CompuServe Messages

Hi, John– Welcome to the forum! I am an amateur mineral collector, but there are others here who know more about fossils. For their benefit, can you say anything about the rock containing the fossils? Given the location and some notion of the enclosing rock, someone may be able to match that rock to an upstream formation and give an estimate of its age. The location might be enough if there is only one dino-bearing rock formation upstream. How long it takes something to fossilize surely depends on the minerals involved, among other things. Gypsum crystals can grow in months, sometimes to enclose modern artifacts, but quartz requires thousands or millions of years to form, at least in geodes. I am guessing calcite might replace something much faster than quartz. Fossils cannot literally "rot", but John was using the word in a figurative sense. Fossils left there will likely be eroded to uselessness within a few years, depending on how tough their composition is. Even if made of a tough mineral, the cohesion between separate parts of the fossil may not be great, so fossils are generally less durable than rocks. This means a fossil could not easily travel far from its home formation, though one cannot be really sure without radioactive dating, sure species or host rock identification, or some such. –Doug