Bizarre, just rock formation?

[expatspain]

To follow my previous post because this was found at the same location. I have never seen anything like this, surrounding the entire rock. I am at your mercy.

 

[Oxytropidoceras]

Differential weathering of quartz veins a felsic igneous (?) rock. The quartz veins are more resistant to chemical weathering then the surrounding igneous rock and thus stand out.

 

Yours,

 

paul h.

[HuckMucus]

Weird.  Photos 3,4&5 look like two pieces of leather lashed together with rawhide, and ripped apart where not together.  Lashing seems to cross two pieces.  I'll defer to Oxytropidoceros though.

[TheInvertebrateGuy]

While I do believe that quartz veins are a good candidate, I think aragonite veins are a more probable candidate because the sandstone the veins are present in is felsic and has no iron oxides, so coloring minerals with chemical compounds wouldn’t be possible.

 

I’d have to say they’re aragonite veins because of where the rock was found, eastern Spain, which is known to have fossils of shelled organisms (shells are made of the same chemical compound as aragonite, calcium carbonate). Eventually, shells can sometimes layer and become veins of carbonaceous material.

Edited July 6, 2022 by TheInvertebrateGuy
Forgot about felsic sandstone.