Fossils in the Field

Alright today we got to see some fossils! Nothing crazy like a dinosaur or anything but to a geologist this is still awesome.

Here is my professor talking about the outcrop that we are looking at. This outcrop actually has two formations. The brallier formation and the Foreknobs formation. As we looked at it we were a little puzzles because the older rock was on top of the younger rock. This either had to be caused by a thrust fault or an overturning of some kind. As we progressed we figured out the it was indeed some sort of fault that had caused this weird pattern. Within the outcrop we had shale with inter-bedded sandstone. The shale was olive green. The Brallier formation was the hanging wall and the Forknobs was the foot wall.

Here you can see the folding right in the center at the bottom. This was also the contact area where the two formations meet.

Here we can see the fossils!!! Yes I know they just look like weird circles but they are actually fossils in the sandstone. They are called Crinoids. Crinoids are marine animals that are in the class Cinoidea of the echinoderms. They can live in deep water to depths of 9000 meters. They also usually have a stalk called sea lilies but can not be seen in this picture. They are pretty old and date back to the Ordovician.

Here you can see clams shells that have been preserved in the rocks. You can even see the rings that make up their shells if you look closely!

Hope you enjoyed reading and maybe even learned something. Please comment if you have anything to add.

Cheers!