Fig. 3
From: Oxidative degradation of archaeological wood and the effect of alum, iron and calcium salts
Initial oxygen consumption rates of archaeological wood samples as μg O2 (g wood)−1 day−1, calculated from data between 100 and 80% oxygen saturation, shown with average values calculated for fresh oak and fresh birch (ref-ambient) references. Different colours designate different groups of samples based on object number/treatment type: recently alum-treated (blue); Oseberg, alum-treated only (red); Oseberg alum-treated and linseed oil coated (green); Oseberg alum-treated and linseed oil soaked (purple); Oseberg ship, not alum-treated (orange); fresh wood references (grey). For alum-treated samples, values in μg O2 (g total sample)−1 day−1 are also shown, where the total sample mass is the mass of wood plus alum. The * indicates that the value calculated for 185-5 is somewhat tentative due to a very low wood content in this fragment