PROVENANCE STUDY OF MARBLE ARTEFACTS FROM THE ROMAN BURIAL AREA OF FASCHENDORF (CARINTHIA,AUSTRIA)*

Numerous marble artefacts were among the extraordinary findings excavated at the Roman burial area of Faschendorf (Carinthia, Austria). The provenance of marble objects, particularly in the Roman provinces, is mostly unclear. Predominantly Mediterranean marbles have been used, but there are also some marble occurrences in the eastern Alpine regions that were exploited in those times. Besides a mineralogical–petrographic analysis, grain‐size evaluation in particular, and the determination of carbon and oxygen isotopes allow an effective characterization of the Faschendorf materials. Their provenance from the Gummern Marble complex in Carinthia is very likely.     

THE POTENTIAL OF CARBONIZED GRAIN TO PRESERVE BIOGENIC 87SR/86SR SIGNATURES WITHIN THE BURIAL ENVIRONMENT*

Carbonized grains survive for millennia in many archaeological contexts. Their stable structure raises the possibility that they preserve biogenic strontium isotope signatures. This hypothesis was investigated using short‐term, laboratory experiments with modern grain immersed in Chalk solution. HCl leaching removed > 95% of secondary alteration from charred grain, and isotope ratios close to the starting value were recovered. This could not be achieved with uncharred grains. HCl leaching of archaeological carbonized grains produced comparable levels of decontamination. Although preliminary, these results suggest that strontium isotope analysis of archaeological carbonized grains from calcareous burial contexts could be used to investigate ancient trade and agriculture.     

SCIENTIFIC CHARACTERIZATION OF THE POHORJE MARBLES,SLOVENIA

As a former part of the great Roman Empire, Slovenia has many archaeological sites featuring buildings and objects entirely or partly constructed from marble whose provenance is doubtful. In Slovenia, the most probable source of such marble is the Pohorje Mountains. For the purpose of supporting further provenance studies, these marbles are fully scientifically characterized. The techniques used are petrographic and geochemical analysis, stable isotope ratio analysis and EPR spectroscopy. The results show that the Pohorje marbles are highly heterogeneous in both their isotopic and geochemical parameters as well as grain sizes. The parameters of the different Pohorje marble outcrops are compared between themselves and with the parameters of known ancient quarries in the Mediterranean and Austria. The use of a multi‐technique approach with combined parameters allows the best possible discrimination.     

CLAY RESOURCES AND TECHNICAL CHOICES FOR NEOLITHIC POTTERY (CHALAIN,JURA, FRANCE): CHEMICAL,MINERALOGICAL AND GRAIN‐SIZE ANALYSES*

Many authors have considered pottery manufacturing constraints and sociocultural elements as factors in change in past civilizations over time. The main issue of this research is to better understand the reasons for changes, or choices, in pottery raw materials. The very precise and detailed stratigraphy and cultural succession of occupations is based on dendrochronological data from the lake‐dwelling sites of Chalain (Jura, France). Petrographic, palaeontological and chemical analyses were used to determine the nature and origins of the raw materials used by the Neolithic potters. Stratigraphy and dendrochronological data were used to reconstruct in detail the evolution dynamics of fabric changes. Several raw material sources were identified for many of the pottery groups. Each of them was sampled for qualitative experimental tests of pottery forming. The experimental results show a high variability between the sediments tested. This variability was quantitatively estimated by XRF, XRD, the Rietveld method, calcium carbonate quantification and laser grain‐size analyses of matrices, indirect measures of plasticity. These analytical results allow a better understanding of the differences observed in the experimental tests. On the basis of these experimental and analytical results, changing parameters such as pottery manufacturing constraints, mineralogical characteristics of raw materials and sociocultural factors are considered. In conclusion, all the social and technical parameters, in each archaeological context, must be taken into account for a better understanding of the changes occurring throughout the chronological sequence.     

WHITE,VEINED MARBLE FROM ROMAN AMMAIA (PORTUGAL): PROVENANCE AND USE

A multimethod approach using petrography and strontium (Sr) isotopic analysis was applied to determine the geological source of 17 marble artefacts from the Roman town of Ammaia (Portugal). All samples are calcitic, with dolomite, quartz and muscovite as accessory minerals. The marbles are characteristically medium‐grained with a maximum grain size (MGS) between 0.98 mm and 1.82 mm, have a heteroblastic texture, and have curved to embayed calcite grain boundaries. ⁸⁷Sr/⁸⁶Sr values of marble leachates range from 0.708488 to 0.708639. Comparison with Hispanic and Mediterranean marbles suggests the Estremoz Anticline as the most likely source for the Ammaia marble, especially for architectural marble. This hypothesis is supported by the geographical proximity of the Estremoz marble district and the long and expensive overland transport required for other marbles to reach Ammaia.     

