Micro-morphological, physical and thermogravimetric analysesof waterlogged archaeological wood from the prehistoric villageof Gran Carro (Lake Bolsena-Italy)

Romagnoli M., Galotta G., Antonelli F., Sidoti G., Humar M., Krizisnik D., Cufar K., Petriaggi Davidde B., 2018. Micro-morphological, physical and thermogravimetric analysesof waterlogged archaeological wood from the prehistoric villageof Gran Carro (Lake Bolsena-Italy). Journal of Cultural Heritage, 30: 30-38.

Abstract

Oak disks from pile dwellings of the prehistoric site of Gran Carro (lake Bolsena, Italy) were analysed inorder to estimate wood degradation. Micro-morphological observations showed that the microbial decaycould be mainly attributed to erosion bacteria. The most important physical properties, i.e. MaximumWater Content (MWC), Residual basal Density (RDb), and the calculation of the Lost Wood Substance(LWS) highlighted that heartwood (HW) was moderately preserved, with MWC values slightly higheror comparable to that of recent oak, whereas sapwood (SW) was very degraded. Thermogravimetricanalysis (TGA) was tested as an alternative method for the chemical characterisation of archaeologicalwood. The TGA profiles were critically discussed taking into account the results of the physical andmicro-morphological analyses. Potentialities and drawbacks of TGA were underlined.