Spectroradiometry

Using models derived from our ethno-archaeological work in New Guinea, in 2003 we succeded in finding different sources of Alpine jades, after a dozen years of prospecting in the high Alps between Sesia in the north and Trebbia in the south-east. Analyses by spectroradio-metry and by X-ray diffraction, together with petrographic thin-sectioning, was essential to the identification and characterisation of the raw materials of each region.
In the Monte Viso massif, five very important primary sour-ces (or secondary sources close to these) had been exploited at a height of between 1 500 and 2 400 metres above sea level : Barant, Alpetto-Murel, Bulè, Milanese and Porco.
In the massif of Monte Beigua (or, to adopt the term used by geologists, the Voltri Group), some secondary sources of jades were identified in the west of the area (in the high valley of the Erro), in the centre (high valley of the Orba) and in the east (high valleys of the Lemme and of the Ardana). As for primary sources, these are limited to a few blocks of jadeitite (at Celle Ligure) or to rounded masses of eclogitic rocks (at Urbe) or of amphibolitic rocks, as at Sassello, Chapel of Rocca Colombo (where there are traces of exploitation). In contrast to Monte Viso, the conditions of prospection and the fossilisation of traces of Neolithic exploitation are much less favourable, due to the intensity of the torrent-based ravine formation process.
It is likely that these two regions - which contain the ma-jority of the sources of Alpine jades - were not the only source areas to be exploited during the Neolithic. Other massifs, with more modest supplies, still need to be ex-plored in detail, such as the area around the Val de Suse and the valley of the Orco.
As for the Alpine nephrites that are attested in certain hoards in the Gulf of Morbihan around the middle of the fifth millennium BC, it is in Valais, in the region of Sion (Switzerland), where one of the most likely source areas exists. This lies close to a primary source of calc-amphibolite at Haudères (in the Val de Bagnes, at 1 900 metres), but other sites may yet await discovery.

Spectroradiometry is an analytical technique that is non-destructive, rapid, portable and cheap. As with thin-section petrography or X-rays diffraction analysis, for example, it is based on comparing specimens with re-ference material of known origin. Although petrographic and other reference collections have existed for several decades and have long since been documented fully, the same cannot be said for spectroradiometry. This is mostly due to its extreme sensitivity to numerous para-meters that are not directly related to mineral or chemi-cal composition - an effect termed the ‘matrix effect’. While this might for a long time have seemed to be an inconvenience - it was not until the 1970s that spectroradiometry began to be used (for purposes linked to remote sensing and to the exploration of Mars) - the matrix effect in fact constitutes the method’s principal point of interest since, in certain cases, it allows one to undertake far finercomparisons than those possible using any other method.
Since 1999, spectroradiometry has been used to analyse several thousand Neolithic artefacts (small and large axeheads, beads, bangles and other items of jewellery) and it is often possible, if one has an adequate set of reference material, to pinpoint the source of the raw material. Thanks to the exploration of the Alpine massif by Pierre and Anne-Marie Pétrequin, as part of their research into the origin of jadeitites, a large number of wellprovenanced raw material samples have been collected and analysed. These form the basis of the reference collection of Alpine greenstones which currently comprises almost 2 500 spectra. The success of these prospections in revealing previously unknown sources of European jadeitite has allowed us, through statistical analysis, to assess the representativity of debitage deriving from raw material blocks that had been completely worked out long ago.
In studying the spectra relating to the large European axeheads, it was first necessary to undertake a general synthesis and to define a certain number of representative and characteristic spectrofacies. Each of these then needed to be described and to be attributed, as far as possible, to a probable origin (by comparing them with the reference collection of Alpine greenstones).
Finally, the geographical distribution of all the axe-heads attributed to an individual spectrofacies needed to be studied. In order to achieve this, all the spectra of the large European axeheads were compared using the classic statistical method as used in remote sensing. In this way, some 1 117 spectra have been allocated to 178 ‘endmembers’. These were then described and analysed, and the main results were synthesised into a diagnostic key. Several subsequent regroupings and simplifications led to the definition of the principal spectrofacies. These spectrofacies therefore represent, statistically, the full range of the spectra relating to the large European axeheads and each newly-determined spectrum can be compared with each of these. Some spectrofacies represent raw materials that did not diffuse far from their place of origin, while others have a distribution that extends over much of Europe. Over half of the spectrofacies represent the most abundant varieties of jadeitites - a fact that demonstrates well the sen-sitivity of the method as applied to these rocks. In contrast, the eclogites, omphacitites and basalts, for example, are only represented by a small number of spectrofacies.
It is thus possible, by using spectrofacies, to rifine significantly our picture of the currents of circulation over which certain large axeheads travelled from their raw material extraction zones.

