Any Cruziana experts here?

[Rhinofly]

I was doing some research on the ordovician cruziana plates I found in Millard Co, Utah a few years ago and noticed something funny. It seems that similar looking specimens from around the world are frequently the same pink color. In my experience pink fossils are rare. But, it seems pink cruziana is not. Google the cruziana found at Penha Garcia park in Portugal for example. Any thoughts as to why? Here are some pictures of mine. 

 

 

[Rhinofly]

Nobody? Does anyone else have pink Cruziana from other parts of the US than Utah?

[Johannes]

I can't recognise Cruziana at your pictures, but I really like the colour and the contrast of the last plate you have shown!

[Rhinofly]

Here is a link to some pictures of similar ichnofossils from Penha Garci.

 

https://finca-al-manzil.blogspot.com/2013/04/naturtejo-geopark-fossils-and-more-at.html

[Rhinofly]

And here is a pink one from Morocco

 

https://ancientearthtradingco.com/fossils/ichnofossils/trilobite-tracks/4-3-in-cruziana-fossil-trilobite-tracks-morocco.html

[Rhinofly]

I bump to see if anyone else has encountered these.

[FossilNerd]

I don’t think the pinkish hue is anything specifically related to Cruziana. I know of no reason why impressions of activity would cause a deposit to be pink. I think to find out the reason for the pink color, one would need to look at other aspects of the matrix itself and why it is the color it is.

 

I have examples (and have seen many more) that are not pink. Being impressions, they are simply the color of the matrix they are in.

 

The common ones from the Holdenville Formation of Oklahoma are a good example. Typically found in grey shale. No pink hue at all.

 

 

 

[LabRatKing]

On 5/13/2020 at 5:41 PM, Rhinofly said:

I was doing some research on the ordovician cruziana plates I found in Millard Co, Utah a few years ago and noticed something funny. It seems that similar looking specimens from around the world are frequently the same pink color. In my experience pink fossils are rare. But, it seems pink cruziana is not. Google the cruziana found at Penha Garcia park in Portugal for example. Any thoughts as to why? Here are some pictures of mine. 

 

 

I have very similar specimens from the same site I bet. The pink color is a result of geology and chemistry. This unique desert varnish is the result of Rhodonite, a manganese silicate. Anywhere you have sedimentary rock, manganese and dry conditions, it will form. My samples are packed away in a box in my work room at the moment which I'm taking a break from installing the new floor in. Perhaps I'll dig them out later today and post them here with yours for comparison.