Stromatolite? Sponge? UNKNOWN!!!

[minnbuckeye]

I had attempted to ID similar fossils awhile ago but feel they were lost in the trilobite photos. So today, I will only present these new unknown "blobs" from the Cambrian , Eau Claire Formation of western Wisconsin in hopes to definitively ID these. Maybe they are even geologic.

 

 

  

 

 Good Luck!!!!! 

 

Mike

 

 

[Megalodoodle]

Stromatolite is my guess, although I'm new and probably in no position to suggest an ID.

[Rockwood]

It may be a trace fossil, but I would lean toward yet another look for concretion.

[minnbuckeye]

2 hours ago, Rockwood said:

concretion.

 

The matrix in the Eau Claire Formation is !00% sandstone. All of the trilo bits and bites are just impressions left in the sandstone. If you broke one of these unknowns in half, it will look just like the matrix.... SAND. I think logic rules concretion out. Some type of trace fossil makes more sense, but of what??? These occur fairly frequent when splitting the matrix. If it helps, hyoliths are present too.

3 hours ago, T. nepaeolicus said:

Stromatolite is my guess

 

I mentioned stromatolite, but similar to a concretion, I would expect a change from sand on cross section, if it was so. They are reef builders, so structurally pretty tough, unlikely to dissolve away???? 

 

 I have wrestled with these for years and most rule everything out in my mind. 

 

But thanks for the suggestions!! 

[Megalodoodle]

I did a google search for the image. Apparently its fossilized flatbread!

[Rockwood]

2 hours ago, minnbuckeye said:

If you broke one of these unknowns in half, it will look just like the matrix.... SAND. I think logic rules concretion out. 

Concretion forms from the migration of minute particles within stationary matrix. All that is required to make these is a slight increase in the durability of the cementation locally.

I think logic very much includes them.

[minnbuckeye]

 @Rockwood, Found this picture reading about sandstone concretions. Lower left looks VERY similar, making your suggestion very plausible.  I just expect the interior to show banding to some degree similar to the second photo.

 

 

I PHOTO: Hugh Copland

  

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 Mike

[Rockwood]

There is a spot, on the southern tip of Alaska I think, where odd snowman like concretions are known to be found.