In August 2007, holidaymakers discovered two pairs of polished axe-heads that had been set vertically in clayey silt on the beach of Porh Fetan, at a place called Petit Rohu. They reported their find to the Regional Ar-chaeology Service of Brittany and to the Carnac Museum. The shape and material of these axeheads allowed them to be identified straightaway as being of Alpine origin, in common with a number of axeheads found in the region. Permission was obtained from the DRASSM (Marseille) for the Laboratory of Archaeological Research (UMR 6566, Nantes), together with the SRA (in Rennes), to undertake archaeological fieldwork, both on land in the vicinity of the findspot, and under water. Initial fieldwork, carried out during the spring tide on 28th September 2007, produced no further artefacts but did produce evidence for a submerged alignment of stelae (lying stones or fallen menhirs), of which only one was still standing; an initial plan of this structure was made at that point, and completed during the next investigation, during the spring tide on 27th October. A third in-vestigation, carried out during the last spring tide of the year on 26th November, led to the discovery of a fifth axehead, this time made of fibrolite, found resting against one of the lying stones. Peaty soils had been inter-mittently observed over many years, buried beneath marine sand; these are being progressively eroded away by the force of the sea, as their sand cover becomes thinner. Traces of cultivation (criss-crossing each other in some areas) and of ungulate hoof-prints have been conserved on the surface of these soils. This palaeo-environmental context allows us to argue that the axeheads had been deposited in a marshy environment that had developed behind a dune system, at the foot of a remarkable stone outcrop. Rises in sea level since the mid-fifth millennium BC – the likely date at which the axeheads were deposited – mean that the shore has advanced by some 500 metres since then. Today, the findspot of the stone alignment and axehead deposit lies beneath 5 metres of sea. These architectural vestiges join the list of recent discoveries (since 1998) of submerged monuments in the Bay of Quiberon, the Etel estuary and the Gulf of Morbihan. Initial spectrora-diometric analysis of the two pairs of axeheads has confirmed that they are of jadeitite, originating in the Italian Alps. Indeed, at least three of the axeheads can be related to a specific block of jadeitite. Their surface finish attests to a considerable investment of time in order to achieve their mirror-like polish (which survives over part of their surfaces). This underlines the fact that these were not utilitarian axeheads, but instead were very special and precious artefacts.

The south-eastern limits of Alpine jades (Greece and Turkey)

Our aim is to identify the outer limits of the circulation of Alpine jade axe- and adze-heads, in Greece and Asia Minor. While the existence of several polished axe/adze-heads of ‘chloromelanite’ or ‘jadeite’ had already been noted by H. Fischer in the 1880s, their origin had not been pinpointed. The issue is complicated by the fact that sources of jades (jadeitites, omphacitites and jadeite-eclogites) exist in the north of the island of Syros, and these may have been exploited during the Neolithic. Thus, there could theoretically have been at least two source areas for the jade axe- and adze-heads that circulated in this zone of the Balkans: the Italian Alps (namely the massifs of Mont Viso and Mont Beigua, 1700 and 1600 km away as the crow flies) on the one hand, and the island of Syros in the Cyclades on the other. It is therefore necessary to find a way of differentiating, by means of lithology and typological characteristics, the examples that had been imported from a long distance away (i.e. the Italian Alps) from those made of Syros jades, which will have travelled a shorter distance.

In order to interpret the results of the non-destructive analytical techniques developed by Projet JADE – namely spectroradiometric analysis and research into diagnostic macroscopic features – it was necessary to build a valid reference collection of raw material samples from the Cyclades, to add to the reference collection of Alpine samples that already exists. In 2014, two prospecting expeditions were mounted to collect such samples from Syros, Sifnos and Tinos, from locations that are known, from the geological literature, to have outcrops of ‘jadeitites’ (in a general sense). While the outcrops on Sifnos and Tinos can be excluded from further consideration, because they are very small and had never been exploited during the Neolithic, those on Syros, in contrast, are of interest. Moreover, we have been able to demonstrate, from working debris, that some of these outcrops on Syros had been exploited during the Neolithic. (See this volume, Chapter 1, p. 25.) There is no standardisation in the artefacts made from these jades, and this is probably due to the difficulty of working material that is so markedly saccharoidal in texture. It was not possible to date the working debris precisely, because it is heavily eroded and has been lying around on exposed surfaces for millennia.

Having undertaken the necessary petrographical comparisons between Syros and Alpine jades, we turned our attention to analysing the polished axe- and adze-heads, found in Greece and Asia Minor, that seemed to belong to the family of jadeitites. Our study of old collections and of assemblages from dated settlements (at Dimini and Cukurici Höyük) enabled us to identify a total of 52 candidate items. This small number highlights the relative rarity of these precious rocks within the ground stone assemblages from settlement sites.

Our analyses showed that 28 examples most probably originated in the relatively nearby sources on Syros and that 14 had probably come from the distant Alpine sources, from both Mont Viso and Mont Beigua. Ten could not be attributed to a specific source area.

