Celtic Oppidum Research Articles

The potential of low-destructive characterization of archaeological sites with stony and eroded soils through geostatistics at the Celtic oppidum of Bibracte (France)

Urbanization during Europe's Late Iron Age brought about a rise of enclosed settlements, or ‘oppida’. These centers of human activity left indelible marks on the environment, influencing its geochemistry. The key goal of the research is to identify zones of anthropogenic activities within eroded and stony soils of the Bibracte oppidum’s ‘empty spaces’. We demonstrate an innovative multivariate and geostatistical approach to integrate relevant geochemical and, when available, geophysical records, thereby facilitating a comprehensive understanding of activity areas within oppida in conditions of soil truncation, erosiona and uneven distribution of cores. Our results indicate varied and potentially intensive past human activities in the southern area of La Terrasse, La Chaume, Le Porrey and Le Verger. This is evidenced by elevated values of magnetic susceptibility and chemical elements such as phosphorus and calcium, which reflect here a diverse historical utilization of these spaces. Our robust multivariate statistical analysis effectively deals with the challenges posed by irregular spatial distribution and missing data, enabling the successful correlation of geochemical and geophysical data and providing compelling evidence of spatially differentiated human activities throughout the oppidum. This extends our understanding of Iron Age urbanization and the nuanced utilization of space within these early urban centers.

Detection of occupational surface remnants at a heavily eroded site; case study of archaeological soils from La Terrasse, Bibracte oppidum

The area of La Terrasse is located at one of the higher parts of the Celtic oppidum Bibracte. No traces of building activities, except for the fortification system which surrounds the plateau from three sides, were archaeologically detected and the area can be therefore labeled as “empty space” with an enigmatic history. Multiproxy investigations of sediments in trenches cutting across various parts of the enclosed area and excavated during the 2019 season revealed a complicated history of the formation, being influenced by erosion and by anthropogenic stabilization.Although the recent relief of the La Terrasse area appears quite stable, there is evidence that the site (and Bibracte oppidum in general) were subject to intense erosion in the past and that the former surface with the archaeological soil dated to the Late Iron Age is preserved only as a relict expressed geochemically by the increase of CEC. The reason for the recent surface stability is the presence of the Iron Age ramparts, which enclose the area and protect it against erosion. An OSL sample collected from the surface of the buried archaeological soil dates the overburden not later than to the early Medieval period (AD 561). The archaeological soil represented by the overburden did not reveal any significant geochemical signal indicative of intensive use despite its location in the most suitable and stable area of the site.It is clear that the detection of former surfaces in eroded and exposed archaeological sites and the properties of the archaeological soils is always a complex matter and can only be addressed through a combination of field observations, geochemical and micromorphological proxies.

NEW FIND OF OLBIAN COINS. TARASHCHA DISTRICT, KYIV REGION, UKRAINE

The aim of the study is presentation of a new hoard of ancient coins discovered in the Ukraine. In the Summer of 2019 fifteen bronze coins of Olbia (Greek polis in the North West Black Sea region) were found in the Kyiv region. Research methodology – principles of science, historicism, objectivity, methods of analysis, classification, generalization, historical-genetic and historical-typological. Scientific novelty. All coins are of “Borysthenes” type (head of river god Borysthenes / Scythian axe, bow in case, ΟΛΒΙΟ). An assemblage has been described by the founder as found in the ground between village Lukyanivka and the town Tarashcha (Kyiv region), near the highway P 04. The coins are dated to the end of fourth and the middle of the third century BC. The assemblage is one of interesting finds of Olbian coins on the way from the North Pontic Region to the West. The hoard from Lukyanivka is one of finds registered very far outside of Greek states of the northern coast of Black Sea. The cognitive value of the hoard lies above all in the region of its finding. The find from Lukyanivka is an important find as in recent years Olbian bronze coins as well as Bosporan coins were found on Celtic settlements in Poland (Upper Silesia; other coin finds were registered in Central Poland) and Czech Republic (Celtic oppidum at Nĕmcice, Moravia; a very rich assemblage of Greek and Roman coins). The find from Lukyanivka is a new important element in the discussion on inflow of Olbian coins to the West. The Lukyanivka hoard consists of 15 bronze coins with the head of river god Borysthenes, one of the most popular coins of Olbia. According to data obtained from the founder, the coins were found together in ‘one place’ but at ‘different depth’. In the founder’s opinion the value of the information on the find can’t be negated. Following to the chronology of “Borysthenes” coins proposed by P. O. Karyshkovskii coins found not far from Lukyanivka should be dated from the late fourth century BC to the ca. 250 BC. The most coins are dated to 290 – 250 BC. The structure of the Lukyanivka hoard should be treated as ‘typical’ for hoards of Olbian coins. The Conclusions. The find from Lukyanivka confirms that in the third century BC the most popular Olbian pieces of “Borysthenes” type penetrated the area of the Central Ukraine, precisely Middle Ros river region, in significant quantity. The “assemblage” is important find as the majority of Olbian and Bosporan coins in Central Europe – find from Germany is doubt all are single finds. The coins described in the article fills “a gap” between finds from Dnieper and Dniester rivers and Central European finds. The find is located inside the “tongue-shaped” area of finds from the North Pntic region). The “tongue-shaped” area dominated’ by single finds. The area of Olbian and Bosporan coin-finds indicates that the appearance of coins minted by Pontic Greek poleis in Central Europe may be connected with activity of people of Scythian culture. This is extremely important as we have in mind a unique find of Greek amphora from the Scythian settlement located in the south-eastern Poland.