Changing Harvest Dates in Post-medieval Ireland

Abstract

During the last three centuries, agricultural writers and other commentators on Irish life frequently criticised Irish farmers for the late date at which they began to harvest both hay and grain. This paper will outline the reasoning behind these criticisms and the defence given by farmers in return. It will be argued that the rationality of common practice is demonstrated by the willingness of farmers to change the dates of harvest once changes in other practice made this desirable. The physical evidence for change will be described, and the paper will conclude with a discussion of possible implications of this for archaeology.     

IDENTIFICATION OF FORGERIES BY MEASURING TIN ISOTOPES IN CORRODED BRONZE OBJECTS*

The reliable identification of fakes consisting of bronze often presents problems, because traditional methods such as stylistic studies, optical microscopy, chemical analysis or X‐ray diffraction of the corrosion may not be conclusive. We present a method that is based on the comparison of the tin isotope ratios ¹²²Sn/¹¹⁶Sn and ¹¹⁷Sn/¹¹⁹Sn in the metal and in the adherent corrosion layer. An artificial patina is usually generated within a short time period. It has been observed that such a procedure leads to a depletion of the light tin isotopes in the corrosion layer, while in naturally corroded authentic archaeological objects no isotopic fractionation has been detected. The method has also been applied to archaeological objects and it could be confirmed, among other examples, that the famous ‘Sky Disc of Nebra’ is authentic.     

DAMAGE ASSESSMENT AND PRESERVATION OF AN EGYPTIAN SILVER VASE (300–200 BC)*

An Egyptian metal vase from the Ptolemaic period was investigated metallurgically and fractographically. The metal is nearly pure silver. Despite its high purity (in archaeological terms) it is severely embrittled and cracked, mainly along grain boundaries. Factors contributing to this damage are work-hardening and residual microstructural deformation (slip and twinning), corrosion along slip lines and twin boundaries, corrosion in bauds that are the remains of coring, large equiaxed grains, externally applied forces and internal residual stresses. The metal is now friable. This must be taken into account during any further restoration of the vase: a procedure is suggested.     

DISCOVERY AND CHARACTERIZATION OF AN UNKNOWN BLUE‐GREEN MAYA PIGMENT: VESZELYITE*

Blue‐green mosaic and polychrome masks and funerary offerings from the royal tombs of Calakmul, Mexico, were analysed by scanning electron microscope equipped with energy dispersive X‐ray spectroscopy (SEM‐EDS), X‐ray diffraction (XRD), and particle induced X‐ray emission (PIXE). This led to the first identification of the use of veszelyite, a rare hydrated copper‐zinc phosphate, as green pigment. Analyses of a geological sample of this mineral have been done to confirm the characterization of this Mayan pigment, which might help determine pre‐Columbian trade routes of precious and luxury objects in the ancient Maya Classic period (ad 250–800).     

The Use of Neutron Analysis Techniques for Detecting The Concentration And Distribution of Chloride Ions in Archaeological Iron

Chloride (Cl) ions diffuse into iron objects during burial and drive corrosion after excavation. Located under corrosion layers, Cl is inaccessible to many analytical techniques. Neutron analysis offers non‐destructive avenues for determining Cl content and distribution in objects. A pilot study used prompt gamma activation analysis (PGAA) and prompt gamma activation imaging (PGAI) to analyse the bulk concentration and longitudinal distribution of Cl in archaeological iron objects. This correlated with the object corrosion rate measured by oxygen consumption, and compared well with Cl measurement using a specific ion meter. High‐Cl areas were linked with visible damage to the corrosion layers and attack of the iron core. Neutron techniques have significant advantages in the analysis of archaeological metals, including penetration depth and low detection limits.     