The geographical distribution of axe- and adze-heads of Syros jades seems to be limited to the Aegean; however we can still expect some surprises as well. To judge from the radiocarbon dates from Cukurici Höyük, exploitation of the Syros sources will have been underway by 6300–6100 BC – that is, during the Final Neolithic, according to the Anatolian chronological scheme. Thus, the circulation of objects of Syros jade began well before the earliest exploitation of jades on Mont Viso which, according to radiocarbon dating, will not have occurred any earlier than the middle of the 5th millennium BC. All of the Syros jade axe/adze-heads are workaday tools, typologically variable and only lightly polished, like their non-jade counterparts used as woodworking tools found elsewhere in this region. The distance travelled by an axe/adze-head of Syros jade would seem to be more than 500 km as the crow flies, restraining the eastward expansion of Alpine jades.

The axe- and adze-heads made from Alpine jades are somehow different from those made from Syros jades. With their very regular, symmetrical shapes and their highly polished, often glossy surface, these objects often stand out as ‘black sheep’ in the collections and assemblages that we studied. Thus they can often be spotted with the naked eye, thanks to their high standard of manufacture and to the use of raw material of very high quality. It also appears that, of all the axe- and adze-heads made from North Italian jades, it was those made from jadeitite that travelled over very long distances. Indeed, there seems to have been a general preference in Europe for examples made from jadeitite: this rock type dominates at distances over 600 to 700 km as the crow flies from the Alpine source areas.

A good number of these Alpine axe- and adze-heads had been hafted and used for chopping down trees and working wood. However, their long use, their successive episodes of repolishing in order to make them thinner and the care taken to curate them over as long a period as possible would seem to show that they had a particular value. Nevertheless, we cannot assess what the ideological value of these objects had been – as we had been able to do for Bulgarian finds (Pétrequin, Cassen et al. 2012b – because no Alpine axe- or adze-head has been found in a hoard or a funerary context in Greece or the Asia Minor.

Two large adze-heads of Bégude type can be dated to the first half of the 5th millennium. In the case of the large axehead found in Istanbul – a Chelles-type example that had been thinned through repolishing – a date in the middle of the 5th millennium can be proposed, by analogy with identical artefacts found in sealed contexts in Bulgaria.

Finally, the question of the routes taken by Alpine jade axe- and adze-heads from North Italy to Greece and Asia Minor cannot be answered with any degree of certainty. In our current state of knowledge, the most likely route from the north of the Adriatic would seem to be via the Danube and Bulgaria, insofar as the Kodžadermen-Gumelnița-Karanovo VI culture complex constitutes a link between the plain of the Danube upstream of its delta and the north coast of the Aegean Sea.

However the analysis of a long polished blade of omphacitite, found in the Antioch region, could suggest the possible presence in Turkey of jadeitite outcrops not yet discovered.

Spectroradiometry, macroscopic approaches and the origin of Alpine jades: Viso or Beigua ?

Two principal raw material source areas have been identified for the large axeheads of Alpine jades (jadeitites, omphacitites and eclogites) which circulated from the end of the 5th millennium to the middle of the 3rd millennium BC: the Mont Viso massif, and that of Beigua (Voltri Group), separated from each other by 120 kilometres as the crow flies.

The authors have sought to evaluate the relative volume of the jades that are still available today, taking into account all the types of outcrop and deposit. Mont Viso represents by far the most important source, especially in the case of jadeitites, which are but poorly represented in the torrent beds of Beigua. However, the situation today need not necessarily reflect that of the Neolithic. Thus, a second evaluation has been attempted, this time focusing on the number of abandoned roughouts found in the production areas around Viso and  Beigua. This has produced an identical result, with Viso largely dominating axehead production in the Italian Alps, and in particular those made from jadeitites and fine-grained eclogites.

In order to determine the origin of the large Alpine axeheads (Viso vs. Beigua) – a consideration of key importance for reconstructing the axes of movement of polished axeheads across the cultural mosaic of Neolithic Europe – two methods were used, following a ‘double blind’ approach: that of spectroradiometric analysis and that of macroscopic research of characteristics that are particular to one or other of the exploited massifs.

Four hundred and thirty eight large jadeitite axeheads were analysed in order to determine their possible origin. The global results allow us firstly to assess the number of axeheads whose origin cannot be located using one or the other method – an important consideration as it affects the statistical analysis of the results. Secondly, they reveal that divergent results are obtained using each of the methods: with spectroradiometry, the figures are 58% of sourceable axeheads for Viso and 42% for Beigua, whereas with the macroscopic approach, the figures are 87% for Viso and 13% for Beigua.

In fact, the number of axeheads whose origin could be determined using both methods together is low. More generally, one could say that an axehead’s origin can only be identified using one or the other method, and not both together. This bias could account for the differences in the global results obtained through spectroradiometry as opposed to macroscopic examination.

This observation that the diagnostic features differ between different methods of analysis shows the necessity of employing the two approaches conjointly, even though the spectra for omphacitites and eclogites offer too little differentiation to allow one to make comparisons and to suggest an origin using spectroradiometry. For those rock types, the use of the macroscopic approach seems promising and allows us to suggest, on the basis of a sample of 214 large axeheads, that 83% of them could come from Viso, against 17% from Beigua.

