Degradation Assessment and Conservation Monitoring of Waterlogged Archeological Wood by Multimodal and Multiparametric NMR Methods

Wood plays a crucial role in cultural heritage, as wooden artifacts preserve records of our past. The anoxic conditions of submerged environments can protect wood for millennia but degradation still occurs. Once excavated, waterlogged wood (WW) rapidly deteriorates, losing mechanical strength unless kept submerged.1 However, this makes it ideal for NMR analysis. Recently, interest in non-destructive NMR studies on fragile heritage has increased, although some possibilities remain unexplored.2,3 From a conservation perspective, WW requires stabilization and when in-situ conservation is unfeasible, consolidation becomes essential to replace water within the wood tissue while reinforcing its structure. Treatment effectiveness depends on consolidants’ penetration and distribution, influenced by their properties and the wood’s porous structure.4 This study combines a multimodal approach using high- and low-field techniques to assess wood degradation and monitor conservation treatments. While MRI and diffusion NMR offer structural and dynamic insights, they lack the resolution to examine the cell wall at the nanometer scale, achievable with NMR cryoporometry.5,6 With these methods, we conducted a comprehensive study of wood from the Neolithic submerged village of La Marmotta, assessing degradation after millennia of submersion. Moreover, we explored portable NMR’s potential for monitoring the consolidation of WW from the 10th century.7 Samples were treated with polyethylene glycol (PEG) solutions at varying concentrations and weights, following standard practices. PEG’s use as a consolidant is well-supported, making it ideal for heavily degraded wood.