinct lead isotope ratios and trace element characteristics, which can be interpreted as evidence for the use of different lead ore deposits and siliceous raw materials in the glazes. This is a strong indication that lead isotopes combined with trace element analysis could be used as a viable approach for identifying the provenance of Tang sancai of unknown origin by linking them to kiln sites, This provenance technique could be significant in the interpretation of ancient ceramic trade and communication patterns. In this study, the provenance of several Tang sancai glazes of uncertain origin were determined using this method: some Tang sancai wares unearthed in Xi'an City were produced in the kiln near Luoyang City and then traded to Xi'an City, providing an idea of ancient Tang sancai ceramic trade routes.