How is petrified wood formed

Water, rich with minerals such as calcium carbonate and silica salts, seep into wood buried in the ground. The organic matter of the wood is replaced or enclosed by the minerals and eventually turns to stone.

With a little searching I have found information that suggests that the petrification process only takes decades, years or even only months given the right conditions. One such example is a natural well at Mother Shiptons Cave in England, take a look www.mothershiptonscave.com..