This evaluation is consistent with the impression gained from our assessment of currently-available Alpine jades around Viso and Beigua and from the number of abandoned roughouts found in each of these production areas.

Finally, the discovery that the two methods of analysis can produce apparent contradictions (albeit rare) in their results has a positive outcome: these methods can indeed be used fruitfully in sourcing axeheads, but they have to be used in a narrow, systematic manner. Since the diagnostic characteristics differ from one method to another, then each axehead must be approached using both spectroradiometry and macroscopic inspection. This is, in our opinion, the only way to reduce the over-large number of ‘indeterminate origin’ identifications which hinder the traceability of long axeheads in their circulation at a pan-European scale.

Trois aires de production de haches ont été identifiées dans les Alpes suisses et dans les Pyrénées, en associant l’étude des déchets de fabrication et la prospection sur le terrain :
- la première, dans les Grisons, correspond à l’exploitation de lentilles et de galets dans la vallée de la Julia (Oberhalbstein), avec des villages spécialisés dans la haute vallée du Rhin ;
- la seconde se situe en Valais dans la haute vallée du Rhône aux environs de Sion ; les exploitations de lentilles de néphrite étaient situées en montagne, entre 1 700 et 2 700 m d’altitude ;
- quant à la troisième aire, en Haute Ariège, elle n’est connue que par une production spécialisée dans la grotte de Bédeilhac ; les gisements de néphrite, eux, n’ont pas encore été précisément localisés.

Ces trois aires de production ont alimenté les échanges régionaux probablement dès le début du Ve millénaire et certainement jusqu’au début du IIIe.

Les analyses spectroradiométriques ont permis de construire deux référentiels pour caractériser ces productions et pister leur circulation à longue distance :
- un référentiel d’échantillons naturels,  qui compte 701 spectres ;
- un référentiel d’objets archéologiques, qui regroupe 834 spectres avec présence d’une amphibole dominante.

En dépit d’une forte variabilité interne dans les gîtes de matières premières et de spectres parfois presque semblables dans des gîtes différents, l’approche spectroradiométrique a permis d’identifier l’origine de grandes haches et d’un anneau-disque en néphrite, découverts à plus de 500 km de leur zone d’origine. Parmi celles-ci figurent des lames polies du tumulus géant carnacéen de Tumiac et du dépôt de Bernon à Arzon (Morbihan), dont l’origine alpine (Grisons et Valais) n’est pas douteuse. Il en va de même pour l’anneau-disque de Languidic, qui est le seul objet de ce type mis en forme à partir d’une plaque de néphrite valaisanne.

À l’échelle régionale, c’est-à-dire dans un rayon d’une centaine de kilomètres, les trois centres de production ont injecté des haches et des ciseaux en grand nombre. Les transferts deviennent beaucoup plus discrets au-delà de 100 km et s’estompent complètement passé 200 km à vol d’oiseau. Cependant quelques objets exceptionnels franchissent cette limite et, dans le cas des Grisons et du Valais, ont atteint le golfe du Morbihan à plus de 800 km ; au contraire, les néphrites pyrénéennes ne semblent pas avoir connu une telle dynamique expansive à très longue distance.

Cette différence entre les deux centres alpins et le centre pyrénéen pourrait s’expliquer par leur position respective par rapport aux grands axes de diffusion des jades alpins (jadéitites, omphacitites, éclogites fines) à partir du massif du Mont Viso en direction de l’ouest. Les jades alpins, socialement valorisés dans les dons entre élites, auraient alors entraîné dans leur sillage des anneaux-disques de type alsacien ou alpin et quelques artefacts alpins remarquables en néphrite – une matière première de moindre valeur idéelle – tandis que les lames polies en néphrite pyrénéenne restaient cantonnées à l’aire habituelle de diffusion des outillages techniques en pierre polie.




Abstract :

Alpine and Pyrenaean nephrites. Prospection, reference samples and spectroradiometric reconnaissance

¬¬Three areas of axehead production have been identified in the Swiss Alps and in the Pyrenees, thanks to a study of debitage associated with field prospection :
- The first, in the Grisons, corresponds to the exploitation of lenses and cobbles in the valley of the Julia river (Oberhalbstein), with specialist villages in the high Rhine valley;
- The second is situated in Valais in the high valley of the Rhône around Sion; lenses of nephrite are to be found on the mountainside, between 1700 and 2700 metres above sea level ;
- The third, in Haute Ariège, is only known from a specialist production site in the cave of Bédeilhac;  the actual outcrops of nephrite are not precisely located.

These three production areas provided material for exchange at a regional scale, probably from the beginning of the fifth millennium, and certainly until the beginning of the third.

Spectroradiometric analyses have allowed us to create two reference collections of spectra in order to characterise these productions and to trace the long-distance circulation of their products, namely:

- A raw material reference collection, comprising 701 spectra;
- A reference collection of archaeological objects, which comprises 834 spectra, with a dominant presence of amphibole.

