The site of Alle, Noir Bois is situated in the Ajoie region of the Canton of Jura (Switzerland) and was discovered between 1986 and 1990 during successive archaeological surveys linked to the construction of the A16 motorway. The extensive excavation of the site by the Section d'archéologie of the Office du patrimoine historique, covering a surface of two and a half hectares, took place during an uninterrupted campaign lasting from 1991 to 1993.

The 1990 survey revealed the first conclusive evidence of an Early La Tène occupation within an archaeological layer covering most of the excavated surface. A part from this horizon and discrete traces of a Late La Tène presence, various other occupations dating from the Palaeolithic to the Early Medieval period were discovered during these excavations and have already been published in three volumes of the series Cahiers d'archéologie jurassienne (CAJ 7, 8 and 10).

The Early La Tène settlement, situated at the bottom of the northern slope of Noir Bois hill is stretches over a distance of 450 m. It lies at a mean altitude of 450 m on the edge of the flood plain of the Allaine river.

The sedimentary context and the conflation of the various archaeological horizons have created a complex situation calling for a detailed analysis of the finds and features. The Early La Tène remains, distributed over three quarters of the excavated surface, became the object of pluridisciplinary research program.

The dating of the Early La Tène occupation is based on a number of chronologically significant artefacts: grooved fine ware pottery, bowls with a groove under the rim, Marzabotto and Certosa fibulae, three other fibulae dated to the La Tène B1 horizon, a stamped ring and a blue glass bead.

The settlement contained at least 38 wood and earth buildings. Spatially, the features and finds formed six clusters or architectural groups combining several probably contemporaneous buildings with perhaps different functions. The buildings can be assigned to three large categories : houses, granaries and other constructions.

Thirteen of these house plans are complete and inspired the reconstruction of the remaining and more fragmentary plans. The buildings have a rectangular or square plan, only a single aisle flanked by wooden posts and generally a north-south orientation. The architectural similarity of these constructions points to a building tradition limited by simple technical considerations. In several buildings, the presence of successive construction phases allows us to reconstruct their relative chronology. Storage pits and hearths were found within nine buildings. One contains nine hearths apparently used for metalworking. Other pits found near buildings served either to extract clay or for storage purposes. In two cases, a shallow ditch was dug along the length of a building, possibly for drainage. Three clusters of features do not include buildings: the first is a cluster of eight pits, the second an isolated outdoor hearth and the third the only oven found in the settlement, accompanied by another hearth.

The lithic artefacts are mostly sandstone querns and whetstones. Fossils were apparently collected as is shown by two crinoid stems with cut marks caused by the fabrication of beads. An iron hook, a sewing needle, clay spindle whorls and loom weights can all be linked to various textile working activities such as spinning, weaving and sewing. A pit containing the remains of several carbonised staves might represent the remains of a vertical loom.

Among the metal artefacts, chisels and axes can be linked to woodworking, two strap hinges must originally have been part of a wooden chest and a cauldron attachment belongs in the kitchen. Ironworking is attested by hammer fragments, jaws of pliers, a poker, various semi-finished products, waste pieces and hammerscale. Small fragments and waste pieces of bronze and a piece of a sandstone mould prove that this metal was cast in the settlement.

Some 25'000 sherds belonging to at least 1880 individuals (108 with completely reconstructed profiles) make up the pottery assemblage. Rough ware is rare. Fine, wheel-thrown pottery, decorated with grooves on the neck or the shoulder, is not common. Most of the pottery was constructed by hand from coils. The six common forms are: wide bowls, carinated bowls, small carinated bowls, goblets, pots and bottles. A few micro-pottery vessels were also found. The pottery fabric analysis revealed several distinct types of ware and about 90% of the assemblage could be assigned to one of these classes. Most of the pots seem to have been made from raw materials gathered within a radius of 1 to 10km around the site. Several imported vessels show strong parallels to pottery produced in the Kaiserstuhl region of Germany. Pottery was generally fired at temperatures of about 600 °C in pits under reducing or changing atmosphere. Several clay wedges, apparently fired at over 800 °C, remain at this time without convincing parallels.

A considerable number of ornamental objects made of bronze, iron or glass were found : fibulae, rings, beads.

The analysis of carbonized plant remains and seeds indicates that the surrounding landscape was mostly open, consisting mainly of fields and pastures. Cereals, legumes and oily plants were cultivated. Various wild plants were gathered and some were probably used as spices, for medicinal purposes or for colouring. Dotted across the plain were small groves of bushes and riverine woods ; the hills were probably covered by a mixed beech forest. The faunal remains consisted mostly of the bones of sheep, goats, pigs, cattle and horses.

The geographical location of Alle, Noir Bois means that it is easily accessible from the Rhine basin, Alsatia and the Franche-Comté. Travel to the East had to cross the passes and valleys of the Jura mountain range. Materials analysis has shown that some artefacts were imported from the Kaiserstuhl, the Vosges Mountains and the Swiss plateau. The site was occupied during the Early La Tène, a period of wide-spread settlement, on the route linking the centers of Mandeure and Basle.

Translation : Robert Fellner