There appears to be little information of phytolith biogenic silica dissolution rates during alkaline digestion in estuarine sediments, that is convincing. How would any digestion be relation to diatom digestion that is usually complete in 2 hrs? Will that include phytoliths? Can I extend the time series ovf alkali digestion to capture a more recalitrant phytoliths dissolution (if that is the case) and extrapolate after to the intercept as in biogenic silica of diatoms. Will this be phytolith biogenic silica or possibly sponge spicules?