Despite the facts that there is a marked variability within the source areas, and that nephrites from different sources can sometimes produce the same spectra, the application of spectroradiometry has enabled us to identify the origin of large axeheads and of one ring-disc of nephrite, found over 500 km from their place of origin. These include the polished axeheads found in the gigantic Carnac-type mound at Tumiac and in the hoard found at Bernon, Arzon (Morbihan). The Alpine (Grisons and Valais) origin of these axeheads is not in doubt. The same is true of the ring-disc from Languidic, which is the only object of this type known to have been made from a plaque of Valais nephrite.

At the regional level – that is, within a radius of a hundred kilometres – large numbers of axeheads and chisels circulated from the three production centres. The numbers show a steep fall-off beyond 100 km and drop to virtually nothing at distances beyond 200 km. However, certain exceptional objects travelled further than this and, in the case of objects from Grisons and Valais, reached the Gulf of Morbihan over 800 km away. By contrast, objects made from the Pyrenaean nephrites do not seem to have travelled over long distances.

This difference between the two Alpine centres and the Pyrenaean centre could be explained by their respective positions with regard to the main axes of travel of objects made from Alpine jades (jadeitites, omphacitites and fine eclogites), moving from Mont Viso in a westerly direction. The flow of Alpine jades, which had a high social value in gift exchanges between elites, would also have brought in its train some ring-discs of Alpine or Alsacian types, and also several remarkable Alpine artefacts made of nephrite – a raw material of lesser social value. In contrast, the distribution of polished axeheads made from Pyrenaean nephrite remained limited to the normal distribution area for polished stone tools.

During the 5th millennium, polished jadeite axeheads circulated from the Italian Alps to Northern Europe, to Brittany, Catalonia, Sicily and even as far as Bulgaria. However, in the Alps, the source of the raw material was unknown to geologists, except for some rolled cobbles that had been transported by rivers. Working on a European scale and using ethnoarcheological models developed in New Guinea, in 2002 we hypothesised that the reason why these axeheads made from Alpine rocks spread so far, among very diverse cultural groups, might be the high altitude of the quarries, far from permanent settlements.In May 2003, after a dozen years of prospecting, two of us (A.-M. P. and P. P.) discovered several Neolithic working sites on the foothills south of Monviso, between 2100-2400m in altitude. The first three AMS radiocarbon dates that we obtained, of 5210 – 4916, 4883 – 4598, and 4671 – 4389 cal BCcal., accord well with the appearance of small polished axeheads of eclogite or jadeite in VSG contexts in the Paris Basin and with the major growth in exports to Brittany, dated to 4684 – 4380 cal BC at the Tumulus Saint-Michel at Carnac.

The jadeitites of Syros (Cyclades, Greece)

In 2005, M. D. Higgins proposed that the source of the polished axeheads of jadeitite that had been found in Greece may have been the island of Syros. This was based solely on macroscopic inspection and comparison.

As part of the JADE 2 Project, prospection was undertaken on Syros, Tinos and Sifnos, the three Cycladic islands where geologists had mentioned the presence of jadeitites or rocks containing jadeite, within the Cycladic Blueschists Unit. This fieldwork rapidly showed that Tinos and Sifnos could be eliminated and that it was only within the ophiolitic mixture of Kambos, at the north of Syros, that genuine ‘boudins’ – bulbous, free-standing blocks – of jadeitite, retromorphosed to varying degrees, and of sufficient size to have been exploited during the Neolithic, are to be found.

On Syros, the primary outcrop of jadeitite is strictly localised within two narrow bands around 100 metres long; the rock also occurs in the form of secondary deposits, in the stream bed between Kambos and the bay of Lia. All the blocks had been tested, to varying degrees, using a hard hammer; however, the small number of debitage flakes, of hammerstones and of roughouts suggests a production that was episodic and of very secondary importance. Elsewhere on the island of Syros, the local jadeitite seems to have been little used during the Neolithic, probably because of its mediocre quality for flaking and polishing.

The jadeite is represented in 120 raw material samples among the totality of samples analysed using diffuse-reflectance spectroradiometry. The comparison of the spectra of the Syros jadeitites with Alpine specimens in the reference collection allows us to argue that the chance of confusion between Syros and Alpine jadeitites is low, and always below 20%. Moreover, the comparison between the Syros raw material spectra and those obtained for jade axeheads found in Bulgaria and Rumania reveals that there are no convincing grounds for claiming Syros as the source area for these Balkan polished axeheads.

Variable degrees of albitization and chloritization, small presence of white mica and rutile in titanite, in some cases also occurrence of retrograde analcime seems to be characteristic petrological signs for the jadeitites or rocks megascopically resembling those from Syros island. Titanite and zircon represent typical accesory minerals. Very low contents of P2O5 seem to be a characteristic quality from the geochemical point of view.

The arguments – as much archaeological as spectroradiometric – are thus strong for proposing an Alpine source for the polished jade axeheads found in south-east Europe, and for a production on Syros that was limited or negligible. The Syros material shows evidence for testing the stone to see how it could be shaped, rather than for the large-scale production of axeheads for long-distance exchange.

