Friday, May 15, 2009

What is this?

So I was recently handed this rock with the question of what are these things in the rock. I am unsure and as far as I know anyone who has looked at the rock doesn't know either. So I ask for any possible ideas. The rock is a limestone and that is about all I know about it. I have my ideas but I want to leave this as unbiased as possible.
Front view
Side view

Top view

It appears that the structures go through the rock in a circular/ cylindrical pattern bosed on the side and top views.


  1. Pretty tough call, given all the unknowns: no scale, no age, soft focus, small images (it would be nice if we could zoom in on them). If by "these things" you mean the brown streaks, they could be brachiopod or mollusc shell fragments, or intraclasts; maybe even ostracod shells, depending on the scale; if you mean the grey, circular/cylindrical object, it could be a scaphopod (tusk shell), or even a plant stem if the limestone originated as a freshwater marl or nearshore deposit. Or, a lined, mud-filled burrow. Or, it could be a partial blastoid theca (if small and Palaeozoic); I've seen certain brachiopods that would have a cylindrical shape in cross-section, too...? Lotsa possibilities.


    --Howard (Calgary, AB)

  2. Oh, duh. Scale. I suck. Ok. I am going on vacation until Thursday so I will post some better pictures then with a scale. I thought they would automatically link to the larger pictures but since not I will put them up on my site as well.


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