Bog oak: characteristics and characterization of two logs from the Venetian Plain

This work presents the characterization of two bog oak logs found in two rivers in the Veneto countryside. One of the trunks dates back to around 400 AD, the other one to 1400 AD. The logs are free of bark, with the black and cracked external surface with a charred appearance. On the inside, underneath the more weathered layer, the wood appears intact, free of signs of apparent degradation, carbon black in color. Going towards the internal parts of the trunk, the colour goes from black to natural brown of the intact wood. The physical characterization (basal density, shrinkage and maximum water content) indicates that degradation phenomena are also present in the apparently intact wood. Bacterial degradation was clearly highlighted through microscopic analysis. From the analysis of the ash content, it seems that the increase in the density of the apparently intact areas is due to the entry of inorganic material. The difference of about a thousand years of stay in the basement site does not seem to have differentiated the physical parameters of the two woods. Instead, the difference with the same parameters of the oak wood of a pirogue dating back to 800 AD is evident.