The programme of surveillance and archaeological study of the sandquarries in the middle valley of the Oise was designed in 1987 in order to temper their massive destruction through the digging out of sand and lasted till the end of the year 2000. During these thirteen years more than six hundred hectare were thoroughly scrapped to study the human occupation of this geographical micro-area. More than a hundred sites from all periods were excavated. Among the se sites thirty seven sites belonging to the La Tène period were actually made up of fifty one settlements as some of them were occupied continuously during two or three periods or were reoccupied in the latest La Tène period. Seventeen are connected with the latest Hallstatt period and the latest La Tène period, fifteen with the middle La Tène period and nineteen with the latest La Tène period.
A CD rom makes this important documentation public. It gathers a thematical data base with all the excavation documentation which once standardized has been distributed over several File Maker linked files. An all-encompassing menu allows the user to explore it in two directions.The first reading axis corresponds to the different themes with on the one hand the cartography, the types of structures (the buildings, the housing structures, the ditches, the burial places) and the summarized presentations of the sites, and on the other hand, the types of furniture discovered (the pottery, the metal and stone objects, the jewels, the tools, the fauna and the carpology). These files include a general bibliography and the pictures.
The second reading axis is accessible from the list of sites and from the summary it allows to join the in line / linear data of an occupation. So this tool gives access to all the documentation about the sites.


These digital data allow a handwritten synthesis of the settlements. This system is organized according to sets of themes :
- after a presentation of the historical context the places of the establishments are tackled according to the geography and the nature of the soil in chronological stages. Geomorphology, palynology and carpology help understanding the ways of settlements in the landscape. The comparison of the data allows to show the logic of occupation and its development ;
- the next theme develops the evolution of the structuring of the sites through an analysis of the demarcation of the areas, of the architectural styles and of the function of the structures. The proper organization of each site is studied from a geographical data system which allows to distribute the fumiture in space according to the structures. Beyond an approach of the functioning of the settlements, these analyses as a whole allow to propose a hierarchical classification of the sites ;
- in the next item the studies about the furniture allow to draw up a hierarchy of the sites and also to tackle the more classical theme of the evolution of the material culture between the earliest La Tène and the latest La Tène ;
- the part devoted to the fauna studies and to the macro- and micro remains of plants intents to emphasize the eating habits of the communites and corroborates the hierarchy of the sites according to the quality of the eaten meat diet. The management of the agricultural and pastoral system is also tackled ;
- the last theme is about the analysis of the funeral sites and the human remains from the settlements as well as the deposits of pieces of furniture. It allows to characterize the funeral and domestic rituals and so it contributes to throw a light on the organizations and statutes of the sites.


Once the results of the thematic studies are gathered they allow to tackle the organization of the La Tène society in the middle valley of the Oise from the earliest La Tène period to the latest La Tène period. In the earliest La Tène period the picture provided by the settlement is one of little establishments located in micro areas but which are not linked together under the care of a strong hierarchical power. Nevertheless, this impression must be mitigated because of the presence of sites with an important storage possibilities the role of which in the organization of the society is not yet clearly identified : centralization of surplus goods in case of bad crops, taxes, presents, exchange spaces or market ?
Does this imply a control of the produces and therefore a hierarchy among the settlements ?The social stratification in the beginning of the second Iron Age could be the consequence here as in other regions of a restructuration of society after the collapse of the previous Celtic principalities.
From this sole geographical area it is possible to detect a change in the organization of society between the earliest La Tène period and the middle and latest La Tène periods. It is obvious that all the forms of housing and the whole of statutes are not present here but this mere section of the valley shows that the sites clearly form a hierarchy. So the intensive research into a micro geographical area allows to sharpen our insight in the important stratification of the La Tène society. The relevance of the pattern of the sites in this geographical space is particularly well adapted. The counting of the settlements is consistent with only one site situated at the highest hierarchical level, two at the lower level and four sites for the most usual settlements. However the statification discerned in this frafiework makes up but the base of the social pyramid, and one must move away frofi this sector and reach the plateaus to make out the other forfis of La Tène settlements. The sites of "Les Noirs Cailloux " at Moutiers, of " La Fosse Muette " at Montmartin show even more brilliant characteristics than those displayed on the site of " Le Vivier des Grès " at Longueil- Sainte Marie. The presence of amphorae , which are absent in the valley sites, and of big horses imported on the site of Montmartin, give evidence for a superior hierarchical layer.
So the diversity of the Gaul settlements becomes clearly visible. It points to a very complicated social stratification in which the farms forfi the base and the settlements as the one at Montmartin, form the highest rank at least in the forfis of settlements as they are discerned in this area at the present time.