Geologic time is often dicussed in two forms: Relative time (chronostratic) -- subdivisions of the Earths geology in a specific order based upon relative age relationships (most commonly, vertical/stratigraphic position).

What are 2 ways to date geologic events?

To establish the age of a rock or a fossil, researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.

What are 2 geological events?

Some examples of events listed on the geologic time scale include the first appearance of plant life on Earth, the first appearance of animals on Earth, the formation of Earths mountains, and the extinction of the dinosaurs.

What are the major geological events?

Geological Events Timeline: Oldest rocks yet discovered - 3950 MY. Significant oxygen in atmosphere - 1500 MY. Start of formation of Appalachian Mountains - 450 MY. Start of supercontinent Pangaea (all continents pushed together) - 360 MY.