Advice- Try looking it up because it has all the facts and explanation..
The Precambrian eon is separated from the Phanerozoic eon in the fossil record because of poorer record of fossils than that of the succeeding Phanerozoic eon.This is because many Precambrian rocks have been heavily metamorphosed,obscuring their origins,while others have been destroyed by erosion,or remain deeply buried beneath Phanerozoic strata.The Phanerozoic Eon covers 541 years to the present while Precambrian Eon covers 4.6 billion years.
Most landforms change very slowly over many, many years. New mountains have formed as the plates of Earth's crust slowly collided, and others have been worn away by weathering and erosion. ... Floods and landslides can change landforms in a matter of seconds. Volcanic eruptions can also change landforms quickly.
Trade laws and federal regulations.
He wrote books and letters defending the Native Americans.
hope this helps!
