History is divided into 3 or 4 major segments of time or eras.
On any timeline, each “era” is labeled and the time is given for each.
Every timeline shows a sequence of major events for each era.
Every timeline uses a scale (example: 1 mm = 1 million years or 10cm = 1 year)
Every timeline has a beginning and an end.
The geological time scale covers billions of years – other timelines are much shorter.
The geological time scale shows more complex and extensive history - including extinctions and major events.
The geological time scale shows human history as well – so most time scales can be considered part of the geological time scale.
Millions of years of Earth’s history are exposed in the Grand Canyon.
Rock layers and their relationships are easily seen.
Earth processes can be seen and inferred (weathering, erosion, deposition)
Landforms provide evidence for differential erosion.
Rock types can be observed.
No comments:
Post a Comment