The circulation of large polished axe blades during the second half of the 5th millennium B.C. is a major phenomenon of the Western european Neolithic. Three recent discoveries of axe blades made of alpine rocks are assimilated to this issue. The two blades from vendeuil, discovered planted in the ground with the cutting edge facing upwards, exemplify the status of these oversized tools, which the social value-system has transported into the domains of ritual and the sacred ; their demonstrated place of origin is from Monviso (Piedmont, Italy), from rock quarried at 2400 metres. We can propose a provenance from Monviso or from voltri for the two other axe blades, although this cannot yet be demonstrated by the spectroradiometric analyses.

L'analyse spectroradiométrique du bloc ébauche de Lugrin permet de déterminer une jadéitite, dont l'origine se situerait dans les Alpes internes, dans les exploitations néolithiques d'Oncino/Porco, au pied du Mont Viso (Piémont, Italie), entre 1700 et 2400 m d'altitude. Ce bloc, détaché par choc thermique, puis partiellement mis en forme par taille et bouchardage, a été scié pour tenter d'obtenir probablement deux haches de type Altenstadt probablement. L'ébauche double de Lugrin a été transportée sur une distance d'environ 200 km à vol d'oiseau au travers des Alpes, soit 340 km par le col du Mont-Cenis. Datée de la deuxième moitié du V e millénaire, elle représente un exemple remarquable du long investissement en temps de travail à l'origine des haches en roches alpines, qui circulent dans toute l'Europe occidentale pendant les V e et IV e millénaires. Plus tard, à partir du dernier quart du V e millénaire, la technique du sciage appliquée à des blocs roulés (et également à des affleurements primaires) va d'ailleurs être développée pour la production de haches de type Puy ; la matière première, devenue rare dans les carrières en altitude, circule alors sous la forme de petits blocs émoussés par l'eau et de blocs bruts, destinés à être travaillés dans les vallées alpines entre Piémont et Savoie. Quant à l'ébauche de Lugrin, le contexte de découverte permet de suggérer qu'elle a été associée, comme ailleurs les haches plantées dans le sol, à un lieu sacré et non pas à une production locale de haches en roches alpines. (Inner Alps, Piedmont, Italy), between 1700 and 2400 m asl. This block, detached by thermal shock, and partially shaped by knapping and hammering, was sawn in an attempt probably for producing two axes of Altenstadt/Greenlaw type. Thus, the Lugrin double blank was transported ca. 200 km across the Alps as the crow flies or ca. 340 km via the Mont-Cenis Pass. Dated to the second half of the 5 th millennium, this axe represents one of a group of remarkable examples of investment in labor-intensive production. Such axes were fashioned of Alpine rocks and circulated throughout Western Europe during the 5 th and 4 th millennia. Later, beginning with the last quarter of the 5 th millennium, the technique of sawing was applied to riverbed pebbles (but also to primary deposits rocks) to produce Puy-type axes. As raw material became rare in high altitude quarries, its replacements were circulated in the form of blunt riverbed pebbles and rough blocks, then knapped and shaped in the Alpine valleys between Piedmont and Savoy. The archaeological context of the Lugrin blank suggests that, as observed elsewhere for axes set upright into the ground, it was associated to a sacred site and not related to some local production center of axes made from Alpine rocks.

Im Rahmen eines größeren Forschungsprojektes wurden 2006 die neolithischen Beile aus Jadeitit und anderen seltenen alpinen Gesteinen aus den Beständen des Berliner Museums für Vor-und Frühgeschichte spektrometrisch untersucht. Dank der Wiederentdeckung der einzigen europäischen Vorkommen dieser Materialien in den italienischen Alpen ist es heute möglich, die Herkunft der fraglichen Funde mit ungewöhnlicher Präzision zu bestimmen. Auch die Rekonstruktion der Tauschrouten ist mittels spektrometrischer Vergleiche möglich. Ergebnisse und Perspektiven des Forschungsprojektes werden beispielhaft anhand eines großen Jadeititbeils aus dem thüringischen Depotfund von MönchpÞ ffel-Nikolausrieth aufgezeigt. Angefügt ist ein Katalog der neolithischen Beilklingen aus "Jade" im Berliner Museum für Vor-und Frühgeschichte.

