Agrarian archaeology in northern Iberia: Geoarchaeology and early medieval land use

This work illustrates the results of a geoarchaeological study carried out at two medieval deserted villages in the Basque Country. These were investigated during large-scale excavations, which exposed inhabited areas alongside production spaces. At Zaballa (Iruña de Oca, Álava), a terrace system from the 10th century AD was studied. At Zornoztegi (Salvatierra, Álava), thick backfill units deposited for agricultural purposes between the late 11th and the early 12th century AD were analyzed. Traces of vegetation clearance, possibly by means of fire, were observed in both sites. Soil micromorphological and physicochemical analyses allowed for the reconstruction of the formation processes of these agricultural spaces, and demonstrated the human impact on the local soilscapes. A multi-proxy approach was applied in order to determine the chronology and to identify the crops that were grown in these agricultural contexts. At Zaballa, terraces were probably used to grow vines, whereas the backfill units of Zornoztegi were linked to cereal growth and to horticulture. Results are discussed in comparison to other sites in the Basque Country and northern Iberia, highlighting a generalized transformation of rural settlements between the 6th and the 12th century AD.