How an integrated diagnostic approach can help in a correct evaluation of the state of preservation of waterlogged archaeological wooden artefacts

• Published in: Journal of archaeological science Vol. 39; no. 10; pp. 3255 - 3263
• Main Authors: Macchioni, Nicola, Pizzo, Benedetto, Capretti, Chiara, Giachi, Gianna
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2012; Elsevier
• Subjects: Cell wall chemical components; Conservation; Diagnosis; Excavation and methods; Laboratory methods; Methodology and general studies; Micromorphology; Microscopic analysis; Other materials; Physical analysis; Physical and chemical analysis; Prehistory and protohistory; Typology, technology and attribute analysis; Waterlogged archaeological wood; Europe; Microscopic analysis; Diagnosis; Physical analysis; Cell wall chemical components; Waterlogged archaeological wood; Micromorphology; Water logged wood; Methodology; Preservation; Conservation; Archaeometry; Microscopy; Deterioration; Wooden object; Physicochemical analysis
• ISSN: 0305-4403; 1095-9238
• DOI: 10.1016/j.jas.2012.05.008

Artefacts made of wood coming from archaeological excavations provide insights into human cultural behaviour of the past. They show how man utilised natural resources and how the development of woodworking techniques and artistic endeavour were developed. Within archaeological contexts, waterlogged anaerobic conditions generally preserve the appearance of artefacts, although wood is subject to severe decay processes. The said conditions can transform the original material into a new one, thus demonstrating specific differences from those of the “fresh” wood of the same species. In order to assess these new properties correctly, an integrated diagnostic approach is needed, one which includes a multidisciplinary (micromorphological, physical and chemical) evaluation of the state of preservation. This paper reports several diagnostic results regarding wood artefacts coming from a series of archaeological excavations carried out in Italy. Different types of artefacts – ships, furniture, foundation piles, etc. – that date to different eras (Roman times, the Middle Ages, the Renaissance) have been included in this study. In addition, several species of wood at different levels of decay were analysed. Our study provides evidence of how a multidisciplinary approach, based on anatomical (micromorphological), physical and chemical analyses, avoids goes beyond the limits of each single type of analysis, thus contributing to a complete and reliable evaluation of the state of preservation of these archaeological artefacts. ► More than 200 waterlogged archaeological samples analysed. ► Several investigation techniques were used to make a reliable diagnostic evaluation. ► Single techniques can be misleading because of wood collapse or high ash content. ► Integrated approach helps to correctly evaluate the artefact state of preservation. ► Possibility of a reliable material grading and, in future, of a tailored treatment.