Soil chemical analyses help in distinguishing the domestic activities of an Iron age building at Rotzo (Vicenza, Italy)

Chemical analyses of the phosphorus (P), carbon (C) and nitrogen (N) content of the soil were applied to an Iron age building located at Rotzo in the Asiago plateau (northeastern Italy). The building was already interpreted as a dwelling with two distinct phases of life. Both total P by ignition and organic P distributions were high in the northeast zone and along the southern wall, where there was an accumulation of organic matter because of the presence of a garbage hole. The clustering of highest inorganic P values along the eastern wall highlighted, for the first phase of life of the building, the contrast between domestic activities in the eastern and western areas, as the highest values of the C:N ratio indicate the accumulation of organic matter. The organic C content and C:N ratio, together with the different forms of P, provided good suggestions about the use of the inner space. In particular, among the P forms, oxalate extractable-P indicated the oldest phase of the house.