Relating to the sea. Native to or formed by the sea.
A formal stratigraphic unit next in rank below a formation. It represents some specially developed part of a formation.
One of the four large divisions of geologic time, it includes three geologic periods, from about 252 to 66 million years ago.
Rock that has changed from one form to another by heat or pressure.
The interval of geologic time between approximately 23 and 5.3 million years ago.
The interval of geologic time from 359 million to 323 million years ago. Rocks deposited during the Mississippian crop out in Kansas only in the far southeastern corner of the state.