Material Culture and the Magical Power of Dance Objects

ABSTRACT This paper takes up the call by scholars such as Alfred Gell to consider objects of material culture as objects, by examining them in the context of production, circulation and reception. Because they are unadorned and without visual interest, langarol, the hand‐held artefacts used in some New Ireland dance performances, do not lend themselves to modes of analysis that see cultural objects as surrogate texts, the hidden meanings of which can be ‘read’. This very ‘lack’ enables us more readily to discern their significance, which lies in their magical potency and in the performance of their creator, the shaman, in attracting, wielding and revealing his awesome power. The power sought is less power over others and more power to — the ability to realise projects that can elicit effects. If consciousness and body are one, such achievements are to be understood as embodiments of intentionality and agency. It is through the production and wielding of such objects that people make themselves.     

TECHNOLOGY AND PROVENANCE OF A COLLECTION OF ISLAMIC COPPER‐BASED OBJECTS AS FOUND BY CHEMICAL AND LEAD ISOTOPE ANALYSIS*

Chemical and lead isotope analyses were utilized to determine the composition, technology and origin of a collection of Islamic copper‐based objects found in Jordan. The atomic absorption spectrometry results show that the objects were made of different types of copper‐base alloys that contain various amounts of zinc, tin and lead. The use of brass, highly leaded brass and quaternary alloys of Cu‐Zn‐Sn‐Pb in the manufacture of everyday, household objects strongly points to Islamic traditions. The lead isotope compositions of the objects match very well that of the copper ore mined from the Dolomite‐Limestone‐Shale unit of the Arabah copper mines.     

Metallurgical Characterization of A Coated Roman Iron Coin By Analytical Investigations

A coated Roman iron coin from Villa Loig in Salzburg, Austria was investigated. The coating is a copper alloy consisting of Cu, Pb, Sn, Zn and negligible amounts of Ag, a variant of gunmetal known as ‘leaded red brass’. The numismatic term for such a coin is subferratus (Latin). From an archaeometallurgical point of view, information about the chemical composition, the microstructure and the manufacturing technique are of interest. To achieve these objectives, different analytical techniques and metallographic examinations were applied. Droplet‐shaped iron inclusions were observed in the red brass coating, while at the grain boundaries, inside the iron core, copper and lead were detected (liquid metal embrittlement). The dendritic microstructure of the coating, the spheroidal‐shaped iron inclusions in the coating and the liquid metal embrittlement show that the iron coin was plated by immersing it in a molten copper alloy. The iron core is a low‐carbon steel with slag stringers, both of which are characteristic of a bloomery iron. Deformation twins (Neumann lines) were observed in the microstructure of the iron core and indicate that the coining was performed after the flan was cooled.     

Dendrochronological Dating of Wooden Artefacts using Photography

Core sampling is normally used for dendrochronological age determination of both timber and living trees. As core sampling can seriously damage artefacts, a photographic method was tried on 29 wooden objects made of Scots pine (Pinus sylvestris L.). These were photographed and tree‐ring sequences for dendrochronological analysis were measured on the photographs in the laboratory. Nine objects could be dated. The undatable objects had few tree‐rings or a non‐matching tree‐ring pattern. The region in Norway where the material had grown could be determined by matching against various regional chronologies.     

Modeling of hydrogen production by serpentinization in ultramafic‐hosted hydrothermal systems: application to the Rainbow field

The production of hydrogen by serpentinization in ultramafic‐hosted hydrothermal systems is simulated by coupling thermodynamic and dynamic modeling in the framework of a thermo‐hydraulic single‐pass model where a high‐temperature hydrothermal fluid moves preferentially through a main canal of high permeability. The alteration of ultramafic rocks is modeled with a first‐order kinetic formulation, wherein the serpentinization rate coefficient, K_r, takes the form: K_r = A exp(?α(T ? T₀)²). In this formulation, α determines the temperature range of the reaction and T₀ is the temperature at which the serpentinization rate reaches its maximum. This model is applied to the Rainbow hydrothermal system, which is situated on the Mid‐Atlantic Ridge, and characterized by a high temperature, a high mass flux, and a very high hydrogen concentration. The results show that a first‐order kinetic law gives a useful representation of the kinetics of serpentinization. The estimated value for the parameter A in the temperature‐dependent formulation of the serpentinization rate coefficient lies in the range (1–5) × 10^?11 s^?1. This effective parameter is several orders of magnitude lower than the values obtained from small grain‐size experiments, but in agreement with other published modeling studies of natural systems. Numerical simulations show that the venting site is able to produce the observed high concentration of hydrogen during the whole continuous lifetime of the Rainbow site.     