This chapter presents the hypothesis that there existed, in north Italy and Provence, a multipolar system involving the movement of small workaday axeheads around networks of contacts, from the two principal areas where Alpine jades were exploited : the massifs of Mont Viso and Mont Beigua (the Voltri Group). The areas of exploitation were, in some cases, primary (i.e. blocks found at high altitude) and in other cases, secondary (i.e. upstream in the beds of rivers).
Several Neolithic sites were chosen in this novel approach : Sassello and Ponzone in the Beigua Massif, Rivanazzano and Arene Candide at the periphery of the massif, Gaione and Sammardenchia, situated between 100 km and 400 km to the east of Beigua, and finally Provence, on the French side of the Alps to the west.
Two techniques for identifying the raw material were used with the polished tools : spectroradiometric analysis, and macroscopic inspection to check for characteristic markers, both being informed by a preliminary study of several thousand raw material specimens, collected in each of the two source areas for Alpine jades.
We noted that all the Neolithic settlements - even including those located within the Beigua massif - were receiving material from both sources (Viso and Beigua). Among the assemblages of workaday polished axeheads (i.e. those used for felling trees and for woodworking) to the south of the Pô river, the proportion of axeheads made from Beigua rock remained high (notwithstanding a considerable use of Viso rock) up to a distance of nearly 400 km as the crow flies at Friuli. By contrast, on the French side of the Alps, Mont Viso rock predominates (with a minority being of Beigua rock); this echoes the pattern seen in the magnificent large axeheads of Alpine rock, where Mont Viso rock predominates among the examples found in north-west Europe.
This approach, which for the first time is based on the systematic comparison of Neolithic axeheads and raw material samples collected at the principal sources of the rocks, allows us to propose a more complex interpretation of the networks of contacts over which these everyday axeheads circulated. With the small polished axeheads and adzes in particular, the fine-grained omphacitites and eclogites of Mont Viso seem to be well represented, at least in assem-blages from the end of the 6th millennium onwards. The rarity of fine jadeitites in the settlements of north Italy is, however, striking : it probably illustrates the social choices made by the people who exploited the raw materials, who seemed to have preferred to use rock from Mont Viso to supply the long-distance movement of axeheads towards western Europe

Dans le creux de la botte italienne, à 950 km à vol d'oiseau de la zone potentielle d'origine ( , une extraordinaire hache en jadéitite a été découverte dans la région de Laterza (Pouilles, Italie), si l'on en croit les conditions incertaines de fouille, dans une tombe du plateau qui domine le Golfe de Tarente aux envi-25 Jahrbuch des Römisch-Germanischen Zentralmuseums 54 · 2007

Mapping the spatial distribution of Mediterranean vegetation is crucial for understanding current ecosystem equilibrium and combating present phenomena, such as desertification and wildfires. Conclusive evidence on the spectral discrimination of such plants is thus necessary. To this end, this study focuses on the discrimination among three trees and three shrubs based on their spectral reflectance measured in a typical Mediterranean environment. Spectra from the plants were acquired by field spectroradiometry in the range between 350 and 2500 nm during an intensive field campaign that took place in Crete island in the spring 2010. Discrimination analysis was performed by applying non-parametric statistical tests on the unaltered spectral reflectance. The multivariate classificatory technique, employed for quantifying the shape similarity between the reflectance spectra, indicated that the majority of the plants possess distinct signatures from one another. The univariate tests implemented pointed out the existence of wavelengths where the plants can be discriminated. The use of unaltered reflectance narrows the statistical difference between the plants to bands in the visible and the shortwave infrared spectrum, but weakens the difference in the near-infrared spectrum, compared to continuum-removed reflectance analysis of the plants already published. The use of unaltered reflectance emphasizes detectable differences induced by the optical properties of the plants, as well as by variation of internal water of the plants related to drought adaptations. All in all, this work highlights the prospect of hyperspectral remote sensing in discriminating those plant species using field spectral libraries coinciding with high-quality radiometrically calibrated imagery.

This article describes research recently carried out on an axehead of Alpine rock found at Marsh Farm, Breamore, and curated by the Wiltshire Heritage Museum. Investigation by one of us has clarified its findspot location, while typological and non-destructive analysis, as part of an international research project, 'Programme JADE', has pinpointed the source of the raw material and clarified the axehead's place among the thousands of Alpine axeheads known from Europe. The article also discusses other Alpine axeheads -and items previously claimed to have such an origin -from central southern England, including the example from the Stonehenge area, housed in the Salisbury and South Wiltshire Museum, that is now used as a type artefact, the 'Durrington type'.

Fra i numerosi reperti in pietra verde delle collezioni ottocentesche del Museo di Archeologia Ligure, viene individuato un abbozzo di anellone in giadeitite proveniente da Bobbio, che è analizzato alla luce dei dati esistenti su tali manufatti nell'ambito dell'Italia del Nord-Ovest. Il contributo dell'analisi in spettroradiometria permette di formulare inoltre fondate ipotesi sulla provenienza della materia prima con la quale il pezzo è stato confezionato.

