Geological Time

Longest subdivision;  based on the abundance of certain fossils

Next to longest subdivision; marked by major changes in the fossil record

Based on types of life existing at the time    

Shortest subdivision;  marked by differences in life forms and can vary from continent to continent.

          Catastrophism is the thought process that Earth history dominated by violent events

                    Uniformitarianism is the thought process that Earth history dominated by violent events

What way to measure time involves known order of events but not dates.

Which principle of relative dating states that younger features cut across older features

Early scientific Attempts of absolute dating the Earth involved what of the following?

         What kind of fossil is when minerals replace the remains and they become rock.