Evaluation of physical and chemical condition of a group of waterloggedarchaeological woods from the Yenikapı 16 shipwreck

This study examined the physical and chemical condition of waterlogged archaeological wood (WAW) samples from the Yenikapı 16 shipwreck of plane (Platanus L.), elm (Ulmus L.), pine (Pinus L.), and fir (Abies L.), representing species with different wood properties. The maximum water content (MWC) and basic density (BD) values of 74 WAW samples from the shipwreck were calculated, and 7 of 74 samples were selected for analysis using scanning electron microscopy (SEM), X-ray fluorescence (XRF), and Fourier transform infrared spectroscopy (FTIR). The availability of samples, appropriate size, the species of the wood, and the wood’s degradation were all considered. The MWC values of the samples ranged between 336% and 1467%, and the BD values ranged between 0.07 and 0.25 g/cm3. Based on the MWC and BD values, the plane WAW samples were classified as highly degraded, while the pine WAW samples demonstrated better preservation with lower MWC and higher BD values. Similarly, the fir WAW samples were considered well preserved due to their low MWC and high BD values. Upon analyzing cross-sectional SEM images of plane WAW samples, significant degradation was observed with collapsed and shrunken tracheids and rays, indicative of surface tension effects. In contrast, SEM images of pine and elm WAW samples showed better preservation than plane samples. Notably, the SEM image of the fir WAW sample revealed excellent preservation without any observable degradation in the rays, tracheids, or tracheid walls. FTIR analyses examined the present, absent, and reduced intensity of the bands associated with holocellulose and lignin components in the structure of the WAW and fresh wood samples. XRF analyses showed that the amount of iron in the samples taken close to the corrosion accumulation was higher than in other samples. After examining all obtained data, it was concluded that the plane and elm samples were highly degraded. Meanwhile, the pine and fir samples were less degraded.