Assessment of Deterioration in Archaeological Wood from Ancient Egypt

Abstract

Archaeological wood from many different ancient Egyptian tombs and diverse areas along the Nile Valley was examined to identify the type of deterioration present and to evaluate the current condition of the wood. Three different forms of degradation were identified and appear frequently among wooden cultural properties excavated from these ancient tombs; soft rot and brown rot fungal decay and a nonbiological form of deterioration. Decay by soft rot and brown rot fungi was prevalent in wood with extensive areas of degradation. Soft rot was characterized by cavities formed within the secondary cell walls. Cells with advanced stages of soft rot had numerous coalescing cavities that caused remaining cell wall layers to collapse. Ultra structural observations of wood decayed by species of brown rot in the class Basidiomycetes revealed swollen, porous cell walls that were disrupted, leaving a granular mass of residual wall material. Many objects also suffered from a nonbiological type of deterioration. Cracks and fissures were evident within secondary walls, and cells delaminated at middle lamellae regions. Chemical deterioration from interactions among wood surfaces, limestone, gypsum, sodium chloride, and moisture are proposed as a cause of this degradation. The types of deterioration identified are common among objects that have survived in these unique physicochemical environments. Knowledge of these different degradation processes and the resulting condition of the wood provide important information that can now be used for developing appropriate conservation and restoration procedures.