The extensive excavation of Delémont - La Pran, a multi-period site situated in the flood-plain discovered during the construction of the A16 motorway, is published in four volumes wich are essentially organised along chronological lines :
- the first volume of the series (CAJ 22) contains a general description of the site location, the excavation methods, the geological setting, as well as the results of the palaeoenvironmental studies. The oldest occupations are presented in the second half of the volume : they date to the Mesolithic, Neolithic, Middle Bronze and the beginning Late Bronze Ages ;
- the second volume (CAJ 23, forthcoming) treats of the Late Bronze Age cemetery, composed of forty cremations ;
- the third volume (CAJ 24, forthcoming) presents the Late Bronze Age settlement ;
- the present volume, the Cahier d'archéologie jurassienne (CAJ 25) describes the Iron Age occupations discovered at Delémont - En La Pran and the two smaller neighbouring sites, Courtételle - Tivila and Delémont - La Pran.

The presentation of the Iron Age occupations described in this volume is organised by site and by period. It is preceded by a short recapitulative chapter offering information on site location, geology and excavation methods (chap. 2).

In chapter 3 two concentrations of features and finds dating to the Hallstatt period are described. Separated by a distance of about 300 m, both are part of the Delémont - En La Pran site : - the first, located at the north-western extremity of the site, is composed of two buildings and several hearths, built within an abandoned meander of the Pran stream. The finds (pottery, bituminous schist bracelets, lithic artefacts, spindle-whorls and organic remains) are characteristic of domestic activities. Several large lined hearths, of unknown function, were built on the sole of the abandoned and partly silted meander. The old stream bed was also used as a waste dump ; - the second occupies the opposite, north-eastern extremity of the site. At least two small buildings seem to have been present. One is delimited by post holes, the other is partly revealed by the structured distribution of a concentration of finds. The large proportion of burnt pottery and daub within this concentration suggests that the building was destroyed by fire. The finds are again typical for domestic activities : a part from potsherds and lithic artefacts, a number of loom weights and a spindle-whorl, used for the production of textiles, were discovered.

Typologically, the pottery and the schist bracelets place both occupations in the Hallstatt C to D1 periods and appear typical of the cultural region covering eastern Switzerland, the Alsace and Baden-Württemberg. Analysis of the plant remains documents the cultivation of spelt wheat, common millet, Einkorn and lentils, as well as several secondary cultivars, a result which is consistent with observations made on contemporary sites in Switzerland, eastern France and south-western Germany. The exact nature of the two occupations cannot be determined, as they were only incompletely excavated. Traces of cooking, weaving, spinning and threshing were observed. It is however unclear whether the occupations were strictly contemporaneous or functionally interrelated. They might be remains of two successive occupations by the same group or traces left by two different groups.

Chapter 4 presents the traces of La Tène period occupations observed on the same site. One building, built partly on posts and partly on sill-beams, could be identified in an area that bore only few traces of other occupations. The building was destroyed by fire. It contains two hearths, one of which was lined with clay. The pottery, a fragment of a glass bracelet and millstone fragments date the building typologically to the La Tène C2 period. Several post holes, a pit and a number of finds clustering several meters to the south of the building appear to be contemporary and might represent a secondary construction. Two north-south oriented ditches are interpreted as contemporary boundary markers, while three other ditches, with an east-western orientation, appear to be older. Finds associated with the latter features appear to date to the late Early La Tène or early Middle La Tène periods.

In chapter 5, the abundant finds discovered upstream at Courtételle - Tivila are described. They were located within an abandoned meander and on the banks of the Pran brook. As the sediment was waterlogged, organic materials were well preserved. Not only charred but also waterlogged plant remains could therefore be studied, which greatly enhanced the significance of the botanical analysis. The faunal remains, equally well preserved, consist mostly of domestic cattle, but both pigs and ovicaprids are also present. Cutmarks observed on a dog bone indicate that this animal was either eaten or skinned. The finds suggest the presence of a nearby farmstead, but no traces of a building could be found in the area. A roughly contemporary ditch appears to be the only associated feature. Typologically, the pottery dates to the Early La Tène period. Wheel-thrown fine ware seems to have been imported from the Kaiserstuhl, so contact must have been maintained with this region in south-western Germany.

Chapter 6 presents the La Tène period occupation of Delémont-La Pran. It consists of a small assemblage of finds (pottery, daub fragments, querns, iron pin and sheet fragment) and a single post hole and appears to represent the remains of a very small settlement. The finds are typologically coherent and date to the Early La Tène period.

The concluding chapter 7 contains a synthesis of the Hallstatt and La Tène occupations of Delémont - En La Pran, Courtételle-Tivila and Delémont - La Pran.

Translation: Robert Fellner