Dating dinosour bones
In 2014, Mary Schweitzer and her colleagues reported the presence of iron particles (goethite-a Fe O(OH)) associated with soft tissues recovered from dinosaur fossils.
Based on various experiments that studied the interaction of iron in haemoglobin with blood vessel tissue they proposed that solution hypoxia coupled with iron chelation enhances the stability and preservation of soft tissue and provides the basis for an explanation for the unforeseen preservation of fossil soft tissues.
This process can occur in very small spaces, such as within the cell wall of a plant cell.
Small scale permineralization can produce very detailed fossils.
There are many processes that lead to fossilization, including permineralization, casts and molds, authigenic mineralization, replacement and recrystalization, adpression, carbonization, and bioimmuration.Fossils may also consist of the marks left behind by the organism while it was alive, such as animal tracks or feces (coprolites).These types of fossil are called trace fossils or ichnofossils, as opposed to body fossils.For permineralization to occur, the organism must become covered by sediment soon after death or soon after the initial decay process.The degree to which the remains are decayed when covered determines the later details of the fossil.