Multi-analytical approach and microstructural characterisation of glasses from the Celtic oppidum of Třísov, Czech Republic, second to first centuries BC

The Late Iron Age–La Tene period in Europe outside the Hellenistic world is characterised by specific glass products in the third to first centuries BC. Evidence of glass-working together with large collections of products (bracelets, ring-beads and other beads) have been reported from several central settlements (e.g. Němcice and Stare Hradisko in Moravia, Manching in Bavaria). These products were made from soda–lime natron-based glass. Raw glass was imported from the Mediterranean and used in local workshops to make personal ornaments. This paper presents a collection of the second- to first-century BC glass from the Celtic oppidum of Třisov in southern Bohemia, Czech Republic. Its archaeology and chemistry were studied in the context of contemporary glass-making and glass-working. The methods of scanning electron microscopy with energy-dispersive spectrometry and laser-ablation–induced coupled plasma–mass spectrometry were used for this purpose. All analysed samples of La Tene glass were found to be made of natron-based glass, comparable with glass produced in the Syro-Palestinian area. For the first time, different layers of body glass and inclusions were separately analysed in ring-beads. In yellow and also white opaque glasses, tin-based opacifiers and colourants were used. Besides typical La Tene ornaments made of natron-based glass, the analysed collection also contains three fragments of vessel made of much later wood-ash glass. As no evidence of glass-working is available from the Třisov oppidum, it is assumed that it functioned as a trading post or a distribution centre for glass products manufactured, e.g. at the Stradonice or Manching oppida. In this respect, the study provides new data on the production and distribution of La Tene glass in central Europe.

Study of archaeological iron objects by PGAA, Mössbauer spectroscopy and X-ray diffraction

Archaeological iron objects often corrode rapidly after their excavation, even though they have survived long times of burial in the ground. Chlorine that accumulates during burial is thought to play a major role in this destructive post-excavation corrosion. It is therefore important for the conservation of such objects to determine the chlorine content in a non-destructive manner and, if necessary, to remove the chlorine from the artefacts by appropriate methods. Such methods are leaching in alkaline solutions or heating in a reducing atmosphere at temperatures up to 800 ∘C. We have studied the efficiency of the heating method using prompt gamma activation analysis (PGAA) for monitoring the Cl content and Mossbauer spectroscopy at room temperature (RT) and 4.2 K as well as X-ray diffraction to study the mineralogical transformations of the rust layers. The heat treatments were performed a N2/H2 (90/10) mixture at temperatures up to 750 ∘C. As test specimens sections of iron rods from the Celtic oppidum of Manching (Bavaria) were used. The initial Cl contents of the pieces varied in the range of several hundred ppm, referring to the iron mass. Annealing for 24 h at 350, 550 and 750 ∘C was found to reduce the Cl contents of the specimens, to about 70, 30 and 15 % of the original values, respectively. The rust consists mainly of goethite with admixtures of magnetite, lepidocrocite and akaganeite, which is thought to be a major carrier of chlorine, probably together with iron chlorides. Much of the goethite is so fine-grained that it does not split magnetically at RT. Annealing converts the rust mainly to maghemite at 350 ∘C, to magnetite at 550 ∘C and to wustite plus magnetite and metallic iron at 750 ∘C. Pure akaganeite behaves in nearly the same manner.

