Question: what are some major events in earth's history?
Answer: Formation of Earth - 4600 MY.
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.
Abundant coal-forming swamps - 320 MY.