## 3 Results and Discussion
### Physical and Chemical Degradation
#### 3.2.3 XRD Results  
The Synchrotron radiation X-ray diffraction (SR-XRD) analysis of the wood sample are shown in Figure 5b. The results revealed significant soil deposits that interfered the wood's structural composition, reflecting the extent to which the burial environment influenced the degradation stage of the boat. The XRD pattern, also supported by energy-dispersive X-ray spectroscopy (EDX) data, demonstrated the presence of calcite, gypsum and quartz--primary constituents of the burial chamber environment. XRD and EDX analyses revealed a complex degradation process driven by the mineral composition of the burial environment, with calcite, gypsum and quartz acting as key agents in wood deterioration. These mineral deposits physically alter the cellular structure of wood, trigger chemical reactions and alter internal conditions, thus creating multiple pathways of degradation. By occupying cellular spaces, altering internal pH, promoting moisture retention and catalysing oxidative processes, these minerals in the burial environment significantly transformed the physical and chemical properties of wood [88; 89; 90].  
The moderate-intensity peak (012) of calcite at about 15.4\({}^{\circ}\) 20 and the high-intensity peak (121) of gypsum at about 13.1\({}^{\circ}\) 20 significantly overlapped with the characteristic cellulose peaks at 15.0\({}^{\circ}\), 12.5\({}^{\circ}\) and 10.5\({}^{\circ}\) 20. Where the (200) lattice plane at 15.0\({}^{\circ}\) 20 represents a critical structural feature encompassing both crystalline and amorphous phases, 12.5\({}^{\circ}\)20 represents the intensity minimum between the (200) and (101) planes, demonstrating the transitional structural characteristics, and the (101) lattice plane at 10.5\({}^{\circ}\) 20 represents the amorphous cellulosic fibres [28; 58; 59]. Therefore, the mentioned interference in the diffraction pattern hinders the accurate determination of the cellulose crystallinity index (CrI) in the composite sample when using the Segal method for quantitative analysis [105].  
Consequently, the CrI measurement was performed on another pure ancient wood sample collected from the same source, yielding a CrI value of 13%. This low value indicates substantial degradation of the crystalline cellulose regions, which aligns with the Fourier-transform infrared spectroscopy (FTIR) results, demonstrating how mineral components systematically degraded the wood's molecular integrity [85; 89]. The findings revealed that the burial environment was not a passive factor but an active participant in wood degradation, with mineral deposits acting as key catalysts that progressively dismantled the wood's structural and molecular composition [88; 89; 90]. The observed shift in diffraction peak positions occurred because synchrotron radiation SR- X-rays have higher energy and shorter wavelengths than conventional laboratory X-ray sources. According to Bragg's Law, shorter wavelengths produce smaller diffraction angles (28) for the same crystal planes. The superior monochromaticity, brilliance and collimation of synchrotron radiation also contributed to this systematic peak shift, requiring appropriate calibration when comparing diffraction patterns obtained from different X-ray sources [106; 107].