Tracking archaeological and historical mines using mineral prospectivity mapping

The present study proposes a technological transfer from modern mining prospection to the field of archaeology, providing a methodology to facilitate the discovery of ancient mining sites. This method takes advantage of the thousands of geochemical analyses of streambed sediments, performed by national geological surveys to inventory mineral substances. In order to delineate geochemical anomalies, the datasets are treated following two different approaches: Exploratory Data Analysis and a fractal-based method often recognised as more powerful. Mineral prospectivity maps are then obtained by combining the results with a geographical information system. The surroundings of the Celtic oppidum of Bibracte, French Massif Central, known to have been mined at least since the Late Bronze Age until Modern Times, have been chosen to exemplify the method's potential in archaeology. First, an exhaustive record of the mining sites was undertaken over a pilot area by pedestrian prospection. If mineral prospectivity maps had been used as guidelines, ∼70% of these mines would have been discovered by prospecting only ∼15–20% of the whole area whatever the method used to treat the dataset. At least for our specific case, the multifractal approach is as powerful as EDA. Besides saving a significant amount of time and effort, the methods described here may supply clues for determining the nature of mineral substances exploited in the past, when such information cannot be straightforwardly obtained from the field or from textual archives. It should however be noticed that this approach is proposed as a first step before peer archaeological investigation following more conventional methods. Technically, there is no real obstacle to the application of the methodology proposed here, because (i) software and associated packages are freely available from the web, as well as original geochemical datasets (at least in France), and (ii) minimal mathematical skills are required.

MODELLING VAGUE KNOWLEDGE FOR DECISION SUPPORT IN PLANNING ARCHAEOLOGICAL PROSPECTIONS

Abstract. Most archaeological predictive models lack significance because fuzziness of data and uncertainty in knowledge about human behaviour and natural processes are hardly ever considered. One possibility to cope with such uncertainties is utilization of probability based approaches like Bayes Theorem or Dempster-Shafer-Theory. We analyzed an area of 50 km2 in Rhineland Palatinate (Germany) near a Celtic oppidum by use of Dempster-Shafer's theory of evidence for predicting spatial probability distribution of archaeological sites. This technique incorporates uncertainty by assigning various weights of evidence to defined variables, in that way estimating the probability for supporting a specific hypothesis (in our case the hypothesis presence or absence of a site). Selection of variables for our model relied both on assumptions about settlement patterns and on statistically tested relationships between known archaeological sites and environmental factors. The modelling process was conducted in a Geographic Information System (GIS) by generating raster-based likelihood surfaces. The corresponding likelihood surfaces were aggregated to a final weight of evidence surface, which resulted in a likelihood value for every single cell of being a site or a non-site. Finally the result was tested against a database of known archaeological sites for evaluating the gain of the model. For the purpose of enhancing the gain of our model and sharpening our criteria we used a two-step approach to improve the modelling of former settlement strategies in our study area. Applying the developed model finally yielded a 100 percent success rate of known archaeological sites located in predicted high potential areas.

Mud-plastered granary-baskets at a Celtic Oppidum near Čarnok (Vojvodina, Serbia)

In the Celtic Oppidum near Carnok (Backa, Vojvodina, Serbia) remains of four mud-plastered granarybaskets were discovered. They are all dated to the period Gomolava VI-B (first half of the 1st century B.C.). Hulled barley and broomcorn millet were stored in the granary-baskets. The mesh of the granary-baskets was composed of young branches of oak tree (Quercus), common English elm tree (Ulmus cf. campestris L.), poplar / willow (Populus / Salix), purgin buckthorn (Rhamnus cf. cathartica L.), wayfaring tree (Viburnum cf. lantana L.), spindle tree (Euonymus cf. europaeus L.), barberry (Berberis vulgaris L.) and a Pomoidae-tree. At least four different tree taxa were used for basket making. Construction of two-thousand-year old mud-plastered granary-baskets from the Pannonian plain is very similar to that of traditional granaries in some present-day villages in Africa. Additionally, one non-plastered basket was also discovered at Oppidum. It was build out of maple (Acer), barberry, buckthorn (Rhamnus) and branches of a pomaceous fruits tree (Pomoidae).

