LOL! Well,there you go. Now I know. Thank 'ye much! 
(I just wondred b/c the place is on the coast w/ damp soil, flooding, etc. etc.)
LOL! Well,there you go. Now I know. Thank 'ye much! (I just wondred b/c the place is on the coast w/ damp soil, flooding, etc. etc.)
Several finds have been in peat bogs, etc., that were swamps at one time..
Given the proper circumstances, climate, environment, these sites provide artifacts with fine, compacting silts and clays, plant and root containing substances like tannic acid, all contributing to an overall preservative effect..
The "bog bodies" are an excellent example, as well as the "ice man" of the alps.. Things like hair, human skin and flesh were preserved, leather, feathers, wooden arrows, etc..
Kansas City has an entire museum devoted to the cargo of the steamship "Arabia" which was found buried in the silt/mud of the former riverbed of the Missouri river..
It would seem that moisture is not a factor as long as there is a lack of oxygen, which promotes the decomposition of... just about everything..