Analytical Techniques for Preservation of Archaeological Wood

Archaeological wood recovered from waterlogged or buried environments often exhibits extensive chemical and structural deterioration caused by bacterial erosion, soft-rot fungi and abiotic processes. Accurate assessment of the state of preservation is essential for selecting appropriate conservation strategies and treatments. Analytical approaches span from low-tech methods, such as basic moisture content and density measurements, to advanced instrumentation including computed tomography, infrared and Raman spectroscopy, pyrolysis-gas chromatography/mass spectrometry, nuclear magnetic resonance and nanoindentation. Micro-drilling techniques and mechanical testing provide rapid, in situ evaluation of residual strength, while light and electron microscopy reveal cellular-level decay patterns. Molecular biology tools, notably DNA metabarcoding, characterise the microbial consortia driving biodeterioration, informing the choice of biocidal and preventive measures. Conservation research places particular emphasis on consolidants—materials introduced into the wood matrix to stabilise dimension and mechanical integrity—ranging from traditional polymers like polyethylene glycol to novel organosilicons, terpene-derived and nano-scale biopolymers. A multi-analytical strategy that integrates complementary techniques ensures a comprehensive understanding of chemical composition, structural integrity and environmental interactions, thereby underpinning globally significant efforts to preserve wooden artefacts from shipwrecks, submerged settlements and terrestrial sites.

Research from Nature Portfolio

Recent studies have evaluated novel polymeric consolidants that penetrate highly degraded wood and reinforce cell walls without compromising retreatability. In one investigation, two small terpene-derived polymers were dissolved in isopropanol and applied to archaeological specimens. Their depth of penetration and consolidative effect were quantified by weight and dimensional changes, colourimetry, infrared spectroscopy, scanning electron microscopy and surface hardness testing. Both polymers achieved uniform penetration at the surface and enhanced mechanical strength, pointing to further optimisation of concentration and soaking time to improve core consolidation. A complementary study explored organosilicon compounds of varying molecular weight and functional groups as reversible consolidants for waterlogged wood. Anti-shrink efficiency values approached 98% for certain silanes, and treated samples exhibited reduced hygroscopicity, minimising dimensional changes under fluctuating humidity. These findings demonstrate the potential for a more diverse toolkit of consolidants with tailored chemical interactions and environmental stability.

Analytical Techniques for Preservation of Archaeological Wood publication trend

The graph below shows the total number of articles in analytical techniques for preservation of archaeological wood across all publications each year (not limited to Nature Index journals).

Technical terms

Consolidant: A material used to strengthen and stabilise decayed wood by penetrating its structure.

Micro-drilling: A minimally invasive technique that measures resistance to tiny drill bits to assess decay and mechanical properties.

DNA metabarcoding: A molecular method that sequences specific genetic markers to identify microbial communities responsible for wood biodeterioration.

References

1. Innovative application of micro-drilling for the assessment of decay and remaining mechanical properties of historic wooden foundation piles in Amsterdam. Developments in the Built Environment (2024).
2. The Neolithic site “La Marmotta”: DNA metabarcoding to identify the microbial deterioration of waterlogged archeological wood. Frontiers in Microbiology (2023).
3. Evaluation of two terpene-derived polymers as consolidants for archaeological wood. Scientific Reports (2023).
4. A review of analytical methods for assessing preservation in waterlogged archaeological wood and their application in practice. Heritage Science (2020).
5. Organosilicons of different molecular size and chemical structure as consolidants for waterlogged archaeological wood – a new reversible and retreatable method. Scientific Reports (2020).
6. Cellulose and Lignin Nano-Scale Consolidants for Waterlogged Archaeological Wood. Frontiers in Chemistry (2020).