It has long been recognised that, in Neolithic and Chalcolithic Europe, there existed a kind of ‘mirror image’ between Carnac and the Gulf of Morbihan in the west and Varna in the east. Around the middle of the Vfth millennium BC, these two areas display a remarkable wealth in their funerary assemblages (with jade and va-riscite being used in the west and gold and copper in the east), and they also shared some social concepts, fea-turing a marked degree of social inequality, expressed through symbols of violence and of power, curved throwing weapons, sceptres and axes.
As part of Projet JADE, a recent expedition to study and analyse artefacts in the museums of Bulgaria has resulted in the recognition of a fine set of axeheads made from jadeitite, of omphacitite and of eclogite. These had previously been identified, incorrectly, as being of serpentinites of Bulgarian origin. We shall try to demonstrate that these axeheads had, in all probability, been imported over a long distance, originating in the high Italian Alps, from the Beigua region and from Mont Viso to a lesser degree.
The artefacts in question - which essentially consist of polished axeheads and small tranchet axeheads - have come from three types of context.
The first comprises several of the graves in the cemeteries at Varna I and II and at Durankulak. One of the most spectacular tombs is Grave 43 in Varna I, one of the richest in the Varna cemeteries, with almost a kilo of gold (around a sixth of all of the gold found at Varna) ; two jadeitite axeheads had been placed between the legs of the corpse. In total, twelve axeheads and small adze-heads of probable Alpine rock have been identified at Varna and Durankulak, both sites lying on the coast of the Black Sea.
The second context is the settlement. Just two jade axe-head are known, one from the tell at Karanovo - and it comes from the base of Layer VI (late Chalcolithic) - and a second from Nevski. However, nothing is known of their find circumstances, so it is unclear whether we are dealing with a domestic site or a sanctuary.
The third context type is the hoard. Around 31 axeheads, both large and small, have been found in hoards, deposited flat. Three come from the Orlovets hoard. In the case of the Svoboda hoard, 28 axeheads are offficially recorded, but there are signs that the original number could have been higher. At Svoboda there was one axehead of Bégude type, one of classical Chelles type, eight of Chelles type that had been repolished, seven of Durrington type, four of Varna type and seven small triangular or trapezoidal adze-heads. This number of axe-heads makes Svoboda the most important hoard in the whole of Europe. The typological range suggests a date just after the middle of the fifth millennium BC, and this accords with the proposed date for Varna II and the Late Chalcolithic.
As for the axeheads from Varna II, these allow us to sug-gest a date around 4600 BC at least for the earliest imports of Alpine axeheads.
This previously unpublished evidence for the eastwards circulation of axeheads over more than 1 700 km needs to be discussed in relation to the discovery of Alpine axeheads in Croatia. It appears that Mont Viso and the Beigua massif occupied a central position in the diffusion of Alpine axeheads (through repeated contacts) across a vast swathe of Europe, from Carnac to Varna.

Mapping the spatial distribution of Mediterranean vegetation is crucial for understanding current ecosystem equilibrium and combating present phenomena, such as desertification and wildfires. Conclusive evidence on the spectral discrimination of such plants is thus necessary. To this end, this study focuses on the discrimination among three trees and three shrubs based on their spectral reflectance measured in a typical Mediterranean environment. Spectra from the plants were acquired by field spectroradiometry in the range between 350 and 2500 nm during an intensive field campaign that took place in Crete island in the spring 2010. Discrimination analysis was performed by applying non-parametric statistical tests on the unaltered spectral reflectance. The multivariate classificatory technique, employed for quantifying the shape similarity between the reflectance spectra, indicated that the majority of the plants possess distinct signatures from one another. The univariate tests implemented pointed out the existence of wavelengths where the plants can be discriminated. The use of unaltered reflectance narrows the statistical difference between the plants to bands in the visible and the shortwave infrared spectrum, but weakens the difference in the near-infrared spectrum, compared to continuum-removed reflectance analysis of the plants already published. The use of unaltered reflectance emphasizes detectable differences induced by the optical properties of the plants, as well as by variation of internal water of the plants related to drought adaptations. All in all, this work highlights the prospect of hyperspectral remote sensing in discriminating those plant species using field spectral libraries coinciding with high-quality radiometrically calibrated imagery.

Field spectroradiometry of land surface objects supports remote sensing analysis, facilitates the discrimination of vegetation species, and enhances the mapping efficiency. Especially in the Mediterranean, spectral discrimination of common vegetation types, such as phrygana and maquis species, remains a challenge. Both phrygana and maquis may be used as a direct indicator for grazing management, fire history and severity, and the state of the wider ecosystem equilibrium. This study aims to investigate the capability of field spectroradiometry supporting remote sensing analysis of the land cover of a characteristic Mediterranean area. Five common Mediterranean maquis and phrygana species were examined. Spectra acquisition was performed during an intensive field campaign deployed in spring 2010, supported by a novel platform MUFSPEM@MED (Mobile Unit for Field SPEctral Measurements at the MEDiterranean) for high canopy measurements. Parametric and non-parametric statistical tests have been applied to the continuum-removed reflectance of the species in the visible to shortwave infrared spectral range. Interpretation of the results indicated distinct discrimination between the studied species at specific spectral regions. Statistically significant wavelengths were principally found in both the visible and the near infrared regions of the electromagnetic spectrum. Spectral bands in the shortwave infrared demonstrated significant discrimination features for the examined species adapted to Mediterranean drought. All in all, results confirmed the prospect for a more accurate mapping of the species spatial distribution using remote sensing imagery coupled with in situ spectral information.