Is This a Fossil?

[FossilsandScience]

Hey everyone!

 

I was recently fossil hunting at Bolinas in California, which is known for its fossilized sand dollars. While hunting, I found this strange piece and I'm not sure if it's a fossil or not. It's from the Merced Formation, which is from the Late Pliocene to the Pleistocene in California. I have no clue what it is, but I am looking forward to hearing if anyone on the forum does. Thanks!

[Rockwood]

I think this looks like banded chert. An interesting rock, but not a fossil.

[Steffen Langusch]

Ja, da stimme ich Rockwood zu. Ein gebändertes, wohl kieselsäurehaltiges Gestein, aber kein Fossil.

 

 

 

Yes, I agree with Rockwood. A banded rock, probably containing silica, but not a fossil.

[Rockwood]

Easy for you to say. 

I think I get the point. 

[DPS Ammonite]

These are classic banded chert from the Miocene Monterey Formation.
 

Behl, R.J., 2011, Chert spheroids of the Monterey Formation, California (USA): early diagenetic structures of bedded siliceous deposits, Sedimentology. published online: 28 Jun 2010; v. 58, p. 325–351.

 

https://www.researchgate.net/profile/Richard_Behl/publication/229542577_Chert_spheroids_of_the_Monterey_Formation_California_USA_Early-diagenetic_structures_of_bedded_siliceous_deposits/links/59f72b3fa6fdcc075ec6325a/Chert-spheroids-of-the-Monterey-Formation-California-USA-Early-diagenetic-structures-of-bedded-siliceous-deposits.pdf?origin=publication_detail