Palaeo-ecological and archaeological analysis of two Dutch Celtic fields (Zeijen-Noordse Veld and Wekerom-Lunteren): solving the puzzle of local Celtic field bank formation

Celtic fields are the best preserved and most widely distributed type of prehistoric agricultural landscape in the Netherlands, and occur throughout northwestern Europe. In this contribution, data from two excavated Dutch Celtic fields are used to explain the process of bank formation and to unravel the agricultural regime of Celtic fields. To this end, traditional archaeological methodologies and geochemical analyses are combined with detailed palaeo-ecological analyses. It is shown that Celtic field banks were constructed from a mixture of non-local soil, wetland vegetation, dung and settlement debris such as charcoal and sherds. A system was in place in which sods and plants were cut in lower-lying wetland landscapes and which were transported to the settlement, where they were presumably used as byre-bedding, became enriched with dung and were mixed with settlement debris. This mixture was carted to the fields, most likely to be spread across fallow plots as a manuring agent. From this primary, functional location, a composite sediment of agricultural sediments and the added manure was incorporated into the field banks. This process of incorporation was very slow and probably started with the uprooting of arable weeds from the fields, which were tossed to the side against the wattlework fences—together with minute quantities of soil attached to their root clusters. As a consequence of this chain of events, over the course of centuries, banks of anthropogenic sediment came to enclose fields within the Celtic field landscape