THE PROVENANCE OF IRON ARTEFACTS FROM MANCHING: A MULTI‐TECHNIQUE APPROACH*

Iron finds from the Celtic oppidum of Manching in southern Bavaria (Germany) are analysed in view of their possible provenance. The exceptional size and the location of Manching are usually attributed to the presence of abundant iron ores in its vicinity. After a review of previous approaches for source determination of iron artefacts, we introduce lead isotope analysis as a new approach. However, only by combining the trace element patterns of slag inclusions and iron metal with lead isotope ratios in the metal is it possible to distinguish various iron ore formations near Manching. As a result, it turns out that, indeed, the most obvious ones—namely, bog ores near the Danube—constituted the main resources for iron production at Manching. It was even possible to select one occurrence as the most likely ore source.

Ceramics from the Celtic Oppidum of Manching and Its Influence in Central Europe

We present an overview on an extended study of Celtic ceramics from the oppidum of Manching and from some contemporary Celtic sites. The results of neutron activation analysis, thin section microscopy and Mossbauer spectroscopy are combined with the existing detailed archaeological typology to provide information on the provenance of Celtic pottery and on details of its production. The data indicate that there was only very limited exchange of material but far reaching transfer of technology.

New Aspects of Celtic Gold Coinage Production in Europe

New archaeological finds at the Celtic oppidum (site) of Tarodunum/Kirchzarten, near Freiburg (South-Germany, Black-Forest Region) and their analytical evaluation add another chapter to the still enigmatic Celtic metallurgy, especially in relation to the production of gold/silver/copper alloys for coinage.

Mössbauer study of graphite ware from the Celtic oppidum of Manching

A systematic investigation of five sherds from the Celtic oppidum of Manching by refiring in different atmospheres is presented. The data are part of an extended and general study of Celtic ceramics in early Europe.

Organic petrology in the service of archaeology

The techniques of organic petrology have been used to study the nature and provenance of 81 ornaments ranging in age from the Celtic (dated as late Hallstatt-early La Tène tims, 500-300 B.C.) to Roman (1st–4th Century A.D.) periods, which have been recovered from graves and settlements in Germany and Switzerland. The ornaments were mainly black or dark brown armlets but also included beads, buttons and medallions. The most commonly used source material was jet (22 objects) which is derived from bituminized drift woods found in Liassic oil shale, probably mainly of English provenance. Eleven objects were made from Carboniferous cannel coal and four from boghead coal, both of unknown geographic provenance. Only one object proved to be made from Posidonia shale, a liassic oil shale from southern Germany. The identification of two distinctive sapropelites, used mainly for the production of armlets, is of particular interest. These sapropelites are the “Schwarte” from the top of the Kounova Seam (Stephanian) of northern Bohemia (15 objects) and the Kimmeridge “coal” of Dorset, England (19 objects). The recognition of these organic materials was made possible by the study of fresh rock samples. All the armlets made from “Schwarte” were excavated in the Celtic oppidum at Manching in southern Germany; the armlets made from Kimmeridge “coal” were found in Celtic and Roman graves. These discoveries suggest the existence of early trade routes crossing the English Channel and passing south to Switzerland, probably along the River Rhine. A very few armlets were made from dark tuff (probably of Bohemian origin), black glass or dark brown bone. These materials were probably all used as substitutes for jet and/or sapropelites. It is interesting to note that all these dark armlets were thought to possess magic properties, which may explain their frequency.

The chemical identification of baltic amber at the Celtic oppidum Staré Hradisko in Moravia

The Celtic oppidum Staré Hradisko north of Brno in Moravia, ČSSR, has long been noted for its wealth of archaeological amber artifacts. Since there are several substantial deposits of fossil resins in the immediate vicinity of the site, it has been an open question whether the settlement was a centre of exploitation and exportation of these local raw materials, or whether it was an entrepôt of Baltic amber on its way to southern and southeastern Europe. Because of extensive weathering, many of the amber finds at Staré Hradisko cannot be identified by infra-red spectroscopy. A new analytical method, which determines the amount of succinic acid by means of gas chromatography, has been developed to show that the amber of Staré Hradisko is, in fact, of the Baltic variety called succinite.