All samples studied which have not been treated with PEG have S/G ratios similar to that of modern oak fresh from the tree (Figure ). In the case of the Mary Rose, the S/G ratios vary greatly depending whether they were treated and the location of the subsample used for THM-GC-MS analysis. Lack of PEG treatment could mean that the surface of the sample has continuously degraded since being recovered from the sea floor in 1982 and chemical degradation due to atmospheric exposure has led to physical degradation and ultimately disintegration and complete loss, therefore the material available for chemical analysis is the underlying, "fresh," oak which has experienced a different level of chemical degradation (Figure ). The S/G ratio and the Ac/Al ratios for this sample are close to those of modern oak, unlike those of the treated Mary Rose samples, suggesting that PEG treatment could have preserved the chemical degradation of the lignin at the time of treatment, consistent with a similar study of the Hanson Logboat, a 3000 year old specimen of English Oak preserved in peat . This study also reported decreased S/G ratios, less dramatic than that observed here, which may be attributed to the different burial environments. These ratios are also consistent with those determined by HMDS-pyrolysis-GCMS on fresh-waterlogged oak samples from 9 th -12 th century Poland .