I'm in an intro archaeology class and we just talked about Monte Verde in South America. A site discovered that meant the people living there lived thousands of years before natives could have passed through Alaska from Asia.
It was preserved so well because organic, easily perishable materials were trapped in a bog this whole time."A bog is a mire that accumulates peat, a deposit of dead plant material." To me, dead plant material sounds like the perfect, moist, bacteria ridden substance that would biodegrade pretty much anything relatively quickly.
I understand how ice can preserve things extremely well, but warm, moist, bacteria-full and wet material? How?
For folks who don't know, Monte Verde is a really important pre-Columbian site in Chile, 500 miles south of Santiago and 31 miles inland. I wrote about its importance a few months ago. We're still learning about the earliest inhabitants of the Americas. A friend of mine just shared some new information from a site here in Alaska, and another spent the summer in the glacial refugia in the Kodiak archipelago, hunting for more evidence of the "kelp highway" theory.
But as to your question, bogs tend to be anaerobic environments. The bacteria that break down things like dead logs (and dead people) need oxygen to do their work. If they don't have that, they can't decompose organic matter very well. As the National Museum of Denmark explains, that anaerobic environment isn't everything, either.
Bogs tend to be acidic, and while the chemistry of each bog differs in detail, they tend to have the same effects as tanning leather over long periods of time. Some may dissolve bone. Others may not.
Generally, to be preserved well in a bog, an organic object such as a wooden or woven object (or body) must be submerged quickly, before the decomposition process begins. The object must remain submerged, and the chemistry must be ideal for preservation. It takes a lot of factors, and it's important to keep in mind that we don't see all the failed attempts at preservation.