Layers

trilobite 2

Tiny trilobite graveyard preserved between the layers of a Cambrian Shale.

There’s a spot on the Conasauga River in northwest Georgia where you can visit a late Cambrian ocean preserved in a 500-million-year old shale. Shale is a relatively soft mudstone that splits easily along laminar planes, so with just a Swiss army knife or flathead screwdriver, you can split the pieces of stone that litter the river bank and often find the remains of some of the oldest complex life on Earth.

trilobite 5

These trilobites lived half a billion years ago when multicellular life was brand new to the oceans (and long before it had colonized the land).  They died 200 million years before the Earth dreamed of dinosaurs or assembled all the continents into one big Pangea-shaped piece. Their little carcasses then drifted to the bottom of the Iapetus Ocean off the coast of Laurentia and were buried in all the soft silty stuff on the sea bottom which eventually became shale liberally salted with their flattened fossils.

 

If you’d like to learn just a little more about trilobites, check out this link:

http://www.trilobites.info/triloecology.htm

Or if you’d like to learn a lot more about the fossils from this site, here’s an excellent paper:

http://ldsp01.columbusstate.edu:8080/xmlui/bitstream/handle/11075/388/schwimmer.d._2012_anaphelaspiszone_southeasterngeology.pdf?sequence=3