Shale is formed from mud. Shale tells us there was a swamp or river bottom, for example. Sandstone was formed from sand. It could have been a sandbar in a riverbed or sand dunes in the desert. Coal is formed from dead plants such as trees and ferns, and so we believe there was a forest in that place at one time.
Fossiliferous rock contains fossils.
This article may not be copied, distributed or reprinted in any form without the author's permission. To contact the author, please use the e-mail address provided. If you are unable to contact the author, please contact the Canadian Rockhound. Authorized reprints must acknowledge the author, original source and the Canadian Rockhound, and include the website URL address of the Canadian Rockhound.