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Fossil or What?

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  • Fossil or What?

    I have 2 things here that was found side by side by the river in a water run off...The first one I thought was petrified tree bark, but the more I looked at it, the pattern on it seemed wrong and I realized that it looked more like reptile skin then it did tree bark, also wondered if the NA's may have used it cause it looks as if been cut around opening....The second pic I thought may have been a stone torch that the NA might have put animal fat in to burn to go inside caves, still not sure on that...Any ideas?

  • #2
    I think that's a "fossilized" mud bubble, like a septarian nodule formation.  The type of material and the "design" of the "cracks" look like a septarian nodule....  Interesting piece there!
    Professor Shellman
    Tampa Bay

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    • #3
      Any ideas on the second one Tom?

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      • #4
        Looks cool but I have no idea what it could be

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        • #5
          To me it looked to be a stone torch, but I also was told it may be a bone

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          • #6
            I think you’re just seeing sedimentary rocks with typical erosion features. The first one looks like limestone and has classic bedding planes, shrinkage cracks and an erosion hole where something has been weathered out. If you think about the way rocks like this form, they are composed of accumulating sediments in watery environments which have dried out. Mostly those sediments are deposited over long periods of time as an ocean or lake bed, together with larger items such as clumps of plant and algal material plus dead animals and their skeletal remains, pebbles and so on. Also, as Tom says, decaying material produces gas bubbles that can be trapped and form a cavity in thick or hardened sediment.
            In most cases, organic material tends to decompose and leave a cavity that gradually fills with minerals which may or may not become a fossil replica of the original organic material. That depends largely on how rapidly more sediments are deposited on top such that oxygen is excluded. The mineral-filled holes are often semi-spherical because they arose from sponge or urchin remnants. The same thing happens to cavities created by gas bubbles – they fill up with minerals.
            Millions of years later when the sediments have been compressed to form rock, those minerals are normally softer and less resistant to erosion than the lithified sediment that surrounds them. They weather out of the rock if they are exposed and leave rounded and odd-shaped holes. Pebbles trapped in the sediment are normally harder than the surrounding rock. What happens in those cases is that the surrounding rock erodes faster than the exposed pebble until it becomes loosened and falls out, again leaving a hole.
            The second item doesn’t have any bone-like features or structure than I can see. It does however have an iron-rich nodule (the brown cluster). Again, that looks like sedimentary rock (limestone or chert) and in that particular case, the minerals that filled the cavity were likely from iron-rich groundwater. Part of that nodule has eroded out and left behind a hole.
            I’m sorry, but I don’t see artefacts or fossils (as such). Just classic sedimentary geology.
            I keep six honest serving-men (they taught me all I knew); Their names are What and Why and When and How and Where and Who.

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