ACCESSORY MINERALS AS TRACERS IN THE PROVENANCING OF ARCHAEOLOGICAL MARBLES,USED IN COMBINATION WITH ISOTOPIC AND PETROGRAPHIC DATA*

Thirty‐eight archaeological marbles (Roman and medieval) from Modena and Reggio Emilia (northern Italy) were provenanced using the accessory minerals as tracers and the results were compared with those inferred for the same artefacts using isotope composition and MGS (maximum grain size of calcite grains). The number of inferred possible sources is generally lower when using the mineralogical method, which therefore seems to be suited to marble provenancing.     

The Mechanism and Kinetics of In Situ Conservation of Iron Cannon on Shipwreck Sites

Analysis of the pre‐disturbance values of the in situ corrosion parameters on historic iron shipwrecks and artefacts has established that the arithmetic product of the pH and corrosion potential is dependent on the burial environment and provides a unique insight into the objects' state of decay. The value of the product changes during in situ conservation treatment with sacrificial anodes, and reaches a minimum at which point the treatment is completed. Treatment times vary with water‐depth, being faster on shallower sites and shorter for more extensively corroded artefacts. The model was developed using data from the Duart Point wreck (1653), the Monitor‐styled warship HMVS Cerberus (1926) and a series of wrecks in Australia and the USA.     

The behaviour of lead as a corrosion resistant medium undersea and in soils

Lead is a highly corrosion resistant metal in some environments and an attempt has been made to show its strength and weakness under long-term corrosion in land and marine conditions by means of examples taken from archaeological contexts. Some analyses and thicknesses are given of the corrosion films found on them. The importance of fine grain size and the role of certain impurities in obtaining this may be one reason why the older leads are often more resistant than modern leads.     

The Use of Optical Coherence Tomography for Monitoring the Subsurface Morphologies of Archaic Jades

We demonstrate the use of the Optical Coherence Tomography (OCT) technique for non‐invasive scanning of the subsurface morphologies of jade objects. The two‐dimensional tomography images show the refractive index or dielectric constant variations in the samples, reflecting their structures. Three samples of archaic jade objects from the Qijia and Liangzhu cultures in China are scanned in order to understand the subsurface morphologies of the naturally whitened jades. Also, two jade objects with artificial treatments (burning) are scanned and compared with the original materials in subsurface structures. In the original objects, the jade materials can generally be quite transparent, such that the backscattering intensity is weak, although the large‐scale (tens of microns or larger) subsurface morphology can be clearly observed. After burning, small‐scale (smaller than a few microns) structures are formed and the backscattering intensity is enhanced. In this situation, the large‐scale structures may be preserved or even newly generated. On the other hand, in an archaic object with natural whitening, small‐scale structures are also formed. Hence, the deeper distributions of significant backscattering intensity are observed, when compared with the unwhitened objects. Nevertheless, the large‐scale features diminish during the whitening process. With OCT scanning, such differences in subsurface morphology can provide us a valuable reference for authenticating archaic jade objects.     

MICROSTRUCTURAL CHARACTERIZATION OF EARLY WESTERN GREEK INCUSE COINS*

In this research, we studied the compositional, crystallographic and microstructural properties of a series of incuse silver didrachmae stemming from the Achaean colonies of Metapontum and Caulonia. In this paper, we address the following points: (i) the metal sources, (ii) the fabrication process and (iii) degradation phenomena, such as incrustation and embrittlement. In this investigation, we employed energy‐dispersive X‐ray fluorescence spectroscopy, X‐ray diffractometry, and scanning electron and optical microscopies. The patina is mainly composed of chlorargirite. The coins consist of a silver‐rich alloy containing ～ 1% of Au and Cu. Metallographic and local compositional analyses revealed a complex scenario of inclusions. In one instance, unalloyed copper grains, two‐phase copper/bismuth globuli and high‐bismuth filaments were observed. In other cases, globular Cu ₂ S (chalcocite) inclusions were noticed. The presence of SiO ₂ and iron oxide inclusions is ubiquitous in these samples. Distorted twin lines and strain lines can be detected, denoting work‐hardening of recrystallized flans. Grain polygonalization can occasionally be noticed, hinting at secondary recrystallization processes. The irregularly shaped iron oxide particles often act as crack initiation sites. Fracture facets are generally intergranular. On some areas, intergranular decohesion is also observed. Open cracks sometimes contain AgCl. The strain lines that can be noticed on the fracture surfaces indicate work‐hardening and residual microstructural deformation. Information regarding inclusions and the presence of significant amounts of gold can be tentatively used to address provenancing and fabrication issues.